Calculator catalog
Choose a category or search by quantity, component or engineering topic.
Found 33 calculators
Annual building energy demand
Calculates annual building energy demand from reference floor area and specific indicators for space heating, space cooling, domestic hot water, and other uses.
Energy cost from kWh and price
Calculates energy cost from energy in kWh and price per kWh.
Simple payback period
Calculates helper payback period from user-provided investment cost and annual savings.
Simple wind turbine power
Simple estimate calculator for wind power from air density, swept area, wind speed, and power coefficient.
Wind capacity factor
Simple estimate calculator for capacity factor from actual energy, rated power, and time.
Hydro power from head and flow
Simple estimate calculator for hydro power from density, gravity, flow rate, head, and efficiency.
CO2 emission from energy
Simple estimate calculator for CO2 emission from energy and a user-provided emission factor.
Energy savings
Simple estimate calculator for energy savings as baseline energy minus new energy.
Energy savings percent
Simple estimate calculator for percent energy savings relative to baseline energy.
Simple LCOE
Simple estimate calculator for unit energy cost from total lifetime cost and lifetime energy.
Simple efficiency
Simple estimate calculator for efficiency as useful output divided by input.
PV power from area and efficiency
Estimates PV power from module area, irradiance, and efficiency.
Simple PV daily energy
Estimates daily PV energy from peak power, sun hours, and performance ratio.
PV module count from power
Calculates the minimum whole number of PV modules required to meet the target power.
Solar thermal collector power
Simple estimate calculator for solar thermal collector power from area, irradiance, and efficiency.
PV string series count with temperature
Calculates temperature-corrected Voc/Vmp and module-count limits from DC voltage and MPPT range.
PV inverter power sizing
Calculates required AC apparent power and recommended inverter power from active power, power factor and loading fraction.
Battery storage energy from voltage and Ah
Estimates storage energy from nominal voltage and amp-hour capacity.
Battery runtime from energy and power
Estimates storage runtime from available energy and load power.
Battery usable energy
Calculates helper usable energy from user-provided nominal energy, depth of discharge, and efficiency.
Battery C-rate
Simple estimate calculator for C-rate from user-provided current and Ah capacity.
Battery charge time
Simple estimate calculator for charge time from user-provided Ah capacity and charging current.
Battery capacity for autonomy
Calculates required load energy, nominal battery energy and Ah capacity for a target autonomy time.
Heat pump COP
Calculates heat pump COP as heat output divided by electric power.
Heat pump electric power
Calculates heat pump electric power from heat output and COP.
Heat pump water flow rate
Calculates helper volumetric flow from user-provided heat power and fluid properties.
Carnot heat pump COP for heating
Simple estimate calculator for ideal Carnot COP in heating mode from user-provided absolute temperatures.
Fuel energy from mass and LHV
Calculates fuel chemical energy from mass and user-provided lower heating value.
Fuel CO2 emission
Simple estimate calculator for CO2 emission from fuel mass and a user-provided emission factor.
Useful heat from fuel and efficiency
Calculates useful heat from fuel mass, user-provided LHV, and efficiency.
Fuel mass from required heat
Calculates fuel mass from required useful heat, LHV, and efficiency provided by the user.
Fuel cost from mass
Calculates fuel cost from mass and price per mass in the same notional currency.
Fuel volumetric energy density
Calculates volumetric energy density from user-provided LHV and fuel density.