I got these solar panels that claim to produce 1W energy with 6V.
Just out of curiosity how much energy might I be able to generate with these?
I live in Finland and in Helsinki there is 1050 sunny hours a year in average. (according to this data: http://ilmatieteenlaitos.fi/kesatilastot)
Lets say I only include in the calculations those hours where sun’s altitude is more than 5 degrees to get into more realistic hours.
So I need to do a bit of calculation: how many hours sun is above 5 degrees?
I wont go into details here now but this is what I got with a little help of python pysolar module.
When latitude and longitude is 60.2347 and 25.08565, sun is up 4482 hours a year (every day sunrise to sun set times summed ).
Sunny percentage is thus 23.4 %
Sun is up more than 5 degrees 3796 hours a year.
23.4 % of that gives 890 hours
I now have 5 of these panels so if my calculations are correct it could be thus possible to get 890 * 5 = 4451 Wh of energy from these in a year.
My energy company estimates I spend more than 410 times that in year.
One of these panels is 6 x 11 cm
It means I would have to have 5 * 0.06 * 0.11 * 410 = 13,5 m2 of these panels and it would cost almost 2500 euros.
Actually it is not that bad, in about 10 years it would pay itself back, roughly.
So here is a start with a design to set these up on my window: