Interesting article on the "tragedy of the commons" and what kind of international CO2 emission regulation system might work.
As usual in engineering-type problems, the devil is in the fine detail, and this article goes deep enough to be interesting.
-- Bill Sloman, Sydney
Interesting article.
Here is my take on a way to improve CO2 recycling, and cut the total fossil fuel input:
There are 3 main systems where we use energy. Ground transport, cars, trucks, etc Air transport, airplanes Fixed base ( non - nuclear ) power stations, the electricity supply. These are roughly equal in size, and contribute about the same both to total energy and total co2 production. So some significant reduction in co2 generation from any one of these would help reduce co2 emissions globally.
Ground transport mostly uses liquid fuel, oil derived, and its pretty efficient in terms of energy use, but cannot easily store or cycle the co2 produced. The extra work to do that would kill the efficiency and raise the cost of transport very significantly. There is the possibility though to replace fuel burning with battery/electric systems, at least for short haul. And battery technology is still improving. But that places an even heavier load on power stations, to generate the electricity required. And the total efficiency drops, so the fossil fuel input and co2 output from the base stations goes up significantly.
Air transport is similar to ground, but the energy density required, and the recycling problem, is even higher. I really doubt there is much room to change there. Best would be just to limit air transport to some acceptable level, to limit the total load.
But fixed base power stations have a unique possibility to be improved.
We have plenty of energy available from the sun, pv, heat, wind, etc. What we dont have is a good cheap, efficient way of storing it for use when no sun, eg night, cloudy day, etc. Electric batteries at the size, energy density and lifetime we need are only just barely possible for small installations. The chemistry puts a hard limit on the energy density, and we are already pretty much at that limit. Safety considerations are also an issue with more exotic chemistry. So instead we burn fossil fuel, and throw the co2 into the atmosphere.
2 effects from that, we lose the non renewable fossil fuel, and we add co2 to the atmosphere. Imho the first of these is more important than the second, since eventually we will run out of fuel. That will fix the second problem too.There is a lot of work being done on carbon capture, after burning the fuel, but almost all on permanently storing the carbon in some inaccessible place, so it wont end up in the atmosphere. But that means we have to dig up more fossil fuel, and cope with the mess that makes, as well as finding a place to store the co2. Both of these are really difficult problems.
So far all the proposals I have seen for carbon capture suffer from serious efficiency problems. If you burn fossil fuel, and use a significant part of the energy processing the carbon into permanent storable form, you dont get enough energy left over to run civilisation. Thats a dead end. As well nobody seems to take account of the fact that co2 is roughly 3 times the mass of the original carbon ( as coal ). So if you dig up and burn 1 million tons of coal, and capture all the co2, you get 3 million tons of co2. Coal has density roughly 2.0, CO2 as liquid under pressure has density 1.1. So the 3 million tons of C02 has volume roughly 6 x the volume of coal mined. Where are you going to put it ? It sure wont fit in the hole you got the coal from.
But there may be a better way. Hydrocarbon fuel (chxx, eg diesel) is an ideal energy store, with a very high energy density, much higher than any electric battery. Wikipedia gives energy density of lithium rechargable battery at around 1.8 Mj/kg. Diesel is around 48. So why not convert co2 to chxx using the energy in sunlight, the hydrogen of course we can get from water, of which we have plenty, and even that is recyclable, if it matters, using a suitable process. But only enough to create a reservoir of fuel to use at night, and over a couple of weeks, to allow for weather events. Recapture the co2 in a fully closed cycle, and use the energy from the sun both as primary source, and to convert the co2 back to chxx. Then the chxx becomes the energy store, much easier to handle using existing technology than big electric batteries. So the whole system is still driven by solar energy, whether as pv or heat, depending on what is needed both to run civilisation, and the chxx-co2 cycle is purely an energy store, using well known technology, tanks, pumps, gas turbines, etc to do the storage and conversion. The only piece missing is the co2 to chxx chemical process. That process has already been done, at least to make methanol, which can either be used directly, or processed further into chxx.
