For my house, this LED bulb became the star as the house has a lot of small recessed lights in high-traffic areas.
All in all we have replaced 34 50W halogen bulbs (that’s 1700 W spread between the kitchen, stairs, hallway and main bedroom) with 29 of 7W Philips LEDs (to 203 W). Just swapping the kitchen lights and hallway/stairs lights made a measurable difference. In this area of the world, days are short in the wintertime and you need lights on until 9AM and from around 4:30 PM. The halogen bulbs required 8 TIMES more electricity.
I liked these Philips bulbs after trying others because of:
- Temperature: 2700K – a nice, warm color suitable or ambient lighting.
- As bright, or maybe brighter, than a 50W halogen (I’ve done the experiment and folks can’t tell them apart without seeing the actual bulb)
- Only 7W
- The 3-element LEDs actually create a nice shadow pattern against walls, making the light a bit more diffuse
- When installed, they look nice, even if a bit UFO-ish (but I don’t care much)
- They are not too expensive compared to other LEDs in the same factor (I’ve found them between $26 and $22 – I mostly got them at Home Depot)
- I also used the opportunity to remove some bulbs that were making lighting too uniform. Now light follows social function of the space better in the family room.
For my “good” goal of 16 kWh/day, having a kitchen circuit with 10 x 50W for 3 hours was blowing 1500 kWh – that’s just one room in the house eating up 10% of the energy budget!
What’s the Return of Investment?
LED bulbs are not cheap and it’s not where you start with an energy reduction effort, but I saw an immediate difference in the electricity use in the bills. Since these are recessed lights, having kill-a-watt meters is not possible (how long until in-wall switches and outlets report their use via wifi?) so there is a little bit of interpolation going on.
I spent a lot of my ‘efficiency’ budget on these bulbs (once I had improved house thermal insulation, and done other basic improvements). It will take around 10 to 15 years for a recovery on the investment assuming the bulbs live their advertised life and assuming some 3hs of daily use. It would take 23 mega Watt-hours to keep the halogen bulbs on, and they would need many many replacements along the way. With these LEDs it’s buy once and 3200 kWh using the same assumptions. Even though my energy sources are now somewhat renewable, they still have a carbon footprint larger than zero, so using less Watts is still good beyond the money.
Remember our economy of fossil fuels is vastly distorted due to externalizations and subsidies so the money-cost of burning coal or gas is quite irrelevant to calculating the real ROI of the bulb. Of course the cost of the bulb itself is lower than it should be too, because of the equally artificially lowered costs in its manufacture and transport – but the difference between the manufacture of different sorts of bulbs (CFLs, LEDs) is so little when done at scale so that difference evens out if we are doing comparisons between bulbs (comparing these bulbs to light from candles made of beeswax in your own backyard is a very different exercise, but I don’t have that luxury). I haven’t seen a great supply-chain analysis of the material, energetic and human costs involved in making and transporting different bulbs; including data for fossil fuel and rare-earth elements, so a lot of externalizations are hiding there; but the ones that I have seen lead me to believe it ‘makes sense’ to go with the LEDs in the larger scheme of things – their 5x + longevity alone offsets a lesser increase in complexity and reliance on mercury. It is a complex landscape with no map…