What output solar panels

50Twuncle

We use on average 4 units of electricity every day
What output panels do we need ?
I am aware that this depends on where we live and direction of roof etc ..

tunnel

So you use 4kWh a day? Is that summer use, winter or an average of them both?
As you have correctly stated...location and direction play a massive part...care to expand?

EricMears

It's not really relevant how much electricity you actually use.

If you want to ensure that you generate 4kWh every day, you'd need a massive system ! My 4kWp system probably averages 2kWh/day in December so an 8kWp system might average around the 4kWh/day you want - but even then there will be many days in December when you don't achieve that and of course you won't generate anything at all between 3pm and 9am any day in December so can never be self-sufficient in electricity unless you have a huge (and hugely expensive !!) battery system attached.

What you really need to aim for is the biggest system you can (a) afford and (b) fit on your roof so that it earns the maximum amount of money over the year.


A good starting point would be to measure the area of your roof and note its slope and the compass direction in which it points then look it up on the pvgis website (details in the faq page) to get a good estimate of what generation your roof might support.

50Twuncle

tunnel wrote: »

So you use 4kWh a day? Is that summer use, winter or an average of them both?
As you have correctly stated...location and direction play a massive part...care to expand?

We vary between (on average) - 3kWh per day in summer and 5kWh per day in winter - so average 4kWh per day !
roof line is roughly NS
We live in SW UK