Next Generation Energy is managed and written entirely by Seed editors and expert guest bloggers. Read more about them All of the energy sources we've discussed on this blog—from nuclear power to tidal power to cellulosic ethanol—have been developed with the ultimate goal of replacing coal and oil. However, the problem remains that even with the right technology, political and economic support, the transition is going to take time that we do not really have; carbon emissions must be cut dramatically and immediately to prevent catastrophic climate change. And at least one method is being tested to control carbon output while we are still dependent on fossil fuels: carbon capture and storage (or sequestration if you prefer).
Carbon capture and storage (CCS) has the potential to cut a modern power plant's emissions by 80-90%. In such plants, carbon gas is trapped as it exits through exhaust pipes into the atmosphere; it is then usually piped to storage sites in oil and gas fields or other suitable underground locations. Some experts are concerned that the gases might leak out of the ground and reenter the atmosphere, although the IPCC believes 99% will remain sequestered over the next thousand years.
Are there other risks involved with CCS? Could it be applied to all current power stations, and how would that affect our power supply? Is CCS an integral part of a short term energy plan or just a bandaid on a festering wound?
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Comments
I think the biggest risk is that carbon capture will never be economical compared to other low emission sources of energy and so will never be installed except possibly in one or two small "demonstration plants" but it will be used as excuse to continue to build coal plants which will dump their CO2 directly into the atmosphere.
Posted by: Ronald Brak | September 24, 2008 12:23 AM
I'm with Brak. I see CCS as being an avoidance of what must be done. It would be horribly expensive, and is just meant to prop up existing fossil fuel technology. At best it could be one aspect of a multi-faceted approach.
Oil companies have to re-invent themselves as energy companies. They have the resources to do it. There are potentially huge markets that would offset losses given up by being dependent on existing fossil fuel technologies.
They have to grow a pair and start doing some basic research, funding efforts by innovators and be savvy enough to recognize when they have their hands on the next big thing and not blow it because of fear-based thinking (the way Xerox blew being the leaders of the PC revolution, and GM blew the opportunity to be the leaders in the electric car/hybrid car revolution).
I don't know if they are up to the challenge (probably not). Hopefully they will be out-competed by smaller companies that are up for the challenge.
It's hard to say. We are running out of time and there may be catastrophic results in terms of human suffering as well as a mass-extinction event.
But simply inventing excuse-techs that stave off the inevitable for a few years is clearly not the best place to put our efforts.
Posted by: yogi-one | September 24, 2008 4:09 AM
As the previous two commenters said, it's a mistake to assume that this is a "cheap" or "easy" stopgap solution, along the lines of just connecting a tube to the coal-burning plant's chimney on one end and to an empty underground cavern on the other, or something. If it were that simple, I'd be all for it, and we'd probably already have at least several demonstration-scale plants operational. But whenever you read about this technology, it seems to be about $millions funding to build a demonstration-scale plant by 2011, and the first commercial-scale ones by 2015, or something. Which is not even vaguely enough, especially as by that time we could just pour the money into energy that is actually clean and probably achieve much greater CO2 reductions.
Posted by: Julius | September 24, 2008 5:10 AM
The big problem with CCS is that it's currently only economic when used for Enhanced Oil Recovery. When used in this way, it actually increases the total amount of carbon emitted by allowing the extraction of more oil than would otherwise be possible.
Posted by: Dunc | September 24, 2008 5:29 AM
Keep in mind, however, that the government should not be deciding which solution is actually the best. We should set the standards for carbon emissions and other pollutants, and let the marketplace figure out which is most efficient. That will vary, of course, over time and depending on the specific location and other factors.
So if carbon capture and storage is not economical, it won't be used. No problem. Sure, there will be demonstration plants and research grants, but a variety of approaches is a GOOD thing.
The government should decide what must be accomplished, but not how it must be accomplished.
Posted by: WCG | September 24, 2008 12:14 PM
I'm no expert on CCS; but someone who is somewhat of an expert told me current plant scale buildable tech can potentially separate and reinject the CO2 at an energy cost of about 20% of the plant's output and that better separation tech is in lab stage which will lower that percentage. If so that pushes coal gen electric up to about 10 or 12 cents per kwh, which is still a lot lower than alternatives.
As to the longevity of the CO2 storage; if our descendants find that a technical problem in a hundred years we may as well hang it up right now and join the voluntary human extinction movement (which has a moderately amusing website). A hundred years ago most of our ancestors were plowing with horses. Feeding the current world population using real horsepower would have us all about a hundred feet deep in doo doo.
Posted by: Sully | September 24, 2008 1:37 PM
That carbon emissions must be reduced immediately is in some ways the least of our problems. Fossil fuel depletion in itself is enough to bring industrial civilization to its knees long before the worst (whatever that may be) of climate change is realized.
Posted by: Eric the Leaf | September 24, 2008 4:26 PM
One known problem with CCS is that, as Sully pointed out, it costs about 20% of the plant's output in overhead.
CO2 is not the only greenhouse gas that comes from the burning of coal. CCS only captures the CO2. It lets go free the other greenhouse gasses. To get the same output, you have to run the plant 25% harder (1.0/0.8), producing 25% of those other gasses.
Methane and Nitrous Oxide don't dominate the calculations, like CO2, because the quantities are lower, but recall that methane (CH4) traps 21 times as much heat as CO2, and that Nitrous Oxide (N2O) traps a whopping 270 times as much as CO2. (reference here)
Posted by: Eric in Santa Fe | September 24, 2008 4:34 PM
The real issue is as Ronald (and others) have said, that CCS might be somewhat developed, but not widely implemented. In addition to the loss of thermodynamic efficiency of the plant, a lot of capital investment must be made -it means a lot of money must be spent up front. Then retrofits are a huge problem. In most cases, there is not enough empty space around existing, and currently planned plants, to allow a capture unit to be added (if such a unit were available).
Now, with all that said. I still support trying to develop the technology. If it works, and it is the only way to get some key emitters to reduce, it just could save our bacon. But, I think realistically we should not treat the probability of it being ready for the bigtime in time to be maybe around fifty percent.
Posted by: bigTom | September 24, 2008 7:04 PM