# Solar panels: do they save money?



## RobinBHM (13 Mar 2022)

With energy costs rising exponentially, I’m thinking of solar panels

has anybody got experience with them?

I live in South East (Sussex), house is conventional gable ended, like an apex roof shed. Pitch is about 35deg, rear side faces about South South East.

my concern is I don’t know how long I will be living here - do solar panels increase house value 

TIA


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## Ollie78 (13 Mar 2022)

My brother has some and he does save money.
However, when he had them fitted the government were doing a buy back tarrif where they buy back excess energy at a good rate.
When I looked into it later the scheme was no longer in effect.

I think they are only worth it if you have a battery system or electric car.
That way you are keeping and using your energy and so not buying that amount from the grid.

There is a website that uses Google earth to see if your roof is suitable, solar checker or something like that.

On another note, not all panels are the same quality. You can also get combined PV and water heating ones.

Ollie


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## Ozi (13 Mar 2022)

I have solar hot water, no buy back etc. but at the time I was told they would last longer, this may or may not be true now. They do mean I don't need to run the boiler for several months each year, I can't calculate the pay back as I changed from a very old gas boiler to a more modern condensing one at the same time but gas usage dropped a lot - very glad of them just now, been running 13 years with one service a year ago. The only way I see to answer the house value question is would you pay more for a house with than without?


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## John Brown (13 Mar 2022)

We have solar water heating and PV. We get the original feed in tariff (which will expire in 6 years or so). I don't think the figures add up for new installations now, although maybe when electricity prices go through the roof it'll make more sense ... Since most FITs don't actually measure exported power, but just estimate it, some people divert any export power to an immersion heater. As mentioned above, if you have an EV, you can get smart chargers that only charge when you would otherwise be exporting, but now the government are pulling the smart charger grand at the end of March. I don't think this government are really interested in that sort of green stuff.


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## Stuart Moffat (13 Mar 2022)

No experience of PV but very good experience of hot water. Bought a large but leaky house about 15 years ago. first 2 years was filling oil tank 3 times a year. Professional quotes for solar panels were very expensive even with grants. After some research designed and bought the stuff to do it myself, but got a roofer to fix the 2 frames on the roof. It paid for itself in about 14 months. PM me if you want any detail.


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## Woody2Shoes (13 Mar 2022)

RobinBHM said:


> do solar panels increase house value?


Answer - don't know but they ought to! I think that EPCs are becoming more important at sale time (and also for anyone looking to rent out a property) and will become more so. EPCs are not perfect, as they sometimes reflect cost of ownership rather than CO2 emissions, but they're not a bad measure. Calculating payback time is a tricky one, as a key input is the cost of grid energy (gas/electric) and we only know what's happening to that after the fact!

I think that although feed-in tariffs (govt incentives) have been done away with, the cost of solar PV panels and other components has gone down significantly and their efficiency and reliability has gone up. There are also other really interesting technologies like thermal batteries e.g. Sunamp | Compact thermal storage for hot water, heating and cooling (and electrochemical batteries too, e.g. GivEnergy ) which allow you to store heat/electricity generated by your PV panels and/or off-peak electricity and use it later - this kind of thing goes a long way to making up for the lack of reward for exporting electricty back to the grid.

This guy talks a fair bit of sense: 

And him: 

The Ecobuble people have some interesting videos too e.g. 

With all renewables, the mantra is usually "fabric first", so your money may well be better spent on insulation, draughtproofing etc. in the first instance (which if done properly and documented should improve your EPC rating and reduce your cost of ownership).


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## Woody2Shoes (13 Mar 2022)

Stuart Moffat said:


> No experience of PV but very good experience of hot water. Bought a large but leaky house about 15 years ago. first 2 years was filling oil tank 3 times a year. Professional quotes for solar panels were very expensive even with grants. After some research designed and bought the stuff to do it myself, but got a roofer to fix the 2 frames on the roof. It paid for itself in about 14 months. PM me if you want any detail.


Was this for space heating as well as DHW?


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## Rich C (13 Mar 2022)

My parents have PV panels without a FIT, they pay for all their electricity and gas with a slight surplus. Worth it given the cost of purchase? I'm not sure.


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## Spectric (13 Mar 2022)

How old are you, they are no good if you are either getting on or do not plan to stay in the property long term, they can also devalue some properties.


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## Lorenzl (13 Mar 2022)

I am a septic and a guy I work with say's he get's about 60% of the energy the salesman told him. I think if you live somewhere very sunny it is worth it.

I went to a council sponsored meeting about thirty years ago and the salesman said you would get payback in about 15 years. In the question and answer session I asked what was the lifetime of the solar panels and he said 15 years! 

I used to work in lab that dose research on solar panels and at the time the very best efficiency was 20% ( in the lab under a lamp ). I can't remember the full details but they were developing panels with a new material which was toxic* but the government were going to let them proceed. I asked what would happen to the panels when they reached end of life and was told they would be recycled in dedicated recycling centres. I can see that being a mess with nobody wanting to take responsibility or pay for it. But hay why worry about that now it will be somebody else problem.

_*However, the commercialization of PSCs has raised some concerns about their safety, as PSCs contain methylammonium lead iodide (CH3NH3PbI3, MAPbI3). Pb is a well-known toxicant, and _*its toxicity varies from genotoxic and carcinogenic to nephrotoxic, neurotoxic, immunotoxic, and reproductive toxic*


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## Sideways (13 Mar 2022)

I'm planning an installation to go in before the summer.
I'm retired and see this as a lifetime buy so I don't have to spend time on it ever again.
As we have a decent sized SE facing roof and I will pair it up with storage batteries, I expect to be self sufficient for electricity 9 months of the year, with surplus to spare to charge a car and / or contribute to the hot water for 6 months.
It's expensive and a big investment for me.
It will take at least 10 yrs to break even, but the panels are guaranteed for 25 yrs and the batteries should do better than the 10 years life that is assumed in the financials.
In your situation, I wouldn't,, but think where you can you put the money that will make enough of a return to keep pace with energy costs ?
In mine, I don't see it as a great investment so much as buying insurance against prices going silly in future, and it has to be now or we won't live long enough to get the benefit of it 

And like everyone, I'd like to do what I can to be "green". I'm not entirely sure that this is because the whole life calculations of what goes into making the parts, installing them and cleaning up afterwards are too complicated for me to figure out with any confidence. At least I'll take a lot of my load off the grid which is going to get hammered as electric vehicle numbers grow.


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## GrahamF (13 Mar 2022)

Lorenzl said:


> ...........
> I used to work in lab that dose research on solar panels and at the time *the very best efficiency was 20%* ( in the lab under a lamp ).



Efficiency has drastically improved over the years. We live aboard a sailing boat for around half the year and solar provides all our needs, with 320w of panels occasionally outputting >300w in Algarve/Med sun. More often though we see mid 200's as boat swings around on anchor so panels not always in best position. 

I did the sums a couple of years ago for home installation but at 75 now, highly unlikely to live long enough to make it worthwhile. For younger folks and possible permanent higher power costs, may well be cost effective.


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## D_W (13 Mar 2022)

if you're able to put them in yourself and hire an electrician for the critical electrical bits and the grid tie in, they would be an enormous money saver. Where I live, you're not allowed to do that, at least not stating that you're doing that. 

The installation and financial packaging groups touting panels triple the cost from a self install and prefer to tie you in to a financial arrangement so that they can sell your debt and cash flow pattern on the secondary market (they keep a spread - as in, they foot the bill for the panel setup, and then sell your agreed payment pattern to bondholders and then the difference between those two is their profit). 

You can pay cash for install here, too, but the mark up is enormous, same as the bond packaging (the virtue of the bond packaging is that someone who can't afford panels can sign in to the lease agreement and guarantees). 

Typical price here for a freestanding grid of smart panels and grid tie in by electrician is about 1k per KW and may be less now. Nobody likes freestanding because it's ugly, but the mennonites and such who are a little less prissy have installed a lot of arrays like that on farms. Their payback will be fast. The lease agreements are about even with regular grid power, but have escalators in them to make the initial rate more competitive and probably over the time will be about the same or slightly better. 

FIL's neighbor has a monthly rate that's flat now, guaranteed output from panels that if the panels don't make the guarantee, the bondholder has to purchase the power to make up for it, and the escalator is 3% per year. Power rates have not gone up that fast in recent history, but if they go up faster in the future, then the panel buyer wins.


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## D_W (13 Mar 2022)

The installers here are pretty savvy with the margins as far as I can tell. They make the packages look about as attractive or slightly more attractive than regular grid power and they don't give much away as a benefit to the buyer.


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## RobinBHM (13 Mar 2022)

Stuart Moffat said:


> No experience of PV but very good experience of hot water. Bought a large but leaky house about 15 years ago. first 2 years was filling oil tank 3 times a year. Professional quotes for solar panels were very expensive even with grants. After some research designed and bought the stuff to do it myself, but got a roofer to fix the 2 frames on the roof. It paid for itself in about 14 months. PM me if you want any detail.


That’s really interesting. I had kind of assumed solar electric was the way to go - it seems to be far more popular in the UK, but I guess that has something to do with the feed in tariff.

PM sent.


