An Easy Way To Save Energy (And Money)

Yesterday, we posted on the dis-economy of investing in solar energy for the home, at least for the average urban or suburban homeowner along the east coast. Today, we'll talk about an easy way the average homeowner can make a significant dent in their electricity usage and reduce their monthly utility bill.

(We forgot, yesterday, to tell you the best part about installing a solar photovoltaic system in your home: watching the electric meter go backward! That's right--during periods of peak sunshine and low electric use, such as when the Curmudgeon is at home alone using just the computer and a few lights, the solar array generates more electricity than we are using, feeding the excess back into the power grid for our neighbors to use. When that happens, our meter runs backwards.)

So now, on to the easier way to save electricity and reduce your power bill. Suppose we told you that for an investment of $300-$400 you could reduce your electricity consumption by 10% or more? Sound worth it? Absolutely! And it's true--by making a one-time investment to replace most of the light bulbs in your home with new compact flourescent bulbs (pictured above) you can immediately reduce your carbon footprint on the world and save money on electricity.

Lighting is not the biggest usage of electricity in most homes, but it's not insignificant either, and in an efficient home with oil or gas heating it may account for as much as 15-20 percent of your electricity usage.

Here's the math in our household. This time of year, when it's dark in the mornings as we struggle to get our middle schooler to his busstop on time, we use an average of 20 lights in the bedrooms, kitchen, bathroom and sunroom over the course of about 2 hours. If you assume each light is 75 watts, then we're using 3000 watt/hours, or 3 kilowatt/hours of electricity at the beginning of the day.

Then, during a typical weekday, we don't use much lighting--just the four lights in the Curmudgeon's office for a few hours. Let's say that's 4 lights X 5 hours X 75 watts, for another 3000 watt/hours (3 kilowatt hours). Then, there's nighttime, which begins at 5:00 this time of year. We probably use about 20 lights over another 6 hours, for another 9 kilowatt hours.

So, in a typical day in the late fall and winter, we use about 15 kilowatt/hours per day for lighting. In the summer, we probably use half that. To simplify, we'll say we use 15 kilowatts per day for 6 months and 7.5 per day for the other six months, and we'll subtract out 30 days for being away from home. We'll spare you the math, but after rounding, that's about 3800 kilowatt hours per year on lighting. (Ouch!)

Seems like a lot, so we did some quick checking on the web. In a 1993 government survey, an average single family home used about 950 kwh per year on lighting. Since then, houses have gotten a lot bigger, with more lighting. Our home is probably at least twice the size of the average home in 1993. Also, we have many light switches that operate mutliple lights, so we're probably burning more lights than most people (and we like it bright--the ol' eyes aren't what they used to be). Still, 3800 may be a high estimate. Let's cut it down to 3000 kwh.

If the Curmudgeon's household uses 3000 kwh of electricity annually for lighting, that's roughly 17.5 percent of our total annual use (before our solar array came on line). (Since we have gas heat, hot water and stove, lighting will be a higher percent of our total than in homes that use electricity for those purposes; in the government's 1993 survey, lighting averaged 10% of a typical household's electricity.)

So what happens if you start replacing all those incandescent light bulbs with compact flourescent lights (CFL)? Each CFL uses about 75 percent less electricity than a comparable incandescent light (and almost as much less than a halogen light). If the Curmudgeon replaces every light in the house with CFL's, we will reduce our energy consumption as much as 2250 kwh per year!

If you read our post yesterday on the savings from our $20,000 plus solar array, you'll know that' the savings from using CFL's are almost as great as the amount of energy we're generating from the sun!

What does it cost to replace your light bulbs with CFL's? A lot less than putting solar panels on your roof, that's for sure! The compact fluorescent's cost about five times the price of a comparable incandescent bulb. For example, you can get 75 watt equivalent CFL's from a major internet bulb supplier for $6.20 apiece versus $1.20 for a standard bulb. We estimate that it will take 50 CFL's to replace the most commonly used lights in our home, at a total cost of roughly $300-$350.

The payoff for this investment in reduced electricity costs will be, at most, two years, probably a lot less than that. (If we reduce our usage by 2250 kwh per year, our electric bill should go down by about $200.)

But there is another, longer term cost saving as well. Compact fluorescents last much longer than standard incandescent bulbs--8-10 times as long. So, once you've replace all the bulbs in your home you won't have to purchase new bulbs for years. Over the long run, you'll save money even without factoring in the decreased electricity usage.

There's more good news: today's CFL's come in an assortment of shapes and sizes to fit most different types of lighting, including decorative shapes and various sizes of floodlights. You might not find all the shapes and sizes at your local supermarket, but go to Home Depot or Lowes and you'll find the full range. (Or shop on the internet.)

Don't buy just a few CFL's at a time, thinking "boy, are these expensive lightbulbs." Instead, go out and purchase enough to replace most of your regularly used bulbs and think of it as a single investment in your home--like that new grill or the HDTV, except that is will save you money in the long run.

At this point, the economics of CFL's are so compelling that you're practically supporting terrorism and causing global warming if you DON'T make the switch.

So, what are you waiting for?