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All Renewable Energy Calculators
Browse our complete collection of free, accurate renewable energy calculators. No sign-up required.
Start by goal
Pick the calculator that matches your next decision
Start with Solar ROI
Estimate payback, net savings, project-year incentive treatment, and quote review risks from your state and electric bill.
Compare EV charging
Check home charging cost, then compare EV vs gas savings before sizing solar around a vehicle load.
Plan battery storage
Size backup capacity for outages or solar storage, then review net metering and incentive caveats.
Review home energy load
Estimate appliance and household usage before changing solar size, EV assumptions, or battery capacity.
Solar Calculators Hub
Overview
Solar Calculators Hub
Use this result
Use the calculator inputs first, then compare the result against local rates, incentives, roof conditions, and utility export rules.
Method, assumptions, and sourcesOpen this section when you want to audit the calculation behind the estimate.ShowHide
Calculation Method
Compare cost, payback, tax credit, and ROI calculators before requesting quotes.
Key Assumptions
- US residential solar context
- Project-year federal incentive caveats
- State pages vary by utility policy
Data Sources
Solar production
NREL PVWatts
Reference solar production assumptions.
Electricity rates
EIA
Residential electricity cost references.
Solar Panel Sizing
Calculate how many solar panels your home needs based on energy usage and roof space.
Open tool →EV ChargingEV Charging Cost
Compare the cost of charging an electric vehicle vs. gasoline for your driving habits.
Open tool →Battery StorageBattery Storage
Find the right battery capacity for home backup or solar storage needs.
Open tool →SolarSolar ROI Calculator
Estimate your solar payback period, net savings, and return on investment over 25 years.
Open tool →Energy EfficiencyEnergy Consumption
Track your appliance energy usage and estimate monthly electricity costs.
Open tool →Wind EnergyWind Turbine Sizing
Estimate power output and annual energy from a residential wind turbine based on blade size and local wind speed.
Open tool →SolarSolar Payback Period
Calculate how many years until your solar panels pay for themselves, with project-year incentive caveats.
Open tool →EV ChargingEV vs Gas Savings
Compare annual fuel costs between an electric vehicle and gasoline car based on your driving habits.
Open tool →GeothermalGeothermal Heat Pump Sizing
Size a ground-source heat pump and estimate savings vs gas heating.
Open tool →Heating & Heat PumpsHeat Pump Cost & Savings
Estimate heat pump install cost, annual heating cost, and savings vs gas, oil, propane, or electric resistance.
Open tool →Energy EfficiencyCarbon Footprint Calculator
Calculate your household's carbon footprint and see how solar reduces it.
Open tool →SolarSolar Tilt Angle Calculator
Find the optimal tilt angle for solar panels at your latitude.
Open tool →