Cost to run

How much does a grow light cost to run?

Grow lights run long, fixed photoperiods — commonly twelve to eighteen hours daily — so even efficient LED fixtures accumulate significant hours. Wattage times photoperiod is the whole story.

Reviewed 2026-07-15 · methodology appliance-energy-1.0.0 · data vintage 2026-04-ytd

Example costs using the Texas state-average rate

These are generated examples for a consistent location. Enter your own ZIP and usage below for a more relevant state-average estimate.

Scenario	Assumption	kWh/month	Monthly range	Most likely/year
Seedling shelf	60-watt panel, 16 hours a day	28.80	$3.07–$6.85	$56.34
Hobby grow tent	300-watt LED, 14 hours a day	126.00	$13.42–$29.95	$246.51
Serious multi-light setup	Two 480-watt fixtures, 12 hours a day	345.60	$36.81–$82.16	$676.13

Source: U.S. Energy Information Administration, Electric Power Monthly Table 5.6.B. Data vintage 2026-04-ytd. State-average pricing is not your exact utility tariff.

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Photoperiods make hours non-negotiable

Plants need their light schedule regardless of electricity prices, so the runtime input is fixed by horticulture: leafy greens and seedlings often get sixteen hours, flowering cycles twelve. The only real lever is fixture efficiency at the required light intensity.

LED efficiency changed the hobby's economics

Modern quantum-board LEDs deliver the same usable light as older high-pressure sodium rigs at roughly half the wall draw and far less heat. Less heat also means smaller ventilation fans, compounding the savings beyond the fixture itself.

Beyond the light: what is not counted

Inline exhaust fans, oscillating fans, heat mats, humidifiers, and dehumidifiers commonly accompany grow spaces and draw separately from the fixture modeled here. Driver efficiency losses and dimmer settings below rated watts are likewise folded into your wattage entry.

Frequently asked questions

How much does a grow tent add to my bill?

The hobby-tent scenario prices a typical 300-watt fixture at fourteen daily hours with the calculation engine. Supporting fans and climate gear add their own share.

Are LED grow lights cheaper than HPS?

For equivalent canopy light, LEDs typically draw substantially less and shed less heat into the space, cutting both direct and ventilation costs.

Does dimming a grow light save proportionally?

Roughly yes — LED drivers scale draw close to linearly with output. Enter the dimmed wattage rather than the fixture's maximum for an honest estimate.

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