Energy & Green Tech
Solar, EV, home energy, and sustainability calculators to help you go green and cut utility costs.
Solar Panel Payback & ROI Calculator
Calculate how long it takes to break even on solar panels, your 25-year lifetime savings, and net ROI after the Federal Investment Tax Credit.
OpenHome Solar System Size Estimator
Calculate the recommended solar system size in kW and the number of panels needed to cover 100% of your home's electricity usage based on your monthly kWh and local sun hours.
OpenGas vs. Electric Vehicle Cost Calculator
Compare the annual and monthly fuel cost of a gas car versus an EV at your local gas price, MPG, electricity rate, and EV efficiency — with a side-by-side bar chart.
OpenEV Charging Time & Range Calculator
Calculate how long it takes to charge your electric vehicle from any battery level to your target, and how many miles of range you'll gain — across Level 1, Level 2, and DC fast charging.
OpenLED Bulb Energy & Cost Savings Calculator
Calculate annual energy and dollar savings from switching incandescent bulbs to LEDs, plus the exact payback period for the upfront bulb cost.
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