So now the euphoria of finally finding my solar power maths / research has finally died down (I slept on it) , I’m starting to question if it will ever “really” be worth it at all and here is why:
Solar Map 3.5Hrs ???
With a quoted sun index of 3.5 hours (seems low from our experience) Burgundy using the Sharp panels as quoted in THIS POST then on average we would generate 191kWh of electricity a month.
Given that electricity is charged per “unit” and one unit is almost equal to 1kWh the panels would ON AVERAGE return 191 units towards our monthly electricity bill.
If we price the cost of a unit VERY high at .10p ( 00.20$ or €00.12 ) then with a projected purchase and install cost of £6,000 the panels would take over 25 years to break even and by that time by everyone’s admission there will be far great panels out there.
UPDATE: After the utility companies in the UK just rocketed up their pricing the above figures are invalid. For that reason the maths needs to be refreshed to these :
- Currently 1unit (kWh) of electricity used including VAT is now £0.1853p
Here is my maths :
Average return x unit price = £19.10 – £35.39
Cost of install = £6,000 / £19.10 £35.39 = months to break even 314.12 169.54
Number of months 314.12 169.54 / 12 ( months in a year ) = 26.17 14.13 years to break even.
Now I am fully aware that some months the rate will be a lot higher and the unit rate is expected to rise but even then the figures aren’t stunning.
ORIGINAL FIGURE WORK LEFT HERE FOR REFERENCE : Lets say that the sun figures for Burgundy are wrong by just 1 hour a day and the unit of electricity doubles from .10p to .20p then the maths still looks like this :
At 4.5Hrs the EC8 will return 245kWh per month so :
Average return x unit price = £49
Cost of install = £6,000 / £49 = months to break even 122.45
Number of months 122.45 / 12 ( months in a year ) = 10.2 years to break even.
Ignore the below statement as it appears that i was NEVER paying .03p for my electricity ( that was gas ) . SORRY ALL
At these figures it “could” be worth it but given I’m currently paying .03p per unit from EDF that puts the pay-back currently at 87 years.
I need someone to point out the error in my calculations and quick before I choose the offset my carbon and electricity by planting some trees. Most disappointed today
The good news is that someone did point out the errors in my figures and I finally got my costs from my energy supplier things changed A LOT ! Feeling better today
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