Last Updated: February 2026
Make Smarter Clean Energy Decisions
Free, data-driven calculators for solar panels, electric vehicles, home battery storage, and electricity rate optimization — built with the latest EIA, DOE, and NREL data.
13 Free Calculators
Every tool you need to evaluate clean energy for your home — all free, no sign-up required.
Solar Calculators
5 tools to model your rooftop solar investment
Popular
Solar ROI Calculator
Calculate the return on investment for a rooftop solar installation based on your location, usage, and system size.
Use CalculatorSystem Size Calculator
Find the ideal solar panel system size for your home based on your monthly electricity bill and location.
Use CalculatorPayback Period Calculator
Estimate how many years until your solar panels pay for themselves after incentives and energy savings.
Use CalculatorBattery Storage Calculator
Determine the right battery backup capacity for energy independence, outage protection, and time-of-use optimization.
Use CalculatorDegradation Tracker
Project your solar panel output over 25 years using manufacturer degradation curves and local irradiance data.
Use CalculatorEV Calculators
5 tools for electric vehicle costs and planning
Popular
EV vs Gas Calculator
Compare the true 5-year total cost of ownership between an EV and a comparable gas vehicle, including fuel and maintenance.
Use CalculatorCharging Cost Calculator
Calculate your monthly home charging costs by EV model, state electricity rate, and driving habits.
Use CalculatorCharger Installation Cost
Estimate the cost to install a Level 2 home EV charger, including equipment and electrician labor by state.
Use CalculatorBattery Degradation Calculator
Project your EV battery capacity loss over time using real-world degradation data by model and climate.
Use CalculatorRoad Trip Planner
Plan an EV road trip with charging stop estimates, time projections, and cost comparisons vs. driving a gas car.
Use CalculatorCombined Tools
3 tools that integrate solar + EV for maximum savings
New
Solar + EV Savings
Model your combined annual savings when you charge your EV at home using solar energy — the ultimate clean energy stack.
Use CalculatorRate Optimizer
Find the best time-of-use electricity rate plan for your utility based on your EV charging and solar export schedule.
Use CalculatorGreen Home Dashboard
Combine solar production, EV charging, battery storage, and utility rate data into one unified savings overview.
Use CalculatorWhy Trust Our Data?
Every calculator is built on authoritative, publicly available government data sources.
US EIA
Electricity rates, consumption data, and energy statistics from the US Energy Information Administration — updated monthly.
Visit eia.govUS DOE
Federal incentive data, EV battery research, and home energy efficiency standards from the Department of Energy.
Visit energy.govNREL
Solar irradiance, peak sun hours by location, and system performance data from the National Renewable Energy Laboratory.
Visit nrel.govAll calculations use US EIA February 2026 residential electricity rates.Last Updated: February 2026