LEDs and electricity savings
 

Oh no another LED thread to discuss electricity savings :biggrin:

Actually I just wanted to share some results I recently measured. Not long ago I wondered how much power I was actually saving with LEDs compared to a lighting source such as metal halides. One of primary reasons many of us make the switch is the potential for such savings, among others, but some of us have often wondered if the savings are that substantial when you consider your heater may have to work a little harder to combat those "cooler" LEDs. So I decided to measure the power consumption of each and see exactly what I'm saving. I'm sharing the results more for "food for thought" purposes, everyone will get different results and may make different assumptions than me.

Executive Summary:

• LED power used: 0.84 kWh per day
• Metal Halide Comparison: 6.12 kWh per day
• Heater power saved from Halides: 0.91 kWh per day
• LED power savings: 4.37 kWh per day
• In this case the power saved with LEDs is substantial including the extra power requirement from heaters.

Some system details

• Display tank volume: 270 gallons
• Connected frag tank and sump volume: 70 gallons
• Realistic water volume approximation: 300 gallons.
• Maintained water temperature: 78F
• Lights: 3 x Mitra
• Heaters: 2 x 300W

Insulation and equipment heat addition:

• 15mm glass with only view-able side but has an open top.
• Sumps are acrylic and contained in a humidity controlled room which stays fairly humid and warm meaning heat loss from the sumps will be minor.
• I'll installed all my pumps internal to take advantage of their heat loss.
• I also have fridges under the main tank which vent around the sides and back.

In other words I've taken some steps to add as much heat to the tank from equipment and keep it in as much as possible without doing something that would have negative effects. I mention this because I think it's important when looking at your own tank you consider how heat loss/addition will effect your savings.

Measured Results:

• Lights run for 12 hours, peak at 135W dimming up and down. Power used per day is 0.84 kWh
• I measured the power used by the heaters a few different ways, during the full 12 hours on different days, during the peak light time and 24-7 to get a feel for any changes in usage that occur. I concluded the heaters duty cycle doesn't fluctuate substantially and they use an average of 0.13 kW per hour.

Now for the debatable part, the comparison.

• The mitras run in high output mode, GHL claims it's comparable to 340W of halide, however I would no way compare the 12 hours of ramping up and down to that of a solid state 340W halide. Rather I believe it's comparable to 6 hours of equivalent halide which is 6.12 kWh per day excluding any inefficiencies.
• In my experience when halides are on, heaters are off. I also think another hour is fair for a cooling off period. In other words I'm assuming the halides save me 7 hours of heat which is 0.91 kWh per day.

Conclusion

• LEDs save me money in electricity even with heating cost included. A total savings of 4.37 kWh per day or approximately 70% decrease. However I believe the steps I've taken to with hold heat are a key player for this savings, I've noticed the heaters activate much less frequently from switching to acrylic sumps alone. I also maintain my temp at 78F while many SPS gurus will keep it closer to 80F which could play a role as well. This of course was also a winter reading, results will be different if house temperature climbs during hot summer days. Other peoples results will vary but the substantial difference I measured should conclude in virtually all cases the electricity savings are real.

Hahaha. I knew you opened this thread as soon as I saw the title :P

We are talking about $10-$12 savings over here right? ;)

BTW I am still wondering one thing; why do reefers have such spikes in electricity bill? Like without something like 300gallons+, you will be pretty much within the $100 range (at max) for running a big tank isinit?

Could be people using a variable electricity rate, which I had last year and it changed from $0.06 to $0.14 throughout the year. Otherwise could be those using chillers at certain times of the year or a number of other reasons relating to equipment changes and tank demands but nothing that shouldn't be fairly obvious to the user.

Yes savings for me works out to around $10-$13 per month.

So let say $120-$156 savings per year plus the costs of Bulbs you would replace. Depending on how many T5's you have plus halides.

Yeah probably roughly $150 per year in power savings. If I only ran 3 halides which I somehow managed to run at 340W for 6 hours per day I'd probably only change the bulbs once a year so it depends what you pay for bulbs but I say around $400 per year. Given the cost of the fixtures it's around 8 years pay back. Given the total cost of my LED adventure the pay back period would be substantially longer :lol: So LEDs haven't and won't actually save me money.

