I know a guy who sells solar panel systems and he says when you install one, buy as many batteries as you can afford. Storage is the key. You can sell some back to the grid but they don't give you much (think he said around 9p per kW). The more you can store the less you use throughout the day at peak cost.
Yes Bear, but the prices for batteries has risen astronomically, over 300% in 2.5 years! And it's possible you wont need them.
We were quoted at a 5kw battery costs €5,300. Fuck's sake!
It's a relatively simple calculation.
Take your last 12 months Electricity usage...
A decent PV panel will give around 400 watts,
So for us we used around 6,777 kw/hr last year (A bit too high actually! Need to reign that in....)
12 panels yield 4,800 kw/hr
You should aim for 60% from your panel over the year. (Apparently you won't ever get 100%)
12 panels €10,375
Inverter (because it comes off them as DC) €250
Diverter (To usage or storage battery) €690
BER Rating for house €300
Battery 5kw €5,300
Totalled €16,965
Less Govmnt grant €2,400
Pay €14,565.
Lower quality batteries will deteriorate of years, - longer to charge, actually hold less.
High quality batteries can come with a guarantee of 100% for 10 years, then it drops off...