Regarding the loss of efficiency in the UK during transmission of electricity. A couple of years ago I was doing some work for National Grid, which is currently upgrading its 1960s era power transmission system (primarily refurbishing steel towers and installation of new more efficient HV cables). Previously the highest voltage parts of the system ran at 275 kV and 70 C at 15 C ambient. All this is being changed to 400 kV and 90 C at 15 C ambient. So the entire UK national grid is like one big electric kettle! (And contributing an awful lot to global warming - literally.)
Now you know why birds do not land on HV power cables.... John F-L ----- Original Message ----- From: Martin Vlietstra To: U.S. Metric Association Sent: Thursday, April 02, 2009 10:21 PM Subject: [USMA:44281] RE: Energy and power units Pat, While you might be correct, I was stating the actual position in the UK. I checked some recent statements and the cost of my gas is 2.26p/kWh, while the cost of my electricity is 9.02 p/unit [sic]. As long as I am aware that a "unit" of electricity is one kWh, I can see that the cost of electrical energy is four time the cost of gas energy. Thus, heating using electricity is much more expensive than heating using gas. If I am interested in the cost of the energy to the planet, then yes, I will take into account the cost of production and transmission. In the UK (where there are a number of gas-fired power stations), I believe that there are considerable losses in the generation of electricity, so gas heating does less harm to the planet that electrical heating. When I was living in South Africa, the inverse was true. Regards Martin ------------------------------------------------------------------------------ From: [email protected] [mailto:[email protected]] On Behalf Of Pat Naughtin Sent: 02 April 2009 07:50 To: U.S. Metric Association Subject: [USMA:44279] Energy and power units On 2009/04/01, at 4:17 PM, Martin Vlietstra wrote: "What is the rationale for billing in kilowatt-hours?" To create a level playing field with the electrical industry. Dear Martin, With respect, using kilowatt-hours to bill people for electricity and for gas does not, In my opinion, create a level playing field. I think that many people have difficulty distinguishing between kW and kWh and between their related physical quantities power and energy. It seems to me that power and energy are more clearly identified when power is measured in kW and energy is measured in kJ (rather than power measured in kW and energy measured in kW.h). Consider an example where natural gas is supplied directly to your home with an energy content of (say) 53 MJ/kg compared to the same gas supplied to an electricity turbine to produce electrical energy that is then transmitted through the grid to your home. The gas that is supplied to you directly should not be compared to the energy supplied as electrical energy because of the production and the transmission losses via this pathway. Cheers, Pat Naughtin PO Box 305 Belmont 3216, Geelong, Australia Phone: 61 3 5241 2008 Metric system consultant, writer, and speaker, Pat Naughtin, has helped thousands of people and hundreds of companies upgrade to the modern metric system smoothly, quickly, and so economically that they now save thousands each year when buying, processing, or selling for their businesses. Pat provides services and resources for many different trades, crafts, and professions for commercial, industrial and government metrication leaders in Asia, Europe, and in the USA. Pat's clients include the Australian Government, Google, NASA, NIST, and the metric associations of Canada, the UK, and the USA. See http://www.metricationmatters.com for more metrication information, contact Pat at [email protected] or to get the free 'Metrication matters' newsletter go to: http://www.metricationmatters.com/newsletter to subscribe.