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## Lorenzl (13 Mar 2022)

@Graham F I made a mistake in my post; the cells are only 20% efficient. So your 320W panel is based on cells that are only 20% efficient. If the cells were 60% efficient your panels would be rated at 960W


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## Spectric (13 Mar 2022)

Reduce energy cost and fit a woodburner, nice and cosy without any huge outlay or complication of panels and invertors plus no increased risk from lightning strikes taking out your wiring.


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## Jones (13 Mar 2022)

Solar PV payback is dependent on costs and feed in tariffs. The salesman will probably slightly exaggerate the benefits ,but there should still be some especially in the south. There's probably lots of other better ways to reduce bills which will also improve the EPC and so saleability and maybe price. Insulation of roof,walls and floors is obviously the big one, but solar hot water is worth looking at, the panels are about 70% efficient and should cut water heating costs by half over a year. Depending on your current plumbing setup the installation can be simple or much more complicated and expensive.


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## eribaMotters (13 Mar 2022)

On a new build the "Tech route" idea is sound, but on an existing home it is not really worth it. I'm making these comments base upon the recent EPC done on the bungalow we are selling. I believe the installation costs quoted are a bit optimistic, but the results interested me:-
Complete Suspended Floor Insulation - £1,200 and save £86 a year.
Install Solar Water Heating - £6,000 and save £26 a year.
Install Solar Photovoltaic panels - £5,500 and save £309 a year.
These figures are on a 126m2 bungalow that we refurbed with new roof along with 400mm of loft insulation, 60mm outside wall insulation, [nothing in the cavity] 1/2 the property with underfloor insulation and new DG windows. Our combined gas & electric is on a deal till 2023 and we pay £89 a month. 

Colin


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## Lorenzl (13 Mar 2022)

Simplistically about 18 years to get back the cost of the Solar panels and 231 years for the water heating


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## thetyreman (13 Mar 2022)

the best solution is going 100% offgrid so the ejits can't keep raising prices


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## MikeJhn (14 Mar 2022)

Lorenzl said:


> I am a septic.


I'm sorry to hear that, hope you are better soon.


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## clogs (14 Mar 2022)

I have been using Hot water panels for 20 years....they are very efficient.....
no idea where Lornzl get 231 yeras from....?
A mentioned a cost of £6000 for a system seems extreme....
Here a 250 liter simple system (no pump just thermal flow) is around €1200 - €1500.....
when in france we wanted to combine the solar system to the wood fired boiler central heating....
this needed a water cylinder with two heating coils.....we bought a st/steel cylinder for the extra high pressure from the water mains....
as an add, better than 50% of standard water cyl in the UK already have an extra heating coil but just blanked off....
Be warned there are two type of system, fully pressurised and gravity....
I chose the gravity system because it so simple and less to go wrong....
Which type really depends on what layout u already have.....
Places like Sweden and Norway use em as well.....
We are lucky here as the sun shines a lot.....
but our rental house 4 bed x 4 bathroom has a 300lit hot water tank with two solar panels
and never once needed a back up for hot water....even tho the guests are very wasteful....
when we ruturn to the house in winter we only need to fire up the wood boiler prob less than 10 days over that time to get water temp up a bit....
I also bought a very large German used wood stove with a back boiler just in case....
If I were in the UK I'd install that in the front room, there's alaways plenty of waste wood around...
just means getting of ur bottom to fill up the fire.....with what I can see of ur gas prices this looks cheap to run.....
As for PV, I'd love it but I need 3phase....so a bit higher cost in setting up and at my age not worth it...but I'd just love to tell the leky board to go shove it....
As for selling back to the board I just wouldn't bother because of the extra cost of the fussy electronics (smart meters etc) anyway I guess they dont wanna pay a decent price ...
So personally I'd throw the extra away.....tho it could help heat a swimming pool......hahaha....
As for PV effic.....it's never better than 20% effic for years....we need the next jump in materials techno to get better effic....
and after 5 years or so doesn't the effic drop by 1% per year or so for the next 10 years ....?

Plus the £1000's profit in the installers pockets of PV would be better used buying a better system and doing it urself apart from the elec hook up....
just sayin....


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## ian33a (14 Mar 2022)

We fitted them 10 years ago when the FIT was at its maximum - as was the cost of the hardware. Due to shadowing being a problem we went down the micro invert route and this is more expensive up front.

The system has, more or less, just paid for itself in pure FIT payment terms at about now. So, 10 years ROI.

What is less obvious are the "soft" benefits: I also fitted a PV dump system myself. With the installation that we have, the system measures power exported from the PV system BEFORE it is available to the rest of the house and the national grid. Thus, if you are able to use all of the generated electricity instantaneously, you receive payment for everything generated as well as being able to use it and not export it. This is perfectly legal and only really effective if you can save the energy in a battery system and re-use it later. Our system does not have the battery. The PV dump system takes some of the surplus and routes it to the immersion heater - but only when there is a surplus. How much we save in hot water heating is unknown but, I suspect that it is far more than the material cost of the equipment.
On top of all of this, we have to some degree, changed the way we use power. We tend to turn on appliances when the sun is out or expected to be out. Being home during the day, this makes it easier to time. Typically though, most people use their power in the evenings when the sun isn't out so, unless they have a battery, the system doesn't benefit them.
Finally, there is a quiescent drain in our house with stuff that is always running. It's something like 450W. So, whatever power the panels are generating offsets this and we get an export payment as well.

If I was in a position to fit them again, I doubt I would. The inverter manufacturer went out of business and thankfully, none of the inverters have died (there are 14 of them). I've heard that the more normal single inverters need replacement every 10 years or so. So this needs to be built into the cost model. Plus, the FIT is far less generous now.

We're in the process of moving and people don't seem that bothered about the panels. Many don't understand them or see them as a benefit - possibly more of an eye sore. Once they get their revised fuel bills, that may change. Our new place, if all goes to plan, also has them. That will be a benefit for us as we will get the FIT. There is also provision for solar water heating (but the panels are not in - just the pipework). It's something that I will look into as the house is heated by oil.

The house also has a couple of wood burners - and a steady supply of wood. I see this as an energy saving method for the future.

I will also consider a ground source heat pump as I see this as a way to reduce energy costs - but only if the maths really works out - and, so far, I'm not convinced.


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## Woody2Shoes (14 Mar 2022)

RobinBHM said:


> That’s really interesting. I had kind of assumed solar electric was the way to go - it seems to be far more popular in the UK, but I guess that has something to do with the feed in tariff.
> 
> PM sent.


I think you get more heat energy out of a solar thermal panel of the same area, compared to PV. The downside is that it's a 'wet' system, which in my opinion is bound to require (some) more maintenance.


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## Woody2Shoes (14 Mar 2022)

Lorenzl said:


> I am a septic and a guy I work with say's he get's about 60% of the energy the salesman told him. I think if you live somewhere very sunny it is worth it.
> 
> I went to a council sponsored meeting about thirty years ago and the salesman said you would get payback in about 15 years. In the question and answer session I asked what was the lifetime of the solar panels and he said 15 years!
> 
> ...


Let's not forget all the lead in our car batteries and on most of our roofs. Then all the chemicals we put into the air and water by burning stuff (wood/coal/gas) etc etc etc.....


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## Spectric (14 Mar 2022)

clogs said:


> I have been using Hot water panels for 20 years....they are very efficient.....


Maybe that has something to do with the Greek climate, I believe you get a lot of sunshine and warmth which is something we can only imagine for six months of the year!


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## Keith 66 (14 Mar 2022)

We had pv panels fitted about 3 years ago just before the feed in tarriff ended. We get about £25 pay back every quarter.
Solar panels make sense if you have an electric vehicle & work from home as you are charging it from home produced electricity. If you are commuting to work in that car you are not gaining anything.


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## Keith Cocker (14 Mar 2022)

I live in the Lancashire Pennines. Solar panels? You must be joking.  🌧⛈🌧


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## Just4Fun (14 Mar 2022)

I installed 90 evacuated tubes for solar heating in 2005 or 2006. Or was it 80 tubes? I can't remember and I am not going out in the snow to check. I think I spent about 3K euro on the tubes, controller etc, plus maybe another 1K to 2K on pipework, heat exchangers and the like. This is from memory and prices have no doubt changed since then, so take that with a pinch of salt. I installed everything myself so there was no installation labour charge.

This set-up produces about 7000 kWh per year of heat, as measured by the controller that runs the pump. During the heating season, which is pretty long here, that supplements our space heating. If no space heating is needed then the solar energy goes into our hot water tank. I manually switch between these two options.

Strangely peak output is during the coldest time of the year (January to March), not the warmest time. This is because we get very clear skies when it is cold, whereas in summer there is often some haze. This is good for me because during the winter I can use all available solar energy for space heating.

I don't actually know what our electricity prices are so I can't calculate the payback period. Even if I could, it would be different in the UK. I have been quite happy with the system though. The only issue is that due to the layout of the house the pipe runs between the solar panels and the hot water tank are quite long. It would be more efficient if these pipes were shorter but I could not manage that.

I have no experience with PV. At the time I installed my system a thermal system seemed to be a better bet. I think PV has dropped in price a lot since then, so maybe a thermal system is no longer the best way to go.


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## Pedronicus (14 Mar 2022)

We have PV panels which were installed before the cut-off date of 12 December 2011. Only a small array at 1.75kWh output maximum. The break-even point was 6.5 years later and we currently get between £850 to £950 pa back in FIT (depending on the weather) which more than pays for our grid input in leccy and goes a fair way towards our gas costs before the recent energy increases.


