In energy conservation, a lot of myths circulate about peak electrical demand. Let’s cut through some of the most common ones.

Fiction: It costs more to start equipment, so don’t turn it off.

Fact: The numbers usually prove otherwise.

Example:

100 kW load
Turned off for 2 hours/day, 30 days/month
Adds 20 kW to demand when restarted. I.e. the utility demand meter registers 120 kW before the motor settles to a steady state load of 100 kW.
Demand charge = $10/kW per month
Consumption charge = $0.05/kWh

Extra demand cost: 20 kW × $10 = $200/month

Energy saved: 100 kW × 2 hrs × 30 days × $0.05 = $300/month

Net savings: $100/month.

So yes—turn it off.

Fiction: Stagger equipment startups by 15 minutes to lower peak demand.

Fact: What matters isn’t a fixed time, but how long the load takes to reach steady state.

Most equipment draws extra current at startup, but the spike usually lasts seconds or minutes, not a quarter hour. Use an amperage logger to measure the exact time. Then stagger loads based on that data. For maximum efficiency, work backward—start the last load first, then space others just enough to avoid overlap. In some cases, you’ll save more by keeping loads off until absolutely necessary.

Fiction: Short-duration loads fully register on the demand meter.

Fact: Most meters need more than 15 minutes to record full demand.

Typical response curve for a peak demand meter.

That means a 30 kW dishwasher booster heater that runs for only a minute or two may only add 5 kW to your demand reading. Always check with your utility for specifics.

And of course, not all loads affect your peak. Some, like outdoor lighting, ice making for thermal storage, or other off-peak processes, may carry zero demand cost. They still use energy, but they won’t raise your billing peak.

The Bottom Line

Don’t assume the myths are true. Do the math, measure your loads, and know exactly when your demand peak occurs. That’s the only way to separate fact from fiction—and to make real savings. Because if you’re not managing your energy, who is?

2-Minute Payback is GRCL’s weekly blog of energy-saving tips and tools for busy building managers. This post was written by Chuck Faulkner.

Electrical Billing Demand: Fact versus Fiction