UV Curing calculator

UV LED Energy Cost Calculator

UV LED arrays draw less wall-plug power than mercury at the same dose, but the kWh still hits the utility bill and shows up on per-part cost. This calculator converts the array's kW, the shift hours it runs, your utility rate, and the parts it cures into a clean shift cost and a per-part energy cost you can drop into a quote or a payback model.

What this calculator does

  • Cost out a UV LED cure system per shift and per part using array wall-plug power, runtime, utility rate, and units cured.
  • Use it when costing a UV LED retrofit, building a job quote with energy as a line item, or reporting energy cost per part to operations.
  • Translates the LED array's electrical draw into shift energy cost and energy cost per cured part.

Formula used

  • Energy used (kWh) = wall-plug power × runtime
  • Shift energy cost = energy used × $/kWh
  • Energy cost per part = shift energy cost ÷ parts cured

Inputs explained

  • Array wall-plug power: Total electrical draw of the LED array(s) and driver electronics — not optical UV output.
  • Runtime per shift: Hours the array is actually energized — most lines idle the array between parts.
  • Blended electricity rate: Use the all-in rate from your utility bill including demand charges divided across kWh.
  • Parts cured per shift: Good cured units — exclude scrap so the per-part number is honest.

How to use the result

  • Use it for UV LED retrofit business cases, energy reporting, and per-part cost rollups when energy is a meaningful line item (high-volume, multi-shift operations).
  • Covers the array and driver only. It does not include cooling water chillers, exhaust fans, ozone scrubbers, or compressed air for nitrogen — wrap those in a separate utilities cost line. Idle periods where the array is dimmed but on still consume power; treat 'runtime' as energized-time, not part-under-lamp time.

Common questions

  • Should I use optical UV watts or wall-plug kW? Wall-plug kW (electrical input). Optical UV watts are the useful output after wall-plug-to-UV conversion (~25–35% on most LED arrays); your utility bills you for the electrical input. Read the kW figure off the array's electrical schedule or measure with a clamp meter on the driver feed.
  • How does this compare to a mercury arc lamp on the same line? Mercury lamps are typically 2–4× the kW for similar dose at the part because they radiate broadband (most of which the chemistry can't use) and need to stay on between parts. Run this calculator twice — once with the LED array kW and once with the mercury lamp kW — then compare shift cost. The delta drives the UV LED Payback calc.
  • Why does my per-part cost drop so fast as parts cured goes up? Energy cost per shift is roughly fixed once the array is on; spreading it across more good parts pushes per-part cost down quickly. That is also why throughput losses (scrap, jams, breaks) hit per-part energy cost harder than they hit per-part labor.
  • Where does demand charge fit in? Demand charges ($/kW of peak) are often 20–40% of an industrial bill. The simplest defensible approach is to roll them into the blended $/kWh you enter here. If demand peaks fall during UV runs, model that separately in your utility rate.

Last reviewed 2026-05-12.