In some Organization for Economic Cooperation and Development (OECD) member countries, policies supporting extensive investment in cleaner electricity generation, alongside the pricing of greenhouse gas emissions, have enabled CFPPs to be successfully retired or replaced and emissions to decline. The situation in developing countries is often more challenging, not least because of the young age of the coal assets, the energy market structure and rules, the growing overall demand for electricity, and the relative weakness of grid infrastructure or the absence of inter connectors between markets.

Repowering, defined as the sustainable reuse of all or part of an existing power plant, offers a solution. Repowering delivers as close to like-for-like (or even expanded) services as possible, minus coal burning. This offers increased energy security, lower overall system costs, and environmental, socio-economic, and political benefits. Examples include the reuse of valuable infrastructure, retention of jobs and firmed¹ electricity generating capacity, and associated community benefits. Reusing existing grid connections, environmental permissions, and permits also offer cost and time savings. Repurposing existing power plant land can circumvent the regulatory and social challenges often faced when securing new land in emerging markets and developing economies. Utilising existing power purchase agreements (PPAs) can streamline the transition process, avoiding the need for new negotiations. Overall, repowering can be a hugely powerful element of a just transition, and yet it is not currently receiving the attention it deserves.

Repowering is not a new concept; it is in its early stages and is yet to achieve large-scale adoption. We provide details of previous examples of repowering in AppendixIV: ‘Summary of Ongoing Coal Repowering Projects’.Existing and newly emerging classes of clean technologies, which can be used to repower coal and other fossil-fired power generation sites, have huge potential to speed the just transition to a clean global economy.

The range of sustainable technological options for repowering include reusing CFPP electricity infrastructure as the interconnection point(s) for new variable renewable energy (VRE) to the power grid, heat batteries², full conversion of the heat source to(or acting as the host site for) advanced geothermal or next-generation nuclear reactors, and the repurposing of certain types of existing generators as synchronous condensers (SCs)³.

The majority of CFPP retrofit projects to date have followed the coal to natural gas pathway. Natural gas burns more cleanly than coal but still emits unacceptable levels of CO₂ emissions⁴ when combusted.Methane can leak from wells, pipelines, and other infrastructure associated with gas production, transportation, and combustion. Therefore, assuming that the natural gas is unabated, this cannot be considered clean “repowering” by our definition, since it will not be considered sustainable in the long term. Although retirement of the CFPPs, ammonia co-firing, coal/gas and carbon capture storage (CCS) are not ruled out, their overall viability may be compromised by factors such as low full-cycle efficiencies for ammonia, limited local availability of sustainable fuels, and significant unabated upstream gas emissions (from wells, pipelines, and other sources). These challenges render these options less competitive than recommended technologies such as next-generation geothermal, concentrated solar power, or advanced nuclear reactors.