Something that I proved in a thread few weeks back ;)

Hint: Just don't tell the dominating factor (eg. wife, girlfriend, not-reef safe person) how much you spent upfront for getting the LEDs and they will be happy with the upfront electricity bill savings ;)

LOL that is because you bought Lights (3 x Mitra) that are in my opinion way over priced, but hey each to there own.

LED industry itself is overpriced :P

TRANSLATION: LEDs can save you money (but it also might not).

Correction: LEDs can save you money (but it also will not)

The point wasn't to compare fixture cost at all, only that LEDs can use substantially less power even with the added heater duty cycle considered. Something a few people have asked me.

PS, I didn't get the Mitras to save money and personally don't think you should buy LEDs for the purpose of saving money cause in all reality you probably won't save anything :wink: But that wasn't the point here.

Yes


No

Then why this line? ;)

I am not planning an LED upgrade any time soon as I am happy with my HQI setup (upcoming summer temps might change that thought), but I truly enjoyed reading your findings and find them very informative.

As a matter of fact, I don't believe anyone else has done a similar mini-study, so THANK YOU for taking the time to perform, document and share with the rest of us.

I presume he meant you will most likely upgrade to LEDs for the purposes of dropping temperature for example.

I said probably which doesn't mean they won't save you money and that's just a personal opinion, far from fact. Quite simply put the potential is certainly there but whether most will be able to take advantage by sticking with the same fixture for long enough is debatable. Again the real point was additional heat isn't a huge factor and if it is it's something that can be minimized.

Yap that's the whole point of LED. Save your reef during the summer and the versatility and aesthetics that LEDs give :)

People tend to upgrade before the break-even point (4 years on average) and hence the "not" unless you use DIY leds or generic chinese $200 LEDs which, I hear, is damn good for the price. :razz:

Maybe that's just your whole point to LED? Mine was solely to reduce evaporation. Nothing more. Sure, they're growing on me, but my point was not your point. And yes, I'll save money as I was changing 3 Radium bulbs every 9 months.

Yes it's a debatable topic, which is why Kiens translation was accurate because it goes both ways (just like Kien) and yours is inaccurate because it only goes one way to state LEDs will not save you many.

Water evaporates to cut down the heat isinit? Like a closed top will evaporate less and rise up the temperature more than a open top. In that case, the heating issue is justified ;)

I like to keep an open mind.

Also, I'll just leave this here..

http://i1002.photobucket.com/albums/...an-o-worms.gif

Ah yah justified :)

BTW how does kien go both ways? Me curious :question:

You'll have to ask him yourself.

do not ask questions you do not want to know the answer to..

How many times have you used that line to run away from productive questions? :twised:

Searching that line gave a result of total 918 threads in canreef. :neutral:

I don't even know what you're saying here.

4.37 kWh per day X 0.0914240 (I just paid my bill, took the highest level for worst case scenario) = $0.40 per day

$0.40 X 30 days (just to average a month out) = $12 per month

$12 X 12 = $144 per year

So if I end up spending $$$$ for 3 Ecotech Radions G2 @ $660 each = $1980, this doesn't inlcuded taxes, figuring out how to put these over my tank using a bar system, etc.

So even if we just take the cost of the lights $2079 including GST... It would take 14.4 years to see the value. Now this isn't taking into the cost of new MH and T5's, but even if I religously replace them every 12 months, with a max cost of $200-300, I don't find LED's worth it. Especially when you hear about them burning out, fans quiting, new software, new lenses, new this and that.

Now in saying this, if you are new to the hobby and need to make an investment on a fixture, then maybe LED is a solution, but for us that have already made investments in what we already have, replacements are not worth it in my opinion.

Plus won't there be something better coming out soon?

Oh I wish Dr. Molson was still available for times like this.. Why pay more for Honey Nut Cheerios when the regular ones serve the same purpose... why why why

Honestly my numbers aren't there to justify how much money you'll save on your tank if you switch to LEDs, the numbers will vary greatly. If you're using them for this purpose then you missed the point completely.

I love my LED's I switched because I was sick of buying new T5 bulbs every year, so if all I save is the $200 a year (bulb replacement) then so be it.

