Weighing up the evidence on CCS

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Dr Sara Budinis and Zara Qadir of the Sustainable Gas Institute review the current state of research on Carbon Capture and Storage.

The global climate deal agreed in Paris last week has set ambitious targets for cutting greenhouse gas emissions and limiting global warming. Carbon Capture and Storage, or CCS, is a technology that could prevent large quantities of carbon dioxide (CO2) resulting from fossil fuel combustion from entering the atmosphere. Yet our understanding of how CCS can contribute to climate change mitigation efforts is still incomplete. In this blog, we give an overview of the current state of knowledge – and some of the key questions that remain.

Why do we need CCS?

The Intergovernmental Panel on Climate Change (IPCC), the International Energy Agency (IEA) and the European Commission have endorsed CCS as a crucial technology in helping to reduce cumulative CO2 emissions as a partner technology, alongside other solutions such as renewables, fuel switching and improved energy efficiency. A network of Environmental NGOs is also calling for a faster adoption of CCS technology.

It’s not a case of CCS vs renewables: both are integral to building a low carbon energy world. Many critics consider that CCS investment reinforces our dependence on fossil fuels. But this doesn’t take into account that while renewables are increasingly becoming a practical option for power generation, CCS is the only option at the moment for some heavy-emitting industrial processes.

While renewable technologies continue to progress towards overcoming shortfalls (e.g. intermittent availability or grid connectivity), it is unlikely that a significant transition away from fossil fuels will happen any time soon. CCS could also provide a mechanism for developing nation states to use fossil fuels resources sustainably as part of their energy mix to improve living standards.

The technology underlying CCS has been in existence for decades as part of applications such as Enhanced Oil Recovery (EOR).  However, according to the Global CCS Institute, there are only 15 operational commercial-scale CCS plants worldwide.

Is it economical?

While the ‘tech’ works, CCS will need to be economical at scale. Unfortunately, concern about the capital costs often ignore the long-term costs of inaction. For instance the IEA estimates that by 2050, the cost of tackling climate change without CCS could be 70% higher than with CCS.

Oil and gas companies should be encouraged to invest in CCS. The absence of fixed carbon pricing is conceivably holding back CCS development; a growing carbon market could provide an incentive. Scale and efficiency is also needed through collaboration across nations and a common action plan.

CCS and the carbon budget

The term ‘unburnable carbon’ refers to the amount of hydrocarbon reserves (if combusted or otherwise converted to CO2) which exceeds the global carbon budget. There is no denying that a percentage of fossil fuel reserves found cannot be burned if the Earth’s average temperature is not to increase beyond 2°C. But it’s difficult to assess how much of an impact CCS will have in abating climate effects, and contributing to meeting these targets.

An important scenario might be how much CO2 can be released while meeting the energy demand, and keeping the temperature rise within 2°C or indeed within the more ambitious target of 1.5°C.

Comparing a CCS world with a non CCS world

So far, studies have produced conflicting reports of CCS’s future capabilities in addressing climate change.

Both the IEA and IPCC report that the technology will have a significant impact in managing greenhouse gas emissions.

However, these reports view CCS from a resource-limited perspective, for example taking potentially conservative views of the amount of CO2 storage capacity available and on availability of CCS before 2050, due to its cost, late introduction (most likely around 2025) and maximum rate of construction.

In her current literature review, Sara is evaluating the role of technology and in particular the role of CCS with respect to ‘unburnable carbon’. It’s a broad topic, and there are so many questions to explore. For example: What is the most promising technological solution? What are the current global storage capabilities?

Known unknowns and unknown unknowns

The potential of CCS is dependent on a number of unknown future parameters including technology cost, lifetime, availability, performance and market potential. The time horizons considered (until 2020/2050/2100) also have a bearing on the potential impact.

There are also number of technological or efficiency challenges that need to be overcome or investigated further such as improving the percentage of CO2 that can be captured by the process.

Technology solutions for a 2°C world

It will take a growing number of technological solutions to ensure we keep to a 2°C world, whether it’s renewables, carbon-neutral technologies or the developments in carbon capture, utilization and storage (CCUS) where the ‘byproducts’ of the process have an economic value.

Although CCS shows promise, the challenges and opportunities still need to be investigated more broadly to ensure it’s effectively employed as a cost-effective solution to climate change.

At the Sustainable Gas Institute, Sara is working on a white paper that will fully explore the role of CCS in unlocking unburnable carbon. The paper will report various technological and climate change scenarios and outline the role CCS has to play in limiting climate change on a global scale. If you’d like to receive a copy of our next White Paper please subscribe to the Sustainable Gas Institute newsletter.

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