☀️ 26 Calculators · 10 Topics · Updated April 2026
Clean Energy & Sustainability Calculators
Free calculators for solar panels, energy savings, carbon footprint, and sustainable living. Estimate production, payback period, and environmental impact.
Make informed decisions about solar panels, energy efficiency, and sustainability. These calculators estimate solar panel production based on your location's peak sun hours, project lifetime savings including the federal tax credit, and measure your carbon footprint against reduction strategies.
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Solar Panel Calculator
Estimate how much electricity a solar panel system generates and how much money it saves you.
Solar Savings Calculator
Calculate how much money you save over the lifetime of a solar panel system.
Solar Payback Period Calculator
Calculate how many years it takes for your solar investment to break even.
Carbon Footprint Calculator
Estimate your annual carbon footprint based on home energy, travel, and lifestyle choices.
LED Savings Calculator
Calculate how much money you save by switching from incandescent or CFL bulbs to LEDs.
Compost Calculator
Calculate the right ratio of green to brown materials for effective composting.
Browse by Topic
Sustainability
3 calculatorsCalculate your carbon footprint and compost ratios for greener living.
Energy Efficiency
1 calculatorSee how much money LED bulbs save compared to incandescent or CFL alternatives.
Solar
7 calculatorsEstimate how much electricity a solar system generates, how much it saves over its lifetime, and when it pays for itself. Accounts for the 30% federal tax credit.
Solar Panel Calculator
Estimate how much electricity a solar panel system generates and how much money it saves you.
Solar Payback Period Calculator
Calculate how many years it takes for your solar investment to break even.
Solar Savings Calculator
Calculate how much money you save over the lifetime of a solar panel system.
Solar Battery Size Calculator
Battery kWh for nights and backup.
Solar Panel ROI Calculator
Years to break even on a solar array.
Solar Break-Even Year Calculator
Year you fully recoup solar costs.
Solar Water Heater Savings Calculator
Annual savings vs electric water heating.
Electric Vehicles
1 calculatorEfficiency
1 calculatorWind
2 calculatorsHVAC
4 calculatorsStorage
1 calculatorUtilities
3 calculatorsFrequently Asked Questions
How many solar panels do I need?
The average US home uses about 900 kWh/month. A standard 400W panel produces about 1.5-2 kWh/day depending on location. You'd need roughly 15-20 panels (6-8 kW system) to offset most of your electricity. Use the Solar Panel Calculator with your actual usage and peak sun hours for an accurate estimate.
What is the solar payback period?
Most residential solar systems pay for themselves in 6-10 years through electricity savings and the 30% federal tax credit. After payback, you get essentially free electricity for another 15-20 years (panels last 25-30 years). The exact timeline depends on your electricity rate, sun hours, and system cost.
How can I reduce my carbon footprint the most?
The biggest individual impacts: drive less or switch to an EV (saves ~2.4 tons CO2/year), take fewer flights (~1.6 tons per transatlantic round trip), eat less red meat (~0.8 tons/year going vegan), and switch to renewable energy. The average American produces about 16 tons per year.