Jenny Love, UCL Energy Institute
Based on a lecture by Prof Geoff Maitland, Imperial College, London
In the energy field, a common saying is, “There’s no silver bullet”. That is, there does not exist a solution to the question of which single clean energy source we should use, since energy demand is too large for any of them to supply on its own and thus we need to combine a lot of technologies. However, when it comes to funding to get these technologies off the ground, there are a lot of possible energy sources and not enough money to fund them all. Therefore the limited money should be used to fund the most promising ones, and this requires a kind of competition between technologies to show that they are more viable than others, in contradiction to our acknowledgement that we need a combination of them.
Carbon capture and storage – the processes of recovering CO2 before it is released into the atmosphere and burying it underground - entails high costs to bring it to commercial reality. In this context of limited funding, what is its potential, and should we invest in it over other technologies?
The following simple overview is mostly shaped by a recent lecture by Professor Geoff Maitland of Imperial College London, filtered of course through my own interpretation and limited understanding.
2. Some brief science
I won’t talk much about the science of carbon capture and storage (CCS) as it can be found elsewhere if you’re interested. Briefly:
There are three ways to do the ‘capture’ part of CCS (which, by the way, is the most expensive bit). You can capture the carbon before or after the burning of fuel (‘pre- or post- combustion’, or you can burn the fuel in a special way (‘oxyfuel’).
Once captured, the CO2 is transported usually via a pipeline, and injected deep into underground spaces as a supercritical fluid (not too quickly, otherwise the rock will crack). Once it’s there, we have to make sure it stays in – from my simplistic understanding, by a combination of not letting it escape while it’s a gas (‘capillary trapping’), getting it to dissolve in water (‘dissolution’) and longer-term getting it to solidify (‘mineralisation’).
3. How positive or negative are the benefits and disbenefits of CCS?
Maitland argues that after energy efficiency, CCS is the cheapest and greenest way to mitigate climate change. He does not by any means suggest that we don’t need other technologies too – for example he points out that even in theory only a third of our CO2 emissions can actually be captured and buried (10 gigatonnes out of our global annual release of 30 gigatonnes). This is because many CO2-releasing applications are not stationary large power stations, but e.g. moving vehicles and domestic boilers, which it would not be cost-effective to fit with CCS.
CCS advocates often describe themselves as realists, since their premise is that fossil fuels are here to stay, at least while we transition [slowly] to a low-carbon economy, and especially for developing countries. Therefore CCS is absolutely essential if we are going to mitigate climate change.
Concerns have been raised about the effectiveness of CCS, especially in terms of the energy it takes to do which decreases the overall energy produced at the power station, the safety and guarantee of storing CO2 underground, and the time it will take to get enough plants working. A Greenpeace document, False Hope, lays out some of these concerns. Maitland’s argument is that while these are real concerns, their extent is not is great as purported in the Greenpeace report.
4. What is the current state of the technology?
According to Maitland, the technology is “in good shape and ready for widespread deployment”. Its constituent parts, such as capturing CO2, and pumping gas into underground reservoirs, have actually existed for decades due to their use by different industries.
There are various CCS pilot projects going on around the world at the moment, including:
- An interesting project in Masdar, United Arab Emirates, who are powering the capture process by concentrated solar power, here:
- A plant operating since 2004 in Algeria, here:
- A French plant operated by Total, here:
As for the UK, CCS is part of the Department for Energy and Climate Change (DECC)’s heat strategy to 2050. For the moment, the government and the UK research councils are going to help fund the construction of up to 2 commercial projects. Those two look like they will be in Aberdeen and Yorkshire. The decision as to whether they will both go ahead will be made in early 2015.
5. So if the technology is ready, why isn’t it being done commercially?
It comes down to lack of two things: incentives and certainty. Lack of incentives is seen in that carbon is not taxed according to the environmental damage it does; lack of certainty in that the carbon price and future regulation about carbon storage have not been set out. Is is therefore too risky for companies to invest in CCS assuming that it will be economic in the future.
I’d like to conclude with the following statement from Maitland’s lecture: “The real cost of energy from fossil fuels is the generation costs PLUS the CO2 mitigation costs”.
In other words, at the moment we’re paying an artificially low price for energy, and any way in which we generate clean energy in the future will come with an increase in energy price. But, remembering the Stern report in 2006, it’s cheaper to pay more for clean energy now then clear up after the mess we make from global warming.
I think we need CCS; I agree with Maitland that we should develop it now but then phase it out if non-fossil-fuel energy can one day provide for energy demand. The main thing we need to get it going is a decent carbon tax, then industry will be falling over to buy CCS and no one will have to wait for government funding.
(More detailed information for keen people here)