Microgrid & Distributed Energy Equipment calculator

Thermal Derating Calculator

Thermal derating energy quantifies the electricity spent running cooling so inverters and battery cabinets stay below the temperature where they throttle output. Microgrid operators and thermal designers use it because every degree above the derate threshold cuts deliverable power, so cooling is not optional overhead but a way to protect rated capacity. It matters when you are sizing HVAC or forced-air cooling for a containerized system and need to weigh cooling energy cost against the revenue lost to a derated inverter on a hot afternoon. The calculator gives you the kWh, the dollar cost, and how that cost spreads across the cabinets you are cooling.

What this calculator does

  • Estimate the cooling energy and cost needed to keep microgrid and distributed energy power electronics below their thermal derating threshold, so teams can budget HVAC energy, compare enclosure cooling options, or include it in the quote.
  • Use it when enclosure cooling for microgrid and distributed energy power electronics is being sized and you want the energy cost of avoiding thermal derating.
  • It computes the kWh used by the cooling load over its runtime, the dollar cost at your blended rate, and the cooling cost allocated per inverter or cabinet.

Formula used

  • Total derating cooling energy cost = connected cooling load × cooling runtime × blended electricity rate
  • Cooling cost per cabinet = total energy cost ÷ inverters or cabinets cooled

Inputs explained

  • Connected cooling load:
  • Cooling runtime:
  • Blended electricity rate:
  • Inverters or cabinets cooled:

How to use the result

  • Use it when sizing or budgeting active cooling for inverters and battery enclosures to keep them out of thermal derating during hot operating windows.
  • It assumes the cooling load runs at a constant kW for the full runtime; staged or thermostat-cycled cooling and ambient swings mean real energy varies, so treat this as a steady-state estimate.

Current U.S. benchmarks

  • As of Apr 2026, industrial electricity averages 8.7 cents per kWh across the U.S. (EIA), up 5.5% from a year earlier. State averages range widely, so plants should confirm against their own tariff.
  • Steel mill PPI stands at 348.53 (BLS, May 2026), up 6.7% from a year earlier. New factory orders are up 2.3% year over year (Census).

Common questions

  • How do you calculate thermal derating cooling energy? Multiply the connected cooling load by the cooling runtime. At 12 kW for 8 hours that is 96 kWh of cooling energy for the period.
  • What does cabinet cooling cost to run? Multiply the 96 kWh by your blended rate. At $0.12/kWh the cooling energy costs $11.52 over the 8-hour window.
  • What is cooling cost per cabinet? Total cost divided by cabinets cooled. With $11.52 across 1,000 cabinets that is about $0.0115 per cabinet, a fleet-level figure; set cabinets to your actual count for a real per-unit cost.
  • Why does cooling matter for derating? Inverters and cells throttle output above a temperature threshold. Spending $11.52 to keep them cool can preserve far more in deliverable energy than the cooling costs.
  • What is the hourly cooling cost? The tool returns it: load times rate, here 12 kW times $0.12 equals $1.44 per hour, useful for comparing cooling spend against derating losses per hour.

Last reviewed 2026-05-12.