Do solar panels pay off in Estonia?

Yes, but more slowly than a few years ago. A heat-pump house with 10 kWp of panels (no battery) saved €586 a year over 2025-10 – 2026-09, and the €6,400 investment pays back in 11.0 yrs. The reason is the low sale price: surplus earns the exchange price minus a margin, while buying adds network fees and taxes.

How big a battery makes sense?

In the default scenario a 10 kWh battery beside the panels adds €821 of saving a year (of which the balancing market €431) and the payback with the panels is 5.4 yrs. Rule of thumb: capacity about one evening and night of consumption (5–15 kWh); on the balancing market power (kW) matters more. Move the slider and watch where the extra saving stops growing.

How much does a 10 kWh battery earn on the mFRR/aFRR market?

The default scenario’s 10 kWh battery (10 kW inverter) got €381 from activations and €50 from the capacity market a year. A battery alone, without panels, saved €696 a year with the balancing market and arbitrage. The numbers rest on the real activations of one home near Tartu, scaled by inverter power.

Does a battery without panels pay off?

A battery alone (10 kWh, 10 kW inverter) earned €696 a year from arbitrage, the balancing market and the capacity market, paying back in 4.7 yrs on a €4,150 investment. That depends more on market conditions than on the sun: the price swings and activation prices of winter 2025 may not repeat.

South or east–west?

A south-facing roof at 30–40° gives the most kWh a year. An east–west layout produces 10–15% less a year but spreads output into the morning and evening, when consumption and prices are higher and the midday surplus smaller. In the calculator each group of panels has its own direction and tilt, so the difference shows at once.

What price do I get for surplus?

The exchange price minus the seller’s margin, for example 1.8 c/kWh at Enefit: at an exchange price of 100 €/MWh you get €0.08 per kWh, while buying the same kWh on the Võrk 4 day rate costs €0.20. Over 2025-10 – 2026-09 the mean exchange price was 82 €/MWh, and usually below that in sunny hours.

What happens with a negative exchange price?

The sale price is negative – you pay to export. Over 2025-10 – 2026-09 Estonia had 60 hours of negative prices and 2,195 hours below 20 €/MWh. By default the calculator does not sell when the exchange price is below 2 c/kWh: the surplus goes into the battery or is not produced.

Why does EV charging barely change the saving?

EV charging comes on top of the yearly consumption. 5,000 kWh a year raises the default scenario’s bill by €513, but the bill without a system rises just as much, and the calculator shows the difference. With smart charging the car already charges in the night’s cheapest hours, where the battery has nothing cheaper to offer, and there is no sun from 17:30 to 06:00: the saving changes by €5. If the car charges as soon as it is home, the battery can take over the expensive evening charging and the saving grows by €81. With your own CSV the car is already in the file and there is no separate slider.

Võrk 4 is almost half the price per kWh (3.69/2.10 vs 6.07/3.51 cents), but the monthly fee with a 25 A fuse is 15 € higher. The break-even is around 7 000 kWh a year – a house with a heat pump or an electric car is above it. Switch the package in the calculator and compare the bills.

Is the capacity-market availability fee worth it?

From the reference park about €0.46 per kW offered per month, i.e. €55 a year with a 10 kW inverter and at least 10 kWh of battery – with no extra investment if you are already on the balancing market. You can only offer what the battery sustains for an hour: a 5 kWh battery offers 5 kW even behind a 30 kW inverter. The fee depends on the aggregator’s portfolio and Elering’s procurements.

What payback time is typical in Estonia?

The default scenario (10 kWp + 10 kWh, €8,150) pays back in 5.4 yrs, internal rate of return 16.7%. Panels alone 11.0 yrs. A year earlier (2024-10 – 2025-09) the same system would have saved €1,188 – without the balancing market, which homes did not yet have.

Are panels worth it on an apartment?

An apartment with 3 kWp (2 500 kWh a year, Võrk 2) saved €206 a year and pays back in does not pay back within 20 years, because much of the output is sold cheaply. The benefit is larger when consumption is in daytime (home office, water heater by day).

How do I upload my own consumption data?

In Elektrilevi’s self-service or Minu Elering you can download consumption as an hourly or 15-minute CSV. Drop the file into the calculator: it is read and sent for the calculation only, never stored. The result shows how much of the period it covers.

How accurate is the calculator?

The model has been compared with a real house’s year of readings: solar production agrees within 15% and balancing income within about 11%. The biggest uncertainty is the future, not the model – next year’s prices and weather will differ.

The dataset is refreshed weekly and the window rolls with it; the current period is 2025-10 – 2026-09. Tariffs are from Elektrilevi’s 1 June 2026 price list and Elering’s 2026 fees.

Frequently asked questions about solar, batteries and the balancing market

Answers with the calculator’s own numbers from 2025-10 – 2026-09: the default scenario (heat-pump house, 10 kWp, 10 kWh) saves €1,408 a year. You can check every answer with your own house.

