Solar revenue and payback calculator

Turn your expected solar output into money: yearly savings or sales, simple payback years and a 25-year net result. Works for homes, businesses and small plants.

System sizekWTotal module power. Homes are often 5–12 kWSpecific yieldkWh/kW/yrRoughly 900 (cloudy north) to 1,800 (sunny south). Look up your site in PVGISValue of 1 kWh$/kWhYour retail price if you use the power, or the export/feed-in rate if you sell itInstalled cost$/WBefore incentives. Typical residential 2.5–3.5 $/W, larger systems lowerIncentives% of costTax credit or grant, if you get one. 0 if noneYearly running cost% of costInsurance, monitoring, cleaning. Often 0.5–1.5%Yearly degradation%Usually 0.4–0.5%

Result

First-year energy–

First-year value–

Net cost after incentives–

Yearly running cost–

Simple payback–

25-year net result–

An estimate. It keeps the power price flat, and leaves out loan interest, tax effects and an inverter replacement (often once in 10–15 years).

How it works

Yearly value = system size × specific yield × value of 1 kWhPayback = (cost − incentives) ÷ (yearly value − running cost)

Example: 10 kW at 1,300 kWh/kW makes 13,000 kWh a year. At 0.16 $/kWh that is worth $2,080. At 2.8 $/W the system costs $28,000, or $19,600 after a 30% credit. Take away $280 of running cost and payback is about 10.9 years.

Self-use or export?

Power you use yourself is worth your retail price. Power you send to the grid is often paid much less. If you export half your output at a lower rate, use a blended value per kWh.

The result scales directly with the yield. A site that makes 10% less because of shading or a poor roof direction pays back about 10% slower, so a site-specific yield matters most.

Get the yield for your own site

Draw your roof or land on a satellite map. PVdesignEYA lays out the modules, checks 3D shading and uses PVGIS weather data for that spot. Put its kWh/kW into this calculator for a much better payback number. Free, no install.

Calculate my site's yield →

FAQ

How long does solar take to pay back?

It depends mostly on your power price, your yield and the cost after incentives. With 1,300 kWh/kW, 0.16 $/kWh and 2.8 $/W less a 30% credit, a 10 kW system pays back in about 11 years.

What specific yield should I use?

Use the kWh per kW per year for your location and roof direction. PVGIS gives it for free for most of the world. South-facing systems in mid latitudes are often 1,100–1,500.

Does this include batteries?

No. It values every kWh at one rate. With a battery, more of your power is used at the retail price, but the battery adds cost.