ÑóẊîöʼn
29th June 2008, 21:38
The Register (http://www.theregister.co.uk/2008/06/20/mackay_on_carbon_free_uk/)
A topflight science brainbox at Cambridge University has weighed into the ever-louder and more unruly climate/energy debate with several things that so far have been mostly lacking: hard numbers, willingness to upset all sides, and an attempt to see whether the various agendas put forward would actually stack up. Professor David J C MacKay of the Cambridge University Department of Physics holds a PhD in computation from Cal Tech and a starred first in Physics, so we can take it that he knows his numbers. And, as he points out, numbers are typically lacking in current discussion around carbon emissions and energy use.
MacKay tells The Reg that he was first drawn into this field by the constant suggestion — from the Beeb, parts of the government etc — that we can seriously impact our personal energy consumption by doing such things as turning our TVs off standby or unplugging our mobile-phone chargers.
Anyone with even a slight grasp of energy units should know that this is madness. Skipping one bath saves a much energy as leaving your TV off standby for over six months. People who wash regularly, wear clean clothes, consume hot food or drink, use powered transport of any kind and live in warm houses have no need to worry about the energy they use to power their electronics; it’s insignificant compared to the other things.
Most of us don’t see basic hygiene, decent food and warm houses as sinful luxuries, but as things we can reasonably expect to have. This means that society as a whole needs a lot of energy, which led MacKay to consider how this might realistically be supplied in a low-carbon fashion. He’s coming at the issues from a green/ecological viewpoint, but climate-change sceptics who are nonetheless concerned about Blighty becoming dependent on Russian gas and Saudi oil — as the North Sea starts to play out — will also find his analysis interesting. Eliminating carbon largely equates to eliminating gas and oil use.
...
MacKay also gets into solar, both the thermal and electric kinds. Thermal has some potential for home energy, it seems, and is a good idea. (Funnily enough, almost all home microgeneration kit in the UK right now is solar-thermal water heating, so he might just be right here.) But solar photovoltaic (PV) electricity is viciously expensive in the cloudy UK, and just sticking panels on roofs won’t do much — it seldom yields any large proportion of the energy used in the building it’s on top of. You need to cover a big portion of the country in cells.
All in all, according to MacKay, if you like solar it probably makes more sense to put the panels in North Africa and bring the power to the UK over efficient high-voltage DC lines.
As an engineering matter the desert-solar idea is quite feasible — not very different in scale from piping in gas across continents and beneath seas, as people already do. Those fretful about buying power from Russia or the more unsavoury Gulf oil producers might be equally unhappy to buy it from Libya or Algeria, however.
...
MacKay also takes a look at the somewhat less right-on options. The biggies here are “clean” coal, in which coal power stations are modified so that the carbon they emit is captured and stuffed away somewhere, perhaps in old gas fields. For a man of his leanings — MacKay is a fairly hardcore pacifist, and more than a bit of a tree-hugger — he’s refreshingly open-minded.
"We must not let ourselves be swept off our feet in horror at the danger of nuclear power. Nuclear power is not infinitely dangerous. It’s just dangerous, much as coal mines, petrol repositories, fossil-fuel burning and wind turbines are dangerous."
MacKay concludes that nuclear scales up easily, and does so without dominating the country the way wind, solar, tidal and biomass do. The scale of engineering required, in terms of megatons of steel and concrete or areas of land and sea taken up, is enormously down on that needed by useful amounts of renewables.
Concerns over fuel price and security of supply aren’t nearly as much of an issue as they are with fossil fuels, because it’s comparatively easy to store energy-dense nuclear fuels like uranium and thorium — you could have several years’ supply stockpiled in the UK. If the price of the fuels rose, even if it multiplied seriously, it wouldn’t affect the price of energy much. Almost all the cost of nuclear energy comes from building, running and decommissioning the plant, and handling the wastes after.
Even so, present day nuclear fission technology is at best “a stopgap”, according to MacKay. His numbers suggest that the present method of using uranium would allow the entire human race to live like power-hog Americans in terms of power use for about a third of a year — assuming that only the uranium reserves now confirmed exist. Here MacKay perhaps reveals his natural anti-nuclear leanings somewhat, as he has put nuclear power to a much stiffer sustainability and fairness test than coal. But, showing commendable intellectual honesty, he goes on.
At present, there being no scarcity of uranium, it is typically dug from the ground and run through simple power stations just once before being classed as waste. Nobody explores for more uranium, and nobody has done so since the 1980s, because supplies are ample to meet current demand. There’s probably a lot more to be found, especially if the price of ore rose a lot. (Which wouldn’t affect the price of the energy significantly, remember.)
