LED Wattage Savings

[Nanook]

Hypothetical at this point. I have a tank that is 8ft x 30" x 30" that currently is lit nicely by 4 250 watt metal halides. So, this is 1000 watts total. How much wattage would it cost to light with 3 watt Cree LED's?

Thanks.

[hvacman250]

I would replace each 250W MH with a cluster of 48 Crees, so 192 LEDs in total.

Hypothetically, run them at full wattage, so 192x3=576 Watts.

576 x 8 (hrs per day) x 365 (days per year) = 1,681,920 Watt Hours (1681.92 KWH)

1681.92 x $0.12 per kW (insert your rate here) = $201.83 for LEDs
Running them at 2 W each = $134.55

Same math for 1000 W MHs= $350.40/year

Savings of $148.57 per year, or $12.38 per month @ 3W or $215.85 , or $17.988 per month @ 2W

Also, dont forget to factor in your bulb savings per year since LEDs are projected to last 10 years, and heat savings since LEDs are MUCH cooler than MHs.

[MosMike]

Originally Posted by Nanook

Hypothetical at this point. I have a tank that is 8ft x 30" x 30" that currently is lit nicely by 4 250 watt metal halides.

Do you have the model of the MHs ? And their lumen output?

[GUILLO1]

Originally Posted by hvacman250

I would replace each 250W MH with a cluster of 48 Crees, so 192 LEDs in total.

Hypothetically, run them at full wattage, so 192x3=576 Watts.

576 x 8 (hrs per day) x 365 (days per year) = 1,681,920 Watt Hours (1681.92 KWH)

1681.92 x $0.12 per kW (insert your rate here) = $201.83 for LEDs
Running them at 2 W each = $134.55

Same math for 1000 W MHs= $350.40/year

Savings of $148.57 per year, or $12.38 per month @ 3W or $215.85 , or $17.988 per month @ 2W

Also, dont forget to factor in your bulb savings per year since LEDs are projected to last 10 years, and heat savings since LEDs are MUCH cooler than MHs.

1 Mean Well driver + 12 Cree LEDs = 58w @ full power according to a Kill-a-Watt

[Nanook]

Originally Posted by MosMike

Do you have the model of the MHs ? And their lumen output?

I am using Phoenix 14K 250 watt bulbs on M80 ballast. Not sure on the lumen output.

[nanojg]

Doesnt the M80 push way more than 250/bulb?

[Nanook]

Originally Posted by nanojg

Doesnt the M80 push way more than 250/bulb?

How about 330 watts.

[zero26]

I started a thread on energy savings for my tank. It was to switch from T5's to LED, but you can see where its going

http://www.reefcentral.com/forums/sh....php?t=1961021

[wfournier]

Originally Posted by hvacman250

I would replace each 250W MH with a cluster of 48 Crees, so 192 LEDs in total.

Hypothetically, run them at full wattage, so 192x3=576 Watts.

576 x 8 (hrs per day) x 365 (days per year) = 1,681,920 Watt Hours (1681.92 KWH)

1681.92 x $0.12 per kW (insert your rate here) = $201.83 for LEDs
Running them at 2 W each = $134.55

Same math for 1000 W MHs= $350.40/year

Savings of $148.57 per year, or $12.38 per month @ 3W or $215.85 , or $17.988 per month @ 2W

Also, dont forget to factor in your bulb savings per year since LEDs are projected to last 10 years, and heat savings since LEDs are MUCH cooler than MHs.

Also keep in mind that with 48 LEDs replacing each 250w halide you will have MUCH more light than you did before. Given that your tank is 30" front to back I think you could make this work out to better coverage rather than higher intensity (unless you want more intensity). 48 Leds is really more like a 400w halide than a 250w.

[sfsuphysics]

Question is do you want to have a uniformly lit tank? Or would you like "hot spots". I think the greatest advantage of LEDs (if you go the DIY route) is that you can really place the light where you want, rather than having the constraint of a big honkin reflector that most people place in some symmetrical location from either side of the tank. For instance if you had any high points in your rock work, you wouldn't need as much light in those locations, if you had corals on the bottom of your tank you could definitely pony up some more LEDs in those locations to get the light down there, assuming it's needed, if its simply some open area that's a "swim space" with no corals, really can minimize the light there. The shape of your rockwork more than likely doesn't make the light look uniform as it is, so probably won't be that big of a deal.... of course it is a much larger PITA to do as opposed to a uniform laying out of LEDs on a heatsink.

That said, screw you guys and your 12 cents per kWh... having a tank that large usually puts us into the 45 cents per kWh tier out there

dont forget to factor in your bulb savings per year since LEDs are projected to last 10 years

I don't know how much I'd trust this number, especially in the environments we would be keeping said lights. ON top of that look at how much LED technology has changed in the past 5 years, how many people have kept their same setups?

[hardin4019]

Originally Posted by GUILLO1

1 Mean Well driver + 12 Cree LEDs = 58w @ full power according to a Kill-a-Watt

To Guillo1's point. 15 stings of 12 LEDs each at full power pulling 58W each blasting the tank with probably way more light than it will need in a nice uniform fashion, would pull around 928w. Dim them, then maybe less, better driver maybe less, etc.

Real savings does also come from the LED technologies long life of up to 50k hours. If you run all of your leds 12 hours a day, would in theory last as long as 11 years. Now in practice, one burns out after a few thousand hours, you replace it for $6, and your tank stays lit till a different technology comes out that catches your eye more and seems like it would be cheaper. You have to consider what your 4 halide bulbs cost you and how often you replace them. Thats where a huge hunk of your savings comes in. Its like buying solar panels, you won't save much, but in a few years they have paid for themselves in savings you didn't pay the power company for your daytime use.