Energy Efficient Home Ideas

This eBook is a good basic treatment of energy saving tips, from selecting the right appliance, maintaining your heating and cooling systems, to checking windows for energy-wasting drafts.

I do want to add a few comments, however, regarding some items talked about in the book. If you have a fairly new hot water tank, it could be insulated well enough that you don't need to add any more insulation to it. An easy way to tell if it's insulated well enough is to feel the outside of it with your hand. If it feels warm to the touch then it does need more insulation, but if it feels cold or at least near room-temperature then insulating it further probably won't save you much. Also, if you have a lot of demand in your home for hot water, such as a large family, or your tank is small, turning down the temperature of your hot water tank can cause you to run out of hot water at times. Keep this in mind if you adjust your tanks' temperature, and make small adjustments to see if it causes such side-effects.

Another suggestion in the book was to unplug various appliances that have lit LED displays while they are off. It is typical for TVs, stereos and such that are remote controlled to use some power even while in the 'off' mode. However, the amount of power these consume in this mode, including to power the displays, is small enough I don't think unplugging them when they're not in use is worth the trouble. Here are some calculations about this. A 100 watt light, if left on for an hour, consumes 100 watt/hours of energy. If you look at your electricity bill it should tell you how much you pay for your electricity and you can calculate how much it costs to have the light on for an hour. My bill shows I pay a little more than 10 cents per kilowatt/hour; I will use 10 cents for simplicity in my example calculations. Replace that number with whatever your bill says you pay in order to determine your actual costs. 100 watts is .1 kilowatt, or one tenth of 1000 watts. Therefore it costs me one cent to power a 100 watt light for one hour: .1kilowatt for one hour times 10 cents equals 1 cent.

If you leave that 100 watt light on continuously for 24 hours it costs you 1 cent times 24 hours, or 24 cents. To leave it on continuously for one year costs 24 cents times 365 days, or $87.60. It does add up to a noticeable number over a whole year, but leaving it on for a few minutes more here and there will make a very small difference to your bill. Still, if you're not using the light in a room, it doesn't seem to make sense to leave it on unless it's inconvenient to turn it off and on, and you're coming back to the room soon. This is why I started talking about electronic appliances. They perhaps consume 5 watts in their off mode, and it's quite inconvenient to unplug and plug them in, so the only time it makes sense energy-wise vs. convenience to unplug them is when the house is going to be unoccupied for a period of time, for example while you've gone on vacation.

Another consideration is the amount of power it takes to turn on the light. A regular incandescent light bulb does use more energy for an instant than it does when it's fully lit, but it is so brief that it doesn't make an appreciable difference to your energy use. This means you may as well, if the light switch for it is conveniently close to the door as it should be, turn off the light as you exit the room and turn it back on again as you come back into the room, even if you're only leaving for a couple of minutes. Flourescent bulbs, however, and this includes compact flourescent bulbs, take a few seconds to a few minutes to reach full brightness. While they are starting up they use much more energy. The rule of thumb on these is if you're coming back to a room within five minutes you may as well leave the CF or flourescent light on, since you likely won't save any money by turning it off for that amount of time.

The book also recommends replacing regular incandescent bulbs with CF bulbs, and this is indeed common practice these days. I have several in my house as well, however I have found the common claim of using 1/3 to 1/4 the power for the same amount of light as incandescents to be overly optimistic. I find it's closer to 1/2 the power. I suspect the reason why they claim the better numbers is they expect people to put up with less light. Now, if a regular incandescent bulb costs you 50 cents, and a CF of half the power costs you $15, but lasts 10 years while the incandescent only lasts six months, that means your replacement cost for incandescents is $10 vs. $15 for the CF. I think a six-month lifespan is a little on the low side, so it's even more of a cost savings than I have stated here to buy incandescent bulbs. However, if your CF uses half the power, let's say 50 watts instead of 100 watts, and you have the light on for five hours per day, then you're using 500 watt/hours per day for the incandescent, which is 5 cents per day or $18.25 per year. The CF would cost you half that, or slightly more than $9 per year. You can see that there is a real savings in using CF bulbs in areas where you leave a light on for a few hours per day. It is also a good idea, for convenience' sake, to use CF bulbs in light fixtures where it is difficult to replace the bulbs. I don't agree, however, that it makes sense to replace every single bulb no matter what the usage with CF bulbs. It makes a difference on how long they will run each time they are turned on. CF bulbs also do not last as long if they are turned on and off a lot.

CF bulbs also cannot have a dimmer on them, so you cannot set the light level lower, for example, over the dining room table. A dimmer, if used properly, also happens to make your incandescent bulbs last far longer than otherwise as well. I recommend you make it a habit to never have your dimmer turned to maximum. Always leave the light slightly lower than full brightness. We have a few rooms in our house with dimmers, and I am not exaggerating to say it has been literally about 10 years since I changed the incandescent bulbs in them, and all of them are used every day, a couple lights for a minimum of 3 or 4 hours each day. Depending on what setting you use on the dimmer such as half-brightness, you could literally, and I'm not kidding here, have the incandescent bulbs last forever. I set the lights in our two main bathrooms, which are used only intermittently, so they are permanently on half-brightness in 1993. It is now 2011, nearly 20 years later, and I still haven't had to change those light bulbs, and I don't expect to ever have to change them.