Energy
Solar Panel Savings Calculator
Estimate annual bill savings and simple payback from a solar panel system using your electricity use, production, and costs.
Quick math
Use this for quick arithmetic, percentages, or to check figures while filling in the main tool, without leaving the page.
Estimate
Estimated annual bill savings: 6,120 NOK
- Annual bill savings
- 6,120 NOK
- Simple payback
- 24.5 years
- Annual solar production
- 6,800 kWh
- Annual electricity use
- 20,000 kWh
- Electricity use covered by solar
- 13.6%
How this breaks down
- Used at home
- 2,720 kWh
- Exported to grid
- 4,080 kWh
- Value of self-used electricity
- 4,080 NOK
- Value of exported electricity
- 2,040 NOK
- Installed system cost
- 150,000 NOK
Annual use caps how much solar electricity can be used at home. If your use is above the self-used solar production, changing annual use alone will not change the savings estimate. This is a planning estimate with constant production and prices; financing, maintenance, degradation, and taxes are excluded.
How to use this tool
- Use Solar Panel Savings Calculator for the question described above, and check that the inputs match your records and time period.
- Enter annual electricity use.
- Enter electricity price.
- Enter system size.
- Enter annual production per kw.
- Enter self-consumption.
- Enter export price.
- Enter installed system cost.
- Change annual electricity use, electricity price, system size, annual production per kw, self-consumption, export price, installed system cost to compare scenarios, then check the units in the result.
Worked example with the prefilled values
This example shows how Solar Panel Savings Calculator uses its starting values. Change the calculator inputs to estimate your own situation.
- Annual electricity use
- 20000 kWh/year
- Electricity price
- 1.5 NOK/kWh
- System size
- 8 kW
- Annual production per kW
- 850 kWh/kW/year
- Self-consumption
- 40 %
- Export price
- 0.5 NOK/kWh
- Installed system cost
- 150000 NOK
Estimated annual bill savings: 6,120 NOK
- Annual bill savings6,120 NOK
- Simple payback24.5 years
- Annual solar production6,800 kWh
- Annual electricity use20,000 kWh
- Electricity use covered by solar13.6%
Annual use caps how much solar electricity can be used at home. If your use is above the self-used solar production, changing annual use alone will not change the savings estimate. This is a planning estimate with constant production and prices; financing, maintenance, degradation, and taxes are excluded.
Formula and calculation logic
Annual solar production = system size (kW) × annual production per kW
Self-used energy = min(annual electricity use, annual production × self-consumption share)
Annual bill savings = self-used energy × electricity price + exported energy × export price
Simple payback (years) = installed cost ÷ annual bill savings
Estimate annual bill savings and simple payback from a solar panel system using your electricity use, production, and costs.
The displayed formula below shows how the entered values are combined.
Assumptions
- Uses the values entered and simplifies real contracts, tax rules or personal circumstances. Update example values before relying on the estimate.
Published sources
Further reading for checking current rules and information. These links are not live inputs to the tool.
Questions about this tool
How are solar savings estimated?
The estimate applies your self-consumption share to annual production and values exported electricity at the export price you enter.
Does it include system degradation or maintenance?
No. It holds production and prices constant and does not subtract maintenance, financing, or degradation.
Is payback guaranteed?
No. Simple payback divides installed cost by estimated first-year savings and does not account for financing or changing prices.
Why can my actual savings differ?
Weather, roof orientation, shading, grid terms, taxes, and when you use electricity all affect actual results.