How do you calculate factory acceptance test energy?

Multiply the connected test load (kW) by FAT runtime (hr) to get kWh. With 12 kW for 8 hr that is 96 kWh. Multiply kWh by your blended rate ($0.12) for the dollar cost — here $11.52 — then divide by units tested for cost per unit.

What is the energy cost per unit tested in the default example?

$0.0115 per unit. The 96 kWh test run costs $11.52 at $0.12/kWh, and spreading that across 1,000 units tested gives roughly 1.15 cents each — small per unit, but it scales with volume and rate.

Why use a blended electricity rate instead of the supply rate?

A blended rate folds in delivery, demand, and rider charges so the FAT cost reflects what actually hits your bill. Using only the energy-supply component understates true cost, often by 30 to 50 percent on commercial accounts.

Does this include the load bank or HVAC heat rejection?

No. The calculator captures only the connected test load you enter. If your FAT pulls real power through a load bank and the bay's cooling runs harder to reject that heat, add the auxiliary kW to the connected load or run a second pass.

How can I lower FAT energy cost?

Shift long soak tests into off-peak rate windows, batch units so the bay runs near full utilization, and use regenerative load banks that return power to the bus instead of dumping it as heat. Even a $0.04/kWh off-peak swing cuts the $11.52 run materially.

Hourly FAT energy cost vs total cost — which should I quote?

Quote total cost per unit ($0.0115 here) in the unit price, but track hourly cost ($1.44/hr) for bay scheduling and to flag tests running longer than planned. The hourly figure is your early-warning metric for overruns.

Microgrid & Distributed Energy Equipment calculator

Factory Acceptance Test Energy Calculator

Factory Acceptance Test (FAT) energy is the electricity consumed while you power up and exercise microgrid hardware — inverters, battery enclosures, switchgear, controllers — on the test floor before it ships. Test engineers and FAT cost estimators use it to convert a load bank or burn-in profile into kWh, a dollar figure, and a per-unit cost they can roll into the build quote. It matters because distributed-energy gear is often soak-tested for hours per unit, and at volume the cumulative meter draw is a real line item — not a rounding error. Knowing the number lets you schedule FAT around utility time-of-use windows and recover the cost in your unit price.

What this calculator does

Estimate the electricity used and cost to run factory acceptance testing (FAT) on microgrid and distributed energy equipment, so teams can budget test-bay energy, compare load-bank setups, or include it in the quote.
Use it when factory acceptance testing on microgrid and distributed energy equipment needs a defensible energy number for the budget or quote.
It computes the kWh drawn during a factory acceptance test, the dollar cost at your blended rate, and the energy cost allocated to each unit tested.

Formula used

Total FAT energy cost = connected test load × FAT runtime × blended electricity rate
Energy cost per unit tested = total energy cost ÷ units tested

Inputs explained

Connected test load:
FAT runtime:
Blended electricity rate:
Units tested:

How to use the result

Use it when quoting a build, sizing your test bay's power and metering, or comparing FAT energy across product lines and shifts.
It assumes the connected load is roughly constant for the full runtime; pulsed, ramped, or step-load FAT profiles will draw less than load × time, so derate with a duty factor for accuracy.

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 factory acceptance test energy? Multiply the connected test load (kW) by FAT runtime (hr) to get kWh. With 12 kW for 8 hr that is 96 kWh. Multiply kWh by your blended rate ($0.12) for the dollar cost — here $11.52 — then divide by units tested for cost per unit.
What is the energy cost per unit tested in the default example? $0.0115 per unit. The 96 kWh test run costs $11.52 at $0.12/kWh, and spreading that across 1,000 units tested gives roughly 1.15 cents each — small per unit, but it scales with volume and rate.
Why use a blended electricity rate instead of the supply rate? A blended rate folds in delivery, demand, and rider charges so the FAT cost reflects what actually hits your bill. Using only the energy-supply component understates true cost, often by 30 to 50 percent on commercial accounts.
Does this include the load bank or HVAC heat rejection? No. The calculator captures only the connected test load you enter. If your FAT pulls real power through a load bank and the bay's cooling runs harder to reject that heat, add the auxiliary kW to the connected load or run a second pass.
How can I lower FAT energy cost? Shift long soak tests into off-peak rate windows, batch units so the bay runs near full utilization, and use regenerative load banks that return power to the bus instead of dumping it as heat. Even a $0.04/kWh off-peak swing cuts the $11.52 run materially.

Last reviewed 2026-05-12.