Lighting, LEDs & Electrical Fixtures worked example

Annual Fixture Energy Cost with total connected load of 7.5 kW: a worked example

This worked example runs the annual fixture energy cost numbers for a tougher week than the baseline: total connected load of 7.5 kW instead of the typical 15 kW. Calculate the annual electricity cost of operating an installed LED fixture system. Enter total connected load, annual operating hours, electricity rate, and fixture count to get total annual energy cost and cost per fixture per year.

The inputs for this scenario

  • Total connected load: 7.5 kW (the input this scenario stresses; the baseline uses 15)
  • Annual operating hours: 3,500 hr / yr (held at the documented default)
  • Electricity rate: 0.13 $ / kWh (held at the documented default)
  • Number of fixtures installed: 100 fixtures (held at the documented default)

Working through the calculation

  • The calculation starts from the formula this tool documents: Annual energy cost = total connected load (kW) x annual operating hours x electricity rate.
  • Annual energy cost works out to 3,413 $ at these inputs, and this is the headline figure for the scenario.
  • Annual energy consumed (kWh) works out to 26,250 kWh at these inputs.
  • Annual energy cost per fixture works out to 34.13 $ / piece at these inputs.
  • Hourly energy cost works out to 0.98 $ / hr at these inputs.

How this compares with the baseline

  • Against the tool's baseline example, where total connected load sits at 15 kW and the headline result is 6,825 $, this scenario comes in 50% below the baseline at 3,413 $.
  • Use it to baseline current lighting spend, justify a retrofit, or allocate energy cost across a fixture inventory. A result at this level usually justifies acting on the stressed input before touching anything else, because every other figure in the table is downstream of it.

Results at a glance

  • Annual energy cost: 3,413 $ (headline result)
  • Annual energy consumed (kWh): 26,250 kWh
  • Annual energy cost per fixture: 34.13 $ / piece
  • Hourly energy cost: 0.98 $ / hr

Run it with your numbers

  • To rerun this with your own numbers, open the live Annual Fixture Energy Cost calculator, set total connected load to your actual value, and adjust the remaining inputs to match your operation.

Last reviewed 2026-05-12.