Sustainable Energy
1 journaler for this copy...
Journal Entry 1 by keithpp from Farnborough, Hampshire United Kingdom on Thursday, December 18, 2008
'We have got an addiction to fossil fuels and it's not sustainable.' -- David MacKay
'We often hear that Britain's renewables are "huge". But it’s not sufficient to know that a source of energy is "huge". We need to know how it compares with another "huge", namely our huge consumption. To make such comparisons, we need numbers, not adjectives.' -- David MacKay
David MacKay is a breath of fresh air. He cuts through the crap, with Ian Fells at one end of the spectrum gung-ho about coal and nuclear, to hype from advocates of renewables at the other end of the spectrum who believe all our energy needs can be met with renew ables but fail to do the sums.
David MacKay does the sums. He puts numbers to all his scenarios. He makes assumptions, produces simple models, but at all times the assumption are made explicit.
He deals with ball park figures. For examples, let us assume we cover 10% of the UK with wind turbines (not in reality possible), but knowing the average wind speed, the power generated in watts per square metre, we have a figure for the total output.
We can do similar calculations for the average car journey etc.
We know what our wind turbines are capable of, we know what our electricity demand is. The former exceeds the latter, and hey presto, problem solved. Unfortunately not so. Electricity is not our only energy demand, we use energy in transport, we use energy to make stuff, whether it be the tat that makes a one way trip to landfill or the material we use to build our homes.
He deals with easy to comprehend figures. An electric kettle at 3kw boiling water for 20 minutes is 1kw-hour. Why is the kettle 3kw? That is the maximum power for a 13 amp socket.
David MacKay starts from the premise that whatever we think of Peak Oil and whether or not we are about to shortly hit that peak, our fossil carbon resources are finite and sooner or later they will become exhausted (or at least not economically viable to extract). We also cannot continue to pump carbon into the atmosphere and David MacKay assumes cuts of 90%. A third premise is that of security of supply.
90% of our energy in the UK comes from fossil fuels and it is not sustainable
A few myths are demolished on the way.
Turn off all those mobile phone chargers in the home, look at all the energy we save, every little bit helps. Little is the important word. Multiply a very small number by a big number and we still have a small number. A mobile phone charger when not charging is consuming maybe 1 watt. This is a fraction of one percent, an insignificant part of our household energy demand.
Do switch off your phone charger if it makes you feel good, but just remember it is about as effective as baling out the Titanic with a teaspoon!
If we are to get anywhere, we have to think big.
Common sense tells us that a large electricity power plant is inefficient, look at all that waste heat going up the cooling towers. Even worse when we consider that high grade electricity is being used for low grade space heating, worse still when we think that to provide that electricity for a low grade use, we have thrown two-thirds of the low grade heat away. Combine heat and power plants is the obvious solution. The output is what we want, heat, electricity is a waste product generated at lower efficiency, but the overall efficiency is much higher.
Wrong says David MacKay. It is much better to use electricity for space heating. This seems to me to go against the grain, but what David MacKay says is we use the electricity for heat pumps. We use 1kw of power to pump 3 kw of heat, and into our building we get 4 kw of heat. Nothing else comes anywhere close to matching this for efficiency.
The best heat pumps, recently developed in Japan, have a coefficient of performance of 4.9; this means that using 1 kWh of electricity, the heat pump delivers 4.9 kWh of heat in the form of hot air or hot water. This is a far more efficient way to use high-grade energy to make heat, than simply setting fire to high-grade chemicals, which achieves a coefficient of performance of only 0.9.
The conclusion David MacKay reaches is that we could just meet all or energy needs with renewables, but he has taken no account of cost, social or environmental impacts. If we take these into account, we cannot meet our demand from renewables. The options we then have is to reduce or energy demand through lifestyle changes and efficiency measures, but even then he does not believe renewables will be enough. We then have the options of nuclear, unproven clean coal which is still using a finite resource (as is nuclear) or renewables located in another country, for example solar in North Africa. By advocating nuclear to fill the energy gap he is echoing the same scenario as James Lovelock. [see The Revenge of Gaia].
David MacKay thinks it is so important to get the message across, that he has placed his book on the net in the public domain under a creative commons license. For traditionalists like myself, it will be available in book form in the New Year.
http://www.withouthotair.com/
http://www.withouthotair.com/download.html
David Mackay is Professor of Natural Philosophy in the Department of Physics at the University of Cambridge. As one would expect from a Cambridge academic, the book is well referenced. It is also highly readable.
