Ouch, that electric bill is gonna hurt this month! With temperatures soaring across the United States, power consumption has been soaring right along with it. Of course you’ve already turned up your thermostat and screwed in the CFLs, so here are some slightly different tips to trim the power bill.
- Get your hands wet. Wash your dishes by hand once or twice a week instead of using your dishwasher. (The dishwasher manufacturers will have you believe that this wastes water; that’s only true if you crazily run the water the whole time you’re washing.) If you wash the dishes by hand one day out of five, you’ll cut your electricity consumption for the dishwasher by 20 percent (a standard dishwasher burns 355 kilowatt/hours per year, so that’s some nice savings).
- Use the solar dryer. Admit it, the main reason you don’t hang your laundry on the line is because you don’t want the neighbors to gawk. Suck up that pride and start using the sun to dry your laundry. Not only will you save electricity (it costs about 50 cents a load to use your dryer) but you’ll burn some calories along the way. If you seriously don’t want your neighbors checking out your skivvies, go ahead and use the dryer for that, but use the clothesline for your less modest laundry.
- Use the microwave. Your microwave efficiently cooks food — it uses a lot less electricity than your normal electric stove or oven — and it doesn’t heat up your kitchen the way those appliances do, so you’ll save air conditioning power, too. And admit it, you like those tasty and easy microwave meals!
- Keep the fridge full. Ironically, the more stuff you have in your fridge, the more efficient it is (unless you jam it so full that you block the air flow). Here’s the idea: If your refrigerator or freezer is nearly empty, each time you open the door much of the cold rushes out with the air. Keep the fridge and freezer full, and the cold stays. Simple. However, you shouldn’t put hot stuff into the fridge or freezer until it cools down to room temperature or you’ll use more power than needed to cool it down. For health reasons you don’t want to leave food sitting out longer than necessary though; sometimes you can cool down hot food quickly with those icy things you put in coolers.
- Zone your house. You don’t need to cool your bedroom if you’re not in it, and you probably never need to cool your closets. Once your family is out of bed, turn off the AC upstairs. Similarly, when they’re in bed, turn off the AC downstairs. If you happen to wake up in the wee hours to go to the bathroom, try turning off the AC completely. If doors and windows are shut, the bedrooms may remain cool until the sun rises. Regarding the closets, there is little need to keep your suits cool, so keep the doors to closets closed so that the cool air isn’t wasted there.
- Skip the screensaver. You guessed it — using a screen saver consumes more electricity than just letting your computer screen go blank. Speaking of computers, turn them off at night and whenever else you’re not going to use them for two hours or more. “Sleep” mode isn’t good enough — even in sleep mode, a typical PC burns 15 watts. After you shut down the computer, turn off the power strip. That makes sure no energy is slowly being consumed by LED lights or other little power suckers.
- Share the wealth. This might be your single best power-saving move. If you have kids, tell them that if they participate in your power-saving schemes, you’ll share some of the savings with them. Tell them about a few ways they can help keep the bills down — turning off lights, keeping doors closed, playing fewer video games. Then show them your power bill from last August and tell them that if they follow your suggestions and the amount of electricity is less this August, they will get a percentage of the money saved.
Do you have any creative ways of saving energy? If so, please don’t hesitate to share them in the comments.
Awesome tips to save energy! Any news that helps people to save money is ALWAYS great news.
I just wish I could zone my apartment.
BG – interesting idea for empty milk jugs.
Paul #5: Great point. One can not discount the tons of energy used to initially cool the water in the first place. Though your example is the extreme it does make your argument clear.
BTW: don’t run your fridge at 34F degrees — that is too cold. You want to keep it around 37-41 degrees.
Perhaps it is best to have your fridge filled with _empty_ milk jugs — to prevent the cold air loss when the door is opened.
I think the dishwasher thing depends on how full it is when you run it, and a bit on how big the items are. I only run the dishwasher when it’s mostly full, and usually I wash pots and pans by hand (in addition to taking up a lot of space, they often don’t get clean in the dishwasher anyways, so I would have had to scrub and pre-rinse them, defeating the purpose)
Also I practice almost all the other tips – line or rack dry clothes, run dishwasher 1 x per week, keep blinds closed when not home, microwave, full fridge and freezer – also I have a tankless water heater that I think makes a huge difference. My total utilties (gas + elec + water) run less than $80/month on average year-round.
Be careful with zoning the house too. I was doing this by keeping the bathroom door shut. Bad idea! While I may have been saving money on AC (afterall who wants a cold bathroom? no one) instead I was fostering mildew growth. Opened up the door and the problem is gone.
“However, you shouldn’t put hot stuff into the fridge or freezer until it cools down to room temperature or you’ll use more power than needed to cool it down.”
Old wive’s tale. For bacteria reasons you should never leave food out that is not going to be consumed. You should put it in the fridge immediately. Modern fridges in particular are designed for this… the whole point is to cool food and preserve it.
Not sure about some of these, but typically a household power consumption is mainly in HVAC & heating water for the bulk of the bill. That’s how the microwave & line drying really make a measurable dent is by not fighting the air conditioning as much as the stove & dyer. Thus one very simple thing in the summer is to close blinds or curtains south and west, getting natural light from north and east (logic is to limit the solar input from direct sunlight while still getting the advantages of natural light from indirect sunlight, so if you have a shade tree on the south side, that might be the best window to get a rooms light).
