What it costs, and how long until it pays for itself.
Panels, panels with a battery, or just a battery if you already have panels. The calculator uses the solar radiation where you live, your household's consumption and local energy prices to estimate the cost, the yearly saving and the payback period.
Every assumption used in the calculation is shown at the end, so the result can be checked.
The result
Panels and a battery, in Northern and Western
- Investment 10,833–18,589 EUR
- Annual savings 1,639 EUR
- Estimated payback: 8.5 years
Estimated yearly balance
- Used on site · 41%
- Energy sent to the grid · 3,602 kWh
- Energy bought from the grid · 587 kWh
What the battery adds, against a system without one
Comparison based on the values you entered
| Indicator | Without a battery | With a battery | Difference |
|---|---|---|---|
| Cost | 9,883 EUR | 14,711 EUR | ▲ +4,828 EUR |
| Saving per year | 1,493 EUR | 1,639 EUR | ▲ +146 EUR |
| Used at home | 24% | 41% | |
| Energy from the grid | 1,643 kWh | 587 kWh | ▼ −1,055 kWh |
| Energy exported | 4,775 kWh | 3,602 kWh | ▼ −1,173 kWh |
| Payback | 6.4 years to pay for itself | 8.5 years to pay for itself | ▲ +2.2 years |
| Saving over 25 years | 35,192 EUR | 28,575 EUR | ▼ −6,617 EUR |
It can still be useful: it gives you evening autonomy, it keeps the lights on during an outage if it has the right equipment, and it shelters you from a price rise or a change in the compensation rules.
How long until it pays for itself
We have no programme on record for your country.
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Production and consumption, month by month
In summer production beats consumption; in winter it is the other way round. The rest of the calculation grows out of that gap.
- Production
- Consumption
See the figures behind the chart
| Month | Production | Consumption |
|---|---|---|
| Jan | 123 kWh | 305 kWh |
| Feb | 239 kWh | 263 kWh |
| Mar | 497 kWh | 273 kWh |
| Apr | 759 kWh | 244 kWh |
| May | 943 kWh | 239 kWh |
| Jun | 916 kWh | 223 kWh |
| Jul | 861 kWh | 233 kWh |
| Aug | 773 kWh | 233 kWh |
| Sep | 548 kWh | 236 kWh |
| Oct | 337 kWh | 265 kWh |
| Nov | 168 kWh | 282 kWh |
| Dec | 89 kWh | 323 kWh |
Where the energy produced goes
Used on site, put through the battery, or sent to the grid. Each kilowatt-hour appears in exactly one place.
- Used on site
- Stored in the battery
- Sent to the grid
See the figures behind the chart
| Indicator | kWh |
|---|---|
| Used on site | 1,477 kWh |
| Stored in the battery | 1,173 kWh |
| Sent to the grid | 3,602 kWh |
| Bought from the grid | 587 kWh |
Balance of the investment, year by year
It starts at minus the cost of the system and climbs with each year's saving. Crossing zero is the moment it pays for itself.
- Cumulative balance
- Payback point
See the figures behind the chart
| Year | Saving per year | Cumulative balance |
|---|---|---|
| 1 | 1,639 EUR | -13,072 EUR |
| 2 | 1,661 EUR | -11,411 EUR |
| 3 | 1,684 EUR | -9,727 EUR |
| 4 | 1,706 EUR | -8,021 EUR |
| 5 | 1,729 EUR | -6,292 EUR |
| 6 | 1,753 EUR | -4,539 EUR |
| 7 | 1,777 EUR | -2,762 EUR |
| 8 | 1,801 EUR | -961 EUR |
| 9 | 1,826 EUR | 865 EUR |
| 10 | 1,851 EUR | 2,715 EUR |
| 11 | 1,876 EUR | 4,591 EUR |
| 12 | 1,902 EUR | 6,493 EUR |
| 13 | 1,928 EUR | 8,421 EUR |
| 14 | 1,955 EUR | 10,376 EUR |
| 15 | 1,982 EUR | 12,357 EUR |
| 16 | 2,064 EUR | 8,702 EUR |
| 17 | 2,092 EUR | 10,794 EUR |
| 18 | 2,120 EUR | 12,914 EUR |
| 19 | 2,148 EUR | 15,062 EUR |
| 20 | 2,177 EUR | 17,240 EUR |
| 21 | 2,207 EUR | 19,446 EUR |
| 22 | 2,236 EUR | 21,683 EUR |
| 23 | 2,267 EUR | 23,949 EUR |
| 24 | 2,297 EUR | 26,247 EUR |
| 25 | 2,329 EUR | 28,575 EUR |
Battery capacity over time
It falls with degradation and returns when the battery is replaced.
