Retrofiting To L.E.D's
Dec 10, 2015
Changing out my CF-L's to LED's
I was shopping at Sam's Club a while back when I ran across a LED shop light for $35. I was intrigued because it was the first time I had become aware that LED tubes were being offered as a replacement for T-8 fluorescent lamps. I had a garage T-8 two tube electronically ballasted fluorescent light fixture that was not working, so I bought it. The fixture was a Lights of America brand which I normally would never buy, but I figured how could they screw up a LED light they probably got from another supplier. It was rated at 40 watts producing 4,200 lumens. That would have made it the most energy efficient lamp at my house at 105 lumens per watt.
I liked the fixture after installing it. It got me into looking around online and I was amazed at the number of T-8 LED replacement lamps on the market. There are varieties covering all the color temperature points, 2,700 K, 3,000 K, 3,500 K, 4,000 K, 5,000 K and up. The CRI's or color rendering indexes run from the 70's and up to the 80's. In other words it is a fully developed market.
There turns out to be two types, one type that works with existing ballast, and another type that allows you to wire around your ballast and wire it directly. The second type requires non shunted tombstones though. We have a total of six two tube troffers in our house that employ t-8 lamps and low power electronic ballast that operate at 54 watts. So I decided we going to retrofit although we were operating at 74 lumens per watt already. The switch would get us to 36 watts for 4,000 lumens or 111 lumens per watt, saving us 18 watts per fixture for the same light.
First things first however, that was some kind of mathematical analysis of the pays backs and options to replace all the CFL's in our house. When we built our house in 1997 it filled it with what was then the state of the art energy efficient lighting. The margins were going to slim on just how much energy and money I could save replacing what was already energy efficient lighting.
It turned out the pay back on the T-8 retrofits wasn't bad, coming in around 7 years, or 16% based upon the price point of the retrofit. Turns out the LED bulb market has matured in the mean time also. I could get LED light bulbs for as little as $3.00 to $5.00 a bulb if I shopped and bought in bulk where I could. For example I ran across a six pack of A-9 (60 watt equivalent 800 lumen bulbs) for $16.67 which meant I was only paying $2.77 a bulb. These were going to replace 13 watt CFL bulbs using only 8.5 watts for a 4.5 watt savings. This would take over 5,129 hours to pay for the bulb price or 4 & 1/2 years at 3 hours of operation a day (3 hours a day is a industry standard).
What persuaded me to plunge into the retrofit was two pertinent points. One was that I could reduce my electrical consumption and potentially reduce my carbon emissions. Secondly, since we have a 5.1 KW photo voltaic grid tie panel array we could potentially get more money back from the utility for our exported power. Essentially we would be buying more solar capacity.
How much depends upon how you price it. We did not spend our Solar Tax Rebate on paying down the loan (spent it on Central AC instead) so our panel array cost us $4.90 a watt. So far we have spent $125 on LED's (are not done yet) and displaced about 150 watts worth of load. This is worth $735 in solar panel terms.
I have more sockets to retrofit, but they are either my lowest wattage fixtures or my least used fixtures. I have all six of the T-8 troffers to retrofit which will cost us about $26 a fixture for a 18 watt reduction per fixture. This will get us to a electrical savings worth one 255 watt panel. One 255 watt panel cost us $1,250 to install, it will cost us about $300 to retrofit the whole house with LED's.
One final note here and that is LED lighting technology is just much better lighting. It is instant on, quiet, brighter, and suffers far less lumens depreciation over time. It uses around 35% less energy to produce the same light output as a CFL.
If you have not looked into LED lighting for your home, you should. If you already have CFL's you may have to wait a while for them to blow out, I would not wait, but that is just me. If you have incandescent lights, it is a no brainer, do it right away for a 85% reduction in energy use. The light quality is as good as incandescent lamps if you stick to 2,700 K or 3,000 K lamps.
That is my nibbling around edges reducing my carbon footprint. We have been using a new pellet stove this heating season instead of our central propane fired furnace. Propane runs just over $3.00 a Therm for heating value and our wood pellets are costing us $1.75 a Therm. We use around 16.38 million BTU's a heating season. That works out to a reduction of 1.14 tons of carbon a year. The pellets are carbon neutral at around 8,000 BTU's per pound. That, and this gives us the capability of having a power outage proof heating source, which is a real consideration.
In the near future we will be working on putting together a power center for back up electricity for power outages. One important end use for this is our pellet stove, as well as our entertainment center, and a refrigerator. I have yet to calculate just how much electricity our pellet stove can save us over the central furnace. I think the furnace blower motor is 300 watts. I need to find out what the wattage of the blower is for the pellet stove is, but I think it is only around 100 watts.
Since we have reduced our carbon foot print to less then 50% of what it was before 2012, I think we are doing good. The only other significant opportunity for us to reduce it further is buying an electric car. We could probably get our carbon footprint down by at least 80% if we get one. Every watt freed up through efficiency in the house could potentially go to charging the vehicle. We figure then we could reduce our gasoline mileage to 5,000 miles a year or less. This would reduce out carbon foot print to 3.6 tons a year. The national average is 17.5 tons of carbon output per year. Hey, it would be way ahead of nothing.
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