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## Owd Jockey (14 Mar 2022)

I have had solar panels fitted for 8 years now. I first noticed neighbours having them installed, but basically they were just renting out their roof for 20 years, the installation cost them nothing, but they got free electricity during daylight hours. The Feed in Tariff was collected by the installer.

At the time I had just retired and had spare cash. I did the math and decided to pay for a full installation which cost £9500. This was for a 5Kw system, although I had room for and wanted a 6Kw system. The bog standard home install is 4Kw and no approval is needed, however, the Energy generator (Western Power) did not allow my 6Kw for local infrastructure reasons, so I had to settle for 5Kw.

Overall, I would have to say this is the best investment I have ever made. I get approximately £800 per annum from my Energy supplier in the form of FIT , which is composed of two elements:- i) power I generated and ii) an assumption that 50% of the generated power will go back to the grid. Also, I get free electricity during the day and if you have the old style electricity meter, the meter will unwind itself over the summer months .i.e go backwards.

The panels and inverter have long guarantees, as well as the Government guarantee that FIT will be paid for 20 years. There is a theoretical reduction of 1% efficiency for each panel, so at the end of 20 years, tehioretically the panels would only be operating at 80% efficiency. Saying that, it really depends on the amount of sunshine we get. In the middle of winter on a dark grey wet day, at best I will generate 150 - 200 watt.

I have had one equipment failure so far, the generation meter, which records the amount of electricity units generated. I replaced this item myself for £30. I am not sure what the current Government arrangements are for solar panels, but it is something I am really glad I invested in.

The only real downside is, if you neighbourhood experiences a power failure during the day, then although you may be generating 4 or 5Kw on the roof, the Inverter shuts the system down. Obviously, you cannot have service repair workers working on the fault when you are sending your own generated energy down the line. In 8 years we have only had one daytime power failure, so not much of a downside.


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## Woody2Shoes (14 Mar 2022)

Owd Jockey said:


> I have had solar panels fitted for 8 years now. I first noticed neighbours having them installed, but basically they were just renting out their roof for 20 years, the installation cost them nothing, but they got free electricity during daylight hours. The Feed in Tariff was collected by the installer.
> 
> At the time I had just retired and had spare cash. I did the math and decided to pay for a full installation which cost £9500. This was for a 5Kw system, although I had room for and wanted a 6Kw system. The bog standard home install is 4Kw and no approval is needed, however, the Energy generator (Western Power) did not allow my 6Kw for local infrastructure reasons, so I had to settle for 5Kw.
> 
> ...


I think that there are now inverters/systems which do allow you to continue to use your own solar and/or battery in the event of a grid power failure - albeit after a short interlude.


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## RichardG (14 Mar 2022)

Everyone's situation is so different that you need to do the sums for your household or get someone to do it for you. You also need to decide on your motivations, is it only to save money or are you looking for some resilience to grid outages or perhaps reducing your carbon footprint. Are you willing to change your usage to make use of the energy when the sun is shining? Battery storage changes the equation completely, again it may work for you. The biggest factor is your energy usage and when and how you use it.

All the data to do the calculations is freely available, if you have a smart meter then you may already have detailed energy usage for your household. A few hours with a spreadsheet will give you a ballpark figure.

The energy saving trust is a useful place to start, they have a simple calculator that allows you to model your situation.
Solar panels


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## manicminer (14 Mar 2022)

I dont think you would add value to the house but it would be an incentive to a potential buyer if you were able to demonstrate the savings you had been making.
I have had a 4kW PV array for 8 years and love it, supplies all the power I need during the day and heats my water (via the immersion heater element) when Im not using it. I had 8kWh go into my water tank today as it was so bright.
Will definitely have them on my next house, even without the incentives its a nice feeling getting energy from the sun.


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## RobinBHM (14 Mar 2022)

manicminer said:


> I dont think you would add value to the house but it would be an incentive to a potential buyer if you were able to demonstrate the savings you had been making.
> I have had a 4kW PV array for 8 years and love it, supplies all the power I need during the day and heats my water (via the immersion heater element) when Im not using it. I had 8kWh go into my water tank today as it was so bright.
> Will definitely have them on my next house, even without the incentives its a nice feeling getting energy from the sun.


Although its a less efficient energy conversion than solar thermal -I like the concept of using a PV array to create electricity and use the hot water tank as an energy store. 

Do you have an unvented or vented hot water tank?


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## Terry - Somerset (14 Mar 2022)

The feed in tariff is history - it only served to subsidise PV when the capital costs were high. Few would otherwise invest if the payback period was 30 years ++.

I first looked at a system 12-15 years ago - my recollection is that the cost was £12-15k and with FiT a payback period of ~15 years was estimated. Cost did not include batteries. I didn't go ahead.

The cost of a 4 KW system installed would now be ~£6k but no FiT. Payback at last years prices would still be 12-15 years.

However energy costs are increasing. My monthly standing order may increase from ~£120 pm to ~£300 pm. Suddenly PV looks like it may be worthwhile.

But it will need to be combined with a battery. If surplus generation is fed back to the grid the returns are poor, and although retired most consumption is in the evening when dark. A battery adds (probably) £5-8k to the total installation cost.

I need to do some number crunching - total installation costs now seem to be £10-15k. Savings may be in the £1000-1500 pa. So payback in around 10 years assuming prices stay at current high levels.

It now starts to look like worth doing - particularly if in the next few years an EV may be an option. A greater commitment to green would make it seem more attractive!


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## heronviewer (14 Mar 2022)

We installed solar panels about ten years ago. All costs recovered after eight years (including the cost of a bird nest removal). We do get the higher FIT, but the installation was more expensive then. It's a better investment than most !


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## hairy (14 Mar 2022)

I would like to make my own solar water heating system. A friend who lived for quite a while in Sweden was told if you pay to heat your water you will save with a solar water heating system. In Sweden, as Justforfuns experience would seem to agree with.
PV on a UK roof I seem to remember could get too complicated at sale time depending on contracts relating to it. If you don't own the panels how can you sell the roof? How many sellers will just walk away at that little complication? How do you fix the roof if needed, who replaces the pv to the suppliers standard after roof repair?
Just wondering.


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## ian33a (15 Mar 2022)

hairy said:


> I would like to make my own solar water heating system. A friend who lived for quite a while in Sweden was told if you pay to heat your water you will save with a solar water heating system. In Sweden, as Justforfuns experience would seem to agree with.
> PV on a UK roof I seem to remember could get too complicated at sale time depending on contracts relating to it. If you don't own the panels how can you sell the roof? How many sellers will just walk away at that little complication? How do you fix the roof if needed, who replaces the pv to the suppliers standard after roof repair?
> Just wondering.



Those of us who own their panels (of which we are one) have a straight forward system: come sale time the buyers solicitor requests information about the installation (MCS Certification) and about the FIT contract and the average annual yield. This is done during the enquiries stage. If they and the buyer are satisfied, the sale goes ahead.

As for "rent a roof" - whole different matter. Some people suggest that a house cannot be sold as there is, basically, a sitting tenant. I've no idea if this is the case. Certainly, I would walk away.

If the system is fitted well, the amount of roof maintenance is minimal. There is a minor amount of disruption where the frame holding the panels is attached to the rafters and there needs to be some place for the cables to enter the roof space. This can either be a single point of entry, several points (one per group) or individually. Each cable is relatively small diameter so can be slotted up under tiles and between roofing felt (that's how ours is done).


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## clogs (15 Mar 2022)

right now the temp is just 10 deg C...here in Crete.....
overcast (all day) but this will give us enough hot water (via a solar water heater) for 2 showers and 1 load in the washing machine if needed...plus the usual washing up etc.....
as there is only the two of us we use hot water for the washing machine on sunny days when available.....my wife hot fills the washing machine by hand, we have a laundry room with a flexi hose direct from the hot water circuit just for that job.......we never cold fill the washing machine as the electric heater sucks away the money....
also remember, in the summer our house is rented, those 4 bedrooms have washing done (sheets etc) twice a week, thats a lot of hot water.....!!!!...

just so u know.....
the water in the closed heating system is just car type anti freeze.....

as for roof maintenece.....any kind of add on solar panels should only be fitted on a GOOD roof, any doubts dont do it.....but if it needs work get it done anyway....who wants a leaking roof.....?
I have fitted a fair few solar panels on different roof types and the only one I would refuse is those small 6-8" square type tiles.....by moderen standards they are a rubbish roof covering anyway...
as for me, there is a def saving in solar water heating....
besides gas and elec prices will never go down.....


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## NormanB (15 Mar 2022)

Sideways said:


> I'm planning an installation to go in before the summer.
> I'm retired and see this as a lifetime buy so I don't have to spend time on it ever again.
> As we have a decent sized SE facing roof and I will pair it up with storage batteries, I expect to be self sufficient for electricity 9 months of the year, with surplus to spare to charge a car and / or contribute to the hot water for 6 months.
> It's expensive and a big investment for me.
> ...


You are going to need a decent acreage of solar panels to charge an EV. Mounting solar panels is essentially ‘buying your electricity forward’ and is probably a good use of capital if you are sure you will be staying in the property for ten years.


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## Sideways (15 Mar 2022)

NormanB said:


> You are going to need a decent acreage of solar panels to charge an EV. Mounting solar panels is essentially ‘buying your electricity forward’ and is probably a good use of capital if you are sure you will be staying in the property for ten years.


