Solar Electricity generation

[wobblycogs]

I've just done a quick calculation of payback for your system and I'm really surprised how cheap solar power has become. I'm going to ignore the FIT scheme as I wan't to see if solar electricity can compete with normal electricity on a level(ish) playing field.

Lets say that a unit of electricity is 12.1p/kwh. That means you generated 59p of electricity that day so the payback time would be 7796 days or 21.3 years. I'm guessing that your panels probably have a 25 year guarantee on them so even if your average day is like winter it seems the price is about what regular power generation is costing (ok, this doesn't take into account the drop in performance of the panels or the transformers failing etc etc).

The point really is that solar power now looks to be about the same price as mains electricity even somewhere less than amazingly sunny like the the UK. Electricity prices in the UK are only going to go up so I suppose the payback time be significantly less than the above.

 

[RogerM]

We have 17 Sanyo monocrystalline panels giving just a smidgin short of 4kw. Our roof faces 10 deg west of south and there is no shade. In the first year (Oct 2011 to Oct 2012) we generated 4451 kwh which is over 10% more than the official estimate, and which paid us just over £2,000 in FIT and export tariff. Our best month by a country mile was May. June was dire - generating less than March. Our annual usage is around 5,000 kwhs. Assuming average RPI is 3% the system will pay for itself in 6 years making the income for the remaining 19 years of the FIT clear profit, by which time we'll be aged 83. Gives us a good incentive to live that long! Best investment we've made for years.

 

[dickm]

We have 17 Sanyo monocrystalline panels giving just a smidgin short of 4kw. Our roof faces 10 deg west of south and there is no shade. In the first year (Oct 2011 to Oct 2012) we generated 4451 kwh which is over 10% more than the official estimate,

That is b****y good! My system is the same size, but on too shallow a pitch and with some shading and our annual generation at best was 3400kWhr. But that's also Scottish weather for you

 

[RogerM]

We have 17 Sanyo monocrystalline panels giving just a smidgin short of 4kw. Our roof faces 10 deg west of south and there is no shade. In the first year (Oct 2011 to Oct 2012) we generated 4451 kwh which is over 10% more than the official estimate,

That is b****y good! My system is the same size, but on too shallow a pitch and with some shading and our annual generation at best was 3400kWhr. But that's also Scottish weather for you

That's the south Devon microclimate for you.

 

[Phil Pascoe]

I think we should have "rain panels" It would make more sense. Rain is fine - except when you have rain before and rain after. You Devon people probably get a bit more sunshine.

 

[andersonec]

Bob

See this thread for plenty of information on PV etc.

Im still not 100% clear on the investment though - it still feels like a long term investment with a significant number of years until you've broken even.

Miles

Miles, I cannot see why the need to calculate a 'break even term' surely the investment you make is to reduce your spending (and all the other benefits) from day one. Does anybody calculate the 'break even point' when they spend £20 grand on a kitchen or £20 grand on a car or £5 grand on a holiday? and can you forecast how much the power companies price rises will be for the next few (and more) years?

The reason companies were bombarding people with phone calls offering free panels was that they were collecting approx ten grand a year from the government for the panels on your roof,

Fit a ground source heat pump and your total heating and hot water bills will be something like £5/600 a year.

A no brainer to me.

Andy

 

[wobblycogs]

This assumes you are lucky enough to have the space for a heat pump of course which most of us don't have.

The difference between a holiday and solar panels is one is done for pleasure and the other as an investment. You'd be crazy not to calculate a break even point and return on an investment. If it takes 10 years to break even you have to either stay in the house for 10 years or be pretty sure that the panels will increase the value of the property (they wouldn't for me) otherwise you are paying to put electricity into the grid.

Solar panels, at the moment, are little more than a savings account on your roof.

 

[johnf]

Bob

See this thread for plenty of information on PV etc.


Fit a ground source heat pump and your total heating and hot water bills will be something like £5/600 a year.

A no brainer to me.

Andy

I can confirm that great things heat pumps 24 /7 heating no extra cost

 

[andersonec]

This assumes you are lucky enough to have the space for a heat pump of course which most of us don't have.

The difference between a holiday and solar panels is one is done for pleasure and the other as an investment. You'd be crazy not to calculate a break even point and return on an investment. If it takes 10 years to break even you have to either stay in the house for 10 years or be pretty sure that the panels will increase the value of the property (they wouldn't for me) otherwise you are paying to put electricity into the grid.

Solar panels, at the moment, are little more than a savings account on your roof.

Heat pump pipes can be drilled down vertically or there are ones for use in water then again you could fit an Air Source Heat Pump outside your back door, admittedly they are best used on a new build and in conjunction with under-floor heating but these things have been in use in Scandinavian countries for the past forty years or more and should be at the top of any home builders shopping list rather than marble worktops or slate floor tiles and other unnecessary luxuries, I built a garden in Surrey a couple of years ago for the CTO of a very well known mobile phone company, while we doing the job he had the rear of the house rearranged so the view onto the garden was improved, he has since spent one hundred thousand pounds on redoing the kitchen after which they moved????
As an aside, while the rear of said house was being rearranged I noticed there was no insulating in the cavity, spoke to the owner who wasn't in the slightest bothered, this was a one million pound house on a gated estate (guarded by ex Gurkahs) built by, you guessed it, Barratts.

You fit such things to cut fuel bills, things such as Insulation and double glazing (what is the break even point on those items?) the rate fuel costs are rising (how long is oil going to last?) you could 'beak even' as you call it in a few short years.
There is no break even point, you will never get the initial outlay back, it's the same as 'start-up-costs' on any new venture, the outlay is to get the thing set up and in motion, from there on in the rewards of greatly reduced bill are reaped,

Frankly I think the only way to calculate said 'break even point' is to put the money saved into a savings account (the amount would have to rise as fuel costs rose) and when the savings equaled the initial outlay, voila, you have broke even.

I will say again, if you are producing electricity you will get paid a 'Feed In Tarrif' by your electricity provider, you also get paid for any excess electricity you export into the grid.

Andy