Saturday 17 December 2011

The True Value of Electricity

The average Irish home uses 5300 kWh of electricity a year (1) an increase of 21% since 1990. Irish households are profligate users compared to other western countries, in 2006 we used 21% more than UK households, and 31% more than our continental neighbours(2). We used more than our trans Atlantic cousins in the USA where average household use in 2009 was 4800 kWh (3).

Electricity is a miracle of the age and yet like so many modern miracles people take it for granted and waste it on an epic scale without thinking. So for this post I am going to try and put some perspective on the real value of electrical power. For this I turn to Lieutenant Colonel Fleming’s U.S. Army War College thesis on Peak Oil (4)

Fleming wrote
“A gallon of gasoline energy content is about 33 kilowatt-hours. In perspective, 33 kilowatt-hours is the equivalent of a healthy male pedaling a stationary bike for 330 hours – if he can maintain 100 watts per hour. If he pedals 40 hours per week, he will generate the same amount of energy as in one gallon of gasoline in about eight weeks”

So one gallon of petrol (as we call gasoline in Ireland) has 33 kWh of potential energy. Average household electrical use is 5300 kWh a year, the equivalent of 160.6 gallons of petrol. Typically up to 60% of potential energy is lost in the generation and transmission of electricity. So to produce the 5300 kWh used by our average household requires the burning of the equivalent of 401.5 gallons of petrol in a power station.

If it takes an adult male 330 hours of pedaling a stationary bike to produce the power in one gallon of petrol. It will take the same male 132500 hours of pedaling to produce the kind of power an average Irish household burns in electricity every year. If we asked our male to cycle 40 hours a week, that would take him 3312.5 weeks (no weeks off) or 63.7 years.

If we paid him a modest 10 euro an hour (and remember that 100 watts is lively cycling) it would cost over 1.3 million Euros in human labour. Right now you can buy this much electrical power in Ireland for 800 Euros. It can be bought for 800 Euros because it is produced with cheap fossil fuels. But the days of cheap fossil fuels are rapidly running out and very soon we will have to start paying the true cost of electricity.

Sustainable Energy Ireland’s booklet “Your Guide to Electricity in Your Home” is packed with electricity saving tips.
http://www.seai.ie/Publications/Your_Home_Publications/Your_guide_to_electricity_in_the_home.pdf

References
(1) The Electricity Supply Board  http://www.esb.ie
(2) http://www.finfacts.ie/irishfinancenews/article_1013935.shtml
(3) http://www.carbonindependent.org/sources_home_energy.htm
(4) http://www.dtic.mil/dtic/tr/fulltext/u2/a545047.pdf

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