8.5kW peak / 6kW inverter / a large storage battery
I'm retired, don't do high mileage and there's no reason we would move from here


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## hairy (15 Mar 2022)

ian33a said:


> Those of us who own their panels (of which we are one) have a straight forward system: come sale time the buyers solicitor requests information about the installation (MCS Certification) and about the FIT contract and the average annual yield. This is done during the enquiries stage. If they and the buyer are satisfied, the sale goes ahead.
> 
> As for "rent a roof" - whole different matter. Some people suggest that a house cannot be sold as there is, basically, a sitting tenant. I've no idea if this is the case. Certainly, I would walk away.
> 
> If the system is fitted well, the amount of roof maintenance is minimal. There is a minor amount of disruption where the frame holding the panels is attached to the rafters and there needs to be some place for the cables to enter the roof space. This can either be a single point of entry, several points (one per group) or individually. Each cable is relatively small diameter so can be slotted up under tiles and between roofing felt (that's how ours is done).


As people here have said some got in early with a worthwhile payment tarriff. That wouldn't apply to the new owners, contracts would not be transferable as far as I've read? So the value to a potential buyer may be considerably less than what it is to you? 
Can you still get a roof ladder to hook on the ridge above where the panels are fitted? If you did would the ladder bend under someone's weight to rest on the black panel and maybe damage it? Again, just wondering, no idea what issues there may end up being?


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## NikNak (15 Mar 2022)

We've had our 3.6kW system, 14 panels, running since Nov 2012. Added a Solar iBoost to heat the hot water tank 4yrs ago. And last summer i changed my car to an ev and had a Zappi installed. House/roof faces ESE so we get the early clear blue morning skies. The initial system paid for itself (if memory serves me) in just over 6yrs. As i understand it you can fit these things yourself, but i am 95% certain you CANNOT commission them to work OR get an electrician to do it either (doesn't matter how competent he is) unless he is MCS accredited to do so.

It looks like you're in West Sussex(?) we're just across the county line East in Hampshire, you're more than welcome to message me and come and have a 'proper' look at our system, see the geeky spreadsheet i have going back 9yrs at all the captured sun data, and ask as many questions as you like over a cuppa 


Nick


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## ian33a (15 Mar 2022)

hairy said:


> As people here have said some got in early with a worthwhile payment tarriff. That wouldn't apply to the new owners, contracts would not be transferable as far as I've read? So the value to a potential buyer may be considerably less than what it is to you?
> Can you still get a roof ladder to hook on the ridge above where the panels are fitted? If you did would the ladder bend under someone's weight to rest on the black panel and maybe damage it? Again, just wondering, no idea what issues there may end up being?



I understand that FIT's are transferrable - certainly we plan to transfer ours to the new owner of our house (and their solicitor has already asked) and we plan to claim FIT payments on the place that we are in the process of buying.


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## NikNak (15 Mar 2022)

ian33a said:


> I understand that FIT's are transferrable - certainly we plan to transfer ours to the new owner of our house (and their solicitor has already asked) and we plan to claim FIT payments on the place that we are in the process of buying.



This is true, see here.... What Happens to Feed-in Tariff Payments When You Move?


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## Stevekane (15 Mar 2022)

Our neighbour has the PV panels with the full feed in tariff plus he realised some years ago that when the sun shines his meter is running backwards,,,so its a triple win,,,its apparently a quirk with some meters and means that they are at times desperate to use some elect on the meter in to push it beyond its last reading,,,lucky pippers!
Steve.


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## Ozi (15 Mar 2022)

There is a lot of talk of pay back time and it's obviously relevant the situation when I installed my hot water system was slightly different, I was earning good money but new that it wouldn't last, I didn't miss the money then but now I earn much less I'm glad I invested when I did. It could be similar for people coming up to retirement, reducing your future bills feels good and provides at least some security against situations such as we see at the moment. Yesterday the cost of my gas and electricity went up 50% with another rise due later in the year. I'm fortunate I will be able to afford it but still very glad of every Watt the panels give. Also switched most of the house lights to LED, cant help saying look at that 18W when I switch on the kitchen lights, have to say it to my self or SWMBO would have me certified by now.


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## John Brown (15 Mar 2022)

NikNak said:


> This is true, see here.... What Happens to Feed-in Tariff Payments When You Move?


We bought a house with both solar water heating and PV almost three years ago. We were lucky enough to "inherit" the original feed in tariff for PV. There may be other scenarios, depending upon the initial contract, but that's what happened for us. When we moved in, the FIT seemed ridiculously high, but the way electricity prices are going, it might well seem low in a couple of years!


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## manicminer (15 Mar 2022)

RobinBHM said:


> Do you have an unvented or vented hot water tank?


Its a pressurised tank so I guess thats unvented? The PV is diverted to a standard immersion element, when a box of tricks detects a surplus of PV energy and when the water can take heat. Whilst inefficient, it is the most visible evidence I have that the roof array is working. A glance up at the meter shows me the energy going into the hot water. Peaked out at just over 8kWh gone in today. PV is more efficient in this colder weather, however the sun is also lower in the sky.


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## manicminer (15 Mar 2022)

Stevekane said:


> Our neighbour has the PV panels with the full feed in tariff plus he realised some years ago that when the sun shines his meter is running backwards,,,so its a triple win,,,its apparently a quirk with some meters and means that they are at times desperate to use some elect on the meter in to push it beyond its last reading,,,lucky pippers!
> Steve.


Our meter also ran backwards. Our new build (Taylor Wimpey) had saved some cash by using recon meters - these had no backstop so when energy was fed in from the PV, the meter went backward.
What started out as a neat parlour trick, eventually started to wear me down, as I was having to cook the books in terms of meter readings, given the energy companies would periodically come round to check the readings themselves.
I couldnt live with it any longer and eventually fessed up to my new energy supplier. They promptly fitted a electronic meter.


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## ian33a (16 Mar 2022)

manicminer said:


> Its a pressurised tank so I guess thats unvented? The PV is diverted to a standard immersion element, when a box of tricks detects a surplus of PV energy and when the water can take heat. Whilst inefficient, it is the most visible evidence I have that the roof array is working. A glance up at the meter shows me the energy going into the hot water. Peaked out at just over 8kWh gone in today. PV is more efficient in this colder weather, however the sun is also lower in the sky.



We have a similar system which I built and installed myself. We have a little box as part of the system which periodically pulses a few LED's onto the wall as a haze - red when the system is importing from the grid, orange when we are heating water and green when we are exporting. It's a nice feeling when the colours are orange or green. The box also shows instantaneous power numerically, be it imported or exported - but the LED's are an easier thing to see from a distance.


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## Oldman (16 Mar 2022)

I really wanted Solar panels when the first FIT was set but I had no spare money, I watched as the FIT payments reduced along with the cost of installation until in January 2014 it got to £5k to install a 12 panel system and I joined the club. The total cost was £4950 and in the sunny south it was all paid for by year 6 with free bonus electricity too. Would I have been better off taking a £15k loan and going for the system when the FIT was maximum? with hindsight yes I would have by a considerable amount each year, but I average £730 back in FIT payments per year and free electricity too though in real terms thats just become a much less percentage of the real cost of electricity. 
In 2011 the FIT was 54pence/kw and dropped to 15pence/kw by the time I joined.
Probably a bit geeky but I monitor my system via Eco eye smart pv, some software to interface to a Raspberry Pi and output to PVoutput.org.


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## Sandyn (16 Mar 2022)

Doesn't FIT come from a green levy paid for by other electricity users? many who struggle to survive and can barely buy their own electricity. I don't think that is fair.


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## Phil Pascoe (16 Mar 2022)

Indeed. It's the poor subsidising the rich. Mustn't let the thread deteriorate into a political rant, though.
My friend took early retirement with a nice lump sum about 20 years ago. He paid £15,500 for his set up, it's long paid for itself and he still gets the 41p or thereabouts per unit from it.


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## NikNak (16 Mar 2022)

Sandyn said:


> Doesn't FIT come from a green levy paid for by other electricity users? many who struggle to survive and can barely buy their own electricity. I don't think that is fair.



Yes it does. As does the massive subsidies paid to the wind energy companies that started over 30 years ago when wind energy was just a whim in the minds of beardy weirdy's. Look where we are now....

When we moved into our current home (20ish yrs ago) there was a scheme at the time to go and buy loft insulation at crazy low prices. Seem to recall it was around £2.50 a large roll..!! We made 'several'  trips to our local B&Q and loaded up the estate car with as many rolls of the stuff as we could squeeze in. Again seem to recall we bought around 20ish rolls of the stuff. Then spent several weekends very painfully (knees on skinny joists) laying the stuff in the loft, we have a very low pitched roof so it wasn't an easy task.

Move on another couple of years and there was a scheme whereby you could have cavity wall insulation installed by the energy companies. Again heavily subsidised by grants. 

I also recall watching an episode of Dragons Den many years ago where Deborah Meaden and Theo Paphitis were very quick to 'jump on the bandwagon' and invest in some project promoting the installation of Solar panels saying that "its a no brainer." Sadly(?) the business folded just a few years later, read here... Dragons' Den solar power business goes bust

just found a clip....  



We are with Octopus energy. And where we have been 'lucky' in the past benefitting from these schemes, quite often we will receive an email from Octopus saying "would you like to donate xyz to those less well off and are struggling to pay their energy bills..." and we always click YES.



