Five Percent: Conserve Energy

Climate Change Is Important: Energy Conservation is the First Step

September 19, 2008

Save Electricity — Our 45% Reduction Saves $1,250/year (Updated)

Category: Household,Save Electricity,Tips – Tom Harrison – 12:46 pm

If you want to save electricity and reduce your electricity bill, follow a few simple tips, make a few inexpensive changes, and you could cut your electrical usage by 40% or more, as my family has. It’s not hard, and it’s worth it!

We will save about $1,250 per year on electricity than if we had not made these changes (assuming the next three months usage are the same as last year’s). That’s the good news.

The bad news? You have probably noticed your electricity rates rising. At the end of 2005, our total cost of electricity was 14.9 cents per kilowatt-hour (kWh). We’re now paying 20.7 cents. Over about four years, our electricity rates have increased about 40%.

Click To Enlarge

Click To Enlarge

In June, I made the same calculations and showed we saved 40%, and we have continued to improve since then, now running at 46% less. I have been tracking our electricity bill in a spreadsheet, and came up with a nice graph, which I have updated through September (click the graph to see a more readable version). Estimates for the rest of the year assume the same usage as in 2007 … maybe we’ll do a little better this year.

Check the previous post to see a broader list of ways to save electricity that have worked for us. Since then, we have:

And as I reported last week, I think I can save more by replacing a computer file server with an Apple Time Machine. And I just ordered another 2 Smart-Strip power strips for my wife’s computer, and for our TV/Stereo system. Yes, some of these things cost money, but it’s only through making small changes, a few every so often, that we now pay about $100 a month less for our electricity. And none of them affect our lives negatively, in fact most make life simpler!

Being successful at saving electricity is all about awareness, and persistence at making little changes. Electricity is cool because it’s comparatively easy to measure. It’s possible to measure the effect of changes in heating costs, gasoline, water, but more difficult to quantify. And there are many other less obvious sources of energy or resource consumption, such as what we eat. More on this in another post :-)

Until then, turn out the light when you leave the room. Good luck!


  1. Tom, I notice spikes each year with smaller spikes between the larger ones. I assume the highest spikes are due to air conditioning in the summer and the smaller ones are for heat in the winter. Is this correct? There seems to be a pattern in annual usage.

    Comment by Paul Lambert — September 19, 2008 @ 3:47 pm

  2. Paul —

    The annual pattern is more evident in the first graph of this I did in June, which I also annotated a little.

    This year we needed very little air conditioning, and there’s no doubt the AC chews up those kWh. The dryer is big. Obviously electric heat is big; we have a finished basement which we use occasionally that has electric heat, but I think the biggest winter factor is that there are fewer hours of light so more lights, TV, computer, etc. are on than in summer.

    As per your example (yesterday) of the cat turning on something you thought was off, little things can make a difference. We found that the dryer used a lot less electricity overall when it was on high-heat mode, than on low. This was a case where the PowerCost meter helped us learn what was up and take a simple action to correct it.


    Comment by Tom Harrison — September 19, 2008 @ 4:22 pm

  3. Don’t forget to turn off all outdoor lighting too. This will reduce your electric bill and also reduce the amount of unnecessary Light At Night (LAN).
    In addition, encourage your local government to reduce outdoor lighting. Because whether the municipality pays the electric bill or the electric utility has a municipal rate, you, the end consumer, still pay for LAN.

    Comment by Debra Norvil — September 19, 2008 @ 7:58 pm

  4. Debra —

    Your comment about outdoor lighting represents two important points.

    First, the outdoor lighting we control — personally we’re plagued by two neighbors who have outdoor floodlights that they often forget to turn off. They shine all night long, 100W x 2 floodlights, in one case two of them, glaring in our eyes (it sometimes feels like we’re in a prison). We have installed a simple motion/heat detector fixture instead (with a single CFL floodlight) — it turns itself on and off as needed, and is very accurate.

    According to studies, motion detector lights outside are far more effective at deterring criminals (they are unexpected, and the change causes people to notice). And no study is needed to determine that there’s not a problem with you forgetting to turn them off. In fact, we have installed inside motion detector switches in our basement (although they are not as accurate as the outdoor ones), they are completely automatics lights. Perhaps if this technology were improved we would not need to turn on and off lights at all!

