How do you calculate grow light energy cost?

Multiply total connected grow light load (kW) by your electricity rate ($/kWh) by the effective lit-hour share, then add fixed demand and meter charges. With 65 kW, $0.12/kWh, a 60% lit share, and $250 fixed, the variable cost is $4.68 and the total is $254.68.

Why is the fixed charge so much larger than the variable cost here?

In the default example the $250 fixed demand and meter charge dwarfs the $4.68 variable figure because the effective lit-hour share is applied as a fraction over a short period. On a full monthly run the variable energy cost climbs sharply, but it shows how demand charges can dominate small or low-duty operations.

What is a good lighting cost per kW of canopy?

The calculator returns $3.92 per kW here, which blends fixed and variable cost across the connected load. Lower is better; modern LED rooms on cheap off-peak power can run well under that, while HPS rooms on demand-heavy tariffs run higher.

LED vs HPS for energy cost?

LEDs typically draw 30 to 40 percent less connected load for the same photosynthetic photon output, so you lower the kW input directly. Re-run the calculator with the reduced load to see the variable savings, but remember fixed demand charges only fall if your peak demand drops too.

How do I cut grow light energy cost without hurting yield?

Shift photoperiod into off-peak rate windows, trim the effective lit-hour share with smart dimming during DLI-saturated periods, and target demand charges with staggered fixture startup so you never spike all 65 kW at once.

Does this include HVAC and dehumidification energy?

No. This figure is lighting-only. Lighting heat drives cooling load, so pair this with a climate-control runtime estimate to capture the full energy picture.

Greenhouse, Indoor Farming & Agri-Processing calculator

Grow light energy cost calculator

Grow light energy cost is the dollar figure a greenhouse or vertical farm pays to run its lighting array over a billing period, combining the variable cost of running the fixtures and the fixed demand and meter charges the utility bills regardless of use. Lighting is usually the single largest controllable cost in indoor cultivation, often 25 to 50 percent of total energy spend, so growers, facility managers, and energy consultants run this number to set photoperiod schedules, justify HPS-to-LED retrofits, and benchmark cost per gram against canopy productivity. Because the calculation separates variable from fixed cost, it also shows how much of the bill you can actually move by dimming or shifting hours versus what is locked in by demand charges. Knowing this lets you decide whether load-shifting to off-peak windows or a power-factor correction project will pay back.

What this calculator does

Estimate the monthly or per-cycle electricity cost of LED or HPS grow lights in a greenhouse, vertical farm, or indoor grow room from fixture count, photoperiod, utility rate, and a daylight credit so growers can budget energy spend per crop.
Use it when you need to budget grow light electricity for a leafy green, herb, microgreen, tomato, or cannabis room, compare an LED retrofit against existing HPS, or check whether a rate change makes a current photoperiod uneconomic.
It computes total grow light electricity cost by adding the variable energy cost (connected load times rate times effective lit-hour share) to fixed demand and meter charges.

Formula used

Variable lighting energy cost = total connected grow light load × cost per kWh × effective lit hours over the period
Total grow light energy cost = variable lighting energy cost + fixed demand and meter charges

Inputs explained

Total connected grow light load:
Cost per kWh of electricity:
Effective lit hours over the period:
Fixed demand and meter charges:

How to use the result

Use it when budgeting a lighting schedule, comparing a tariff or photoperiod change, or building the energy line of a cost-per-pound model.
It treats the effective lit-hour figure as a single coverage percentage, so it does not capture time-of-use peak pricing, demand-charge spikes, or fixture-level dimming curves that vary hour to hour.

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.
U.S. housing starts run at 1,177k per year (Census, May 2026), down 8.7% from a year earlier, the demand driver for building products.
Industrial natural gas averages $4.9 per Mcf (EIA, Apr 2026), down 7.7% from a year earlier, with industrial electricity at 8.66 cents per kWh. Process heating and refrigeration budgets track both.

Common questions

How do you calculate grow light energy cost? Multiply total connected grow light load (kW) by your electricity rate ($/kWh) by the effective lit-hour share, then add fixed demand and meter charges. With 65 kW, $0.12/kWh, a 60% lit share, and $250 fixed, the variable cost is $4.68 and the total is $254.68.
Why is the fixed charge so much larger than the variable cost here? In the default example the $250 fixed demand and meter charge dwarfs the $4.68 variable figure because the effective lit-hour share is applied as a fraction over a short period. On a full monthly run the variable energy cost climbs sharply, but it shows how demand charges can dominate small or low-duty operations.
What is a good lighting cost per kW of canopy? The calculator returns $3.92 per kW here, which blends fixed and variable cost across the connected load. Lower is better; modern LED rooms on cheap off-peak power can run well under that, while HPS rooms on demand-heavy tariffs run higher.
LED vs HPS for energy cost? LEDs typically draw 30 to 40 percent less connected load for the same photosynthetic photon output, so you lower the kW input directly. Re-run the calculator with the reduced load to see the variable savings, but remember fixed demand charges only fall if your peak demand drops too.
How do I cut grow light energy cost without hurting yield? Shift photoperiod into off-peak rate windows, trim the effective lit-hour share with smart dimming during DLI-saturated periods, and target demand charges with staggered fixture startup so you never spike all 65 kW at once.

Last reviewed 2026-05-12.