Nick


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## Sandyn (16 Mar 2022)

Phil Pascoe said:


> Mustn't let the thread deteriorate into a political rant, though


no, agreed. I did look at a 8kWp system but according to the calculator, lifetime net benefit was only £193. I'm sure it would perform better than that, but in my case I would be better spending some of the £10k installation cost on reducing the heat loss from my property.


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## Terry - Somerset (16 Mar 2022)

The average domestic 4kw array produces ~3000kwh pa - higher down south, lower where the weather is less clement.

20 years ago it would cost (say) £15k to buy a 4kw system. A FiT of (say) 40p per unit would generate an income of £1200 - it would take 13 years to payback the system cost. Add interest on a loan, or interest foregone, and the payback would be ~15 years.

Without FiT almost no-one except the financially illiterate or the environmentally very concerned would have invested in PVs.

Payments under the FiT scheme are not a simple case of subsidising the rich at the expense of the poor - it was the only way in which PVs were ever likely to be generally adopted.


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## Phil Pascoe (16 Mar 2022)

NikNak said:


> We are with Octopus energy. And where we have been 'lucky' in the past benefitting from these schemes, quite often we will receive an email from Octopus saying "would you like to donate xyz to those less well off and are struggling to pay their energy bills..." and we always click YES.
> Nick



We did the same with the cheap insulation. I still have large box of CFLs (2p each).

Ours is Octopus as well, but I strongly object to their giving money to BLM. I'll see what happens when the fix ends in August. Maybe the people whose solar systems I'm subsidising are the ones who should be giving money to the less well off? Just a thought.

I know off no one who's had solar systems fitted for altruistic reasons, it's always for financial reasons. Saving the planet always comes way down the list.


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## Phil Pascoe (16 Mar 2022)

Sandyn said:


> no, agreed. I did look at a 8kWp system but according to the calculator, lifetime net benefit was only £193. I'm sure it would perform better than that, but in my case I would be better spending some of the £10k installation cost on reducing the heat loss from my property.


Yes. We've done everything realistically possible. The EPC when we moved said we could go up a level if we went over to low energy lighting - there was one lamp in the whole place that wasn't already low energy. It did however miss 6mtrs of single skin 100mm block wall between the garage and the bungalow which was actually against building regs. when it was built, it should have been cavity. It suggested we dug up solid concrete floors and fitted insulation ............. which would have justified its installation in about three centuries.


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## Phil Pascoe (16 Mar 2022)

Terry - Somerset said:


> Payments under the FiT scheme are not a simple case of subsidising the rich at the expense of the poor - it was the only way in which PVs were ever likely to be generally adopted.



The obvious way (I said this four decades ago) would have been to make their installation mandatory on all new builds and commercial buildings. For one thing installation is far cheaper at the building stage than as a retro fit. The price by now would have plummeted and their development possibly be far more advanced. Hundreds of thousands of hectares of industrial estate, shopping centre, railway and bus station roofs all of which could be covered in solar panels - no need to take farm land for them.


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## Crazy Dave (16 Mar 2022)

Many energy companies claim that they supply 100% renewable energy so why does the price go up with the wholesale gas prices?
The answer is that all electric energy is pooled together and then sold so as it's mixed the price of renewable energy goes up as well.
So in that case it's NOT 100% renewable then is it?

We're all being scammed by energy companies, as always.


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## Ollie78 (16 Mar 2022)

Crazy Dave said:


> Many energy companies claim that they supply 100% renewable energy so why does the price go up with the wholesale gas prices?
> The answer is that all electric energy is pooled together and then sold so as it's mixed the price of renewable energy goes up as well.
> So in that case it's NOT 100% renewable then is it?
> 
> We're all being scammed by energy companies, as always.


I argued this point with someone from an energy supplier. 
I said they cannot possibly guarantee they supply renewable energy only when attached to the national grid. 
I further stated that it is possibly illegal to do so, especially in relation to sales of something and consumer rights.
They could not ( or would not) understand what I was saying. 

I would love to be able to have solar and maybe a bit of wind power and a huge battery just to be off the grid.

Ollie


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## Crazy Dave (16 Mar 2022)

*"How does the renewable energy supply chain work?*
Renewable energy is generated, added to the national grid, mixed with energy from other sources, and finally piped out to houses and businesses in the UK."

Source: Octopus Energy
Published on 15th May 2018 by: Pete Miller
Head of Customer Experience


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## Crazy Dave (16 Mar 2022)

Ollie78 said:


> I argued this point with someone from an energy supplier.
> I said they cannot possibly guarantee they supply renewable energy only when attached to the national grid.
> I further stated that it is possibly illegal to do so, especially in relation to sales of something and consumer rights.
> They could not ( or would not) understand what I was saying.
> ...


Yeah me too.


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## hairy (17 Mar 2022)

We could profitably have a wind turbine. A 3.5KW plumbed into the mains would be about £25K installed. Excess production locally limits me to 3.5 down from 5 originally. Plus an annual service plus insurance with it being within quite a long way of a road/house for when the blades fly off.
The turbine itself only costs something like £5K, or did at the time.
Instead of FIT and grid connections I wonder if there is a future in each property having its own production and storage?
Any"renewable" grid connection requires a duplication in capacity for when the wind/sun is being cheeky because demand doesn't take that cheekyness into account.
As some on this thread have said, it is perfectly possible if you know it's going to be sunny you put the washing on, because you profit from your installation. Individual decision making is possible.
A lead acid battery bank in your shed (communal?) of a size to run a washing machine, charged from your own turbine and or solar panels could be a scalable kit installed by a nationwide govt sponsored contractor. You in control of your supply in a limited way, no profit directly just savings as life goes on ever more expensively. The house remaining on grid as now, just a mains battery sourced supply for whatever you plug into it.
Not lithium of course, limited lifespan and much more expensive in a use where paying more for the weight saving is irrelevant. Lead would require perhaps more maintenance but that could be interested competent householder or a visiting techy.
Using ones shiny Tesla as a battery bank is only sensible if your wallet is deep and you shut your eyes when you watch how fast it's emptying. Such a cars lithium battery at say £10K new lasts 1000 full charge cycles. Every time the leccy company borrow some of your stored capacity you may get paid a profit on the energy cost down the cable but does it cover battery degradation?


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## Blister (17 Mar 2022)

I had a 10 panel system with a 3.5 kw battery fitted a month ago 
It is a learning curve , Things like doing washing on days when the sun is shining , same with the dish washer that way you are using energy your system produces , my battery was charged to 98% by 10.30am , then the system powers the home anything else is exported into the grid , I now should not get a monthly electric bill and have worked out on my February energy exported this amount is £25 , as the sun gets higher and the days get longer this will go up , on the flip side it will also go down in winter , Overall I am happy


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## Blister (17 Mar 2022)

My panels are on the garage roof , Direct south facing 


84FAF74E-6255-4395-9311-0EB692AF2478 by https://www.flickr.com/photos/[email protected]/, on Flickr

Inverter inside the garage 



52DF6E52-8620-4171-BB59-601FC70F7CAC by https://www.flickr.com/photos/[email protected]/, on Flickr

And the battery 



1E739F41-6B66-4EA1-882C-04452EA58544 by https://www.flickr.com/photos/[email protected]/, on Flickr

All fitted in a day


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## Sideways (17 Mar 2022)

hairy said:


> Using ones shiny Tesla as a battery bank is only sensible if your wallet is deep and you shut your eyes when you watch how fast it's emptying. Such a cars lithium battery at say £10K new lasts 1000 full charge cycles. Every time the leccy company borrow some of your stored capacity you may get paid a profit on the energy cost down the cable but does it cover battery degradation?


You are very wise to be sceptical but the battery situation is better than you describe.
The more durable type of storage battery for solar PV is lithium iron phosphate. These don't have the highest energy density like you need in your electric car, but they do last better. The major brands all guarantee their battery packs for either 6,000 or 10,000 full cycles, at the end of which they still have 80% of the initial capacity.
Using rough numbers, £10k will cover the cost of the electronics and 16kWh battery in my own planned solar install. Battery is guaranteed for 10,000 cycles, and over the guarantee, will drop from 16kWh to about 13kWh capacity. Average about 14.5kWh.
So £10k / 10,000 cycles is £1 for every 14.5kWh I put through it. Or 7p / unit to store my "free" (not really of course) solar power to use when it's needed.
In practice, I expect a few years for free after the 10yr warranty period because I won't bother replacing they cells until they are down to (say) 65% capacity.
Now the feed in tarrif is gone and the export guarantee pays only 5 to 6p per unit, there is no benefit to me letting the grid draw on my planned battery storage. They pay less than it cost me. The key to modern residential solar is: you make it, you use it.

BTW, lead acid isn't a good technology for any of this. China is full of electric scooters powered by 4,5 or 6 lead acid batteries. They are cheap and great fun, but the batteries are worn out after a couple of years commuting to work. Those really don't achieve 1,000 cycles, and by the end have nowhere near 80% capacity left.
There are other wet cell batteries with far longer than 10 year lives but bulky and not lead acid tech.


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## Bob Chapman (17 Mar 2022)

Crazy Dave said:


> Many energy companies claim that they supply 100% renewable energy so why does the price go up with the wholesale gas prices?
> The answer is that all electric energy is pooled together and then sold so as it's mixed the price of renewable energy goes up as well.
> So in that case it's NOT 100% renewable then is it?