    Your second point, regarding outdoor municipal lighting, is a whole different topic. We live in a suburb of Boston, where most streets have one or two lights on whenever it is dark, and of course intersections and high-traffic areas, parking lots and … well everything else is lit up bright as day. We have one of these streetlights outside our bedroom window (and, ironically, about 50 feet from the floodlight that our neighbor frequently forgets to turn off). The light seems pointless to me — we live on a quiet street in a safe city. Yet lights are burning every night, everywhere.

    Sure, they have replaced many (but not all, by any means) of the lights with more efficient types (some of which are even directed LED lights, which can reduce some aspects of light pollution). But if you don’t really need the light (and this is the thing people have to come to grips with), there’s nothing more cost-effective than not spending any money at all!

    The calculus of where to place outdoor lighting seems similar to the disappointing “I need a big vehicle because I have kids” argument some use to justify SUVs and minivans. The problem is, some cases make sense (public lighting, vehicles), others are just silly, but it’s hard to differentiate. I guarantee that nothing bad would happen if the light outside my bedroom window were removed completely.

    In fact, perhaps this is what I’ll try to accomplish next time I have a free day: get them to take down the damnable light. It will be interesting (if perhaps not particularly fruitful) to see how our city government reacts to my suggestion.

    Comment by Tom Harrison — September 19, 2008 @ 10:05 pm

  5. There are other consequences with LAN besides money. Tom, you mention that your neighbors have flood lights and that there is a street light that infiltrates your bedroom windows. The light from these sources is enough to distrupt you circadian rhythm and reduce your melatonin levels while you sleep. If the street light is metal halide, this gives off a strong blue/green wavelength which is particularly harmful to your health and that of the environment.

    The same is probably true with the LED street lights that have been installed. The most efficient LEDs are in the 6000 K range and give off a cool blue white light with a spectrum in the 420 to 470 nm range. It would be better if the LEDs were in the warm white range with a color corrected temperature of about 2800 – 3000 K. The color is similar to incandescent and has a longer wavelength spectrum with more orange/yellow. You lose some efficiency with the lower Kelvin temperature but the efficiency is still much better than metal halide. In addition, LEDs have an electronic ballast which means that they have the ability to dim to 50% of their lumen output at a preset time – say from midnight to 5 am. This dimming capability saves more money and extends the efficiency of the LED by reducing the heat generated in the LED assembly.

    In my opinion, we must begin to move away from the notion of creating a 24 hour day. The environment is already suffering from the stress of LAN and we will be next to feel its effects.

    Comment by Debra Norvil — September 19, 2008 @ 11:17 pm

  6. 40% is feasible I agree. What do you think of programmable thermostats? I found another site with more tips Also, what can we do to get help after we use methods to save? Any other tips or info on gov’t programs? Thanks

    Comment by John — September 29, 2008 @ 9:32 pm

  7. John —

    The programmable thermostat is a great step. They are inexpensive, simple to install and give you fine-grained control over house heating and cooling.

    This is especially true if your house, like ours, has a single heating zone. We have our thermostat programmed to come on at 5am, heating the house to 69 degrees, then turning down to 55 degrees at 7am — that jolt is enough to give up a warm bathroom and kitchen; the house stays warm enough for hours afterward. Then it kicks on again at 5pm and runs until 8pm at 69 degrees, turning down to 50 at night. The house rarely reaches these low temperatures because we have done a lot to insulate and make it tight. If it does get too chilly, we can just override to whatever temperature we like. Ours allows a different schedule for weekends.

    When we moved into our house in 1997, we had a cold winter and the boiler couldn’t keep up with colder days — it ran pretty much continuously. After a good deal of upgrading (including: new boiler, insulating and new windows) it’s only on really cold winter days that the boiler will run for anywhere near close to the 5 hours (in fact, it was set up to circulate water once it got hot, so probably a lot more like a couple hours a day). This cost a lot: insulating was several thousand dollars, new windows was in the 10’s of thousands, the boiler was thousands. We’re saving at least $1500 per year on fuel (at least, probably more), and our house is more comfortable and more valuable as a result.

    It all adds up.

    Comment by Tom Harrison — September 30, 2008 @ 9:47 am

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