I enjoy watching Mythbusters. I also like your share the wealth tip. It is tough to get kids to turn off the lights, but this is a good idea.
You can hang your clothes up in a room in your house if you want also. We hang ours inside so the birds don’t poo on them and it works out great. If someone comes over we just move the clothes racks into another room. They usually dry over night so we can run a load and have them dry by the morning. Especially in the winter time.
The fridge full vs. empty is interesting. It would seem to me that Paul has a very good point. If I have a fridge that is 25% full, then I have 75% air. Sure that air has to be cooled every time I open the fridge, but the amount of energy required to cool air is 3000 times less than cooling an equal volume of water. So if I replace 50% of the air with water in milk jugs, I would have to open the fridge 3000 times, give or take, to recoup the initial energy investment to cool down the water.
The energy savings seems negligible at best over a very long period.
Me again. I’d like to propose an unbiased 3rd party test the full vs nearly empty refridgerator energy consumption … Mythbusters!
Another engineer here and I agree with Nickel. In Paul’s example of the door opening on a water-filled fridge, less heat gets in because the primary method of heat transfer while the door is open is by convection of the air, which is greatly reduced by having less volume of air and more obstacles to keep the air from swapping as fast. When you close the door, even the smaller volume of air remaining is cooler than the air in the empty fridge.
I use my dishwasher usually, but if I just have a few dishes or need a specific dish washed, I’ll do it by hand. I often wash the larger items by hand if the dishwasher is short on space. I probably do a load in the dishwasher slightly more than once per week. I don’t have a clothesline and since my uniforms at work are washed by the service my laundry is reduced. My computer runs all day at full capacity. The CPU is running [email protected] and the video cards are running a different distributed computing project.
All great tips, especially the share the wealth tip. I use this to help get the kids to clip coupons with me. If they find a good deal they get to keep half of the savings as a weekly bonus to their allowance!
Paul, your calculations are not dealing with the scenario that the energy usage is about. The savings is not about the first time you fill up a refrigerator and get it cold, but what it takes to maintain the cold temperature in a refrigerator that is already on and cold and is kept running. Anyway, do your calculations deal with the energy required to condense the water vapor from the air? My air conditioner for example probably spends more energy getting the moisture out of the air than it does in cooling the air temp because of the high humidity. This can suck up energy and not even change the temperature initially.
I agree with Nickel. The loss comes from cold air esacaping from the refrigerator when opened and having to recool the air. There is less loss when there is less air that is escaping. Would your cans of beer in a cooler at a party stay cooler longer if you just had cold air in ther initially or if you had cold water and/or ice in there with the beer?
Let us say we have a refridgerator with 1 cubic meter of interior volume. Choice one is to fill it 100% with air, which would be 1180 grams of air. To cool the air down from 70F to 34F (delta of 36F = 20C) would require 1180 * 20 * 1.012 = 23,883 Joules of energy (using the specific heat capacity of 1.012 J/gramC for air). Alternatively, let us fill the fridge with water. This would be 1,000,000 grams of water, and water has a specific heat capacity of 4.1813 J/gramC. To drop the water down from 70F to 34F would take 1,000,000 * 20 * 4.1813 = 83,626,000 Joules of energy, or 3500 times more energy than cooling down the fridge full of air. So you are replacing a tiny effort in cooling down the air for the enormous effort of cooling down the unnecessary jugs of water (or other fridge filling material). By the way, when you open the water filled fridge, it raises its temp slightly and must be re-cooled… with I believe the same energy that it takes to re-cool the air filled fridge after its door is opened, even though the air experiences a more dramatic temperature rise.
Per the refrigerator: keep it full! Simply filling it with milk-jugs filled with water is much better than letting an empty fridge run.
Think about it this way: if the power goes out, which refrigerator will hit room temperature first, a full one or an empty one?
http://planetgreen.discovery.com/home-garden/empty-refrigerator-efficiency-tips.html
Paul: It makes sense to me, but I’m not an engineer. When you open it, much of the cold air falls out, but the cold items don’t. Thus, if you open an empty fridge, it will partially fill up with warm air that needs to be cooled. But if you open a completely packed fridge, there is less air to swap out, meaning that there’s less to cool back down after you close it. Or am I wrong?
Now, if you were talking about a sealed system (the fridge while it’s closed), then I don’t think there would be a difference.
Regarding a dishwasher, the 355 KW-hours per year translates into $35 per year for most folks (outside the New England region, where it would be more like $50). So we are talking about a dime per day in savings.
Regarding a PC in sleep mode at 15 watts, over a year that translates into 131.4 KW-hours, or approximately $13, or about 3 to 4 cents per day.
Regarding solar drying, assuming 3 dryer loads per week (my family average) this translates into approximately $75 per year in savings.
I think the refridgerator tip is a myth. It doesn’t make sense to the engineer in me that maintaining a heavier mass to a temp of 34F is less energy than maintaining the same volume of air.
Out of all of these ideas, I think “zoning the house” and “microwave vice oven” provide the most savings.
Good tips all around. They’re the small kinds that are easy to do and add up over time.
“If you seriously don’t want your neighbors checking out your skivvies, go ahead and use the dryer for that, but use the clothesline for your less modest laundry.”
I think you meant, more modest laundry for the line. 🙂