One small gripe, David Mackay occasionally cites Wikipedia as a reference source. One would have expected better from a Cambridge academic!
Highly recommended. A must read.
Also read:
Lester R Brown, Plan B 2.0, Norton, 2006
http://www.earth-policy.org/Books/PB2/Contents.htm
Jared Diamond, Collapse: How Societies Choose to Fail or Succeed, Penguin, 2005
Kate Evans, Funny Weather, Myriad Editions, 2006
http://www.heureka.clara.net/books/funny-weather.htm
Paul Hawken, Amory B Lovins & L Hunter Lovins, Natural Capitalism, Earthscan, 1999
James Lovelock, The Revenge of Gaia, Penguin, 2007
http://www.bookcrossing.com/journal/6805905
William McDonough and Michael Braungart, Cradle to Cradle: Remaking the Way We Make Things, North Point Press, 2002
George Monbiot, Heat, Penguin, 2007
Keith Parkins, Natural Capitalism, October 2000
http://www.heureka.clara.net/gaia/nat-cap.htm
Keith Parkins, Soft energy paths, May 2001
http://www.heureka.clara.net/gaia/energy.htm
Keith Parkins, Brittle power, October 2003
http://www.heureka.clara.net/gaia/brittle-power.htm
Keith Parkins, Curitiba – Designing a sustainable city, April 2006
http://www.heureka.clara.net/gaia/curitiba.htm
Keith Parkins, Do we need industrial agriculture?, Indymedia UK, 19 February 2007
http://www.indymedia.org.uk/en/2007/02/362714.html
Keith Parkins, Waste, recycling and packaging, Indymedia UK, 8 September 2008
http://www.indymedia.org.uk/en/2008/09/408329.html?c=on
Keith Parkins, Fuel poverty, Indymedia UK, 15 September 2008
http://www.indymedia.org.uk/en/2008/09/408783.html?c=on
Keith Parkins, Energy gap, Indymedia UK, 17 September 2008
http://www.indymedia.org.uk/en/2008/09/408898.html?c=on
Keith Parkins, Transition towns, Indymedia UK, 9 October 2008
http://www.indymedia.org.uk/en/2008/10/410292.html?c=on
Keith Parkins, Beyond sustainability, to be published
Ernst von Weizsåcker, Amory B Lovins and L Hunter Lovins, Factor Four: Doubling Wealth, Halving Resource Use, Earthscan, 1997
'We often hear that Britain's renewables are "huge". But it’s not sufficient to know that a source of energy is "huge". We need to know how it compares with another "huge", namely our huge consumption. To make such comparisons, we need numbers, not adjectives.' -- David MacKay
David MacKay is a breath of fresh air. He cuts through the crap, with Ian Fells at one end of the spectrum gung-ho about coal and nuclear, to hype from advocates of renewables at the other end of the spectrum who believe all our energy needs can be met with renew ables but fail to do the sums.
David MacKay does the sums. He puts numbers to all his scenarios. He makes assumptions, produces simple models, but at all times the assumption are made explicit.
He deals with ball park figures. For examples, let us assume we cover 10% of the UK with wind turbines (not in reality possible), but knowing the average wind speed, the power generated in watts per square metre, we have a figure for the total output.
We can do similar calculations for the average car journey etc.
We know what our wind turbines are capable of, we know what our electricity demand is. The former exceeds the latter, and hey presto, problem solved. Unfortunately not so. Electricity is not our only energy demand, we use energy in transport, we use energy to make stuff, whether it be the tat that makes a one way trip to landfill or the material we use to build our homes.
He deals with easy to comprehend figures. An electric kettle at 3kw boiling water for 20 minutes is 1kw-hour. Why is the kettle 3kw? That is the maximum power for a 13 amp socket.
David MacKay starts from the premise that whatever we think of Peak Oil and whether or not we are about to shortly hit that peak, our fossil carbon resources are finite and sooner or later they will become exhausted (or at least not economically viable to extract). We also cannot continue to pump carbon into the atmosphere and David MacKay assumes cuts of 90%. A third premise is that of security of supply.
90% of our energy in the UK comes from fossil fuels and it is not sustainable
A few myths are demolished on the way.
Turn off all those mobile phone chargers in the home, look at all the energy we save, every little bit helps. Little is the important word. Multiply a very small number by a big number and we still have a small number. A mobile phone charger when not charging is consuming maybe 1 watt. This is a fraction of one percent, an insignificant part of our household energy demand.
Do switch off your phone charger if it makes you feel good, but just remember it is about as effective as baling out the Titanic with a teaspoon!
