Waste-to-Energy Equipment worked example

Boiler Heat Recovery at 52% economizer recovery efficiency: a worked example

This worked example runs the boiler heat recovery numbers for a tougher week than the baseline: 52% economizer recovery efficiency instead of the typical 72%. Estimates the annual value of waste-to-energy boiler heat recovery from recovered megawatt-hours, per-MWh heat value, recovery efficiency, and a fixed capital charge.

The inputs for this scenario

  • Recovered steam output: 22,000 MWh (held at the documented default)
  • Steam heat value: 45 $/MWh (held at the documented default)
  • Economizer recovery efficiency: 52 % (the input this scenario stresses; the baseline uses 72)
  • Economizer capital charge: 180,000 $ (held at the documented default)

Working through the calculation

  • The calculation starts from the formula this tool documents: Total = recovered MWh x heat value x (recovery efficiency รท 100) + capital charge.
  • Total boiler heat recovery cost works out to 694,800 $ at these inputs, and this is the headline figure for the scenario.
  • Boiler heat recovery cost per unit works out to 31.58 $ / piece at these inputs.
  • Variable boiler heat recovery cost works out to 514,800 $ at these inputs.
  • Fixed boiler heat recovery adder works out to 180,000 $ at these inputs.

How this compares with the baseline

  • Against the tool's baseline example, where economizer recovery efficiency sits at 72% and the headline result is 892,800 $, this scenario comes in 22.18% below the baseline at 694,800 $.
  • Use it when appraising an economizer or flue-gas heat-recovery retrofit, or when setting an internal transfer price for the steam the boiler exports. A result at this level usually justifies acting on the stressed input before touching anything else, because every other figure in the table is downstream of it.

Results at a glance

  • Total boiler heat recovery cost: 694,800 $ (headline result)
  • Boiler heat recovery cost per unit: 31.58 $ / piece
  • Variable boiler heat recovery cost: 514,800 $
  • Fixed boiler heat recovery adder: 180,000 $

Run it with your numbers

  • To rerun this with your own numbers, open the live Boiler Heat Recovery calculator, set economizer recovery efficiency to your actual value, and adjust the remaining inputs to match your operation.

Last reviewed 2026-05-12.