How much do your LEDS use in electricity


Hi All

Just had a shocking electric bill - trying to narrow things down

I’m running two of these

18hrs per day, our kilowatt measuring device is saying approx $49-50 per month, and yet, our electric bill for last month increased by $350 from last year!

Trying to figure out if it’s my Grow stuff or other …

What do people generally spend for 300W LEDS!?

Thank you!


Mine did the same running 2 Viparspecta 900’s.


Mine also did the same thing running three 300 W LEDs and a 600w all meizhi leds


Omg ready for a laugh? Hubby forgot to pay last month’s bill ! Phew!
Our energy meter is recording correctly - 2 300W LEDS, 1 24 x48 plant heating mat, one 6" oscillating fan, one small T5, and one inline fan w controller and carbon filter = $49.75 a month.


I was gonna say that sounds a little weird and then you figured it out… lol
I run 700 watts of t5 ho lighting and two 1160 air pumps at 70 watts each and 2 oscillating fans at 40 watts a peace in veg and 1800 watts of HPS and three 1160 air pumps at 70 watts each and four oscillating fans at 40 watts each and an 8 inch extraction fan at around 100 watts with speed controller and a radio in flower…I forgot to mention the 12000 btu window ac that runs about 10 hours a day depending on time of year also…
And when everything is running it usually only ads 150 to 250 depending on what time of year it is.... But if you can get a donation of 200 an Oz , it’s not really a big deal… :wink:
Glad you figured out the problem… :wink:

:v: :sunglasses:


My bill went up somewhere around $15/month.


Mine is around 15 bucks more a month as well


Running a 600w HID fixture and 2-300w MarsHydro LEDs (130 actual watts each)
puts me at $50 extra each month



LEDs have the potential to be more efficient than HID if they put out light blue and orange-red: Specific bands the plants can use. HID lamps put out a wide range of light and all the green and yellow light is wasted. Dollars to the electric company down the toilet!


Led’s are more electrically efficient than hid even when put together poorly and driven beyond their test currents.

As far as photosynthetic efficiency, we had a pretty good discussion about that just the other day. Do you have any examples of blue/red led’s outperforming white leds?


No. I’m just looking at the absorption spectrum for plants versus wavelength. I know LEDs are about as efficient as CFL for making white light. HID is a bit better. But for making grow lights, LEDs don’t bother with green or yellow. They just make the wavelengths plants can use, which is why many photos look weird.


I’ve made several led lights, and I disagree. I also disagree the cfl or hid is equal or more efficient. I have Samsung white diodes on my bench that are 200 lumens/watt. When configured properly they’re capable of 3 ųmols per joule. Even when driven harder they’re well over 2. So I’m not sure where your info comes from?

Targeting the wavelengths that are most easily absorbed by plants is great, but it doesn’t tell the whole story. There’s hundreds if not thousands of documented grows of white led’s pulling 1.5+ gpw.


Actually, I said that CFL is the same as LEDs and HID is more efficient at making white light. You can find that information all over the internet. I know a lot about it because I needed a light source for my DIY LCD projector. But white LEDs don’t really make broad spectrum white (all colors) light like HID or CFL. White LEDs either make red, green, and blue light in separate semiconductors or they make blue light and use a yellow phosphor to look like white to the human eye. Either approach wastes energy making either green light or yellow light the plants don’t need. In fact because of human eye response, they use most of their energy to make green or yellow light. Photosynthesis does not use that, which is why leaves are green!

I’m looking at a Samsung datasheet at the produced spectrum and it has a huge bulge in the yellow portion. Try matching that against the absorption spectrum of chlorophyll.

citation: “Luminous efficacy” entry on Wikipedia


To the topic on hand: bought a kill-a-watt and plugged it in. All up I’m pulling 1,340 watts of overhead illumination with led’s in a 4 X 6 X 6 grow box.


