Do LED Grow Lights Use Less Electricity? Find Out What LED Lights Do to Your Electric Bill

Co-authored by wikiHow Staff

Last Updated: December 6, 2021 References

LEDs are extremely efficient at converting electricity into light, unlike older bulb styles that can be up to 90% inefficient at producing light.^{[1]
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Go to source} This same efficiency advantage holds true when you compare LED grow lights to common alternatives. To help you make an informed grow light decision, this article delves into key questions you probably have about the many advantages (and few potential drawbacks) of LEDs.

Question 1

Question 1 of 7:
Do LED grow lights use less power?

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Yes—LEDs are more energy-efficient than similar HIDs or CFLs. To produce the same amount of light (measured in lumens), an LED grow light uses about 17% less electricity than a CFL (compact fluorescent) grow light.^{[2]
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Research source} The difference is even greater when compared to HID (high-intensity discharge) grow lights—LEDs are around 20%-30% more energy-efficient.^{[3]
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- Say, for example, your plants require 7000 lumens of lighting. To produce this amount of light, an LED uses 96W (watts), a CFL uses 115W, and an HID uses 117-140W.
- Here’s another way to look at it: a 100W LED produces 7300 lumens, a 100W CFL produces 6100 lumens, and a 100W HID produces 5000-6000 lumens
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Question 2

Question 2 of 7:
Are LED grow lights cheaper to run?

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Yes—especially when you focus on the monthly cost to run the light. There are way too many variables here to give you a specific savings amount, but LEDs might save a typical indoor grower $20 USD per month. That said, keep in mind that LEDs can cost 2-5 times as much to buy and that they produce less heat per lumen (as addressed elsewhere in this article). But, all things considered, LEDs nearly always save you money, especially in the long term.^{[4]
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- If you run your lighting (1000W/1kW HID or 650W LED) for 12 hours per day and your electricity rate is $0.14 USD per kWh (kilowatt-hour), here’s the monthly comparison:
  - HID: 12 hr x 1 kW x 30 days x $0.14 = $50.40 USD
  - LED: 12 hr x 0.65 kW x 30 days x $0.14 = $32.76 USD
  - Here’s another way to think of it: during every hour of operation, you’re saving 0.35 kW (350 watts) and 5 cents (USD).

Question 3

Question 3 of 7:
How much power does a “1000 watt equivalent” LED use?

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A 1000W equivalent LED grow light uses around 600-650 watts. You generally won’t find LED grow lights that use 1000W of power; instead, you’ll find LEDs that produce the lighting equivalent of a standard 1000W grow light. But, because LEDs are more efficient, they require only around 600W-650W of power to produce this equivalent lighting.^{[5]
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Question 4

Question 4 of 7:
My electric bill is based on kWh—how does that work?

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One kilowatt-hour (kWh) simply means you used 1000 watts for 1 hour. For example, if you run a 1000W (1 kilowatt or kW) HID grow light for 1 hour, that’s 1 kWh; if you use it 12 hours a day for 30 days, that’s 360 kWh added to your monthly usage. Similarly, a “1000W equivalent” LED grow light that actually uses 600W per 1 hour adds 0.6 kWh to your bill; used 12 hours daily, it adds 7.2 kWh per day and 216 KWh per month.^{[6]
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Question 5

Question 5 of 7:
Do LEDs produce less heat than other grow lights?

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LEDs produce less heat when creating the same amount of light. It’s true that in a watt-to-watt comparison, LEDs produce a similar amount of heat per watt used as a CFL or HID grow light. However, remember that you’re getting more light output “bang for your buck” (in the form of lumens per watt) from an LED.^{[7]
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- Think of it this way: if you’re able to switch out your current 1000W grow light for a 650W LED that produces the same amount of lighting, the heat output will be reduced by around 35%.
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LEDs produce substantially less radiant heat aimed at your plants. This is another major difference between LEDs and other grow lights—they produce primarily convection heat that dissipates into the surrounding air, not radiant heat (in the form of infrared radiation) that is directed in the path of the light. This means you can place an LED much closer to your plants without scorching them!^{[8]
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- The “leaf temperature”—caused by radiant heat—can be at least 30 degrees F (17 degrees C) hotter if you use an HID grow light instead of a comparable LED.
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Question 6

Question 6 of 7:
Will using LEDs affect my heating and cooling costs?

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Yes, you might pay less for cooling and more for heating. If, for example, you’re switching from a 1000W HID grow light to an equivalent 600W LED, both the plants and the surrounding area may be noticeably cooler. This may save on cooling costs if you live in a warm climate, but can also increase your heating costs if you live in a cold climate and depend on your grow lights to help keep your plants warm.^{[9]
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- So, will the energy usage savings of LEDs outweigh the increased heating costs if you live in a cold climate? There are so many variables that it’s impossible to say for sure, but the answer is typically “yes.”

Question 7

Question 7 of 7:
How much LED lighting do I need for my growing area?

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You’ll need around 16W-25W per 1 sq ft (0.093 m²) of growing area. Different plants have different lighting and temperature needs, so there’s no one-size-fits-all answer here. Generally speaking, though, plants that thrive in low-light conditions typically need around 16W of LED lighting per 1 sq ft (0.093 m²) of growing area, while high-light plants require more like 25W for the same area. Confused? Here are a few examples:^{[10]
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- If you’re growing ferns that prefer low light conditions in a growing area of 6 sq ft (0.56 m²), you’ll need about 96W of LED lighting.
- If you’re growing aloe plants that like high light conditions in a 6 sq ft (0.56 m²) growing area, you’ll need roughly 150W of LED lighting.
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