Good questions BudBuddy. If you read my whole journal you'll see I'm always saying "this isn't a fair comparison."

The real numbers for me, however, are price vs output. The way I look at it, I pit a top of the line LED against a top of the line, but much less expensive HID. The HID outperformed the LED within the same footprint, for less money.

I never said it was good science, but this test showed me exactly what I needed to know regarding the cost efficiency of LED lighting today.

Hope that helps.

P.S. I don't think that cooling is that different between HID and LED. The SS400w uses about 310w, and it kicked out about as much heat as my 400w HID lamps. So, if 1w of consumption puts out the same amount of heat regardless of the type of light you're using, and HID lamps produce more cannabis per watt, you actually need less cooling to produce the same amount of mmj with an HID than you'd need with an LED.

Don't let the marketing fool you. LEDs are cool tech, but they actually aren't as efficient as HID (HPS and MH) and they're way more expensive. Watt for watt, dollar for dollar, HID is still the clear winner IMO.

Budbuddy:
You are 100% correct that the SS400 obviously uses less electricity than 1000w HPS (315w < 1000w) but that's actually a small factor compared to the amount gained with the better light. As beefxer explained there are many reasons that wasn't a fair comparison, including the wasted space under the HPS. He was mainly testing...
1) The ability to flower and
2) A penetration and intensity comparison of 1 plant vs 1 plant at equal w/sqft strengths.

Unfortunately, he uses a #/jars measurement rather than grams (or g/w) but the quality/size of the flowers clearly shows how much better a 1000w HPS is even with the LED at the same watts per square foot. He could have fit many more plants under the 1000w HPS which more than makes up for the cost of the electricity. I've done the cost/benefit analysis for 1-2kw HID vs LED and even factoring in the cost of bulbs 1000w HPS is still more cost effective over the life of the lights due to the high initial cost of LED and the much better yield with HPS.

Let's say that the cost of running a 1000w HPS for 12 hours per day while flowering is about 100-150 USD per month (lets use 100 for this example since it's a nice round number) and the SS400w use 315-ish watts of just LED which is about 70% less electricity or about 30 USD per month. While that sounds like a lot (200 vs 60 for 2 months of flowering) that 140 dollars is less than 1/2 ounce of yield and the HPS should yield about 70% more than the LED. At 1g/w (which the HPS has exceeded and the LED still has not) that's 330 grams vs 1000 grams or 11.4 ounces vs 34.4 ounces. That's 23 more ounces for 140 dollars more in electricity for the lights alone. Since the SS does have those powerful 5w diodes you still need fans or AC (although slightly less) to deal with the heat but again, 23 ounces EXTRA every 2 months pays for a lot of fans or AC cost.

LED may be king in the future but not the present...based on results.

I'll have accurate yield weights in the next week so we can do the g/w and g/w/m numbers.

Another thing to remember is that the 5w diodes that CLW uses in their lights have the same power/penetration whether they are mounted in a small fixture, or a large one. So, testing it along side one of the more powerful HID options isn't that ridiculous.

Also, since only 1/4 of the footprint was used, it's not really accurate to say that the HPS plant received 10A of power throughout the grow. Sure, it did get a spot directly under the bulb for a few weeks when other plants were harvested, but most of the time it was in one of the 4 corners so I think it's fair to say that it got about 3A worth of light average.

I'm glad I tested it out for myself. Now who wants to buy this light.

If you got it for 1/2 retail, for the GFP, you could still keep it and use for supplemental flower/veg/clones/mother keeping/etc but that is up to you...

The final numbers are in!


HPS: 7.38oz (209.22g), ?g/w, g/kwh: ???

LED: 4.27oz (121g), .39g/w, g/kwh:

310w / 1000 = .31kw

.31kw * 12hrs = 3.72kwh per day

3.72kwh * 56days = 208.32kwh total

121g / 208.32kwh = .58 grams per kilowatt hour.

Yeah, I wouldn't even bother with the g/w for the HPS, this time, since it was a one plant test. We know what HPS is capable of anyway. However, we also know that the SS800 is capable of nearly 1g/w (so far) so hopefully we can get your LED numbers up a bit next time. How's the smoke test working for you?

Any plans for the next one?

Yeah g/w is a bit of an arbitrary metric anyway. I prefer g/w/m or g/kwh.

I'd give the LED another run, but it's already packed away to make room for more HIDs.

That's an interesting use of shelving for screens, how many watts are you running now, 2kw? Does that mean you'll be doing a HID journal in the Grow Journals section?

Yeah that's my solution to my footprint coverage problem. I'm up to 3kw now, and the screens let me cover every inch (once I get my vegging time adjusted) of the 11x4 area. The expectation based on the size of the plants this system is growing is an increase in yield by at least 1/4. We'll see what the numbers look like in a few weeks here.

CO2 and a fancy environment controller are my next additions. Unfortunately I'm going to need a mini split or a full size split AC system if I want to go for a sealed room. That means I need to get my electrician out here first.

I wish there was a way to make these journals private. I want to keep posting for a select few, but I don't really want my ass hanging out to the whole world. y'know?