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Calculate a suitable solar energy system

Enter a few basic details to get an indicative estimate of system size, annual production and price.

Select the property details

Choose the location and roof details, then add your annual electricity use. The calculator will show an initial estimate straight away.

1. Location
Default point
2. Roof details Orientation, roof pitch and shading affect the production estimate.
30°
3. Electricity use Electricity use is the starting point for system sizing.
10 000 kWh/year
Choose the property's annual electricity use.
18 c/kWh
Total electricity price including energy, transfer and taxes.
Choose annual electricity use to see an estimate for a suitable system size.
4. System size relative to electricity use Choose how much of annual electricity use you want to cover with solar energy.
Sizing target 82%
This choice affects how large a system is suggested compared with annual electricity use.
5. Self-use of production This affects savings and payback time.
55 %
Daytime use matters. The more electricity you use during production hours, the larger share of the output can be used on site.

Result and savings

See the estimated system size, price, annual production and savings in one place.

Selections update the estimate

Indicative total price

10 800 €
The price estimate includes VAT.
This is a quick first estimate of a suitable system size. Final sizing is confirmed based on the roof, shading and electrical setup.
Estimated annual production covers about 82 % of annual electricity use.
The price estimate includes
  • quality solar panels, inverter and mounting materials
  • standard installation and electrical work
  • required measurements, documents, switches and protective equipment
  • commissioning, basic guidance and the grid company notification
Not included without a separate quote
  • exceptionally long cable runs or unusually difficult cable routes
  • an additional fuse board if needed
  • roof repairs, excavation work or other extra work
  • travel and freight costs
The final delivery scope, VAT breakdown and any extra work are always confirmed in the written quote.
System size 9.2 kWp
Estimated annual production 8 260 kWh
Panels / required roof area 21 panels (about 44 m²)
Estimated annual benefit 950–1 250 €/year
Estimated payback time 6.3–8.2 years
Annual CO2 savings 1 240 kg/year
Production used on site 55 %
Used on site55 % Exported to the grid45 %
Green shows the share of production used on site; blue shows the share sold to the grid. These shares follow the self-use selection and total 100%. Annual production relative to electricity use is shown separately above. This shows how the estimated production is divided; it does not represent a battery.
Checked during the site assessment
  • available roof space
  • roof-plane layout, obstacles and shading
  • possible changes needed in the electrical panel
  • cable routes and installation method
Request a quote with these details Free quote with no commitment.

Calculation review

A summary of the assumptions used for the first estimate. The PVGIS system loss of 10–14 % also includes inverter and cabling losses.

Panel 500 W / 2,30 m² Total losses 10–14 % Losses include Inverter and cabling Degradation 0.5% / year Electricity price 18 c/kWh Export price 5 c/kWh Self-use 55 % PVGIS data 841 kWh/kWp/year Nearest point Pirkanmaa / Tampere PVGIS source Regional reference point and orientation Dataset PVGIS city v1, 14 % loss PVGIS means European Commission solar data
Monthly panel production
Annual production 8 260 kWh

How does the calculator estimate production?

The calculator result is indicative. It helps you estimate a suitable system size, annual production, savings and payback time. Final sizing and the production estimate are always confirmed for each property individually.

PVGIS-based initial estimate
1 Production Annual production is estimated from the PVGIS reference point, roof orientation, roof pitch, shading and panel count. The calculator uses 500 W panels measuring 200 x 115 cm.
2 PVGIS source The calculator uses a regional default point or the selected nearest reference point. It is not an address-specific measurement; production is refined based on the roof location, roof planes and shading.
3 Savings Savings are based on self-use, the total electricity price and the assumed price for electricity sold to the grid. The self-use choice directly affects the benefit and payback time.
PVGIS data includes system losses Loss assumption about 10–14 % Panel degradation about 0.5% per year Export electricity assumption 5 c/kWh A more precise production estimate is made after the site assessment
€

Household tax deduction

Indicative example for a solar energy system installation

A household tax deduction can reduce the real cost of a solar energy system. The deduction only applies to the labour portion.

The final split between labour and materials is confirmed during the assessment and in the quote.

Deduction 40 % of the labour portion (2026–2027)
Excess 150 € / person / year
Maximum deduction 2 100 € / person / year
Indicative example calculation

The actual labour share varies depending on the property, roof and scope of installation.

Total price 8 000 €
Labour portion 3 500 €
Deduction 40 % -1 400 €
Excess -150 €
Total tax deduction 1 250 €
Net cost 6 750 €

The final deduction depends on your taxation and the invoice breakdown.