CoalSwarm/Greenpeace Report Shows Pathway to 1.5°C

In its special report Global Warming of 1.5°C, the Intergovernmental Panel on Climate Change (IPCC) assessed mitigation pathways limiting warming to 1.5 degrees Celsius (2.7° Fahrenheit) above pre-industrial levels. The IPCC analyzed various pathways for coal, all of which require a near-total reduction in coal use for electricity generation by 2050, with reductions of approximately two-thirds by 2030. (For additional background on the IPCC recommendations, see “IPCC Findings on Coal” (SourceWatch).

Greenpeace/CoalSwarm press release here.

CoalSwarm and Greenpeace have analyzed the IPCC findings to see how a two-thirds reduction in coal power generation in 2030 and a near-total reduction by 2050 can be achieved. Their report, “A Coal Phase-Out Pathway for 1.5°C,” can be downloaded here.

According to the CoalSwarm/Greenpeace analysis, or “1.5°C Pathway,” a rapid transition away from coal is technically and economically possible, but it will require aggressive retirement of coal plants coupled with equally aggressive deployment of efficiency measures and low-carbon power sources. The 1.5°C Pathway shows how the transition can be implemented over the coming three decades at the plant level, given the geographical distribution and age structure of the global coal plant fleet and the new coal plant pipeline.

The 1.5°C Pathway is based on CoalSwarm’s Global Coal Plant Tracker (GCPT), which provides unit-specific details on all coal-fired generating units of 30 MW or more. It models two “oldest-first” phase-out schedules, one for OECD countries and the other for non-OECD countries. For the OECD countries, which tend to have older coal plants, the schedule retires plants by reverse age order until the entire fleet is phased out in 2030. For the non-OECD countries, where coal fleets are newer, the schedule retires plants by reverse age order at a pace rapid enough to meet the IPCC findings for 2030 and 2050.

The 1.5°C Pathway includes three critical measures:

  • Plugging the pipeline. Only coal plants currently under active construction are completed. No more coal plants are built, which means cancelling all current proposals in pre-construction status.
  • Retiring the current coal fleet, oldest first. Under the 1.5°C Pathway, OECD fleets are fully retired by 2030, and non-OECD fleets by 2050. This means average levels of retirement of approximately 47 gigawatts (GW) per year in the OECD countries from 2019 to 2030. For China, it means retirements of about 28 GW per year through 2050, although the greatest amount of retirements are from 2040 to 2050. For the rest of the world, retirements are about 13 GW per year through 2050.
  • Making room for renewables. As solar, wind, and other clean sources gain a larger share in the generation mix, coal plants shift toward a supporting role. As a result, the global average coal plant load factor (i.e. energy output compared to maximum possible) declines at a rate of 3.5% per year, as coal plants transition from a baseload to a back-up role. This rate of decline in utilization is slightly lower than the rate of decline observed in the U.S. over the past decade (3.6% per year).

Figure 1. Under the 1.5°C Pathway, coal plants are phased out first in the OECD countries, where the coal fleet is older, then in China and the rest of the world, where plants are newer.

It should be noted that this coal reduction pathway cannot be interpreted as a “climate safe” scenario. Only a scenario that provided a much higher probability of success could be judged “safe.” Rather, since it models the median level of decarbonization shown by the IPCC models to be consistent with 1.5°C temperature increase, it should be judged as providing only a one-in-two to two-in three likelihood of limiting climate change to 1.5°C.

Step 1: Plug the Coal Power Pipeline

Reducing power generation by two-thirds in the next 12 years cannot be achieved if the global coal power pipeline continues to grow. Under the 1.5°C Pathway coal power projects currently under construction are assumed to be completed and added to the global fleet, but projects that have not yet begun construction are cancelled. These include 365 GW of projects in pre-construction development (announced, pre-permit, and permitted) and 573 GW of projects in the “shelved,” i.e. on hold, category. The shelved category includes 57 GW of shelved construction in China which are currently judged likely to resume construction if not cancelled by their sponsor or government officials. (See CoalSwarm’s recent report Tsunami Warning: Can China’s Central Authorities Stop a Massive Surge in New Coal Plants Caused by Provincial Overpermitting?)

Step 2: Retire Plants, from Oldest to Youngest

A process of retiring coal plants from oldest to youngest will tend to concentrate the initial retirements (2018 to 2030) in the OECD, since the OECD has far more plants over 40. The fleet of “older than 40” plants in the U.S. and the EU was 203 GW in January 2018, as shown in Figure 1. Phasing out the entire OECD fleet will mean average levels of retirement of approximately 47 gigawatts (GW) per year in the OECD countries.

Figure 2. Global Coal Power Capacity by Age and Region (GW). (China = blue, India = yellow, US/EU28=green, Rest of the World = grey)

Outside the OECD, China and other non-OECD countries will also need to reduce their coal fleets by 2030. In order to accomplish the IPCC’s finding of a two-thirds reduction in coal power generation by 2030, plants built before 2008 will need to be cancelled in the non-OECD countries, according to the CoalSwarm/Greenpeace analysis.

Overall, the CoalSwarm/Greenpeace analysis finds that 85 GW per year globally must be retired from 2019 to 2030, or about two and a half times the current three-year moving average of global retirements, shown in Figure 2.

Figure 3. Global Coal Power Retirements 2000–2017, Yearly and Three-Year Moving Average (GW)

That level of plant retirements amounts to a coal power capacity reduction of 5.75% per year from 2019 to 2030. This is faster than the rate of contraction of the U.S. coal fleet from 2006 to 2016 (1.59% per year) but slower than the average rate of contraction of the UK coal fleet over the same period (7.21% per year).

Step 3: Shift the Remaining Coal Plants to Support Renewables, Thereby Lowering Load Factors

As zero-marginal-cost renewable power sources have increased their penetration and taken on a greater share in the overall power generation mix, the role of fossil plants has begun to shift. Coal plants have been pushed back from their usual baseload position to mid-load/balancing roles; the result has been a steady decrease in global coal plant load factors, from 64% in 2006 to 52% in 2016.

Contrary to conventional wisdom, which views coal-fired power plants exclusively as providers of baseload power, many utilities have considerable experience with deploying coal plants in load-following roles that in some cases require cycling up to four times per day. Extensive studies have been performed detailing modifications to boilers, turbines, and other plant equipment, as well as operational changes, that can allow cycling to take place without producing excess wear and tear. Such modifications make it possible for coal plants to shift into new roles in support of renewable power sources. (For additional information on modifying coal plants, see to U.S. Department of Energy study “Flexible Coal: Evolution from Baseload to Peaking Plant.”)

As penetration of renewables rises, average coal plant load factors can be expected to continue declining. From 2018 to 2050, the 1.5°C Pathway assumes the average load factor of the global coal power fleet declines at a rate of 3.5% per year, from 52.5% in 2018 to 16.8% in 2050. This rate of decline is slightly lower than the rate of decline seen over the past decade in the U.S., where the coal fleet’s average load factor dropped from 73.6% in 2007 to 53.1% in 2016, a 3.6% average annual reduction. It should be noted that average load factors well below 50% are already observed for certain countries and in certain seasons. U.S. coal plant load factors of of 36% and 37.8% were recorded in March and April of 2016, respectively (US EIA 2016), while Russia’s average coal plant load factor was 31.8% in 2016 (IEA 2017).

Other factors assumed to reduce load factors are various country policies restricting the use of coal power capacity except as reserve capacity, or policies increasing the cost of coal power, for example reducing local air pollution and setting a cost for carbon dioxide emissions.

A Coal Phase-Out Pathway for 1.5°C