Here’s an excellent talk by biologist Willie Smits detailing a sucessful attempt in regrowing a rainforest in a relatively short period of time. This talk also serves as an excellent example for what kinds of approaches do work and which ones don’t.
Archive for April, 2009
Today we’re talking about Carbon Capture and Storage which has been getting a bit of press lately. Personaly I’m skeptical of it, not so much because I doubt it’s usefulness as much because I’m concerned that it could be used to sell dirtier technologies with a half hearted promise that they would be cleaned up later. I paticularly didn’t like the way the phrase “Clean Coal” was tossed around like a football during the American Presidential debates.
Clean Coal reminds me of the claim made by cigarette companies that their new toasted tobacco had rendered their product safe. However there’s a lot more to CCS than just marketing hype so I’ll turn to a pair of commentators who are a bit more knowledgeable than me on the subject.
We need CCS. And we need it soon. It is the only technology that can possibly hold down the emissions of the newly industrializing world. China and India will use coal for their power stations. Without CCS, their need to electricity will destroy the world’s ambitions to start reducing emissions by the middle of the next decade. Even in the UK coal burning power stations contribute about a quarter of the country’s total emissions. Because coal is now the cheapest source of fossil fuel energy, the incentive on power generators to install more coal burning plants is enormous. The only way we can make this acceptable is by rapid roll-out of carbon capture.
CCS, Carbon Capture and Sequestration is a suite of technologies, some enormously problematic. Broadly speaking, it refers to any technology which can capture and keep carbon out of the atmosphere more or less permanently. This encompasses a wide range of methods, some for removing carbon dioxide from the atmosphere (biochar schemes and the like) and some for preventing its emission in the first place, by capturing the CO2 which woud be released by burning fossil fuels and then storing it.
It is the latter form of CCS which is controversial. The largest application of this type of CCS is likely to be the capture of emissions from coal fired power stations. Ignoring for now the exact method of capture, the CO2 is concentrated and liquefied, and then transported, via pipeline or similar arrangement, to a suitable geological formation, where it will be injected into the ground and where it will, in theory remain. All of the stages of this process have been demonstrated as feasible from an engineering standpoint, although they have not yet been put into practice on an industrial scale or demonstrated as economically feasible. None of the large coal power stations currently under construction anywhere in the world has been designed with CCS in mind, meaning that the capture systems will have to be retrofitted at some future date, as will transportation networks from power plants to the storage formations.
It is estimated that the CC part of the systems will require 25%-40% of the electricity produced by the power station, with the sequestration element adding a further cost depending on how far away the plant is from a suitable site for storage (which, generally, will be a fair distance). The total increase in the cost of electricity produced at a plant equipped with CCS over electricity produced at a conventional coal power station is impossible to gauge particularly accurately, as the technology is still very much at the experimental stage, but is estimated at an increase of between 21% and 91%.
Since the cost of electricity generated by coal is currently comparable with the cost of electricity from wind power, the economic argument for CCS looks weak. The case is worsened by the rapid development and deployment of wind, solar and other renewable sources, and the equally rapid improvements in energy storage techniques which will iron out the intermittencies of renewable energy tech.
The practical argument, which is that coal is readily available and cheap and will therefore inevitably be used by rapidly developing nations such as China and India, is somewhat more compelling, but remember that no commercial power station under construction or on the drawing board makes any provision for CCS technologies, meaning an expensive refit at some future date in order to use prevent that CO2 being emitted. Plus the construction of the infrastructure needed to transport and store the CO2 produced. Plus the cost of commercialisation of all of the above.
All this without even mentioning the environmental damage caused by the mining and transportation of the millions of tonnes of coal to feed all these power stations or the damage caused by the millions of tonnes of mildly radioactive and toxic ash they produce.
So, to sum up, CCS in the form most frequently talked about is a suite of unproven, expensive, technologies whose sole purpose is to enable us as a species to continue one of the most heavily polluting activities we carry out, albeit with greatly reduced emission of CO2 into the atmosphere. It’s not ready now, and will require a huge programme of remedial works to the worlds coal power station stock if it is ever to be of significant use.
As a ‘green’ technology most of the money for the above will probably come from a funding pool shared by genuinely benficial tech such renewables, electricity grid redesign, large scale energy storage etc.
CCS greenwashing? I’m not sure that’s entirely fair, and I’m sure there will be a role for it, simply because the situation is desperate and we’ll be obliged by inertia and the general uselessness of our leaders to do something with all those fossil fuel burning power stations or else totally destroy our beautiful biosphere, but it is on the level of giving a liver transplant to an alcoholic who refuses to stop drinking – an act of desperation which will probably deprive someone else of their chance at life.
Charles Robinson is a Meme Therapy contributor and freelance Sustainability Consultant.