Just keep an open mind, @1BigFella,

It’s been once believe so, however, I kindly and strongly suggest that you read this resume from Nasa that you will found in this link before make claims that goes against recent research…

Friendly your’s,

~Al :v: :innocent:

@dbrn32 :wink:


I did read it. It pretty much agrees with me: White LEDs are inefficient because they waste a lot of blue light to drive the yellow phosphor that plants can’t use. It does make the point that turning on some green makes it easier for humans to see problems. but what percent of the time are you actually looking at your plants? Just turn on an incandescent or fluorescent lamp if you want to inspect them. Or it might make sense to put red, green, and blue LEDs in your array and only switch on the greens when you want to inspect the plants. But then you are paying for a bunch of high power green LEDs you only use <1% of the time.

It does say that green light is better at penetrating the canopy, but that’s probably because it bounces off leaves better. Besides, we cannabis growers thin or deplete the leaves below the canopy anyway.

One thing of interest is that it says the percentage of red versus blue you want varies with the plant and what it’s doing. You might want an array that can drive the two colors independently so you can vary the mix between veg and bloom.


I agree on several levels. You are correct that white led’s use a phosphor coating. Just because it has phosphor doesn’t mean it’s not a white light source. And pretty much all of the color temps produce some amount of light in all wavelengths from 400-700nm. Which does indeed make them full spectrum. I wouldn’t question a plants ability to absorb blue and red better than other colors either. Yet to argue that a white led can’t produce both seems silly. They produce plenty of blue and red wavelengths, in addition to the yellow and green. On top of that, they do it at higher intensity typically with a lower cost.

I have looked all over the Internet for other lighting that’s more efficient than led. Here’s what I found… a de gativa is like 1.9 ųmol/joule max. A Cree cxb 3590 even at 2.1 amps is still over 2 ųmol/joule. And the cxb is nowhere near as efficient as the Samsung top bins. Those two are just the easiest to compare due to the quantity of each in use for horticulture purposes.

The Samsung like every other “white led” does produce a lot of yellow and green. And yet they still yield more weed than blue/red alone, and absolutely crush hid yeilds. And cfl yeilds aren’t even worth throwing into that conversation.

It doesn’t matter if you look at lumens per watt, or ųmols per joule, it doesn’t even take the latest and greatest led to crush them all in efficacy. So I’m not even sure where “all over the Internet” you would find such data? You don’t have to agree with me. @Niala’s report says way more than green light helps you see plants. Perhaps look at some grow journals. Hid growers are still chasing a gram per watt. You can screw up an led grow and hit that.

Unless of course you have examples of grows using cfl, hid, or blue and red diodes alone yielding 1.5 grams per watt plus? If you can show me, I’ll believe it. Otherwise I have access to 5 different grows that have converted to led and I’ve yet to see anything of the sort. In my opinion, with the current technology, the best use of the colored diodes is to supplement white. Using them alone it becomes to expensive to match the par levels. And even then, they still don’t seem to yeild as much.


Okay, I’m convinced. Real world wins over theory. I went out to Digikey and looked at their LED selection and they have almost no LEDs that match the chlorophyll peaks. And LEDs are almost all fairly monochromatic. You are seeing broad spectrum light because of the phosphor, not the LED. So anybody using pure LEDs (at least from Digikey) is missing the peaks anyway. I was looking at lumens per watt, not PAR which is more appropriate for plants where chlorophyll is linked to a bunch of proteins that make the absorption spectrum much wider (and greener).

I’m just doing my research to see if I should switch from HPS to LED and it looks like I don’t want red/blue LED arrays. Aside from building my own arrays, can you recommend any commercial products? I can build arrays and switching power supplies to drive them, but it’s usually cheaper to just buy the light.


When you get into the higher end or “on the cutting edge” you’ll be cheaper to build for sure. Whether it’s cheap enough to justify is up to you.

What’s your grow area, and what are you looking to get out of it? @1BigFella


I’m medical in Southern California, so I should keep with the six flowering plants limit. So I was going to veg inside under lights and bloom outside, 6 at a time during the winter. In summer, I need to flower inside under lights to limit the photoperiod or just go to autoflowering. About 4 feet by 9 feet.