If we are to get anywhere, we have to think big.
Common sense tells us that a large electricity power plant is inefficient, look at all that waste heat going up the cooling towers. Even worse when we consider that high grade electricity is being used for low grade space heating, worse still when we think that to provide that electricity for a low grade use, we have thrown two-thirds of the low grade heat away. Combine heat and power plants is the obvious solution. The output is what we want, heat, electricity is a waste product generated at lower efficiency, but the overall efficiency is much higher.
Wrong says David MacKay. It is much better to use electricity for space heating. This seems to me to go against the grain, but what David MacKay says is we use the electricity for heat pumps. We use 1kw of power to pump 3 kw of heat, and into our building we get 4 kw of heat. Nothing else comes anywhere close to matching this for efficiency.
The best heat pumps, recently developed in Japan, have a coefficient of performance of 4.9; this means that using 1 kWh of electricity, the heat pump delivers 4.9 kWh of heat in the form of hot air or hot water. This is a far more efficient way to use high-grade energy to make heat, than simply setting fire to high-grade chemicals, which achieves a coefficient of performance of only 0.9.
The conclusion David MacKay reaches is that we could just meet all or energy needs with renewables, but he has taken no account of cost, social or environmental impacts. If we take these into account, we cannot meet our demand from renewables. The options we then have is to reduce or energy demand through lifestyle changes and efficiency measures, but even then he does not believe renewables will be enough. We then have the options of nuclear, unproven clean coal which is still using a finite resource (as is nuclear) or renewables located in another country, for example solar in North Africa. By advocating nuclear to fill the energy gap he is echoing the same scenario as James Lovelock. [see The Revenge of Gaia].
David MacKay thinks it is so important to get the message across, that he has placed his book on the net in the public domain under a creative commons license. For traditionalists like myself, it will be available in book form in the New Year.
http://www.withouthotair.com/
http://www.withouthotair.com/download.html
David Mackay is Professor of Natural Philosophy in the Department of Physics at the University of Cambridge. As one would expect from a Cambridge academic, the book is well referenced. It is also highly readable.
One small gripe, David Mackay occasionally cites Wikipedia as a reference source. One would have expected better from a Cambridge academic!
Highly recommended. A must read.
Also read:
Lester R Brown, Plan B 2.0, Norton, 2006
http://www.earth-policy.org/Books/PB2/Contents.htm
Jared Diamond, Collapse: How Societies Choose to Fail or Succeed, Penguin, 2005
Kate Evans, Funny Weather, Myriad Editions, 2006
http://www.heureka.clara.net/books/funny-weather.htm
Paul Hawken, Amory B Lovins & L Hunter Lovins, Natural Capitalism, Earthscan, 1999
James Lovelock, The Revenge of Gaia, Penguin, 2007
http://www.bookcrossing.com/journal/6805905
William McDonough and Michael Braungart, Cradle to Cradle: Remaking the Way We Make Things, North Point Press, 2002
George Monbiot, Heat, Penguin, 2007
Keith Parkins, Natural Capitalism, October 2000
http://www.heureka.clara.net/gaia/nat-cap.htm
Keith Parkins, Soft energy paths, May 2001
http://www.heureka.clara.net/gaia/energy.htm
Keith Parkins, Brittle power, October 2003
http://www.heureka.clara.net/gaia/brittle-power.htm
Keith Parkins, Curitiba – Designing a sustainable city, April 2006
http://www.heureka.clara.net/gaia/curitiba.htm
Keith Parkins, Do we need industrial agriculture?, Indymedia UK, 19 February 2007
http://www.indymedia.org.uk/en/2007/02/362714.html
Keith Parkins, Waste, recycling and packaging, Indymedia UK, 8 September 2008
http://www.indymedia.org.uk/en/2008/09/408329.html?c=on
Keith Parkins, Fuel poverty, Indymedia UK, 15 September 2008
http://www.indymedia.org.uk/en/2008/09/408783.html?c=on
Keith Parkins, Energy gap, Indymedia UK, 17 September 2008
http://www.indymedia.org.uk/en/2008/09/408898.html?c=on
Keith Parkins, Transition towns, Indymedia UK, 9 October 2008
http://www.indymedia.org.uk/en/2008/10/410292.html?c=on
Keith Parkins, Beyond sustainability, to be published
Ernst von Weizsåcker, Amory B Lovins and L Hunter Lovins, Factor Four: Doubling Wealth, Halving Resource Use, Earthscan, 1997
