Renewable Calculators
Precision calculators for renewable professionals and operations.
Battery Bank Capacity Sizing Calculator
Determine the total raw battery capacity in Amp-Hours needed to survive off-grid cloudy days, adjusting for strict chemistry safe discharge limits.
Firewood Cord BTU Heating Estimator
Calculate gross and net thermodynamic heat yield from firewood by species, volume, and stove efficiency — plus equivalents in natural gas therms and grid electricity.
Geothermal Loop Length Sizer
Estimate the required linear footage of buried high-density polyethylene (HDPE) pipe required to support a geothermal heat pump based on mechanical tonnage and sub-surface soil conductivity.
Hydroelectric Penstock Head Loss
Calculate friction head loss in hydroelectric penstock pipes using the Hazen-Williams formula to ensure sufficient net head reaches your turbine.
Inverter Dc Ac Clipping Ratio
Calculate the DC/AC loading ratio of a solar array to its inverter AC rating and see whether the design is in a low, commonly used, or higher-clipping band before running production modeling.
Off Grid Inverter Dc Amp Draw
Calculate the true DC battery amp draw and cable sizing requirements when powering AC appliances through an off-grid inverter at real-world efficiency losses.
Peukert's Law Battery Discharge Capacity Calculator
Calculate true usable battery runtime under heavy DC loads using Peukert's Law to account for electrochemical capacity collapse at high discharge rates.
Solar Array & Inverter Sizing Calculator
Determine the physical solar panel array size and minimum inverter surge rating required to power a daily Watt-hour target based on your local peak sun exposure.
Solar Panel Temp Coefficient Power Loss
Calculate real-world solar panel power output after applying the manufacturer's temperature coefficient — showing exactly how many watts are lost to rooftop heat.
Solar Pv String Sizing
Calculate the maximum number of solar panels you can safely wire in series. Prevent cold-weather voltage spikes from instantly destroying your solar inverter.
String Cold Weather Max Voltage
Calculate cold-temperature module Voc and maximum series string voltage from the module Voc temperature coefficient and the design low temperature, using the NEC 690.7(A) manufacturer-coefficient method.
Wind Turbine Betz Limit
Calculate the total kinetic energy passing through a wind turbine and the absolute maximum power it can extract based on the physical Betz Limit of 59.26%.
Wind Turbine Power Output
Calculate theoretical wind turbine power output using the Betz wind power equation — accounting for swept area, air density, wind speed, and a real performance coefficient.
Wind Turbine Tip Speed Ratio Tsr
Calculate the dimensionless aerodynamic Tip Speed Ratio (TSR/λ) for wind turbines to verify the rotor is tuned for peak Betz efficiency at your wind speed.