Continued heavy dependence on coal for electricity generation is one of the world’s top environmental challenges and yet the future of coal depends largely on only one country. China is simultaneously the world’s leader in renewable electricity capacity and the world’s largest emitter of energy-related carbon dioxide, with around half of these emissions coming from coal-fired power stations. Despite encouraging signs that China is limiting new coal plant construction, China currently has over 900 gigawatts (GW) of installed coal-fired power capacity, representing almost 50% of the global total, and had nearly 200 GW under construction at last count. China’s coal fleet is one of the youngest in the world, with two-thirds of the plants built since 2005 and most of its plants could run for another three or four decades.
Reducing greenhouse gas emissions while expanding electricity use in China’s growing economy is likely not achievable without the early retirement of many coal plants or carbon capture and storage (CCS) retrofits. CCS presents a significant opportunity to match energy security and climate goals while avoiding cancelling or scrapping otherwise productive generating capacity.
Retrofitting existing coal-fired power stations with CCS can reduce their emissions rate by up to 100%, though an 85% reduction is most commonly proposed, representing emissions around four times lower than a gas plant. Compared to investing in new generation capacity, equipping an existing power plant with CCS only requires only the investment in the additional CO2 control equipment – for CO2 capture, transport and storage – and not in the power plant itself. However, in certain situations it makes sense to upgrade the power plant at the same time as CCS retrofit, delivering several additional decades of lifetime to the plant.
Costs will determine whether it is attractive to retrofit a coal-fired power plant in China in CCS. For example, older plants tend to have higher retrofit costs, as do those without sufficient pollution controls or low-cost cooling options. A principal determinant of cost is access to CO2 storage. According to the IEA, about 385 GW of China’s coal-fired capacity could find suitable CO2 storage within a 250 km radius.
Distribution of CO2 storage resources in China, including saline aquifers and oil fields. Over 2/3 of coal-fired power plants operated by the China Electricity Council are situated within 250 km of a CO2 storage site (Source: Chinese Academy of Sciences)
In total, about 310 GW of existing coal-fired power capacity meet a number of basic criteria for being suitable for a retrofit. This number is increasing as new coal plants are commissioned and the new plants are all sufficiently large for retrofitting. Many of them are among the most efficient plants in the world.
“We’ve taken a novel approach to estimating the additional cost of electricity due to adding CCS to each Chinese coal plant, taking into account the option of lifetime extensions,” said Simon Bennett, IEA Energy Analyst and lead author of Ready for CCS retrofit: The potential for equipping China’s existing coal fleet with carbon capture and storage. At the lower end of the cost range, delivering lower emissions via CCS retrofits looks competitive with new low-carbon generation capacity, such as renewables. CCS retrofits also have the additional benefit of delivering electricity on demand, providing the grid with a flexibility resource.
While retrofitting can represent a significant opportunity for emission reductions in China, it will require establishing the right drivers. Including CCS in China’s climate policy, or retaining the option of future CCS retrofits, means it is imperative to keep analysing CO2 storage opportunities and to develop suitable storage sites.
Alongside other measures to maintain energy security, ensuring that CCS technologies are available in China over the next two decades will require effort from a variety of stakeholders. Alongside efforts elsewhere in the world, government and industry in particular will need to continue their efforts in technology innovation and cost reduction, to further bring down costs of CCS in general and retrofitting in particular. For any further permitting of new coal-fired power stations, promoting locations and technology choices that are CCS-ready could be a significant step in this direction.