All Calculators
Browse all 20 free clean energy calculators — solar, EV, and home energy efficiency — powered by real NREL and EIA data.
Solar ROI Calculator
Calculate your payback period and 25-year net savings with real NREL solar data.
Solar Panels Needed Calculator
Find exactly how many panels you need to power your home.
Solar Installation Cost Calculator
Get a cost estimate for your installation based on location and system size.
Solar Battery Storage Calculator
Size your battery backup and calculate days of off-grid storage.
Solar Panel Degradation Calculator
See how panel output decreases over time and its long-term ROI impact.
Net Metering Savings Calculator
Calculate your grid export credits and annual net metering savings.
Solar Panel Tilt Angle Calculator
Find the optimal tilt angle for your location to maximize solar output.
Solar vs Grid Cost Calculator
Compare 25-year total costs of going solar versus staying on the grid.
Solar Loan Calculator
Estimate your monthly loan payments for a solar installation.
Solar Tax Credit Calculator
Calculate your federal solar Investment Tax Credit (ITC) savings.
EV Charging Cost Calculator
See your monthly and annual charging costs based on your driving habits and local rates.
EV vs Gas Cost Calculator
Compare the total 5-year cost of ownership between an EV and a gas vehicle.
EV Range Calculator
Estimate your EV's real-world range based on speed, temperature, and driving conditions.
EV Charging Time Calculator
Calculate how long it takes to charge with Level 1, Level 2, or DC fast charging.
EV Charger ROI Calculator
See the payback period for installing a Level 2 home charger.
Electric Bill with EV Calculator
Find out how much your electric bill increases after adding an EV.
Heat Pump Savings Calculator
Calculate your annual savings by switching from a gas furnace to a heat pump.
Insulation ROI Calculator
Find out how much you can save on heating and cooling with better insulation.
Carbon Footprint Calculator
Measure your home's carbon footprint and see how clean energy reduces it.
Appliance Energy Cost Calculator
Compare the energy cost of different appliances and identify high-cost items.