Solar panels.

[Phil Pascoe]

Is anyone thinking to have them fitted or more to the point to fitting their own? The time has come. Our major consumption of electricity is water heating which could well be done by day. Strangely enough bearing in mind a shortage of generating capacity we've just come off economy 7 as a standard tariff is cheaper.

 

[Sideways]

I had 24 panels fitted to my roof in March.
Because I'm fussy and had specific requirements that I wanted met, it turned out to be quite complicated to choose and source the panels in the face of the global supply chain issues but I was working with a good installer so I'm very pleased with the outcome. June and July, the roof made over 850kWh per month, more than half that went to the grid because we couldn't use it all up despite heating between 1 and 3 tanks full of 70C water daily using a solar diverter.
A friend who was similarly inspired but less fussy about it had a much smaller system installed within a fortnight of contacting one of the national outfits that he found on the internet.

I could rabbit on about this for hours but don't want to bore or monopolise the conversation. I'm happy to share if it would help. Feel free to ignore me, to ask for the war story or just pose any questions you may have

 

[Stuart Moffat]

I keep thinking of doing it (I did my own solar heating about 10 years ago and it is still excellent). I wouldn’t want it on the roof, but do have a lot of ground space where I could lose it. I’d be very interested to know what components you bought from where, and why, and which you’d buy again , or wouldn’t.

 

[clogs]

I'm in the same boat but going fully off grid.....
here the gov/elec company makes almost impossible to take ur overflow......
U have to connect to a special site/transformer, and for us it's around 2 kilometers away and we have to pay for the poles and the cable plus the connection...all that work has to be completed by the elec comp....!!!!!!!!!!!..
so for us it's use it or loose it.....stuff em...so much for greenability.....
here, apart from commercial systems it's very rare to see photo/v panels....
Strange as we have so much sunshine....but guess nobody wants to go off grid totally....
I will be fitting everything myself...the only specialist outsider will be the electricien for the connection.........
sideways,
do u have batteries.....? guess not.....
can I ask what ur special arrangement....?
was it only to be fitted by big busted ladies..? hahaha.

we already have solar water heating and what a saving that is.....
just an example...
a 250 ltr system with two panels here is about 1200euros...materials only..
when I did mine in France 10 years ago and without written planning it was just 4000euros...for mats.....
no idea on cost in the UK.....
when I was in Africa 25 years ago there were no panels avail at all, so I made my own and supplied my own tank.....
be very happy to hear anyones troubles/progress on the above....
I def think it's gonna be the future as elec anit gonna get any cheaper....EVER....

 

[John Brown]

The great thing about water heating with solar PV is that you can get devices which divert any surplus (i.e. potential exported power) to an immersion heater.
We don't, as it happens, because we have solar water panels as well, but in your situation I think it would be ideal.

 

[Sideways]

It will take a few days and rather than messing up Phil's thread I'll write up my story separately and in the same fashion that @deema and myself do our machinery renovation threads.
I'm an electrical engineer, so I wanted and got 100% involvement in the design and selection of the system. This is very unusual.
I did most of the design before choosing an installer and then we bounced it back and forwards a few times to make it practical for him without compromising on something that mattered to me.
I don't expect that anyone else should take the approach that I did, but there may be a couple of keenies who'll find it interesting

I'll put a link in here to the other thread once it's up.
Meanwhile - 24 panels, Sunpower Maxeon 3 black, 9kW peak, Fronius GEN24 6kW and (old style) Primo 3kW inverters plus Fronius Smart Meter, 16kWh BYD HVM LiFePo battery stack on order but the boat doesn't get here until September (maybe). MyEnergi Eddi solar diverter, with the plan of adding their Zappi 2 car charger in due course.

 

[Droogs]

@Sideways, very keen to hear. We are hoping to move at the end of the yearish and hope to get a property with enough land area to go totally off-grid. So the more info I can get the better, especially as I would like to power the house and a workshop (incl 3 phase).

 

[MJ80]

We are looking into the options that are offered where we lease the space on our roof. I haven't looked too much into it because I'm more concerned with getting heating pellets at a good price. They have gone insane in Germany. We do have solar water on the roof which is really very good, but to get another tank with an immersion would be fantastic. Teenagers just can't get enough hot water!

 

[Phil Pascoe]

All opinions, experiences and buying advice welcomed. A lot depends upon the future kWh prices, of course, but it would be helpful if we can have a rational discussion without silly political diatribes. I for one doubt they'll ever fall to where they were, but neither will they stay at the level to which they are forecast to rise even if they do rise that far. I have a south facing roof and will have a 12' x 9' (flatter) east facing one (though any panels on that could be angled better).

