Let’s get one thing straight off the bat: carbon capture and storage (CCS) technology has a ways to go before it convinces anyone that it is a real long term solution. Personally, I think there’s a greater chance of seeing the hydrogen economy develop before we see CCS achieve any real success, and we all know that the hydrogen economy is always ten years away…
Nonetheless, there is reality to contend with. The reality is that there is an ever-increasing demand for more power that is available all the time. For now, at least, we can’t meet all of that demand without resorting, at least a little bit, to things like coal. That being said, let’s take a look at a proposal being made by the MIT Energy Initiative regarding what they call “partial capture” CCS.
The basic idea is that states are starting to regulate CO2 levels. No one knows what to do. No one wants to invest in the CCS solutions that are on the table, since they increase capital costs by 30-60% and they make the power plant less efficient, so the price of electricity per kwh goes up. But, says the MIT team, that all depends on how much carbon you actually capture.
Full carbon capture has been defined as capturing 90% or more of the CO2. The working assumption has been that CCS follows economies of scale. For example, when you build a plant that can manufacture a lot of something, the cost per thing goes down. Similarly, the expectation is that if a CCS plant captures a lot of carbon, the cost-per-ton-captured will go down.
What the MIT folks did was build a model to see how the cost changes as more CO2 is captured by the device, taking into account the technological reality. One key aspect of that technological reality is that at a certain point between 0% and 90% CO2 captured you need to add another CCS device. Thus, the study found that it is optimal to design a "partial capture" system. Instead of capturing 90% of the CO2, only capture 60%. This will still reduce emissions to acceptable state levels (comparable to those of a natural gas plant), and is cheap enough for the power providers to actually consider.
Does this mean we should try to wean ourselves off of coal? Absolutely not! But this is still a good thing. It gives coal power plants a chance to at least move in a green direction. It may even give CCS a chance to prove itself. More than anything, it gives credence to the notion that the green revolution can be achieved through a process of discrete, realistic steps.
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