See the figures behind the chart
| Year | Battery |
|---|---|
| 1 | 7.5 kWh |
| 2 | 7.4 kWh |
| 3 | 7.2 kWh |
| 4 | 7.1 kWh |
| 5 | 6.9 kWh |
| 6 | 6.8 kWh |
| 7 | 6.6 kWh |
| 8 | 6.5 kWh |
| 9 | 6.4 kWh |
| 10 | 6.3 kWh |
| 11 | 6.1 kWh |
| 12 | 6.0 kWh |
| 13 | 5.9 kWh |
| 14 | 5.8 kWh |
| 15 | 5.7 kWh |
| 16 | 7.5 kWh |
| 17 | 7.4 kWh |
| 18 | 7.2 kWh |
| 19 | 7.1 kWh |
| 20 | 6.9 kWh |
| 21 | 6.8 kWh |
| 22 | 6.6 kWh |
| 23 | 6.5 kWh |
| 24 | 6.4 kWh |
| 25 | 6.3 kWh |
Assumptions used
Below are the values used in the calculation and the source of each one, so the result can be checked.
| Assumption | Value | Source |
|---|---|---|
| Coordinates used | 53.80, -8.60 — Northern and Western | PVGIS PVGIS-SARAH3 · 2026-09-13 |
| Specific yield of the location | 817 kWh/kWp | PVGIS PVGIS-SARAH3 · 2026-09-13 |
| Orientation used | 90° | PVGIS PVGIS-SARAH3 |
| Tilt used | 30° | PVGIS PVGIS-SARAH3 |
| Temperature, spectral and incidence-angle losses | 9.7% | PVGIS PVGIS-SARAH3 · 2026-09-13 |
| Price of energy on the bill | 0.387 EUR/kWh | Eurostat nrg_pc_204, 2026-S1 |
| Price of energy sent to the grid | 0.203 EUR/kWh — I don't know | Eurostat nrg_pc_204, 2026-S1 |
| Consumption you entered | 3,120 kWh per year | entered by you |
| System efficiency | 89.5% | EuroEnergy.live estimate |
| System losses | System losses: 10.5% · inverter 2.5% · cabling 1.5% · soiling 2.0% · mismatch 1.5% · shading 3.0% | EuroEnergy.live estimate |
| Reference panel | 450 Wp · 2.0 m² | EuroEnergy.live estimate |
| Annual panel degradation | 0.5%/an | EuroEnergy.live estimate |
| Lifetime | 25 years | EuroEnergy.live estimate |
| Assumed energy price growth | 2.0%/an | EuroEnergy.live estimate |
| Annual maintenance | 0.5% | EuroEnergy.live estimate |
| Evening and night consumption | 47.6% | EuroEnergy.live estimate |
| Shape of the consumption day | peak at 19:00 | EuroEnergy.live estimate |
| Mounting type | Pitched roof | entered by you |
| Usable area | 90.0% · 4.3 m²/kWp | EuroEnergy.live estimate |
| Battery round-trip efficiency | 90.0% | EuroEnergy.live estimate |
| Usable battery capacity | 6.8 kWh (90.0%) | EuroEnergy.live estimate |
| VAT | 23.0% | EuroEnergy.live — interval european de referință, neverificat |
| estimated cost, turnkey | 10,833 EUR – 18,589 EUR | EuroEnergy.live — interval european de referință, neverificat · unverified |