Solar ROI Resources

Guides for reading PV Yield results and building better solar investment assumptions.

These resources explain the assumptions behind solar payback, IRR, NPV, LCOE, weather data, tariff values, and production losses. They are written for users who want to check a proposal before paying for detailed engineering or financial advice.

Start with the calculator, then use the guides below to replace generic defaults with project-specific inputs. The most important improvements usually come from using a complete installed cost, a realistic self-consumption ratio, the correct utility tariff, and conservative loss assumptions.

If your search starts from a personal-finance question such as “is solar better than bank savings?”, begin with the return comparison guide before moving into payback and tariff details.

The guides are also useful when two proposals show different returns. Work through the relevant topic, identify which assumption changed, then rerun the calculator with the same inputs so the comparison is based on the project economics rather than presentation style.

For country-specific searches, start with the national guides below. They help users move from generic “is solar worth it?” intent into location-based assumptions such as export compensation, self-consumption value, and interconnection friction.

• Global Solar ROI CalculatorInteractive calculator for PV payback, IRR, NPV, LCOE, losses, and local tariff assumptions.
• Solar Panel Savings CalculatorEstimate annual bill savings from self-consumption, export value, electricity tariffs, O&M, and net system cost.
• Solar Panel Payback CalculatorCalculate break-even years from installed cost, annual savings, export tariff, O&M, degradation, and incentives.
• Solar Panel Cost CalculatorEstimate gross and net installed cost from system size, cost per watt, batteries, upgrades, and incentives.
• How Many Solar Panels Do I Need?Calculate panel count from annual usage, roof area, panel wattage, and local irradiation with worked examples.
• Are Solar Panels Worth It in 2026?A decision framework using payback, IRR, electricity rates, self-consumption, and risk to judge whether rooftop solar makes sense.
• Solar Panel Cost Per Watt GuideInstalled cost breakdown, price by country, cost vs quality, and how to compare solar quotes using cost per watt.
• Solar Tax Credit 2026 GuideWhat changed for the US residential solar tax credit, which incentives may still apply, and how to model net system cost.
• Is Solar Worth It in Germany?How EEG feed-in tariffs, self-consumption, and retail electricity prices shape rooftop solar economics in Germany.
• Is Solar Worth It in Australia?How strong solar resource, retailer feed-in tariffs, and daytime self-consumption affect payback in Australia.
• Is Solar Worth It in Texas?How REP plans, export compensation, and high cooling loads influence solar savings in Texas.
• Is Solar Worth It in California?How NBT export credits, high retail rates, and self-consumption change rooftop solar returns in California.
• Is Solar Worth It in Spain?How surplus compensation, self-consumption, and electricity prices shape rooftop solar economics in Spain.
• Is Solar Worth It in Portugal?How autoconsumo rules, export options, and local electricity value affect payback in Portugal.
• Is Solar Worth It in Brazil?How distributed generation rules, daytime consumption, and financing affect solar ROI in Brazil.
• Is Solar Worth It in Mexico?How strong solar resource, CFE interconnection, and tariff structure shape rooftop PV returns in Mexico.
• Is Solar Worth It in China?How 2026 distributed solar rules, July 1 Southern nodal pricing, and self-consumption shape rooftop PV returns across Chinese provinces.
• Is Solar a Good Investment?How to judge rooftop solar using payback, IRR, electricity savings, holding period, and risk.
• How Much Does Solar Save Per Year?Use self-consumption, export value, and electricity price to estimate annual savings.
• What Is a Good Solar IRR?Interpret solar return rates for homes and businesses without relying on payback alone.
• Solar Payback by Electricity PriceWhy higher retail tariffs often make rooftop solar pay back much faster.
• Solar vs Bank SavingsHow to compare rooftop PV IRR, payback, cashflow timing, and risk against fixed bank deposit returns.
• Solar ROI Data SourcesWeather APIs, geocoding, tariff defaults, installed-cost assumptions, and when to override defaults.
• Solar ROI Calculation FormulasGeneration, losses, degradation, revenue, payback, NPV, IRR, LCOE, and sensitivity formulas.
• How to Use a Solar ROI CalculatorInputs, outputs, and common mistakes when comparing PV projects.
• LCOE Explained for Solar ProjectsHow levelized cost of electricity helps compare project economics.
• IRR and NPV for Solar CashflowsWhy two profitable projects can have different financial profiles.
• PVGIS vs NASA POWER Weather DataHow irradiation data choices affect generation estimates.
• Solar Payback AssumptionsWhich assumptions move payback the most.
• Solar Losses GuideShading, soiling, thermal, wiring, inverter, and availability losses.
• Feed-in Tariff GuideHow export value changes project revenue.
• Residential Solar ChecklistQuestions to answer before trusting a rooftop solar quote.
• What Is PV Yield?What the calculator does, how the model works, and who it is for.
• Solar ROI Calculator GlossaryPlain-English definitions of payback, IRR, NPV, LCOE, and related terms.
• Solar Panel Technology in 2026How TOPCon, HJT, perovskite tandem, and bifacial cells compare.
• Residential Solar Policy & Incentives in 2026A global update on incentives and export compensation rules.
• Solar Industry Trends 2026Deployment, prices, storage, and grid challenges shaping PV.
• Solar Panel Efficiency ExplainedWhat the efficiency number means and which traits affect ROI.
• Best Solar Panels in 2026How to choose by efficiency, warranty, and cost per watt.
• Solar Panel Degradation RateTypical annual loss, causes, and effect on lifetime energy.
• Solar Break-Even Calculator GuideHow to calculate the year your system pays for itself.
• 2026 Global Solar IRR RankingResidential solar IRR and payback ranked across 30 countries.