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Questions and answers

Do solar panels pay off in Estonia?: Yes, but more slowly than a few years ago. A heat-pump house with 10 kWp of panels (no battery) saved €586 a year over 2025-10 – 2026-09, and the €6,400 investment pays back in 11.0 yrs. The reason is the low sale price: surplus earns the exchange price minus a margin, while buying adds network fees and taxes.
How big a battery makes sense?: In the default scenario a 10 kWh battery beside the panels adds €821 of saving a year (of which the balancing market €431) and the payback with the panels is 5.4 yrs. Rule of thumb: capacity about one evening and night of consumption (5–15 kWh); on the balancing market power (kW) matters more. Move the slider and watch where the extra saving stops growing.
How much does a 10 kWh battery earn on the mFRR/aFRR market?: The default scenario’s 10 kWh battery (10 kW inverter) got €381 from activations and €50 from the capacity market a year. A battery alone, without panels, saved €696 a year with the balancing market and arbitrage. The numbers rest on the real activations of one home near Tartu, scaled by inverter power.
Does a battery without panels pay off?: A battery alone (10 kWh, 10 kW inverter) earned €696 a year from arbitrage, the balancing market and the capacity market, paying back in 4.7 yrs on a €4,150 investment. That depends more on market conditions than on the sun: the price swings and activation prices of winter 2025 may not repeat.
South or east–west?: A south-facing roof at 30–40° gives the most kWh a year. An east–west layout produces 10–15% less a year but spreads output into the morning and evening, when consumption and prices are higher and the midday surplus smaller. In the calculator each group of panels has its own direction and tilt, so the difference shows at once.
What price do I get for surplus?: The exchange price minus the seller’s margin, for example 1.8 c/kWh at Enefit: at an exchange price of 100 €/MWh you get €0.08 per kWh, while buying the same kWh on the Võrk 4 day rate costs €0.20. Over 2025-10 – 2026-09 the mean exchange price was 82 €/MWh, and usually below that in sunny hours.
What happens with a negative exchange price?: The sale price is negative – you pay to export. Over 2025-10 – 2026-09 Estonia had 60 hours of negative prices and 2,195 hours below 20 €/MWh. By default the calculator does not sell when the exchange price is below 2 c/kWh: the surplus goes into the battery or is not produced.
Why does EV charging barely change the saving?: EV charging comes on top of the yearly consumption. 5,000 kWh a year raises the default scenario’s bill by €513, but the bill without a system rises just as much, and the calculator shows the difference. With smart charging the car already charges in the night’s cheapest hours, where the battery has nothing cheaper to offer, and there is no sun from 17:30 to 06:00: the saving changes by €5. If the car charges as soon as it is home, the battery can take over the expensive evening charging and the saving grows by €81. With your own CSV the car is already in the file and there is no separate slider.
Võrk 2 or Võrk 4?: Võrk 4 is almost half the price per kWh (3.69/2.10 vs 6.07/3.51 cents), but the monthly fee with a 25 A fuse is 15 € higher. The break-even is around 7 000 kWh a year – a house with a heat pump or an electric car is above it. Switch the package in the calculator and compare the bills.
Is the capacity-market availability fee worth it?: From the reference park about €0.46 per kW offered per month, i.e. €55 a year with a 10 kW inverter and at least 10 kWh of battery – with no extra investment if you are already on the balancing market. You can only offer what the battery sustains for an hour: a 5 kWh battery offers 5 kW even behind a 30 kW inverter. The fee depends on the aggregator’s portfolio and Elering’s procurements.
What payback time is typical in Estonia?: The default scenario (10 kWp + 10 kWh, €8,150) pays back in 5.4 yrs, internal rate of return 16.7%. Panels alone 11.0 yrs. A year earlier (2024-10 – 2025-09) the same system would have saved €1,188 – without the balancing market, which homes did not yet have.
Are panels worth it on an apartment?: An apartment with 3 kWp (2 500 kWh a year, Võrk 2) saved €206 a year and pays back in does not pay back within 20 years, because much of the output is sold cheaply. The benefit is larger when consumption is in daytime (home office, water heater by day).
How do I upload my own consumption data?: In Elektrilevi’s self-service or Minu Elering you can download consumption as an hourly or 15-minute CSV. Drop the file into the calculator: it is read and sent for the calculation only, never stored. The result shows how much of the period it covers.
How accurate is the calculator?: The model has been compared with a real house’s year of readings: solar production agrees within 15% and balancing income within about 11%. The biggest uncertainty is the future, not the model – next year’s prices and weather will differ.
Is the data fresh?: The dataset is refreshed weekly and the window rolls with it; the current period is 2025-10 – 2026-09. Tariffs are from Elektrilevi’s 1 June 2026 price list and Elering’s 2026 fees.

Read on

Balancing market – How a home battery earns on the mFRR, aFRR and capacity markets through Qilowatt, KratTrade and MarkeDroid – real numbers from one Estonian home over the last 12 months.
Network packages and taxes – Elektrilevi Võrk 1, 2, 4 and 5 rates, day and night hours, peak hours, state fees and VAT – what a kWh costs and which package suits a solar home.
Methodology – How the calculator works: solar output from weather data, load profiles, battery dispatch, price arbitrage, the balancing-market model, tariffs and payback – formulas, data sources and simplifications.

Sources

Prices and tariffs: Elering – Nord Pool EE day-ahead API, Elektrilevi võrguteenuse hinnakiri (1.6.2026), Enefit väiketootja
Balancing market: Baltic Transparency Dashboard, Qilowatt – paindlikkusturg

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