All we need now is the will and the planning to convert our major ground based power systems over to this form of generation. At least the technology for each part is already available, we just have to rearrange the components into the correct configuration.
-- Regards, Adrian Jansen
Just tell all those billions of poor people in China and India and Africa and South America that they can't have electric lights or cars or tractors or clean water or ever fly in airplanes.
Tell them that they have to recycle their CO2 first.
Lots of luck.
-- John Larkin Highland Technology, Inc picosecond timing precision measurement jlarkin att highlandtechnology dott com http://www.highlandtechnology.com
Extraordinarily long-winded "solution". Disposing of all leftists would be easier, more fun, and more efficient reduction of energy consumption >:-} ...Jim Thompson
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ternational CO2 emission regulation system might work.
and this article goes deep enough to be interesting.
George Monbiot's "Heat" went into the problem posed by air-transport in som e detail, and came to the conclusion that mass tourism by air was a luxury we couldn't afford, at least until we got the kind of bulbous air-planes th at could carry enough liquid hydrogen to get someplace useful - it's not a dense liquid.
Not entirely accurate. Thermal solar can store several days worth of heat a s molten sodium nitrate - big tanks have a long thermal time constant, and if you insulate them carefully, you can make the time constant even longer.
Storing the energy before you turn it into electricity is a lot cheaper tha n turning electric power into stored energy and recovering that stored ener gy.
There are a couple of practical examples running today.
only > just barely possible for small installations. The chemistry puts a hard
.I'm not so sure about that.
uses a liquid electrolyte which can be charged up, pumped into storage tank s and pumped back into the battery when you need power. If you want lots of power you need big batteries, but if you only need to store lots of energy , you just need big storage tanks and they can be a lot larger than your ba ttery.
Not fast enough. We can afford to burn most of the oil we know about, but n owhere near all the coal.
You could run our current civilisation on solar power. You'd probably make a few compromises about when the power was used, and you might end up using a bit less of it.
There's nothing magical about our current level of energy use. We already d o more with the energy than we use than we used to, and there are quite a f ew social choices which would allow us to use less. The free market way of encouraging people to make those choices would be to raise the price of ene rgy, but there are a lot of commercial interests that want to make more mon ey by selling more energy, and they don't like the idea of selling less, ev en if they can get a higher price for what they do sell.
Probably. But it might be useful step along the road to completely renewabl e energy sources.
The deep ocean comes to mind. That's where half the CO2 we are injecting in to the atmosphere ends up anyway. It won't stay there forever - the time co nstant seems to be about 800 years - but it would stay there long enough to tide us over until we had got close to fully renewable.
But a whole lot less efficient.
Sure, but not a lot of the energy captured from sunlight ends up in the fue l.
Capturing CO2 from places where it is fairly concentrated is a necessary pa rt of the process - 400ppm of atmospheric CO2 is not an ideal feedstock.
Solar cells capture a lot more energy from incident sunlight than photosynt hesis usually does, and they do pretty cheaply. Photovoltaic energy is curr ently level-pegging with regular grid generators, and if we built enough of them to do most of the job we'd almost certainly at least halve the price.
The rule of thumb for economies of scale is that ten times the volume halve s the unit price, and the cost of solar power is still pretty much the inte rest on the capital invested in the solar cells themselves.
Building lots more photovoltaic cells makes a good deal more economic sense .
makes the point that if everybody has electric cars, there will be a great many more electric batteries doing nothing at any given moment than there w ill be shifting commuters around. The smart grid could exploit them for lot of the energy smoothing required. You still need clever domestic appliance s that can unload the grid when too many solar cells are clouded over, but it does look like a more feasible way to go.
Friedman's book - from 2008 - does predate any working thermal solar plants , and more modern solutions might be less reliant on a smart grid.
-- Bill Sloman, Sydney
Of course not. Only Al Gore, Barbara Streisand, and Barak Obama are allowed to fly anywhere.
or tractors or clean water or ever fly in airplanes.
Solar power can give them electric lights, electric-powered cars and tractors and clean water.