Furthermore, the use of fast-breeder reactors would get sixty times as much juice from a given amount of uranium, according to MacKay. Then, most get-at-able uranium is actually in the oceans, not in the ground — and the scale of the effort needed to mine the oceans for uranium, while noticeable in the same way as the nuclear stations themselves, is much less than mining the sea for wind and tide power.
Then, too, there’s thorium — probably a lot more abundant than uranium, and likewise full of juice.
Even MacKay admits that fast breeders and oceanic uranium together would power the entire human race at hoggish American levels for well over a thousand years, or at current European consumption for several millenia. He also says that known thorium reserves, used with current tech, would run the whole race at rich-westerner levels for several decades.
There’s also a thing called a thorium energy amplifier reactor which would be a lot more efficient. If it works as its Nobel prize-winning designers predict, known thorium reserves would run six billion people at American luxury for sixty thousand years.
...
MacKay is keen to stress that oceanic uranium extraction, the thorium energy amplifier and especially fusion are all unproven — though fast breeders are established kit. This is why he sees nuclear as a “stopgap”. He freely admits, however, that building new nuclear power stations is the most economic way of generating low-carbon power — and he confirmed to The Reg that in his view there would certainly be ample supplies of uranium to last the lifetime of any likely number of new UK plants.
...
You can see why he’s worried about getting that label [pro-nuclear], though. Worst case, assuming that only the known technologies work and only the known reserves exist, MacKay tells us that the entire human race could power itself — transport, domestic, industry, the lot — at hugely profligate American levels using nothing but fission for around a century. Since it’s unlikely that everyone will suddenly ditch fossil and ramp up to that level of use overnight, realistically you’re talking about at least a couple of centuries; longer if people only fancied being Europeans rather than Americans. It wouldn’t even cost much, compared to renewables.
A pretty useful stopgap, then. And if any of the gambles pay off — oceanic uranium, new thorium tech or fusion — the human race can pretty much relax. We’re sorted for at least a millennium, by which point we’ll hopefully be mining other planets.
...
Then, there’s the hard-green option for those who won’t have nukes or coal at all — plan G. “Greenpeace, I know, love wind,” says Mackay, “so plan G is dedicated to them, because it has lots of wind.”
"Nudging up the wave contribution … and bumping up wind power by a whopping 24 to 32 kWh per day per person … wind delivers 64 per cent of all the electricity.
Under this plan, world wind power in 2007 is multiplied by four, with all of the increase being placed on or around the British Isles. Roughly one hundred of Britain’s major lakes and lochs would be required for the associated pumped storage systems.
This plan gets 14% of its electricity from other countries.
The immense dependence of plan G on renewables, especially wind, creates difficulties for our main method of balancing supply and demand, namely adjusting the charging rate of millions of rechargeable batteries for transport. So in plan G we have to include substantial additional pumped storage facilities, capable of balancing out the fluctuations in wind on a timescale of days … Most major lochs in Scotland would be part of pumped storage systems."
It’s worth noting that in earlier analysis, MacKay suggested that pumped storage on this scale would be very hard to achieve using existing lakes and lochs. In actuality, vast amounts of seawater would probably get pumped up and down mountains and cliffs routinely to bridge the huge demand swings of a mostly-electric Britain and the massive variations in a mostly-wind powered grid.
MacKay made no effort to cost plan G, but he offers maps and figures indicating the staggering scale of the engineering. Britain would be literally covered with — and girdled by — massive wind farms, tidal barriers and wave barrages, and every sizeable body of water in the land would rise and fall to the strange new tides of the national grid. We would have literally rebuilt the British Isles as a single mighty renewable generator, pouring concrete and erecting steel on a scale so far matched only by human habitation — industrialising the land and sea in a way that would make intensive agribusiness look like a wildlife refuge. And still we’d be importing power.
That’s the reality of the Greenpeace plan for the UK, in hard numbers. You can see why MacKay is worried about their response.
Emphasis has been added. Mackay also has his own website (http://www.withouthotair.com/) where you can download his (currently unfinished) book.
I think there are some inescapable conclusions from this article - that renewables alone will not be able to deal with current energy demands let alone any future increases, meaning that nuclear power is essential. Biofuels are a total waste of energy and land which could otherwise be used to feed people (the energy gathered from biofuels is only enough to sustain medieval[ levels of energy consumption!).
I'm not a fan of "clean" coal but it's concievable that some currently existing coal plants may be converted into such while nuclear power plant construction gets up to speed.
My opinion of the best way forward would be to ramp up nuclear power plant production, begin construction of a vast Saharan solar farm that can provide Europe and North Africa with energy (Perhaps North America could do something similar in the American Southwest/North Mexico), and give maximum priority to fusion research in order to replace fission.
