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System size
The kWp size, number of panels and inverter class form the base of the price.
2026 price guide
Solar panel prices
The price of solar panels depends on system size, roof pitch, cable route, the electrical board and whether the roof should be serviced before the panels are installed.
On a straightforward roof, a 4 kWp system is often about 4,000 €, an 8 kWp system about 6,000 € and a 10 kWp system about 7,000 €.
A steeper roof, long cable runs, an additional fuse board, roof repairs or unusual installation routes can all raise the overall cost.
The right size is not always the biggest one possible. Sizing should reflect electricity use, roof direction, shading and how much of the production will be used on site.
Solar panel costs by system size
These are indicative size-based prices for a normal roof. A steeper or otherwise more demanding roof, a longer cable route and electrical changes can all increase the total.
| Panels | System size | Roof area needed | Standard roof | Steep or demanding roof |
|---|---|---|---|---|
| 8 pcs | 4.0 kWp | about 18 m² | about 4,000 € | about 4,400–4,800 € |
| 10 pcs | 5.0 kWp | about 23 m² | about 4,500 € | about 4,900–5,400 € |
| 12 pcs | 6.0 kWp | about 28 m² | about 5,000 € | about 5,500–6,000 € |
| 16 pcs | 8.0 kWp | about 37 m² | about 6,000 € | about 6,600–7,200 € |
| 20 pcs | 10.0 kWp | about 46 m² | about 7,000 € | about 7,700–8,400 € |
| 24 pcs | 12.0 kWp | about 55 m² | about 8,000 € | about 8,800–9,600 € |
| 30 pcs | 15.0 kWp | about 69 m² | about 9,500 € | about 10,500–11,400 € |
| 40 pcs | 20.0 kWp | about 92 m² | about 12,100 € | about 13,300–14,500 € |
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Roof pitch and material
A simple, low-slope roof is faster to install on. A steeper roof or a less common roof type needs more time and more safety measures.
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Cabling and electrical work
A short, clear cable route keeps the job straightforward. Changes to the main board or an additional fuse board increase the total.
What is usually included?
- Solar panels, inverter and roof-specific mounting hardware.
- Standard installation on an existing roof.
- Normal electrical work, protection devices, switches and measurements.
- Commissioning, basic handover guidance and project documents.
- Grid company notification where included in the agreed scope.
- A basic roof suitability check before installation.
What is usually outside the base price?
- Roof coating, roof repairs or full renewal of roof safety products.
- Exceptionally long or difficult cable routes.
- Larger changes to the main electrical board or an extra fuse board unless listed in the quote.
- Ground-mounted systems, excavation work or special structures.
- Travel or freight costs if the site is outside the normal service area.
A practical note: the roof should be part of the solar plan
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Solar panels are a long-term solution. If the roof is likely to need washing, coating or smaller repairs within the next few years, that should be considered before installation. A good solar project is not only about electrical work. It also means sensible roof planning.
What system size usually suits a detached house?
A smaller 4–5 kWp setup can suit moderate use, a cottage or a property with limited roof space. In many detached houses, 6–10 kWp is a practical range when electricity is also used during the day.
A larger 10–15 kWp system can make sense if annual consumption is higher, the house has electric heating, a hot water tank, an EV or other daytime load. The size should always be chosen according to consumption, roof direction and shading.
Quick solar price examples
These examples are indicative. The exact total depends on the roof, electrical work and the final delivery scope.
| Situation | Often suitable size | Price level | Notes |
|---|---|---|---|
| Small detached house or cottage | 4–5 kWp | about 4,000–4,500 € | A good fit for moderate consumption or limited roof space |
| Typical detached house | 6–10 kWp | about 5,000–7,000 € | Often a sensible middle range when there is daytime use |
| Electric heating or higher use | 10–15 kWp | about 7,000–9,500 € | Self-use should be assessed carefully |
| Large roof and high annual use | 15–20 kWp | about 9,500–12,100 € | Roof area, grid connection and cabling become more important |
Solar panels and household tax deduction
The labour share of a solar panel installation may qualify for household tax deduction on an owner-occupied home or holiday property under the current rules. The deduction applies to labour, not to equipment or materials. The latest conditions should always be checked with the Finnish Tax Administration.
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It helps when the quote separates equipment, materials and labour. That makes it easier to see which part of the package may affect the deduction.
Solar panels, roof condition and overall planning
A solar energy system works best when the panels, the roof and the electrical side are planned as one practical whole.
Solar energy
- Solar panel prices
- Home solar systems
- Solar energy systems
- Practical sizing options
Installation
- Solar panel installation
- System sizing
- Inverter and protection devices
- Commissioning
Roof
- Roof review before panels
- Mounting method assessment
- Shade and roof slope review
- Roof type considerations
Calculation
- Solar calculator
- Self-use
- Exported electricity
- Indicative payback
Want an estimate for your own roof and electricity use?
You get a better estimate when you send the address, annual electricity use, roof photos and whether the roof is metal or tile. At the same time we can review whether the roof is in sensible condition for solar panels.
Frequently asked questions
How much do solar panels cost for a home?
On a straightforward roof, a 4 kWp solar system is often about 4,000 euros, an 8 kWp system about 6,000 euros and a 10 kWp system about 7,000 euros. Roof steepness and electrical work can change the total.
What is included in the price of a solar power system?
The price usually includes the panels, inverter, mounting hardware, standard installation, electrical work, protection devices, measurements, documents, commissioning and a basic handover.
What increases the price of a solar energy system?
A larger system, a steeper roof, a difficult cable route, changes to the electrical board, an additional fuse board, roof repairs and unusual installation conditions can all increase the price.
Should the roof be checked before installing panels?
Yes. If roof coating, washing or repairs are likely to be needed in the next few years, that should be reviewed first. Removing panels later just to do roof work creates unnecessary extra cost.
What system size is often sensible for a detached house?
In many detached houses, 6–10 kWp is a practical range, but the right size depends on annual use, daytime use, roof direction and shading.
Can solar panel costs be estimated from photos?
An initial estimate can often be made from the address, electricity use data and roof photos. The final quote becomes more precise once the site and the electrical side are reviewed.