Energy with CCS: unlocking negative emissions.
It’s free to attend, no need to book. Dr Gough kindly answered some questions about BECCS – see full unedited interview below. Questions in bold.
The basic idea of capturing and ‘storing’ carbon dioxide has been around since the 1970s. Other than a couple of super-expensive ‘demonstration’ projects (Boundary Dam etc), what actual proof is there that it could ‘work’ at scale?
These technologies have been more than an idea since the 70s, the component technologies have been in commercial use for several decades. As you say, there are several (around 20) large scale demonstration projects for CCS in operation, but the only way to “prove” it on a larger scale now is by increasing its use. That would be the same for any technology
In a nutshell, what is BECCS?
BECCS stands for biomass energy with carbon capture and storage.
Biomass (i.e. plants) take up carbon dioxide from the atmosphere via photosynthesis; if the biomass is burnt in an energy conversion facility (such as a power station) that carbon dioxide is released back to atmosphere.
Carbon capture and storage (CCS) was originally designed in the context of fossil fuels – by capturing the carbon dioxide normally released in flue gases during fossil fuel combustion (for example in a power station), then by compressing, transporting and storing that CO2, it can be prevented from being emitted to the atmosphere. The CO2 is stored in geological formations very deep underground; potential storage sites in the UK are all offshore – 100s meters below the seabed.
By combing biomass energy with CCS (BECCS) the CO2 taken up from the atmosphere by the biomass is captured and stored. If the amount captured and stored is greater than any emissions along the supply chain, more CO2 is removed from the atmosphere than is emitted and there is a net removal of CO2 from the atmosphere. This is sometimes called negative emissions.
A lot of people criticise BECCS as an unworkable/fantasy technology that distracts us from the urgent task of immediate mitigation. What’s your take on that?
Technically, there is no reason why BECCS should not work; there is widespread use of biomass energy in large scale facilities (such as Drax power station for example) and CCS is technically well-understood and has been demonstrated to work.
Furthermore, for BECCS to deliver net negative emissions on a global scale, such that atmospheric concentration of CO2 is reduced, would require ambitious mitigation – emissions will only be ‘global net negative’ when the negative emissions from BECCS are greater than all the emissions from other sources. It is not an alternative to mitigation, it can only work with mitigation.
The issue is one of scale.
Firstly, given the current lack of progress in delivering ambitious/radical mitigation (emissions reduction) many scenarios include an extremely large scale contribution from BECCS – the technology may have a role but its potential should not be overestimated.
Secondly, there are very many non-technical challenges to implementing BECCS on a global scale that become more challenging as the scale increases – I will discuss these in my forthcoming seminar at the Tyndall Centre.
So, yes, there are some very optimistic claims made about the potential for BECCS. However, even with the best efforts to reduce emissions elsewhere, there will remain some sectors which are very difficult to decarbonise (aviation, for example) – if BECCS can contribute by effectively removing the emissions from these sectors it could make an important contribution to realising the climate goals agreed in Paris.
Anything else you’d like to say?
Come to the talk and I will explain these issues in more depth!