How do you calculate the energy cost of a UL compliance test?

Multiply the average test load (kW) by the runtime (hours) by your lab electricity rate ($/kWh). At 90 kW for 40 hours at $0.16/kWh that is 3,600 kWh and $576 in energy. Dividing by 3 test articles gives $192 per article.

What is a good energy cost per UL test article for EV chargers?

There is no universal benchmark — it scales with charger power. For a 90 kW DC unit, $192 per article (as in the example) is typical for a 40-hour sequence at $0.16/kWh. AC Level 2 units running far lower power land in the single-digit to low-tens of dollars per article.

Does this include the demand charge from utility billing?

No. The calculator uses only the energy ($/kWh) component. A 90 kW sustained test can trigger a monthly demand charge of $10–$25 per kW, which can exceed the energy cost — add it separately when budgeting.

How many test articles should I plan for UL certification?

NRTLs typically require a small representative sample — often 1 to 3 units per model and rating — plus retests after any design change. The default of 3 reflects a common single-model submission; multi-rating product families need more.

Why is my real lab bill higher than this estimate?

Heat rejection. Every kW the charger dissipates during test becomes a cooling load, so lab HVAC can add 20–40% to the metered energy. The 3,600 kWh figure here is the device draw only, not the conditioned-space total.

In-house testing vs NRTL lab — which is cheaper on energy?

In-house energy at your industrial rate (here $0.16/kWh) is usually cheaper per kWh than an NRTL's billed rate, but NRTL labs fold energy into a fixed test fee. Use the per-test number ($192) as the floor to compare against a lab's all-in quote.

EV Charging Infrastructure Manufacturing calculator

UL Compliance Workload Calculator

UL Compliance Workload measures the electricity cost of running EV charger UL 2202 / UL 2594 safety and performance test sequences — the soak, thermal cycling, and full-power dwell runs that draw real power from your lab feed. Test engineers and compliance managers at charger OEMs use it to budget pre-certification energy spend and to allocate that spend across each device under test. It matters because DC fast-charger compliance runs can pull 90 kW or more for dozens of hours per article, and at commercial lab tariffs that energy line item is easy to under-quote on a certification project. Knowing the per-test cost also helps you decide whether to test in-house versus at an NRTL lab.

What this calculator does

Estimate energy cost for UL/ETL compliance, safety, and certification workload on EV charging equipment.
a compliance engineer needs to estimate lab energy cost for charger certification workload
It computes the total electricity cost, kWh consumed, and cost per test article for a UL compliance test campaign from average load, runtime, lab rate, and number of test runs.

Formula used

Compliance workload energy cost = average compliance-test load × compliance runtime × lab electricity rate
Energy cost per compliance test article/run = energy cost ÷ test articles or runs

Inputs explained

Average compliance-test load:
Compliance test runtime:
Lab electricity rate:
Compliance test articles or runs:

How to use the result

Use it when budgeting a UL certification project, quoting in-house compliance lab time, or comparing the energy burden of test plans for AC versus DC charger lines.
It models only metered electricity drawn during the test; it excludes demand charges, HVAC load to reject heat, lab labor, fixture amortization, and NRTL witness fees, which often dwarf the raw energy cost.

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.
Global copper trades at $13,484 per tonne (IMF via FRED, May 2026), up 41.5% in a year, and U.S. industrial electricity averages 8.66 cents per kWh. Both feed electrified-hardware unit economics.

Common questions

How do you calculate the energy cost of a UL compliance test? Multiply the average test load (kW) by the runtime (hours) by your lab electricity rate ($/kWh). At 90 kW for 40 hours at $0.16/kWh that is 3,600 kWh and $576 in energy. Dividing by 3 test articles gives $192 per article.
What is a good energy cost per UL test article for EV chargers? There is no universal benchmark — it scales with charger power. For a 90 kW DC unit, $192 per article (as in the example) is typical for a 40-hour sequence at $0.16/kWh. AC Level 2 units running far lower power land in the single-digit to low-tens of dollars per article.
Does this include the demand charge from utility billing? No. The calculator uses only the energy ($/kWh) component. A 90 kW sustained test can trigger a monthly demand charge of $10–$25 per kW, which can exceed the energy cost — add it separately when budgeting.
How many test articles should I plan for UL certification? NRTLs typically require a small representative sample — often 1 to 3 units per model and rating — plus retests after any design change. The default of 3 reflects a common single-model submission; multi-rating product families need more.
Why is my real lab bill higher than this estimate? Heat rejection. Every kW the charger dissipates during test becomes a cooling load, so lab HVAC can add 20–40% to the metered energy. The 3,600 kWh figure here is the device draw only, not the conditioned-space total.

Last reviewed 2026-05-12.