Mass air-tourism does seem to be a luxury that we will all have to give up until somebody designs a plane bulbous enough to accommodate liquid hydrogen fuel tanks - liquid hydrogen offers good energy density per unit mass, but not per unit volume.
If you make enough solar cells to satisfy that energy market, they'll get their electric power at half the price they'd pay now for getting it from burning fossil carbon.
Since fossil carbon is a finite resource, and we've been digging it up from progressively more difficult and expensive sites for the last century or so, it's getting progressively more expensive.
Making solar energy dispatchable is tricky and expensive - unless you build big and capital intensive solar thermal stations.
It's possible that the third world will work out how to live with cheap power that isn't available exactly when you want it. Getting it for half the price would encourage quite a bit of ingenuity.
-- Bill Sloman, Sydney
Yes, tell the "poor" Chinese that they can't manufacture any more solar panels until they recycle their CO2.
-- Rick C
Trust Jim not to notice that rightists are even more prone to drive gas-guzzling muscle cars.
-- Bill Sloman, Sydney
I have an article saying the 35% global deforestation replacement would take care of all vehicle emissions.
Greg
There's some hope for that, actually; orbital solar power installations, with laser output, can get enough energy on a wing dorsal surface to drive electric motors. Can't do it with microwaves, though, they won't focus as small as a wing.
So, you use fuel for takeoff, emergency maneuvers, and landing. You cruise on rays.
So you have both gas engines as well as electric? That's going to be one heavy aircraft. I guess you save on fuel weight.
It might be a bit expensive. How large will the sat have to be to power just one airplane? Then multiply it by how many thousands of planes?
-- Rick C
... snip ...
All good comments, thanks Bill.
My aim was to point out that there is enough existing technology to make some major improvements to how we run our energy supply.
The major problem seems to me to get started, which is a political problem, not an engineering one. But new unproven technology, no matter how seemingly good, suffers from the risk averse nature of big enterprises, and political systems.
So rather than endlessly debate over which is the better of many competing solutions, how about we start with stuff we already know how to do, and build from there. That after all is how we built our current systems.
If someone said in 1900 that we were going to build a 200 Mw powerstation, and run it with a computer, it would never have been built. But a 5 Kw coal fired steam engine coupled to an alternator could be built, and was.
-- Regards, Adrian Jansen
sounds unlikely to be correct.
-- This email has not been checked by half-arsed antivirus software
and likewise alternative energy infrastructure will be built as the technology develops to make it practical.
But __forcing__ it to be built BEFORE it's practical is counter productive.
m
Hopefully it will be practical & worthwhile one day, but it's far from it now. This thread is riddled with so many large errors in understanding that discussing them is not very practical either.
NT
Research is not cheap. Companies will only do it when they see a payoff. In order to get research going we can either have the government pay for it directly, or find a way to create a payoff for the companies. One way is to subsidize existing technology so they have profit to reinvest in research in order to increase their profits. Once that reaches some point it becomes self-sustaining. Before that point progress will be very slow if not funded somehow.
-- Rick C
Carbon sequestration by growing forest is a stop gap measure. It has a finite impact. Once that is exhausted, unless the carbon creation is reduced, the release of more carbon will continue to increase the CO2 in the atmosphere. In other words, deforestation replacement can't counteract continuing carbon exhaust.
-- Rick C
hnology develops to make it practical.
ive.
That's a good standard approach when the resulting products have real utili ty. Now that they don't it's cheaper to pay for research directly. And sinc e none of the existing technologies have a real likelihood of becoming viab le, it make sense to restrict funding to the few projects that have a shot at changing the map.
NT
ology develops to make it practical.
e.
Far from it. Germany largely took over the photovoltaic market between 2000 and 2005 by over-investing in production capacity - they essentially went for production on ten times the scale that had been built earlier, on the - correct - assumption that this would allow them to halve the price of each unit of generating capacity they produced, and knock everybody else out of the market.
China did exactly the same thing rather more recently, pretty much wiping o ut the German photovoltaic production industry.
You get the innovations you pay for. There's always the risk that somebody will invent a factor of two better mousetrap, but university research is we ll publicised so that risk is small.
-- Bill Sloman, Sydney
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