I am slowly converting our household from CFLs (compact fluorescent lights) to LED lights. The problem today is the same that dogged CFLs two decades ago: price and lumens.
(Our house was one of the first to switch from incandescent light bulbs to CFLs, having done that back in 1991.)
Locally, LED light bulbs start at $8. Those use just 1.5W, but are too dim anything other than mood lighting.
Up the wattage to 3, and the price jumps to $14. Now the bulbs are bright enough for area lighting.
Up the wattage to 8, and the price slides up to $20. Finally, we have bulbs that are as bright as the CFLs and tungsten bulbs they are meant to replace. But 8W isn't all that energy efficient, considering many CFLs we use in our house use just 5W more. That 5W savings just barely pays for the $20 cost of the LED bulb.
(Why is it that only Wal-Mart sells LED bulbs locally?)
I've ordered some 8W LED bulbs through eBay, which were $3 each. It'll be interesting to see their brightness.
It's Lumens that Matter, Not Watts
One problem is that we were taught to evaluate the brightness of light bulbs through Watts, rather than lumens. Watt is the amount of volts and amps the bulb consumes, not its brightness. Lumens is how much light it puts out.
For the bulbs I mentioned above, the lumens scale farily vs price:
- $8 gets you 100 lumens (8 cents a lumen)
- $14 gets you 220 (6 cents a lumen)
- $20 gets you 350 (6 cents a lumem)
It's the Watts that Cost, Not Lumens
Our utility company, however, doesn't charge by the lumen, but by the watt. So, we need to figure out the cost-effectiveness of switching to LED bulbs through watts.
Even at 10c/kWH, saving 5W (24 hrs a day, 365 days) works out to $4.38 a year. It will take 4.5 years for that $20 LED bulb to pay for itself. By then, it may be burned out.
With the high cost of LED bulbs, I am first switching those bulbs that are on a lot, such as at the front door and the two inside the house that are on all night or all day (laundry room/night light), as well as the ones in my office.