Tunnel Boring & Heavy Civil Equipment worked example

Cooling System Load with cooling system connected electrical load of 30 kW: a worked example

Push cooling system connected electrical load up to 30 kW and the picture changes. This example computes every intermediate figure at that operating point. Use it when cooling system load in tunnel boring and heavy civil equipment is up for an upgrade and you want a defensible savings story.

The inputs for this scenario

  • Cooling system connected electrical load: 30 kW (raised for this scenario; the documented default is 12)
  • Cooling system runtime this shift: 8 hr (unchanged)
  • Blended underground electricity rate: 0.12 $ / kWh (unchanged)
  • Advance output during runtime: 1,000 units (unchanged)

Working through the calculation

  • Applying the documented formula (Total cooling system load energy cost = cooling system load connected load × cooling system load runtime × blended electricity rate) to the inputs above produces each figure below.
  • At this operating point the engine returns 240 kWh for cooling system load energy used, the number this scenario is built around.
  • At this operating point the engine returns 28.8 $ for total cooling system load energy cost.
  • At this operating point the engine returns 0.03 $ / piece for energy cost per kwh.
  • At this operating point the engine returns 3.6 $ / hr for hourly cooling system load energy cost.

How this compares with the baseline

  • Against the tool's baseline example, where cooling system connected electrical load sits at 12 kW and the headline result is 96 kWh, this scenario comes in 150% above the baseline at 240 kWh.
  • It computes energy used from connected load and runtime, multiplies by the electricity rate for total cost, and divides that cost by advance output for a per-unit energy cost. The value of this scenario is the size of the gap it exposes: that gap, priced out over a year, is the budget you can justify spending to close it.

Results at a glance

  • Cooling system load energy used: 240 kWh (headline result)
  • Total cooling system load energy cost: 28.8 $
  • Energy cost per kWh: 0.03 $ / piece
  • Hourly cooling system load energy cost: 3.6 $ / hr

Run it with your numbers

  • Every input above is editable in the live Cooling System Load calculator, which recalculates instantly and can be shared with the inputs intact.

Last reviewed 2026-05-12.