Wall-plug efficiency stopped being a footnote when electricity prices moved

A 30 kW machine running two shifts consumes a meaningful share of a factory's electricity. Source efficiency and chiller load are now appearing in purchase evaluations.

By LasersNews Desk·20 Jul 2026·2 min read

Laser equipment with accessories including goggles and carrying cases on a white background. — Photo by Đậu Photograph on Pexels

Wall-plug efficiency — optical output divided by electrical input — was for years a specification buyers noted and ignored. Fiber lasers reach roughly forty to fifty per cent, far better than the CO2 and lamp-pumped systems they replaced, and that comparison was treated as settling the matter.

Electricity price volatility in several major manufacturing regions has moved it back onto the evaluation sheet.

The arithmetic

A 30 kW source at forty-five per cent efficiency draws about 67 kW electrical for the source alone. The waste heat, roughly 37 kW, goes into the chiller, which consumes further electricity to move it outside — typically adding twenty-five to thirty-five per cent on top of the heat load depending on chiller efficiency and ambient conditions.

Running two shifts, the annual consumption is substantial enough that a five percentage point efficiency difference between sources becomes a visible operating cost.

What is often missed

Duty cycle matters more than rated power. A cutting machine spends significant time in rapid moves, piercing and unloading, so average draw is well below peak. Comparing sources on rated consumption overstates the difference; comparing on measured energy per part is the meaningful test.

Standby behaviour matters too. Sources and chillers that idle efficiently, and that can be put into low-power states between jobs, save more in a shop with intermittent running than a marginally more efficient source does.

The heat side

Waste heat is a facility problem as well as an energy one. In warm climates or crowded factories, rejecting tens of kilowatts of heat raises ambient temperature, which lowers chiller efficiency and raises diode junction temperatures — connecting the electricity bill to source lifetime through thermal management.

What buyers are now asking

Evaluations increasingly request measured consumption over a representative production cycle rather than rated figures, chiller specifications alongside source specifications, and standby and idle consumption data.

That is a more useful comparison than headline efficiency, and it tends to favour machines designed as complete thermal systems rather than as sources with a chiller attached.

This article was produced by the LasersNews AI desk and reviewed by our editors.