Solar ROI & Payback Calculator
PV Yield is a free solar ROI calculator that estimates photovoltaic payback period, project revenue, IRR, NPV, LCOE, system losses, and long-term cashflow. Enter country, city, system size, electricity price and installed cost to screen a rooftop, commercial, or ground-mount PV project before paying for detailed engineering.
- PVGIS, NASA POWER, lat/lng and custom monthly POA weather sources.
- Cashflow, revenue breakdown, generation, losses and sensitivity analysis.
- Suitable for residential, commercial and ground-mount PV early screening.
- Compare solar vs bank savings using local weather data and electricity tariffs.
- Estimate solar panel savings from self-consumption, export tariffs and annual bill offsets.
- Calculate solar panel payback from net installed cost and annual solar savings.
- Estimate solar panel cost from system size, installed cost per watt and verified incentives.
What this solar investment calculator estimates
The solar ROI calculator turns a handful of project inputs into a full financial screening. It starts with installed capacity and turnkey system cost, then applies module degradation, system losses, operations and maintenance cost, self-consumption ratio, retail tariff, export feed-in tariff, loan terms, discount rate, and project lifetime. The result is a year-by-year cashflow model that shows when the project breaks even and how much net value it creates over 25 to 30 years.
Outputs include first-year energy yield, first-year revenue, static payback period, cumulative net cashflow, internal rate of return (IRR), net present value (NPV), levelized cost of electricity (LCOE), sensitivity ranges, and a monthly production breakdown. Use them to cross-check installer quotes and test conservative scenarios before committing capital.
How solar ROI is calculated
Solar return on investment is not a single number. PV Yield models the project as a stream of annual cashflows: energy generation multiplied by the value of self-consumed electricity plus exported energy, minus operating costs, loan payments, and taxes. Depreciation and degradation reduce output each year. The payback period is the year when cumulative net cashflow turns positive. IRR is the discount rate that makes NPV zero. LCOE divides lifetime cost by lifetime energy. Each metric answers a different question, so PV Yield reports all of them together.
Solar payback period explained
The solar payback period measures how many years it takes for accumulated electricity savings and export income to recover the upfront system cost. A shorter payback means lower risk and faster return. Payback is most sensitive to installed cost per watt, self-consumption ratio, retail electricity price, export tariff, and local irradiation. In markets with high retail rates and strong solar resource, residential payback can fall below 6 years. In lower-tariff or higher-cost regions it may extend past 12 years. Use the solar payback assumptions guide to see which inputs move payback the most.
IRR vs NPV for solar projects
Internal rate of return (IRR) and net present value (NPV) are the two financial metrics most lenders and investors use to judge a solar project. IRR expresses return as an annualized percentage, making it easy to compare against bank deposit rates or bond yields. NPV measures absolute value created in today's money after discounting future cashflows. A project can have a high IRR but low NPV if the system is small, or a modest IRR but large NPV if the system is big. PV Yield reports both so you can judge whether rooftop solar is a good investment for your situation. See the IRR and NPV for solar cashflows guide for worked examples.
LCOE — levelized cost of electricity
LCOE divides the total lifetime cost of a solar system by the total lifetime energy it produces, expressed in currency per kilowatt-hour. It lets you compare solar against grid electricity on an apples-to-apples basis. If your LCOE is below your retail tariff, self-consumed solar is cheaper than buying power from the utility. PV Yield calculates LCOE using the same discount rate as the NPV model, so the two metrics stay consistent. Read the LCOE explained guide to understand how it interacts with degradation, financing, and maintenance.
Is solar a long-term investment?
For rooftop projects with high electricity rates, high self-consumption, and reasonably priced systems, most of the return comes from avoided electricity bills over 25–30 years plus partial export income. In such cases project IRR can exceed bank deposit returns, subject to equipment, generation, policy, maintenance and liquidity risk. PV Yield is built for solar vs bank savings comparisons, payback, IRR, NPV and conservative scenario testing before you enter the quoting and grid-connection stage.
Data sources and limitations
Coordinate weather data comes from public meteorological services including PVGIS and NASA POWER. Default electricity prices and system costs are starting points only. Real projects still need local grid contracts, roof orientation, shading, equipment selection, subsidy policy, taxes and financing terms. PV Yield is an early screening tool, not a substitute for engineering design, tax advice, or bank-grade financial modeling. Review the methodology page for the full calculation framework.
Country and city solar calculators
PV Yield ships with pre-built landing pages for 30+ countries and major cities, each loaded with local currency, residential system cost, self-use tariff, and export tariff defaults. Start from the solar calculator directory to find your location, then refine the inputs with your actual installer quote. For country-specific economics, read guides like is solar worth it in Germany, Australia, California, or China.
