All 34 Free Green Energy Calculators
Free calculators for solar savings, EV costs, battery storage, heat pump savings, wind energy and more. No signup, instant results.
Solar
Net Metering Calculator — How Much Will You Earn Selling Solar Back?
Calculate how much money you earn selling excess solar electricity back to the grid through net …
Off-Grid Solar Calculator — System Size & Battery Bank
Calculate the complete off-grid solar system size you need — panels, battery bank, inverter and …
Solar + EV Charging Savings Calculator — Combined Annual Savings
Calculate combined annual savings from pairing solar panels with EV home charging. See how much …
Solar Lease vs Buy Calculator — 25-Year Comparison 2026
Compare solar lease vs buying in 2026 over 25 years. See total costs, savings and which option puts …
Solar Loan Calculator — Monthly Payment & Total Interest Cost
Calculate your monthly solar loan payment, total interest cost and true net cost after the 30% …
Solar Panel Output Calculator — Daily, Monthly & Annual kWh
Calculate how much electricity your solar panels will produce per day, month and year. Enter system …
Solar Payback Period Calculator — When Do Panels Pay for Themselves?
Calculate exactly how many years until your solar panels pay for themselves, including the 30% …
Solar PPA vs Buy Calculator — Full Financial Analysis 2026
Compare a solar PPA vs outright purchase in 2026. Calculate 25-year payments, savings and which …
Solar ROI Calculator — 25-Year Return on Investment
Calculate the full 25-year return on investment for solar panels. See IRR, NPV and cumulative …
Solar Savings Calculator — How Much Will Solar Save You?
Calculate your exact annual solar savings based on your electricity bill, roof size and location. …
Solar Self-Consumption Rate Calculator — Grid Export vs Home Use
Calculate what percentage of your solar production you use directly at home vs export to the grid. …
Solar System Size Calculator — How Many Panels Do You Need?
Calculate the right solar panel system size for your home based on your electricity usage and …
EV
EV Battery Degradation Calculator — Range Loss Over Time
Calculate how much range your EV battery will lose over 5, 10 and 15 years. Enter battery size and …
EV Charger Installation Cost Calculator — Level 2 Home Charger
Calculate total Level 2 EV charger installation cost including equipment, labour and panel upgrade. …
EV Home Charging Cost Calculator — Monthly Cost 2026
Calculate your EV home charging cost per month and per mile in 2026. Compare home charging rates vs …
EV Road Trip Cost Calculator — Total Charging Cost 2026
Calculate total EV road trip charging cost in 2026. Compare home vs public fast charging for any …
EV vs Gas Cost Calculator — Compare Annual Fuel Costs
Calculate and compare the true annual fuel cost of driving an electric vehicle versus a gasoline …
Battery
Home Battery Storage Calculator — Is It Worth It?
Calculate the right battery storage capacity for your home, estimated cost after federal tax credit, …
Solar Battery Bank Size Calculator — DIY Off-Grid Sizing
Calculate exactly how much battery capacity you need for an off-grid or backup solar system. Enter …
Tesla Powerwall ROI Calculator — Is the Powerwall 3 Worth It?
Calculate Tesla Powerwall 3 return on investment, payback period and annual savings. Based on your …
Home Energy
Heat Pump Savings Calculator — vs Gas Furnace Comparison
Calculate how much you'd save by switching from a gas furnace to a heat pump. Includes annual …
Heat Pump Water Heater Savings Calculator 2026
Calculate annual savings from a heat pump water heater vs electric resistance in 2026. Includes 30% …
Home Energy Cost Calculator — Bill Breakdown 2026
Calculate your monthly electricity bill by appliance in 2026. Find your biggest energy users and see …
Home Insulation Savings Calculator — Attic, Wall & Basement ROI
Calculate annual heating and cooling savings from improving home insulation. Enter current HVAC …
LED Lighting Savings Calculator — Replace Incandescent & Halogen Bulbs
Calculate annual savings from switching to LED bulbs. Enter number of bulbs, old wattage and usage …
Smart Thermostat Savings Calculator — Nest & Ecobee 2026
Calculate how much a smart thermostat saves per year in 2026. Nest, Ecobee and Honeywell ROI based …
Time-of-Use Rate Savings Calculator (2026)
Calculate savings from time-of-use electricity rates with solar and battery storage in 2026. See how …
Incentives
IRA Rebate Calculator — Inflation Reduction Act 2026
Check your IRA rebate eligibility in 2026. See income tiers, rebate amounts for heat pumps, EVs and …
Solar Tax Credit Calculator 2026 — Federal ITC 30%
Calculate your exact 2026 federal solar Investment Tax Credit (ITC). See how much the 30% tax credit …
Commercial
Agricultural Solar Calculator — Farm Solar ROI & USDA REAP Grant
Calculate solar ROI for farms and agricultural businesses including USDA REAP grant (up to 50% of …
Commercial Solar ROI Calculator — MACRS & ITC 2026
Calculate commercial solar ROI with 30% ITC and MACRS depreciation in 2026. Instant payback period …
Wind
Climate
CO₂ Offset Calculator — How Much Carbon Does Solar Save?
Calculate how many tons of CO₂ your solar panels offset per year and over their lifetime. Compare to …
Home Carbon Footprint Calculator — Energy & Transport
Calculate your household's annual carbon footprint from electricity, gas heating and driving. See …