Maths Check Please.

kindai

kindai

kindai

Sgarrista
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Bromsgrove
Can someone confirm to me what I think I have here is right (give or take a few quid for rounding purposes)

Or have I missed something.


24 June 2014 we had our electricity meters read at
Day: 75405
Night: 15779

Today I read them at
Day: 85725
Night: 18475

So the number of days between them is 293 equaling an average usage of
35.2 KWH in the day
9.2 KWH in the night

Our current tariff is 17.7p day and 6.2p night. The yearly bill ~ 2500 or about 209 per month.


Just been quoted for 29 solar panels which would generate ~ 6496kwp based on the government spreadsheet thing. (Note we would be using all of the generated power due to 2 ponds, so most only account for 50% usage, we will be 100%).

The estimate returns are £787 feed in tariff, 50% export payment at £157 plus the solar we use which at the current 17p rate works out at £1055.28 saved.


We are on a high rate, so on a price comparison site, we can get down to 5.5p night and 11p day rates. Based on the average usage of those 2 numbers before, it brings the monthly bill down from £209 to £100.

Factor in the reduced cos on the solar benefit that goes down to £685.

So am I right in assuming.


Current yearly bill: £2500
New yearly bill on new tariff: £1200
Minus solar benefit (1200-685): £515
Minus £787 feed in tariff: -£272
Minus £157 export: -£429.



So if my maths is right, by buying these panels and switching providers, not only will I get free electricity, but every year im going to be up £429?

For a total net gain to the tune of £2900 a year (minimum, as prices and inflation etc go up).

Meaning this £9k system will pay for itself in just 3 years?!


What have I missed for this too-good-too-be-true maths?
 
NoobCannon said:
£209 a month on electricity???

With that sorta usage i wouldnt have thought you'd be worrying about money!
Click to expand...

Not worried about anything, but 3 grand a year benefit for switching providers and lumping £9k of panels on the roof seems like a no brainer... inf act... such a no brainer im convinced its wrong.
 
Hmmm, do you have ideal conditions for the panels? i.e. south facing roof, no tree's shading the roof etc?
 
Last edited:
xxalxx said:
Hmmm, do you have ideal conditions for the panels? i.e. north facing roof, no tree's shading the roof etc?
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No, thats why its a 7.6kw system but only estimated to generate 6.5, which from what I understand is based on the "worst case" scenario of the light available, the actual will be higher.
 
Is the cheaper rate deal /linked/ to getting the solar panels? If you can get it anyway, I wouldn't count that as a saving against the solar panels.

Going by that logic, the savings per year from the solar panel would be £1600, still a tidy sum but it means you'll be paying it off in 6 years, rather than three.

Still a no-brainer, mind you.
 
Kuros said:
Is the cheaper rate deal /linked/ to getting the solar panels? If you can get it anyway, I wouldn't count that as a saving against the solar panels.

Going by that logic, the savings per year from the solar panel would be £1600, still a tidy sum but it means you'll be paying it off in 6 years, rather than three.

Still a no-brainer, mind you.
Click to expand...


I understand that, however instead of reducing our outgoings, we would simply put that 209 a month back into the panel cost for the first 3 years to pay them off quicker, so for the first 3 years we would still pay 209 a month into an account somewhere, then drop that down after to, effectively zero afterwards.
 
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