 

[Terry - Somerset]

I have had a fairly detailed look at this - with the very recent increase in the price cap it is increasingly attractive, but note:

• output from solar panels in summer is (I estimate) 3-4 times that in winter due to reduced daylight hours and increased cloud cover.
• conversely consumption in winter is higher due to lower daylight hours and lower temperatures. Approx. 60% of energy consumption is space heating.
• export tariffs for surplus energy generated is lower than the cost of PV - a real improvement would be for a minimum export tariff which properly reflects the price cap.
• storing surplus energy generated by hot water heating is a sensible option - although if gas central heating and hot water is already installed the benefits are marginal.

My conclusion is that with PV panels alone there is an extended payback of 10 years++. Going off grid with PVs would require huge capacity to cope with low output in winter which means huge overcapacity in summer when demand is lower and generation higher.

The next thought is storage. A battery bank is not a trivial expense but allows energy generated during the day to be consumed at night. Again the winter/summer issue rears its ugly head - sufficient battery storage to meet overnight demands in winter means a PV and battery installation which in summer has far too much capacity.

To make finances work needs EV ownership with its battery used to store surplus energy generated during the day, released for domestic use overnight. I assume draw from the EV can be managed by the user setting a minimum the residual power anticipating the next days use.

This is a sort of corrupt financial analysis as it effectively loads the cost of battery storage on to the EV, not the PV system. However in the not too distant future EVs will be the only game in town for new personal transport.

Both PV and battery installations require material investment. A grid connection will be required for (a) export and (b) meet peak demands to be financially viable. Space heating will need additional PV and battery capacity + air or ground source heat pumps (more investment).

Reducing energy costs may be through better insulation and controls. It matters not whether a KWh is saved through green generation or reduced consumption.

If driven primarily by financial considerations going off grid is not an option for most. If one is fortunate enough to have woodland as a fuel source, or if environmental concerns dominate finances one may reach a different conclusion.

 

[sploo]

I've been wanting to get solar panels too (still trying to convince the wife).

I looked into the details a month or two ago, and it would appear that the payback period is getting more favourable/shorter (partly due to the improvements in the panels, but also because of the rising costs of electricity from the grid). The gist I got was that you can expect to roughly double your installation cost if you want to add battery storage - so if you're at home during the day and would expect to use most of the energy created by the panels then it might make sense to just get the panels and an inverter.

 

[John Brown]

I have had a fairly detailed look at this - with the very recent increase in the price cap it is increasingly attractive, but note:

• output from solar panels in summer is (I estimate) 3-4 times that in winter due to reduced daylight hours and increased cloud cover.
• conversely consumption in winter is higher due to lower daylight hours and lower temperatures. Approx. 60% of energy consumption is space heating.
• export tariffs for surplus energy generated is lower than the cost of PV - a real improvement would be for a minimum export tariff which properly reflects the price cap.
• storing surplus energy generated by hot water heating is a sensible option - although if gas central heating and hot water is already installed the benefits are marginal.

My conclusion is that with PV panels alone there is an extended payback of 10 years++. Going off grid with PVs would require huge capacity to cope with low output in winter which means huge overcapacity in summer when demand is lower and generation higher.

The next thought is storage. A battery bank is not a trivial expense but allows energy generated during the day to be consumed at night. Again the winter/summer issue rears its ugly head - sufficient battery storage to meet overnight demands in winter means a PV and battery installation which in summer has far too much capacity.

To make finances work needs EV ownership with its battery used to store surplus energy generated during the day, released for domestic use overnight. I assume draw from the EV can be managed by the user setting a minimum the residual power anticipating the next days use.

This is a sort of corrupt financial analysis as it effectively loads the cost of battery storage on to the EV, not the PV system. However in the not too distant future EVs will be the only game in town for new personal transport.

Both PV and battery installations require material investment. A grid connection will be required for (a) export and (b) meet peak demands to be financially viable. Space heating will need additional PV and battery capacity + air or ground source heat pumps (more investment).

Reducing energy costs may be through better insulation and controls. It matters not whether a KWh is saved through green generation or reduced consumption.

If driven primarily by financial considerations going off grid is not an option for most. If one is fortunate enough to have woodland as a fuel source, or if environmental concerns dominate finances one may reach a different conclusion.

While I agree with most of this, Phil did say that he has electric water heating.

As for EVs being the only game in town - that presupposes that new houses are being built with EV charging in mind, which I'm not sure is the case.

 

[macca]

Hi phil, I work with a v.good sparky who lives in tuckingmill, he is employed by flockharts but he can be persuaded to take on private jobs, if you were in need of someone to have a look I'd be happy to put him in contact.

