Michael, you have had some good responses already. I have added some thoughts below.
Michael Nehring wrote: > Hi all, > In about 8 months or so, I and my (future) wife will buy our first > house. One of my goals is to have a relatively high level of energy > self-sufficiency (without going bankrupt since we currently don't have a > ton of cash lying around). > > First question: does anyone know of any charts/statistics of household > energy consumption. I'm not so much interested in kilowatthours per day, > but rather how the usage is divided up. This will make it easier to plan > what areas typically need to be improved. Unfortunately, the answer is, it depends. I am presuming that you are looking primarily at electrical energy consumption, rather than overall energy consumption. Electrical energy consumption is strongly related to which electrical appliances you plan to use. There are all-electric houses which will have very high electrical consumption, and the off-grid minimalist home that will have very low electrical consumption, and the whole range in-between. (There are also homes that have no electricity, but I gather that is not a lifestyle you are looking to embrace. So, what do you plan to power electrically? Heating? AC? Cooking? Hot water? Refrigerator? Freezer? Washer? Dryer? Television? Sound system? Computer(s)? Fax machines or other office equipment? Electric vehicles? (They're a factor in our household.) Personally, I'm a big fan of low-tech solar thermal approaches to displacing fossil fuel and electrical energy consumption where appropriate. As part of your house hunting, are you considering the sun-facing exposure of the houses, and the potential for using solar energy to displace other energy use? > On another note, have any of you guys already looked at this: > http://mtbest.net/chest_fridge.html. It's a fridge that uses only .1 > kw-hours/day (that's around 37 per year, and at $.1/kWh, that's less > than $4 year if you're on the grid). The idea is surprisingly simple. Chest fridges are definitely an interesting option. So are non-electrical and seasonal cooling fridges. There is a refrigeration alternatives list on Yahoo you might want to have a look at for some other ideas. > Another question: does anyone know how many kilowatt hours are stored in > a "normal" car battery (a battery for a standard sedan, I suppose)? I've > been thinking about hooking an inverter up to a car battery (or probably > an array) to power various devices in the house. However, I don't know > how much power is actually in a fully charged battery. > Here would be one idea to charge the batteries: I just install a few > extra alternators in my car, and have those charge the batteries which > would be stored in the trunk. Assuming the car is running biodiesel, > then the electricity would be produced by biodiesel. Does the idea sound > reasonable? Or does it have too many drawbacks and pitfalls? Are there > other 12V batties that are better designed for household-type uses? (12V > so that I can charge it with an alternator, since I have a few > alternators lying around, and can get them for near to free if I go for > used). How long does it take to charge an empty car battery? If it > doesn't take long, maybe I could build a simple treadmill-like device > for the car, so the car spins a wheel, which in turn spins a dozen or so > alternators to charge a dozen batteries at once. While it isn't the most > efficient method, it would be cheap, since the motor would stay in the > car, and the car would serve other purposes (that is, getting places). For lead-acid batteries, my rule of thumb is 15 watt-hours per pound. So, if you have a 40 pound battery, it will store about 600 watt-hours (0.6 kWh). Personally, I would not recommend this approach. The batteries will have a short life in a deep-discharge application. For this use you want deep-cycle batteries. Still lead-acid, but the construction is different. If you are looking for bargains, check with golf-cart service operations for batteries they are removing from service. Check them over for obvious damage, low water and load-test them. Most will be 6-volt batteries, so you need to put two in series to get the 12 volts you want. Automotive alternators typically have poor efficiency, in the order of 60% (including regulation). That's after allowing for the efficiency of the heat engine (likely less than 40%). In general, grid electricity in North America is cheap compared to producing your own. If the alternator is rated for 40 amps, that's about 560 watts. Given the capacity of a typical battery is about 600 watt-hours, it would take a bit over an hour to fully charge the battery from this alternator. I have spent plenty of time moving and connecting batteries. It gets tired fast. Each move also involves the risk of damage and spilling the dilute sulphuric acid. Not as hazardous as most people assume, but it makes a mess of cotton-based clothes, notably jeans and shirts. > I guess that's it for now. If any of you guys have any tips for common > sources of waste in a house, I'd be happy to hear them (I'm already > planning a rainwater harvesting system and a greenhouse for winter food > production). For information on reducing your electrical bill, visit my web page on the subject. http://www.econogics.com/en/poweroff.htm Are you located in an area that experiences freezing temperatures? If so, make sure your rainwater system is designed to deal with that, as well as your greenhouse. You may want to look into the Four Season Harvest (Eliot Coleman is the author IIRC) before getting too far into your greenhouse design. > > Thanks, > -Michael > > _______________________________________________ > Biofuel mailing list > Biofuel@sustainablelists.org > http://sustainablelists.org/mailman/listinfo/biofuel_sustainablelists.org > > Biofuel at Journey to Forever: > http://journeytoforever.org/biofuel.html > > Search the combined Biofuel and Biofuels-biz list archives (50,000 messages): > http://www.mail-archive.com/biofuel@sustainablelists.org/ > > > -- Darryl McMahon http://www.econogics.com It's your planet. If you won't look after it, who will? _______________________________________________ Biofuel mailing list Biofuel@sustainablelists.org http://sustainablelists.org/mailman/listinfo/biofuel_sustainablelists.org Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html Search the combined Biofuel and Biofuels-biz list archives (50,000 messages): http://www.mail-archive.com/biofuel@sustainablelists.org/
