Renewable Energy Calculators
Battery Backup Calculator
Calculate required battery backup capacity in watt-hours and amp-hours from load, backup hours, voltage, depth of discharge, and efficiency.
Energy Storage Cost Calculator
Calculate battery storage cost per kWh and levelized cost of storage over the battery's lifetime from total cost, capacity, and cycle life.
Geothermal Heat Pump Calculator
Calculate geothermal heat pump heat output and energy savings versus resistance heating from electrical input and coefficient of performance.
Hydropower Output Calculator
Calculate hydropower output in kilowatts and annual energy in kWh from water flow rate, head height, and turbine efficiency for site assessment.
Net Metering Calculator
Calculate the net solar bill or credit from energy generated, energy consumed, and separate grid import and export electricity rates.
Off-Grid System Size Calculator
Calculate the solar panel wattage and battery capacity needed for a complete off-grid power system from daily load, sun hours, and autonomy days.
Solar Panel Output Calculator
Calculate daily and annual solar panel energy output from panel wattage, panel count, peak sun hours, and system efficiency for accurate sizing.
Solar Panel Size Calculator
Calculate the solar system size in kW and number of panels needed from daily energy usage, peak sun hours, and system efficiency.
Solar Payback Period Calculator
Calculate solar payback period in years and months from system cost, incentives, and expected annual electricity savings for a clear return timeline.
Wind Turbine Output Calculator
Calculate wind turbine power output in kilowatts from blade radius, wind speed, air density, and power coefficient using the standard wind power formula.
Sizing a Clean Energy System Before You Buy It
Renewable energy systems are a large upfront investment that only pays off if sized correctly — an undersized solar array leaves a home still dependent on grid power, while an oversized system wastes money on capacity that goes unused, especially without proper net metering credit. Ten calculators here work through system sizing and payback math for solar, wind, and battery storage.
Popular Renewable Energy Calculators
Ten tools span solar, wind, and storage:
- Solar Panel Size Calculator — sizes a solar array based on household energy consumption and local sun exposure.
- Solar Payback Period Calculator — estimates how many years until energy savings recover the system's installation cost.
- Battery Backup Calculator — sizes battery storage capacity needed to cover a home's critical loads during an outage.
- Wind Turbine Output Calculator — estimates energy output based on turbine specs and local average wind speed.
- Net Metering Calculator — estimates credits earned from excess solar production sent back to the grid.
Why Wind Turbine Output Scales So Steeply With Wind Speed
Wind power available to a turbine scales with the cube of wind speed, not linearly — which means doubling wind speed increases available power by roughly eight times, and even a modest difference in average site wind speed can produce a dramatically different energy output over a year. This is exactly why turbine siting is so sensitive to local wind data, and why a site with seemingly "similar" average wind speed to a great location can underperform expectations substantially if that average hides more time spent at lower speeds than the comparison site.
Frequently Asked Questions
Does solar payback period change based on where you live?
Significantly — local electricity rates, available incentives and rebates, and regional sun exposure hours all shift the payback period, which is why the same system size can pay back much faster in one region than another.
Is net metering the same everywhere?
No — utilities and states have different net metering policies, including different credit rates for excess power sent to the grid, which materially affects the actual financial return of a solar installation.
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Estimating broader environmental impact too? See the Environmental Calculators, or check home energy efficiency in the HVAC Calculators.