Ollie78 said:


> I argued this point with someone from an energy supplier.
> I said they cannot possibly guarantee they supply renewable energy only when attached to the national grid.



I don't understand this. My energy company says it supplies 100% renewable energy. I take this to mean that my energy consumption (wherever and however it was generated) is replaced by an equal amount of energy generated by renewable methods. The actual electrons used by me may not be the ones generated renewably but so what - an electron is an electron. Your argument is like saying that when you withdraw money from your bank account it's not your money because it's not the same pound coins you paid in.

I'm not trying to start an argument - have I simply misunderstood something?


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## Sideways (17 Mar 2022)

No Bob. You understand it just right.
AVERAGED OVER A PERIOD OF TIME is the key.
In a flat calm in the middle of the night, renewable energy customers are dependant on nuclear, gas, etc energy like everyone else. So the grid draws on those sources. On sunny / windy days renewable generation provides the power even for those who haven't opted for 'renewable energy" so I picture it like borrowing and paying back.


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## Blister (17 Mar 2022)

Look at the National grid as a huge pot , All energy goes into the pot , Clean and dirty , Solar / wind farm / nuclear , over half the uk energy is now clean. and my little bit goes in the pot as well.


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## Phil Pascoe (17 Mar 2022)

The objection is to their using 100% renewable as a selling point when it obviously isn't - if they can advertise that when there is next to no renewable energy generated (a dead still night) some companies therefore must be 100% non renewable. Planting a few trees doesn't compensate, either, and I bet if all the supposed renewable energy sold by all companies were to be calculated it would be way more than the total generated.


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## RobinBHM (17 Mar 2022)

Sideways said:


> No Bob. You understand it just right.
> AVERAGED OVER A PERIOD OF TIME is the key.
> In a flat calm in the middle of the night, renewable energy customers are dependant on nuclear, gas, etc energy like everyone else. So the grid draws on those sources. On sunny / windy days renewable generation provides the power even for those who haven't opted for 'renewable energy" so I picture it like borrowing and paying back.



renewables dont work all the time -I always thought that was a major disadvantage but in fact what it really means is that there is a need for back up -for when renewables do not generate, however renewables are still beneficial for the time when they do produce -and the UK is increasing its battery storage.


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## Blister (17 Mar 2022)

My system produces power during daylight hours , 
My home uses stored power from my battery at night.


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## hairy (17 Mar 2022)

Sideways said:


> You are very wise to be sceptical but the battery situation is better than you describe.
> The more durable type of storage battery for solar PV is lithium iron phosphate. These don't have the highest energy density like you need in your electric car, but they do last better. The major brands all guarantee their battery packs for either 6,000 or 10,000 full cycles, at the end of which they still have 80% of the initial capacity.
> Using rough numbers, £10k will cover the cost of the electronics and 16kWh battery in my own planned solar install. Battery is guaranteed for 10,000 cycles, and over the guarantee, will drop from 16kWh to about 13kWh capacity. Average about 14.5kWh.
> So £10k / 10,000 cycles is £1 for every 14.5kWh I put through it. Or 7p / unit to store my "free" (not really of course) solar power to use when it's needed.
> ...


Lead acid is perfectly fine and well established over many years. If you discharge to a great extent they will not last as I'm sure for a commuting scooter as you suggest. For long life you aren't supposed to discharge below 80% of full so need a bigger bank than some might think. Many campers running 120Ah in their van discharge extensively and then wonder why the lifespan is so short. 120Ah may be the required capacity from use, but there won't be payload or space to fit five of them in a typical 3500kg van. Lithium works very well as a replacement because of the weight saving (assuming no cold temps to stop recharge).
If you only skim the top 20% from lead acids they will last probably better, I've never looked into the decades of experience of lead acid, but have looked into the spurious claims of lithium in EVs or storage. The current version of the lithiums in my camper suggest an expected life of 5000 cycles discharged to 50%, 2500 down to 80% used. Not a manufacturer know for telling porkies.
Will anyone fully discharge their lithiums every day? No. On average assume 50% perhaps? So the guarantee you mention for 10,000 full cycles is 20,000 days, 54 years. The tech has been in existence for less than half that so a guarantee based on accelerated lab based theory?
I would be quite happy with heavy 6v lead acids for storage at home, much more so than something guaranteed for 54 years


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## hairy (17 Mar 2022)

I wasn't miles off, since I remember the Tesla 1000 cycles and £10000 replacement cost figures I mentioned from a Tesla owner. And even then young Elon says should not will.


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## Ollie78 (17 Mar 2022)

RobinBHM said:


> renewables dont work all the time -I always thought that was a major disadvantage but in fact what it really means is that there is a need for back up -for when renewables do not generate, however renewables are still beneficial for the time when they do produce -and the UK is increasing its battery storage.



A while ago a bloke was lurking about by my workshop which is in some scruffy farm buildings along with several other units. 
He was looking for the landlord. I asked him why and he said he was looking for a site to house a giant battery for the local grid. 

Turns out our site is right next to the transformer for the village and would be a perfect location. I have not seen anyone do anything yet but it shows they must be on the case with local battery stations.
Interestingly he said it was more for the purpose of reducing usage spikes than anything else.

Ollie


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## Phil Pascoe (17 Mar 2022)

The obvious way of reducing spikes is to alter the cost per kilowatt hour............ which I assume is the ultimate purpose of smart meters.


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## Dabop (18 Mar 2022)

hairy said:


> We could profitably have a wind turbine. A 3.5KW plumbed into the mains would be about £25K installed. Excess production locally limits me to 3.5 down from 5 originally. Plus an annual service plus insurance with it being within quite a long way of a road/house for when the blades fly off.
> The turbine itself only costs something like £5K, or did at the time.
> Instead of FIT and grid connections I wonder if there is a future in each property having its own production and storage?
> Any"renewable" grid connection requires a duplication in capacity for when the wind/sun is being cheeky because demand doesn't take that cheekyness into account.
> ...


Just to correct a few points...

L/A is obsolete and despite it being 'apparently' cheaper, in terms of actual storage versus life expectancy, is the poorest choice by far....
Say you want a '200ah' capacity (which in a 12v bank would be 2.4kwh, in a 24v bank 4.8kwh)

With lead acids- you get 300-500 cycles if taken to 50% DOD (depth of discharge)- which means you actually need (sticking with 12v here) 400ahr of 'label' ahr...
if you want 1000-1200 cycles, you have to stay under 25%DOD- but that means you are now up to 800ah of label capacity
You 'might' get 3000 cycles if you keep your DOD under 10%- but that means to get that 200ah of actual capacity, you are up to 2000ah of actual batteries required!!!!

Li-ion (as used by Tesla and in your phone- depending on quality, they can get up to 1200-1500 cycles at 80% DOD with active BMS and cooling etc- without it, 300-500 cycles is more common- they have the advantage of a lot of storage in a very light package...

The outright winner in terms cycle life is the LiFePO4- which is what is found in most 'home batteries' (except Tesla Powerwalls which currently use Li-ion)they weigh about twice as much as Li-ion per kwh, but at 80% DOD last in excess of 5000 cycles, and at 70% DOD in excess of 7000 cycles- yet cost about 2-2.5 times the price of L/A...

In terms of equal storage capacity to lifespan- a 200ah 'actual capacity' bank means you will have to oversize your L/A bank by a factor of TEN, and even then, it will only last half as long as a LiFePO4 bank- meaning that you need to buy 20 times the 'ah label' of L/A to equal the same as a LiFePO4 battery- which costs only 2.5 times the price...
This is important to understand if you actually want to use the system in reality...
(I installed offgrid systems,boats and 4wd dual battery systems since the 80's and live offgrid myself electrically, due to the cost of getting 'the mains in'- my own system cost under $18k Au, where getting the powerline run in was $42k...)
To equal my approx 200kg of LiFePO4 cells (I got 20kwh of storage at 20 years with 70% DOD) with L/A- I would need to buy close to six TONNES of L/A batteries over twenty years...
:-O


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## hairy (18 Mar 2022)

My subsequent post mentions LiFePO4 life cycles from a long standing reputable brand.
80% full is a common limit suggested for lead acid meaning five times required capacity not twenty. Weight in a house is not really an issue surely?

"(I got 20kwh of storage at 20 years with 70% DOD)" do you mean you installed LiFePO4 in 2002, or those figures are what you've been told to expect?

"it will only last half as long as a LiFePO4 bank" according to who, the lithium battery industry?

One or two lead acids in a 4x4 or camper drained pretty much flat every use running a fridge etc or in a hire scooter won't last long because they are not ideal fitments. Abused would be the word perhaps. LiFePO4 will work much better in many situations if your use justifies the much higher cost. In a house, if you side step the hype?

Thank you for your opinion though 






Dabop said:


> Just to correct a few points...
> 
> L/A is obsolete and despite it being 'apparently' cheaper, in terms of actual storage versus life expectancy, is the poorest choice by far....
> Say you want a '200ah' capacity (which in a 12v bank would be 2.4kwh, in a 24v bank 4.8kwh)
> ...


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## Dabop (18 Mar 2022)

hairy said:


> My subsequent post mentions LiFePO4 life cycles from a long standing reputable brand.
> 80% full is a common limit suggested for lead acid meaning five times required capacity not twenty. Weight in a house is not really an issue surely?
> 
> "(I got 20kwh of storage at 20 years with 70% DOD)" do you mean you installed LiFePO4 in 2002, or those figures are what you've been told to expect?
> ...


