Skip to content
Calculator Collection

Compare calculators

Both calculators run independently — change the inputs on either side to compare results.

Solar Energy

Solar Water Heater Savings Calculator

Estimates annual energy savings from a solar water heater based on household size, fuel type, solar fraction. Use it when comparing solar thermal to conventional water heating costs.

Annual Savings

668.14 $

167
80
140
220
Gas displacementPropane/oil rangeElectric displacementHigh per-capita savings

167.04: $140-220/person is typical when replacing electric resistance heating (2.8 factor), the most expensive fuel to offset and the fastest payback.

This is annual water-heating savings per person; per-capita savings depend heavily on displaced fuel, since electric resistance heating costs far more than gas to offset.

Solar Energy

Optimal Solar Panel Angle Calculator

Estimates the optimal fixed tilt angle for a solar panel based on your latitude and the season you want to optimize for. Useful for fixed-tilt mounting decisions, seasonal-adjustment planning, and rough-design sizing for off-grid systems.

Fill in the required fields to see your result.

Key differences

Solar Water Heater Savings CalculatorOptimal Solar Panel Angle Calculator
CategorySolar EnergySolar Energy
Inputs required32
ResultAnnual Savings ($)Optimal Tilt Angle (degrees)
What it doesEstimates annual energy savings from a solar water heater based on household size, fuel type, solar fraction. Use it when comparing solar thermal to conventional water heating costs.Estimates the optimal fixed tilt angle for a solar panel based on your latitude and the season you want to optimize for. Useful for fixed-tilt mounting decisions, seasonal-adjustment planning, and rough-design sizing for off-grid systems.