I have been discussing solar with him as he just installed it on his own place, buy back to the grid is a shocking return at the moment IIRC circa 7-8p per kwh buy back and sold to you around 25p (although thats probably gone up now)

In regards to batteries i have heard talk of old forklift batteries being used as a cheap alternative, I have no idea how feasible this actually is but could be worth looking into for you guys looking to go off grid on a budget, a friends father has created his own battery storage and charges them over night on a car charging tariff when he has a poor yield in the day

 

[Phil Pascoe]

We have absolutely no intention of buying an electric vehicle. We have no gas, mains or bottled. We have no electric heating, our "space heating" is a 48w in line fan ducting hot air from the multi fuel stove to other rooms. We are fortunate, our winter temperatures dip below 0°c half a dozen times a year, and mostly isn't below maybe 5°c. Ultimately the feasibility of panels depends upon the future price of a unit.

^^^^ thanks for the offer.

The FIT is ludicrous - it's either lousy or excessive. It needs to be fair, maybe 3/4 of the average unit price? They could still make money at that rate.

 

[Ollie78]

I looked into to it a bit and decided its only worth it with a battery system and another way to use it all yourself, heating water for example.
Unfortunately the local grid provider can dictate the size of your array on its potential maximum output even if you don`t intend to put anything back onto the grid at all (I suppose just in case of possible overload ). The potential installer will know about this and is required to ask before doing anything.
Still looks a good bet long term, the payback period is reducing considerably, it was over 10 years and is now nearer 5 or 6.

Ollie

 

[ian33a]

My conclusions are rather similar to Phil Pascoe - we have a 4KW array here, installed by the previous owner. The FIT rate is better than offered now but far from generous. We have no gas in the village and no wish to go LPG. Heating is oil.

In my previous house I built an electronic solar diverter. I took it with me but it's more challenging to install here.

A friend of mine in the village installed a large solar array on his roof, part PV, part solar thermal and he has a 5KWah battery pack as well, plus a thermal store. He believes that he is almost getting his energy for nothing now. I haven't asked him what the installation cost was but believe it to be significant.

I have considered adding a battery pack to mine. I've also considered heat pumps, even a wind turbine. My hot water is a thermal store and I could add a solar heating coil. It would be cheaper, though, to re-introduce the solar diverter. We still embrace the internal combustion engine and wont be going EV anytime soon.

I go around and around the green energy debate in my head and with Excel and I struggle to balance the numbers. If I apply purely green credentials to it then it's an easy win. If I apply pure return on investment maths, the payback seems way out and my money could be spent better elsewhere.

Over the past couple of days I've been cutting up fallen wood ready for storage/drying out. This should feed the two wood burners for quite sometime. We have some woodland so there is a ready supply of free wood. That said, the cost of a chain saw and a way to safely cut the wood and haul it around is significant and makes even the initial outlay for this significant.

Perhaps over the next year or I will have a better idea of the running cost of our house and will change my mind. At the moment though, the ROI on much of this stuff seems rather long, even with the alarming increases in fuel costs. And on that subject, somehow I suspect that any Government in power will come to realise that simply letting fuel costs go up and up is a sure fire vote looser, even with the short memories of voters. Something will inevitably have to be done to keep people out of fuel poverty irrespective of the band of council tax that they pay - unless those in power have no wish or need for re-election.

 

[Keith]

I nearly progressed an installation with 18 panels, and a 5.8kW battery.
Would have needed to cut back some lovely beech trees shadowing the garage roof.
Winter :summer difference not defined.
Then came the details
Company stated 25yr guarantee on solar panels, solid state inverter (lifetime manufacturers warranty) and battery 10,000 cycles - 26-28 yrs

Then found they only guarantee for a year and will help you claim off the manufacturers after that - if they can be bothered! - and the inverter had a 5 year guarantee.

Wife not happy that we would need to schedule activity (showers, washingetc ) to smooth demand and avoid pull from grid.

Big killer was that we would get ZERO payment for any export as we aren’t on a SMETS 2 meter due to our rural location.
Suspect that energy companies will in future charge and pay according to when you use/ export electricity

And so much for self sufficiency - the system needs to be connected to the grid to operate - so if the power goes down it won’t work.

The supplier might have been selling me a load of rubbish - but all the points led me to back out quickly.
Will consider again if export rates are reasonable and better batteries are available.

 

[Fitzroy]

Fascinating thread folks. Thanks for all the detailed inputs. Are there any recommended sites where I can look at info on sun levels for each area? I’m Aberdeen based so I think this is a non starter as our days are so short in winter. But with the new price cap I’m investigating all avenues.

 

[akirk]

I am currently looking into this, we are high electric users as I work from home with computers and servers on 24/7 as well as a range of fridges and freezers here…

as we play not to move, we could take a longer payback, but still lots to explore…

@Fitzroy, I found a map on bristol council website which seems to be a national overlay which colour codes every house for suitability presumably based on orientation etc, and the government does have sun level figures across the country, if I find the urls I will post them

biggest question for me is how to find a reputable company

 

[Tris]

Talking to our local plumber who has done a lot of work on 'eco refits' many of his customers report the best return is on solar water heating, if that's an option and you don't use much electric otherwise it could be worth considering