A topflight science brainbox at Cambridge University has weighed into the ever-louder and more unruly climate/energy debate with several things that so far have been mostly lacking: hard numbers, willingness to upset all sides, and an attempt to see whether the various agendas put forward would actually stack up. Professor David J C MacKay of the Cambridge University Department of Physics holds a PhD in computation from Cal Tech and a starred first in Physics, so we can take it that he knows his numbers. And, as he points out, numbers are typically lacking in current discussion around carbon emissions and energy use.
MacKay tells The Reg that he was first drawn into this field by the constant suggestion — from the Beeb, parts of the government etc — that we can seriously impact our personal energy consumption by doing such things as turning our TVs off standby or unplugging our mobile-phone chargers.
Anyone with even a slight grasp of energy units should know that this is madness. Skipping one bath saves a much energy as leaving your TV off standby for over six months. People who wash regularly, wear clean clothes, consume hot food or drink, use powered transport of any kind and live in warm houses have no need to worry about the energy they use to power their electronics; it’s insignificant compared to the other things.
Most of us don’t see basic hygiene, decent food and warm houses as sinful luxuries, but as things we can reasonably expect to have. This means that society as a whole needs a lot of energy, which led MacKay to consider how this might realistically be supplied in a low-carbon fashion. He’s coming at the issues from a green/ecological viewpoint, but climate-change sceptics who are nonetheless concerned about Blighty becoming dependent on Russian gas and Saudi oil — as the North Sea starts to play out — will also find his analysis interesting. Eliminating carbon largely equates to eliminating gas and oil use.
...
MacKay also gets into solar, both the thermal and electric kinds. Thermal has some potential for home energy, it seems, and is a good idea. (Funnily enough, almost all home microgeneration kit in the UK right now is solar-thermal water heating, so he might just be right here.) But solar photovoltaic (PV) electricity is viciously expensive in the cloudy UK, and just sticking panels on roofs won’t do much — it seldom yields any large proportion of the energy used in the building it’s on top of. You need to cover a big portion of the country in cells.
All in all, according to MacKay, if you like solar it probably makes more sense to put the panels in North Africa and bring the power to the UK over efficient high-voltage DC lines.
As an engineering matter the desert-solar idea is quite feasible — not very different in scale from piping in gas across continents and beneath seas, as people already do. Those fretful about buying power from Russia or the more unsavoury Gulf oil producers might be equally unhappy to buy it from Libya or Algeria, however.
...
MacKay also takes a look at the somewhat less right-on options. The biggies here are “clean” coal, in which coal power stations are modified so that the carbon they emit is captured and stuffed away somewhere, perhaps in old gas fields. For a man of his leanings — MacKay is a fairly hardcore pacifist, and more than a bit of a tree-hugger — he’s refreshingly open-minded.
"We must not let ourselves be swept off our feet in horror at the danger of nuclear power. Nuclear power is not infinitely dangerous. It’s just dangerous, much as coal mines, petrol repositories, fossil-fuel burning and wind turbines are dangerous."
MacKay concludes that nuclear scales up easily, and does so without dominating the country the way wind, solar, tidal and biomass do. The scale of engineering required, in terms of megatons of steel and concrete or areas of land and sea taken up, is enormously down on that needed by useful amounts of renewables.
Concerns over fuel price and security of supply aren’t nearly as much of an issue as they are with fossil fuels, because it’s comparatively easy to store energy-dense nuclear fuels like uranium and thorium — you could have several years’ supply stockpiled in the UK. If the price of the fuels rose, even if it multiplied seriously, it wouldn’t affect the price of energy much. Almost all the cost of nuclear energy comes from building, running and decommissioning the plant, and handling the wastes after.
Even so, present day nuclear fission technology is at best “a stopgap”, according to MacKay. His numbers suggest that the present method of using uranium would allow the entire human race to live like power-hog Americans in terms of power use for about a third of a year — assuming that only the uranium reserves now confirmed exist. Here MacKay perhaps reveals his natural anti-nuclear leanings somewhat, as he has put nuclear power to a much stiffer sustainability and fairness test than coal. But, showing commendable intellectual honesty, he goes on.
At present, there being no scarcity of uranium, it is typically dug from the ground and run through simple power stations just once before being classed as waste. Nobody explores for more uranium, and nobody has done so since the 1980s, because supplies are ample to meet current demand. There’s probably a lot more to be found, especially if the price of ore rose a lot. (Which wouldn’t affect the price of the energy significantly, remember.)