That's not opinion- its fact...
The brand I bought I chose for my own place because of their long term known reliability.... they have been on sale in Australia since 2008, so their longterm lifespan is a known quantity... many are already at 14 years old... (mine were bought in 2019, I know from experience however that if anything the factory cycle life is understated, I expect these to outlast me...)







I am well aware of lead acids performance levels and their limitations- having been using them in offgrid houses here in Australia since the 1980's (when they were the only practical solution) as well as in motorhomes, 4wds, boats etc...

There is no 'hype' in my comment- the limits of each of the types is a known quantity, and on purely economic grounds, the LiFePO4 wins hands down for stationary (and even many mobile) applications, lead acid 'looks' cheaper- but it isn't- by a huge amount... (the cost difference isn't even that great- 'label ah' to 'label ah' the price difference isn't that great (LYP being about 2 to 2.5 times the price of L/A) and given the huge difference in performance (in actual capacity and in service lifetime) choosing L/A is simply a bad choice...


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## RobinBHM (18 Mar 2022)

I’ve just had a thought, if global warming means more sunshine in the UK, maybe that means we should use coal fired power stations for a few years, that way solar power will be more efficient more quickly………


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## Ollie78 (19 Mar 2022)

I keep considering solar with battery, this discussion is useful and its good to hear from people who actually have systems installed.
I just keep thinking that it's a shame to put holes in my perfectly good roof. Knowing my luck I would need to fix my roof one year after installing the panels ! 
For this reason I like the idea of the actual tiles/slates being solar so you could replace the roof in one go and get less issues with wind loading etc, it looks better etc. The price is mad for these at the moment. 
I wouldn’t mind if the entire roof was made of big panels actually but not sure this is available. Seems silly to have a roof on the roof.

Ollie


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## Sideways (19 Mar 2022)

For roof replacements there are a few options. Tesla are in the early days of promoting a solar roof tile that looks about 3-4x the width of a common UK tile.
There is a system where a black plastic tray is fitted to the roof timbers in place of the usual felt + battens. Solar panels are then fitted close over that making a tidy and low profile "in roof" installation.
Lastly, and pretty new, there is a brand of panels on the market which interlock and seal along the edges so that they can be installed as an alternative roof covering without the plastic tray below.
The main drawback of the in roof system and the latter one which I think is by Viridian Solar (owned by Marley), is that the panel outputs are weak compared to the better standard panels. The "in roof" installations suffer from heat because they don't have ventilation behind (solar panels work best in the bright but cold) and the Viridian panel just isn't an especially high performance variety at present.

No doubt that the best time to install solar is when you build a house or when you need to reroof for other reasons. I'm too late for one and if I wait for the other, it'll be too late for me  We're going for it. Only time will prove whether it was the right decision.


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## Dabop (19 Mar 2022)

Sideways said:


> No doubt that the best time to install solar is when you build a house or when you need to reroof for other reasons. I'm too late for one and if I wait for the other, it'll be too late for me  We're going for it. Only time will prove whether it was the right decision.


In Australia, most roofs are metal, with older buildings using clay tiles (falling out of favour these days)- and rarely if ever require 'reroofing'- the Colourbond on my shed for example is guaranteed for 35 years- and there are buildings in the area that are a hundred year old 'corro iron' on them- rusty but still in use...

In fact the older clay tiles are more prone to damage from hail storms- so the panels actually protect them lol (and you would be surprised at just large the hail has to be to break a modern solar panel...)

Another factor in hot areas is that covering a good percentage of the roof actually makes the ceiling cavity cooler- which translates to cooler temperatures inside the house (at the old place, you could actually feel the areas of the roof that had panels over it when in the ceiling- noticeably cooler at those areas...)- of course this might not be a 'good thing' in some colder areas lol

Some opt for ground mounts-personally I don't like them (despite my 'tempoary array' being one lol)- they tend to get dirty faster 
(my old place was roof mount- we cleaned them once in four years with a hose from the ground- after a bushfire got to within a km of the house!!!- they were covered in ash...), where my current ground mounts need a wash every few weeks because they get covered in dust...

I have seen quite a few 'double car carports' being made with only the 'skeleton frame' and no 'roof' at all- with the solar panels taking the place of the metal roof commonly used- a 5mx6m double carport could readily hold around 4.5kw of panels- of course in that case, just silicon the panel edges together, it really doesn't matter if it has a 'few leaks' being an open sided carport lol


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## John Brown (19 Mar 2022)

RobinBHM said:


> I’ve just had a thought, if global warming means more sunshine in the UK, maybe that means we should use coal fired power stations for a few years, that way solar power will be more efficient more quickly………


I'm not entirely sure that global warming does mean more sunshine. But I appreciate the ironic spirit of your post. Reminds me of when one of my younger cousins suggested that looking directly at the sun, around the time of the eclipse, wasn't such a bad idea, because if you went blind, it would be like me a permanent total eclipse. I think he was joking.


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## Sideways (19 Mar 2022)

These reports make interesting listening from a USA perspective

and 7 minutes in, this reinforces Dabop's point about the toughness of solar panels.


From a UK perspective it's interesting to see video of shingles being replaced after just 10-15 years vs common or garden concrete tiles used on a large proportion of UK homes which have a design life of 60 years in typical use and many last for decade(s) longer.

But our hailstones are rarely more than 3 to 4mm diameter ....


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## Dabop (20 Mar 2022)

Sideways said:


> But our hailstones are rarely more than 3 to 4mm diameter ....






This was about ten km away from where I was just before Christmas, most arrays were still intact, there was a few broken panels here and there, but mostly they survived...
(they did better than the cars did- smashed windscreens and 'panelbeaten' bodywork everywhere- the local car dealership lost every car on the lot- all brand new and not a straight panel left on any of them....)


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## Crazy Dave (20 Mar 2022)

Removed


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## ian33a (20 Mar 2022)

Crazy Dave said:


> Here's a little something I knocked up to reduce my energy bill and with the pending price increases next month should pay for itself quite quickly.
> 
> View attachment 132061
> 
> ...



I bet your neighbours love you


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## Crazy Dave (20 Mar 2022)

ian33a said:


> I bet your neighbours love you


Neighbours don't have any problems at all, in fact they are considering doing the same and were asking me how much it all costs.
Edit: Anyway it's not just about me it's about all of us doing what we can to improve our environmental impact.


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## Dabop (20 Mar 2022)

Crazy Dave said:


> Here's a little something I knocked up to reduce my energy bill and with the pending price increases next month should pay for itself quite quickly.
> 
> View attachment 132061
> 
> ...


Just realised that I was in PM when I was talking about this lol, but direction is of far less importance than many think...
Your roof looks like it would be ideal for an 'east/west' split...


Dabop said:


> Another factor is direction is actually far less important than many believe....
> My previous house (because of building constraints) had 3kw of PV facing east, and 3kw of PV facing west (the very small north facing roof was almost entirely taken up by solar HWS thermal panels)
> We actually had an identical system (6kw all facing north) installed by the same company two days after ours, by the same crew even lol-was installed at the neighbours place
> 
> ...


That was from a PM conversation


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## Crazy Dave (20 Mar 2022)

Dabop said:


> Just realised that I was in PM when I was talking about this lol, but direction is of far less importance than many think...
> Your roof looks like it would be ideal for an 'east/west' split...
> 
> That was from a PM conversation


Thank for sharing, unfortunately I couldn't view the images as I don't have permission. LOL


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## Dabop (20 Mar 2022)

Crazy Dave said:


> Thank for sharing, unfortunately I couldn't view the images as I don't have permission. LOL


lol- showed up for me...
first one was


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## Blister (20 Mar 2022)

Ollie78 said:


> I keep considering solar with battery, this discussion is useful and its good to hear from people who actually have systems installed.
> I* just keep thinking that it's a shame to put holes in my perfectly good roof. *Knowing my luck I would need to fix my roof one year after installing the panels !
> For this reason I like the idea of the actual tiles/slates being solar so you could replace the roof in one go and get less issues with wind loading etc, it looks better etc. The price is mad for these at the moment.
> I wouldn’t mind if the entire roof was made of big panels actually but not sure this is available. Seems silly to have a roof on the roof.
> ...



When my 10 panels were fitted the installer pushed one tile up over the one above it , after the bracket was fixed to the roof timber the tile was slid back down , NO holes


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## Stevekane (23 Mar 2022)

This clearly needs checking out but a chap I know said his elderly mother is getting her totally free solar panels fitted today, its a scheme for anyone with an income of less than £30.000, and its not one where the company keeps the FIT or anything,,,I must look into it.
Steve.


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## Phil Pascoe (23 Mar 2022)

I had the same offer from the county council - it depends upon the EPC of your property. If yours qualifies you should probably have had it. (Mine has been insulated etc. since the EPC was done - it was a joke, anyway).


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## Richard_C (23 Mar 2022)

You've probably heard today that VAT on energy saving products - including solar panels - will be removed so an installation will (should) be 20% less from 1 April. That and rising electricity prices might change the equation. 

