How do you calculate billet preheat energy cost?

Multiply furnace load by runtime to get kWh, then multiply by the electricity rate. With 420 kW for 6 hours at $0.11/kWh, that is 2,520 kWh costing $277.20, or about $2.89 per billet across 96 billets.

What is a typical preheat energy cost per billet?

It depends on billet size, furnace type, and power rate, but a few dollars per billet is common on electric and induction systems; the $2.89 here reflects a 420 kW load over 6 hours at 11 cents. Gas furnaces shift the cost to therms instead of kWh.

Why use connected load instead of nameplate rating?

Furnaces cycle on and off to hold temperature, so nameplate kW overstates real draw. Plug in a measured average load from your meter or PLC for the period to get a cost that matches the actual bill.

How can I reduce billet preheat energy cost?

Tighten furnace insulation and door seals, use taper or gradient heating to cut soak time, recover press exhaust heat, schedule preheat off peak-demand windows, and avoid reheating billets that sat too long after a stoppage.

Does this include induction vs gas furnace differences?

This model is for electric or induction furnaces billed in kWh. For a gas furnace, swap to therms and a $/therm rate and account for combustion efficiency, which is typically lower than electric or induction.

What is the cost per hour telling me?

It is total energy cost divided by runtime — here $46.20 per hour — a quick benchmark for comparing furnaces or shifts and for spotting when a furnace is left soaking with no billets to extrude.

Aluminum Extrusion & Profile Manufacturing calculator

Aluminum Billet Preheat Energy Cost Calculator

Billet preheating to the 850-950 degF extrusion window is one of the largest controllable energy loads in an extrusion plant, and on an electric or induction furnace it shows up directly on the power bill in kilowatt-hours. This calculator turns furnace connected load, runtime, and your electricity rate into total energy, total cost, and the cost per billet that flows straight into profile cost per pound. Plant engineers and energy managers use it to benchmark furnace efficiency, justify induction upgrades or taper-quench heating, and see how demand-rate timing changes the per-billet number. A few cents per billet adds up fast when a press eats dozens of billets an hour, every shift.

What this calculator does

Estimate billet preheat energy use and cost from furnace load, heat time, electricity or gas-equivalent rate, and billets processed.
a process engineer or estimator needs to estimate billet preheat energy cost for an extrusion run
It multiplies furnace load by runtime to get energy used, costs it at your electricity rate, and divides by billets processed to get cost per billet plus cost per hour.

Formula used

Billet preheat energy used = billet preheat furnace load × billet preheat runtime
Preheat energy cost per billet = total billet preheat energy cost ÷ billets processed

Inputs explained

Billet preheat furnace load:
Billet preheat runtime:
Electricity rate:
Billets processed:

How to use the result

Use it to benchmark preheat energy, evaluate furnace or rate changes, and feed an accurate energy cost into your per-pound profile cost.
It assumes the furnace draws at its stated load for the whole runtime; real furnaces cycle on thermostat, so a measured average load gives a far truer cost than nameplate kW.

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.
The producer price index for aluminum mill shapes stands at 404.859 (BLS, May 2026), up 36.8% from a year earlier. Quotes priced off last quarter's material cost miss this move.
The U.S. has 3,569 primary metal manufacturing establishments employing about 354,911 workers (Census County Business Patterns, 2023).

Common questions

How do you calculate billet preheat energy cost? Multiply furnace load by runtime to get kWh, then multiply by the electricity rate. With 420 kW for 6 hours at $0.11/kWh, that is 2,520 kWh costing $277.20, or about $2.89 per billet across 96 billets.
What is a typical preheat energy cost per billet? It depends on billet size, furnace type, and power rate, but a few dollars per billet is common on electric and induction systems; the $2.89 here reflects a 420 kW load over 6 hours at 11 cents. Gas furnaces shift the cost to therms instead of kWh.
Why use connected load instead of nameplate rating? Furnaces cycle on and off to hold temperature, so nameplate kW overstates real draw. Plug in a measured average load from your meter or PLC for the period to get a cost that matches the actual bill.
How can I reduce billet preheat energy cost? Tighten furnace insulation and door seals, use taper or gradient heating to cut soak time, recover press exhaust heat, schedule preheat off peak-demand windows, and avoid reheating billets that sat too long after a stoppage.
Does this include induction vs gas furnace differences? This model is for electric or induction furnaces billed in kWh. For a gas furnace, swap to therms and a $/therm rate and account for combustion efficiency, which is typically lower than electric or induction.

Last reviewed 2026-05-12.