Output comes from PVGIS for your town. Everything else is what you type in from your own bill. We do not pre-fill electricity prices, because a made-up price would make the result look more certain than it is.
The self-use share is your own assumption: it depends on when you are at home and on whether you add a battery. Your installer should estimate it from your consumption profile.
–kWh produced a year (PVGIS)
–saved on energy you use yourself
–credit for surplus energy
–estimated yearly saving
Output month by month for this system
Month
kWh
How this is calculated
Production = size in kWp × kWh per kWp for your town (PVGIS v5.2, 14% losses, optimal south-facing tilt).
Energy you use yourself = production × your share; it saves the price you enter.
Surplus = the rest. Under Spain’s simplified compensation, surplus is valued at the surplus price on your bill and can never exceed the value of the energy you still buy from the grid in the billing period (Royal Decree 244/2019, article 14). We apply that cap to the whole year; in reality it applies month by month, so your real credit may be lower.
IBI: the bonus in the town’s ordinance (see its page), applied to the yearly IBI bill you enter, as an approximation of the IBI quota.
Not included: ICIO discounts, regional or national tax deductions, battery, degradation, price changes and financing.
Fill in the town, the size, your price per kWh and your yearly consumption to see the result.
IBI rules: the ordinance of each town, linked from its page. Where a page says the source is an announcement or an older text, the calculator uses that figure but you should confirm it.
This calculator estimates; it does not quote. For a real price, ask for a quote below.
Free and without obligation
Ask for a quote from an installer who speaks English
The installer who contacts you speaks English, so you can ask about the paperwork in your own language.
Tell us about your home and your electricity bill; we pass the request on so you do not have to repeat it.
You compare and decide. Sending this form does not commit you to anything.
Your request is marked “English” so that it reaches an English-speaking installer. We do not publish or sell your details to the public.