I have thought carefully about pv panels on and off for some years but still not done it. I will think again now. A few things bother me - life of panels and the decline in efficiency over time being one, but the main worry was and perhaps still is the dodgy-ness of the industry. It seems a bit wild west, first there was rent a roof with no proper explanation of any risks on house sale, then there are guarantees and if they will be honoured, companies come and go *, cost and margin - all companies need to make a profit but I remember when FIT was cut suddenly the installation cost fell massively which suggests that margins were very high, cold calling from 'energy consultants' ** and so on. Unregulated or lightly regulated businesses shouldn't really be trusted with something of major long term importance. Who can you trust? I'm sure there are some good installers out there and many happy customers but I'll bet that there are a good many unhappy ones as well.

_* A company set up with great fanfare on the edge of our village, rented barns/workshop/showroom etc from local farmer and offered everything 'green' from wood pellet boilers to pv installations. Someone I know had work done by them but they wouldn't come to sort out a problem. I had a dig around - they had disappeared. Companies house search, wound up but because it was a voluntary wind up no directors were disquaified. Search the directors on companies house and they had started and wound up companies before.

** A good reply to a cold call from an energy consultant is "so what are your qualifications?" Stops them in their tracks - "you say you are energy consultants so I presume you must be qualified in some way otherwise anyone could set up and start phoning people " ... I just make the appointments .. "fine, but will the person you send be qualified..." _


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## MARK.B. (23 Mar 2022)

I could be wrong but i think that the VAT on solar installations was only 5% , the 20% was only charged on items fitted after the main installation, So the price would only come down 5% and not 20%.


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## Pedronicus (23 Mar 2022)

MARK.B. said:


> I could be wrong but i think that the VAT on solar installations was only 5% , the 20% was only charged on items fitted after the main installation, So the price would only come down 5% and not 20%.


Correct. 5% on solar installs.


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## Crazy Dave (23 Mar 2022)

Richard_C said:


> You've probably heard today that VAT on energy saving products - including solar panels - will be removed so an installation will (should) be 20% less from 1 April. That and rising electricity prices might change the equation.
> 
> I have thought carefully about pv panels on and off for some years but still not done it. I will think again now. A few things bother me - life of panels and the decline in efficiency over time being one, but the main worry was and perhaps still is the dodgy-ness of the industry. It seems a bit wild west, first there was rent a roof with no proper explanation of any risks on house sale, then there are guarantees and if they will be honoured, companies come and go *, cost and margin - all companies need to make a profit but I remember when FIT was cut suddenly the installation cost fell massively which suggests that margins were very high, cold calling from 'energy consultants' ** and so on. Unregulated or lightly regulated businesses shouldn't really be trusted with something of major long term importance. Who can you trust? I'm sure there are some good installers out there and many happy customers but I'll bet that there are a good many unhappy ones as well.
> 
> ...


Have you considered DIY, I did and all worked out fine, you just need to watch the numbers Generated Vs Usage.


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## RobinBHM (23 Mar 2022)

Crazy Dave said:


> Have you considered DIY, I did and all worked out fine, you just need to watch the numbers Generated Vs Usage.


I presume you need an electrician to connect up and certify?


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## Phil Pascoe (23 Mar 2022)

5% will get swallowed by other cost increases.


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## Jameshow (23 Mar 2022)

Blister said:


> My panels are on the garage roof , Direct south facing
> 
> 
> 84FAF74E-6255-4395-9311-0EB692AF2478 by Allen Wells, on Flickr
> ...


How much did that setup cost??


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## Crazy Dave (23 Mar 2022)

RobinBHM said:


> I presume you need an electrician to connect up and certify?


Well...... That depends on whether you have the necessary understanding to do it yourself, who signs off when you plug the Toaster in? The inverter simply plugs in to a standard 3pin socket, of course the socket has RCD protection the inverter circuit handles the rest. It's not as simple as it sounds but as long as you have the necessary DC and AC isolator switches in place and you have the PV panels connected in a way that suits the inverter you're using you're good to go. But if you're not absolutely sure what you're doing *don't do it *because you could be handling voltage from the panels that has the potential to be Dangerous to life.

Edit: Jack Daniels has paid a visit, maybe my reply would be different it hadn't. Just saying


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## Jameshow (23 Mar 2022)

Don't do this as you could send current back down an isolated (from the mains) circuit and kill a network electrician.... 

Think I heard this correctly... 
.


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## Crazy Dave (23 Mar 2022)

Jameshow said:


> Don't do this as you could send current back down an isolated (from the mains) circuit and kill a network electrician....
> 
> Think I heard this correctly...
> .


No you can't, the inverter has to sense mains before it will process the power from the panels, if the mains goes down the inverter will shut off until the mains is restored again. I can't speak for the cheap Chinese eBay/Amazon inverters but a MCS certified Growatt Grid tie inverter does exactly that.

This is exactly what I meant when I said don't do it unless you're sure what you are doing.


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## RobinBHM (23 Mar 2022)

Crazy Dave said:


> Edit: Jack Daniels has paid a visit, maybe my reply would be different it hadn't. Just saying


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## Dabop (23 Mar 2022)

Richard_C said:


> I have thought carefully about pv panels on and off for some years but still not done it. I will think again now. A few things bother me - life of panels and the decline in efficiency over time being one, but the main worry was and perhaps still is the dodgy-ness of the industry. It seems a bit wild west, first there was rent a roof with no proper explanation of any risks on house sale, then there are guarantees and if they will be honoured, companies come and go *, cost and margin


Unless you are a teenager or younger....
then the panel life is of absolutely no importance- there is a lot of - well what you find coming out of the south end of a male bovine facing north- about 'short panel lifespans'...
In reality- any panel made in the last quarter of a century that costs more than $2- the expected lifespan is up over half a century or more... I know the ones I used in the 1980's here in Australia are still being used at a neighbours place today...
Many confuse (some intentionally) the 'output guarantee' with the lifespan- note that even the 'elcheapo' panels have a 80% or better one at 25 years, the upmarket ones are 90% at 25 years...
Do you replace your car tyres when they use 10% of their tread depth???
No???
So why would you replace your solar panels???
To put it in perspective- my panels were brand new in 2018- each panel is rated at 250W... (at the specified light and temperature)
They have a 82.7% minimum 25 year guarantee- ie they will be producing 82.7% OR MORE in 25 years... (they were at the cheaper end of the market lol)
So in 2043, the will still be producing 206.75W- or more...
And with most having a 0.6% or lower per year drop in output... when (IF lol) I break 100 years old- mine will still be making 175w per panel (dropping the total output from 18kw down to 11kw...
PANIC TIME- at 100, I doubt I will be climbing on the roof to replace them...

Oh and the warantee- thats from the panel MANUFACTURER- not the installing company- so stick with the long term players...


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## Blister (24 Mar 2022)

Jameshow said:


> How much did that setup cost??



£9500


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## Sandyn (24 Mar 2022)

Crazy Dave said:


> Have you considered DIY, I did and all worked out fine, you just need to watch the numbers Generated Vs Usage.


Can you give us a bit of information on the equipment you chose. which panels and controller. Also expand a bit on numbers Generated Vs Usage


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## Crazy Dave (24 Mar 2022)

Sandyn said:


> Can you give us a bit of information on the equipment you chose. which panels and controller. Also expand a bit on numbers Generated Vs Usage



The equipment I chosen suits the application which I intend to use it for, your situation will no doubt be different from mine.
It would be wrong of me to try and explain everything in a text format because 1) I'm not qualified to do that and 2) there is too higher risk of misunderstanding that could result in someone getting hurt and I don't want that on my conscience. Sorry.

The basics: Solar panels should be facing south (northern hemisphere) and depending on where you are tilted at an appropriate angle to maximize their potential.
The energy generation is in the form of a DC voltage which can be in the range 12volts for a parallel connected string to 100s of volts for a series connected string or even a series/parallel set up to match the inverter MPPT (maximum power point tracking).
A grid tie inverter is used to convert the DC power into AC so it can be added to the Grid or used in your home. With a pure sign wave inverter you could use the energy via a battery bank and that is a whole other topic.

Try YouTube if you just want to learn more about it.


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## RobinBHM (24 Mar 2022)

this is my reason for looking at solar


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## Sandyn (24 Mar 2022)

Crazy Dave said:


> The equipment I chosen suits the application which I intend to use it for, your situation will no doubt be different from mine.
> It would be wrong of me to try and explain everything in a text format because 1) I'm not qualified to do that and 2) there is too higher risk of misunderstanding that could result in someone getting hurt and I don't want that on my conscience. Sorry.


Thanks. I had a quick look. it all seems pretty straight forward. I haven't had any interest in it before, but just started thinking about doing my own installation. Which manufacturer did you use for your equipment? I don't think there is any risk telling me.


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## Crazy Dave (24 Mar 2022)

Sandyn said:


> Thanks. I had a quick look. it all seems pretty straight forward. I haven't had any interest in it before, but just started thinking about doing my own installation. Which manufacturer did you use for your equipment? I don't think there is any risk telling me.


I went for a Growatt 1500tl-x inverter and 4 X 295W Smaller Size Perlight Black Plus Mono Percium Solar Panel - 54 Cell Smaller 1.5m high.

Check out Bimble Solar as they supplied most of my equipment.


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## Sideways (24 Mar 2022)

Do be aware that even if you go down the route of something like "plug in solar" a system in a box with low enough capacity that it can be added to an existing circuit in your house without the need to notify building control - you still need to submit a g98 application to your electricity company (your "DNO").


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