How much electricity does an average 2-story 3-bedroom house use per day per month or per year?
As an electrical engineer for a power company I see on average a house that is 1600-2000 square feet and having electric appliances except for the furnace use an average of 1500Kwatt-hours per month making 50 Kwatt-hours per day and a total of 18,000 Kwatt-hours per year.
If one is trying to determine usage as part of a plan for creating an alternative energy system for the house, one really needs to find out the actual usage for the house. Average numbers can be very misleading. Nova ran a story about a couple that installed a solar based 6 kWatt system who were generally running a surplus. No data is provided for actual consumption and converting the rating of a solar system back to Kwatts/day is moderately complex.
On the other side of the spectrum, it has been reported that Al Gore's mansion uses about 221,000kWh per year. If you scale this number down to the requested 1600-2000 square foot house, the result is around 60,000 kWh per year. It is reasonable to assume that Mr. Gore has already done all of the obvious things to reduce his energy footprint (e.g. energy star appliances, energy efficient lighting) so this clearly should not be considered an upper bound on electrical usage. Mr. Gore also purchases carbon offsets and extra wind power to balance out the remainder of his home's energy consumption.
The most important part about this question is that knowing the average value is useful if you just want to know the average but knowing the specific number may be significantly more important in some cases.
The United States Department of Energy Information estimates from the US Energy Information Agency put the average at about 8,900 per year, which is consistent with recent data from a project my company did for a large energy-related public service company.
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