Dim-Witted Lighting? Well, Cut Its Energy Waste

Hey Mr. Green,

In the living room of our new house, light is provided by 10 recessed halogen bulbs in the ceiling, each using 35 watts. The light is fine, but the energy in the house is provided by solar panels and a propane-fired generator. The generator comes on too often, and the solar man says it is because of the halogen lights use too much energy. He had recommended that the architect not use the halogen system. The architect said the problem comes from some place else. Some people told us that it may not be the bulb itself, but the transformer attached the bulbs that is using too much energy. What is your opinion? --Claudine

The solar guy is right, the architect is wrong. The main problem is not with the system itself, but with the wiring in this designer’s brain. With people like him on the loose, it’s no wonder that lighting consumes around 10 percent of our home electrical power.

Those ten 35-watt bulbs need 350 watts to operate, and that’s a lot of power, and a lot more light than most people really need to navigate their living room. But if simply you must have that much light you could get the same amount from fluorescent bulbs that use less than a third as much power. (If the halogens are hooked to a transformer, it would only lose around 10 percent of the original electricity, requiring a total of around 390 watts—so it’s doubtful that the transform is the culprit.)

Even if you have batteries hooked to your solar system to store electricity for use at night when the sun isn’t smiling on your solar panels, this extravagant lighting system could indeed run them down and make the generator kick in, especially if they’re already drained by other uses or on cloudy days when they might not be fully recharged.

I recommend simply boycotting these wasteful lights, and converting to "task lighting," using small lamp or two for reading or whatever activity requires light. (As I write this, there are four people in our house, with tasking that ranges from reading the immortal Dante to frying a brain on video games, and we’re using only about 75 watts total for lighting.)

Finally, another option is to see if you can find any state-of-the art LED lamps that would give you a satisfactory quality of living-room light. Although LEDs are still quite pricey, they are considerably more efficient than halogens.

 

 

Comments

[Compliance Officer]

Try incandescent lights or LED lights. Incandescents are really cheap now.

[White Led Bulb]

yeah, using small lamp or two for reading or whatever activity requires light.

[Chris Jones]

LED lighting would be ideal for Claudine's house, but for more reasons than their higher efficiency. To run them on high voltage alternating current (like what's in the electric grid), the power has to be converted. In a new build with solar power, use LED fittings designed for low voltage DC instead of those that are designed to retrofit into older housing. Skip the energy loss from power conversion. Since that allows the LEDs to run cooler, it also extends their working lives.

My blog explains this and more about the state of the art in artificial lighting in easy to understand terms. The big holdbacks for LEDs have been cost, lack of intensity and poor quality of white light. The first two are rapidly improving. In a UK lab I have seen the solution to both intensity and light quality (very exciting!), but it isn't commercially available yet. When it becomes available I'll shout about it on my blog.

[security]

Familiarize yourself even with the terms that they use.