Furthermore, the use of fast-breeder reactors would get sixty times as much juice from a given amount of uranium, according to MacKay. Then, most get-at-able uranium is actually in the oceans, not in the ground — and the scale of the effort needed to mine the oceans for uranium, while noticeable in the same way as the nuclear stations themselves, is much less than mining the sea for wind and tide power.
Then, too, there’s thorium — probably a lot more abundant than uranium, and likewise full of juice.
Even MacKay admits that fast breeders and oceanic uranium together would power the entire human race at hoggish American levels for well over a thousand years, or at current European consumption for several millenia. He also says that known thorium reserves, used with current tech, would run the whole race at rich-westerner levels for several decades.
There’s also a thing called a thorium energy amplifier reactor which would be a lot more efficient. If it works as its Nobel prize-winning designers predict, known thorium reserves would run six billion people at American luxury for sixty thousand years.
...
MacKay is keen to stress that oceanic uranium extraction, the thorium energy amplifier and especially fusion are all unproven — though fast breeders are established kit. This is why he sees nuclear as a “stopgap”. He freely admits, however, that building new nuclear power stations is the most economic way of generating low-carbon power — and he confirmed to The Reg that in his view there would certainly be ample supplies of uranium to last the lifetime of any likely number of new UK plants.
...
You can see why he’s worried about getting that label [pro-nuclear], though. Worst case, assuming that only the known technologies work and only the known reserves exist, MacKay tells us that the entire human race could power itself — transport, domestic, industry, the lot — at hugely profligate American levels using nothing but fission for around a century. Since it’s unlikely that everyone will suddenly ditch fossil and ramp up to that level of use overnight, realistically you’re talking about at least a couple of centuries; longer if people only fancied being Europeans rather than Americans. It wouldn’t even cost much, compared to renewables.
A pretty useful stopgap, then. And if any of the gambles pay off — oceanic uranium, new thorium tech or fusion — the human race can pretty much relax. We’re sorted for at least a millennium, by which point we’ll hopefully be mining other planets.
...
Then, there’s the hard-green option for those who won’t have nukes or coal at all — plan G. “Greenpeace, I know, love wind,” says Mackay, “so plan G is dedicated to them, because it has lots of wind.”
"Nudging up the wave contribution … and bumping up wind power by a whopping 24 to 32 kWh per day per person … wind delivers 64 per cent of all the electricity.
Under this plan, world wind power in 2007 is multiplied by four, with all of the increase being placed on or around the British Isles. Roughly one hundred of Britain’s major lakes and lochs would be required for the associated pumped storage systems.
This plan gets 14% of its electricity from other countries.
The immense dependence of plan G on renewables, especially wind, creates difficulties for our main method of balancing supply and demand, namely adjusting the charging rate of millions of rechargeable batteries for transport. So in plan G we have to include substantial additional pumped storage facilities, capable of balancing out the fluctuations in wind on a timescale of days … Most major lochs in Scotland would be part of pumped storage systems."
It’s worth noting that in earlier analysis, MacKay suggested that pumped storage on this scale would be very hard to achieve using existing lakes and lochs. In actuality, vast amounts of seawater would probably get pumped up and down mountains and cliffs routinely to bridge the huge demand swings of a mostly-electric Britain and the massive variations in a mostly-wind powered grid.
MacKay made no effort to cost plan G, but he offers maps and figures indicating the staggering scale of the engineering. Britain would be literally covered with — and girdled by — massive wind farms, tidal barriers and wave barrages, and every sizeable body of water in the land would rise and fall to the strange new tides of the national grid. We would have literally rebuilt the British Isles as a single mighty renewable generator, pouring concrete and erecting steel on a scale so far matched only by human habitation — industrialising the land and sea in a way that would make intensive agribusiness look like a wildlife refuge. And still we’d be importing power.
That’s the reality of the Greenpeace plan for the UK, in hard numbers. You can see why MacKay is worried about their response.
Emphasis has been added. Mackay also has his own website (http://www.withouthotair.com/) where you can download his (currently unfinished) book.
I think there are some inescapable conclusions from this article - that renewables alone will not be able to deal with current energy demands let alone any future increases, meaning that nuclear power is essential. Biofuels are a total waste of energy and land which could otherwise be used to feed people (the energy gathered from biofuels is only enough to sustain medieval[ levels of energy consumption!).
I'm not a fan of "clean" coal but it's concievable that some currently existing coal plants may be converted into such while nuclear power plant construction gets up to speed.
My opinion of the best way forward would be to ramp up nuclear power plant production, begin construction of a vast Saharan solar farm that can provide Europe and North Africa with energy (Perhaps North America could do something similar in the American Southwest/North Mexico), and give maximum priority to fusion research in order to replace fission.