"This change of phase (from a liquid to a gas) requires heat, called "latent heat". When water evaporates, it removes heat, lowering the temperature of whatever the water was in contact with. For both water and land surface, most of this heat energy comes from the surface, not from the air. "

Ref: http://www.weatherquestions.com/What_is_evaporation.htm

OK, I just noticed a huge flaw in my numbers. The 0.84 kWh per day for the mitras is only one fixture. See correction below:

Executive Summary:
LED power used: 2.52 kWh per day
Metal Halide Comparison: 6.12 kWh per day
Heater power saved from Halides: 0.91 kWh per day
LED power savings: 2.69 kWh per day
In this case the power saved with LEDs is still substantial including the extra power requirement from heaters.

Some system details
Display tank volume: 270 gallons
Connected frag tank and sump volume: 70 gallons
Realistic water volume approximation: 300 gallons.
Maintained water temperature: 78F
Lights: 3 x Mitra
Heaters: 2 x 300W

Insulation and equipment heat addition:
15mm glass with only view-able side but has an open top.
Sumps are acrylic and contained in a humidity controlled room which stays fairly humid and warm meaning heat loss from the sumps will be minor.
I'll installed all my pumps internal to take advantage of their heat loss.
I also have fridges under the main tank which vent around the sides and back.
In other words I've taken some steps to add as much heat to the tank from equipment and keep it in as much as possible without doing something that would have negative effects. I mention this because I think it's important when looking at your own tank you consider how heat loss/addition will effect your savings.

Measured Results:
Lights run for 12 hours, peak at 135W dimming up and down. Power used per fixture per day is 0.84 kWh, total for all three fixtures 2.52 kWh per day.
I measured the power used by the heaters a few different ways, during the full 12 hours on different days, during the peak light time and 24-7 to get a feel for any changes in usage that occur. I concluded the heaters duty cycle doesn't fluctuate substantially and they use an average of 0.13 kW per hour.

Now for the debatable part, the comparison.
The mitras run in high output mode, GHL claims it's comparable to 340W of halide, however I would no way compare the 12 hours of ramping up and down to that of a solid state 340W halide. Rather I believe it's comparable to 6 hours of equivalent halide which is 6.12 kWh per day excluding any inefficiencies.
In my experience when halides are on, heaters are off. I also think another hour is fair for a cooling off period. In other words I'm assuming the halides save me 7 hours of heat which is 0.91 kWh per day.

Conclusion
LEDs save me money in electricity even with heating cost included. A total savings of 2.69 kWh per day or approximately 44% decrease. However I believe the steps I've taken to with hold heat are a key player for this savings, I've noticed the heaters activate much less frequently from switching to acrylic sumps alone. I also maintain my temp at 78F while many SPS gurus will keep it closer to 80F which could play a role as well. This of course was also a winter reading, results will be different if house temperature climbs during hot summer days. Other peoples results will vary but the substantial difference I measured should conclude in virtually all cases the electricity savings are real.

LEDs and electricity savings
 

My fish told me they would run away if I took away their Mitras. And take their corals with them!

I have lots of other reasons to use LEDs but the main one for me is the ramping up and down and color choice, so much more realistic than the on / off of other lighting options. I spend tons of time and money trying to duplicate the ocean, the sun is just part of it.

Thanks for the numbers Steve!

I may have missed something (not reading all the led's are great or garbage) but when did Mrhasan turn from the biggest led fan to having to debate how crappy they are in led threads.

-On to the original topic I have noticed the power savings just by looking at my power bills over the last couple years. My bill is down compared to when I ran my 90gal with MH over it vs the 225 I'm running with 2 massive return pumps (albeit dc) a huge increase in skimmer and the 4 mp40's I run now instead of 2 mp10's. I didn't go into full research mode like Steven did (he's way smarter than I am) but looking over my power bills for a similar 6 month period comparing the 2 setups.

Will the savings pay for my 3 Mitras? No bloody way lol (not in my lifetime considering all the money I lost trying all the other fixtures :twised:) That being said I would ever go back to T5 or halides.

There is nothing in this hobby that will save you money outside of shutting down and staring at the blank wall where your tank used to sit.

Even that doesn't work out so well, I'm sure Brett will agree :surprise:

lol only works if you never come back :mrgreen:

Although the build is of my favorite parts......maybe when I move again lol

i just got bitch slapped right through a wall :lol:

Steve ain't holding nuthin back today. Let's go sit in a corner and cry together. :cry: