5 kW solar system: what it may cost and when it pays back
Five kilowatts suits a house using about 3,000 to 4,500 kWh a year. Enter the use from your bill and the quoted price.
Yearly saving on your bills
PLN 2,902
5,250 kWh produced · 28 % used on site
| Used directly and from the battery | 1,480 kWh |
| Exported to the grid | 3,770 kWh |
| Deposit (×1.23) | PLN 1,283 |
| Deposit spent on energy | PLN 1,235 |
| Overpayment refunded | PLN 48 |
| Bill before / after | PLN 3,827 / PLN 974 |
| Pays back in 10 years up to | PLN 29,015 |
Hourly model of an average day in each month; surplus priced at the last 12 months of RCEm (PSE) plus the gain from negative RCE counted as zero. An estimate, not an offer; fixed charges excluded.
A 5 kWp solar system usually means 11 or 12 panels of 430–450 W, or about 22–25 m² of roof. According to PVGIS it produces about 5,250 kWh a year in Warsaw, and between 4,625 and 5,570 kWh depending on the municipality. The question “how much does a 5 kW system cost” has two answers: the installer’s quote and the price at which the investment pays back. We work out the second from the saving. A house using 3,500 kWh a year, spread over the whole day, uses about 28 % of the output straight away and saves about PLN 2,902 a year at 2026 G11 prices with RCE settlement. To pay back within 10 years the system may therefore cost at most PLN 29,015 after grants and tax relief. The calculator above reworks this for your municipality, use and quote.
Checked by Radif Partners · Editorial policy · Method
What 5 kWp may cost at different levels of use
The table shows the system price after grants and relief at which the saving repays it within 8, 10 or 12 years. Figures are for Warsaw, a roof at 35° facing south, use spread evenly over the day and RCE settlement.
| Yearly use | Yearly saving | 8-year payback | 10-year payback | 12-year payback |
|---|---|---|---|---|
| 2,500 kWh | PLN 2,400 | PLN 19,199 | PLN 23,998 | PLN 28,798 |
| 3,500 kWh | PLN 2,902 | PLN 23,212 | PLN 29,015 | PLN 34,818 |
| 4,500 kWh | PLN 3,173 | PLN 25,382 | PLN 31,727 | PLN 38,072 |
Net-billing settlement lasts 15 years, and panels usually carry a longer power warranty, so a 12-year payback still leaves several years of clear gain. A payback longer than 15 years means the quote is too high or the size is badly matched to use.
5 kW or 6 kW: when to pay for more power
The sixth kilowatt adds about 1,050 kWh of yearly output in Warsaw. In a house using 3,500 kWh, most of it goes to the grid in summer, so it adds less saving than the earlier kilowatts: PLN 362 a year. It pays when the installer charges less than ten times that amount for it. The larger size is covered on the 6 kW solar page, the smaller on the 4 kW solar page.
If you already have a quote, enter it in the calculator’s “Quoted price” field. You will see the payback in years for your municipality, use and roof direction. How to read a quote and compare several is explained on the solar price page.