So, if I have an LED bulb that says...

[SaltyNuts]

its estimated annual cost is $1.44 per year. Does that mean $1.44 if its running all the time? Or 12 hours a day? Or what are the assumptions there? And let's say that said bulb is 12 watts. If I have another LED light that is 24 watts, does that mean a good guesstimate of its annual cost (using those same assumptions) is $2.88 per year? I'm looking into bulbs for growing and up-front costs, costs over time, etc.

Thanks everyone!!!

 

[Red Squirrel]

I think it goes by a certain number of hours per day, but I would not even go by those numbers, hydro rates vary all the time and location, and with on peek, mid peek, off peek etc which rate are they basing it on, who knows.

Just take the number of watts, divide it by 1000 to get kw, times it by 24, then 30 to get how many kwh per month it uses if left on 24/7, then times it by your kwh rate on peek. That will be your absolute worse case scenario cost.

If you want to be more accurate then you could break it down for the different rate tiers then add it up.

 

[shortylickens]

I have found with any energy claims the company posting numbers is usually underestimating, to make it look better.
They assume you use the bulb WAY less than average, and they also assume you pay less than average for electricity in your area.

 

[nitsuj3580]

Every LED bulb I've ever purchased has the information they use on the box. For example, "Estimated Cost $1.20 per year" is advertised on the front of the box. On the side it says in the Facts, "based on 3 hrs/day, 11 cents/kWh, cost depends on rates and use"

 

[SaltyNuts]

All that makes perfect sense guys, thanks! So, I think the REAL thing to do to compare how energy efficient various bulbs are would be to plug the light into a watt-o-meter or whatever. See how many watts it pulls. Then compare that to the lumens it puts out, as measured by my phone a uniform distance from the light. Then do the math to get a lumens/watt ratio. The highest one is the most efficient. Everything else, like what the electricity costs, is irrelevant when comparing the two bulbs. That make sense? Thanks!

 

[Micrornd]

Then do the math to get a lumens/watt ratio

All quality LED bulbs come with that info in their ads and/or paperwork.
At least the ones I buy, 'cause that's how I select them.
Do remember though, that the more lumens per watt, generally means more heat output, so those bulbs need more "breathing room" in fixtures for the best lifespan.