Industrial Heat Pumps & Electrified Thermal Systems worked example

Thermal Storage Sizing at 11% storage loss and reserve allowance: a worked example

Here is what the math looks like when conditions slip. We hold every other input steady and drop storage loss and reserve allowance to 11%, then walk the calculation through step by step. Estimate usable thermal storage capacity for process heat buffering from average load, required coverage time, and loss or reserve allowance.

The inputs for this scenario

  • Average process heat load: 750 kW (held at the documented default)
  • Required storage duration: 4 hr (held at the documented default)
  • Storage loss and reserve allowance: 11 % (the input this scenario stresses; the baseline uses 15)

Working through the calculation

  • The calculation starts from the formula this tool documents: Base thermal storage energy = average process heat load × required storage duration.
  • Energy used works out to 3,000 kWh at these inputs, and this is the headline figure for the scenario.
  • Energy cost works out to 33,000 $ at these inputs.
  • Cost per piece works out to n/a $ / piece at these inputs.
  • Hourly cost works out to 8,250 $ / hr at these inputs.

How this compares with the baseline

  • Against the tool's baseline example, where storage loss and reserve allowance sits at 15% and the headline result is 3,000 kWh, this scenario lands almost exactly on the baseline at 3,000 kWh.
  • The practical read: the gap between this scenario and the baseline is entirely attributable to storage loss and reserve allowance, so recovering it is worth quantifying in dollars before considering equipment or staffing changes. It assumes a steady average load; a process with sharp peaks may briefly draw more than the average and can underflow a store sized purely on the mean.

Results at a glance

  • Energy used: 3,000 kWh (headline result)
  • Energy cost: 33,000 $
  • Cost per piece: n/a $ / piece
  • Hourly cost: 8,250 $ / hr

Run it with your numbers

  • To rerun this with your own numbers, open the live Thermal Storage Sizing calculator, set storage loss and reserve allowance to your actual value, and adjust the remaining inputs to match your operation.

Last reviewed 2026-05-12.