China’s once-booming coal power sector is facing an existential challenge as continued breakneck expansion of new capacity is colliding with flattened growth in power demand, despite increasingly strenuous government efforts to put the brakes on new construction. According to a pair of new studies, China’s overcapacity in coal-fired generation could reach a staggering 400 GW by 2020—an amount larger than the total installed capacity of every other nation worldwide besides the U.S.

Overcapacity Leads to Plummeting Utilization

The studies by Greenpeace East Asia and the Coal Power Economics Study Group at North China Electric Power University (NCEPU) note that plant utilization rates in China have been falling rapidly over the past several years (Figure 1). This is because while total thermal generation has barely changed since 2011—resulting from a combination of slowing economic growth and efforts to boost renewable energy—installed thermal capacity has grown by a third, around 250 GW, over the same period.

According to a report in the South China Morning Post (SCMP), this rapidly growing overcapacity is causing financial challenges for plant owners.

As recently as 2012, China was facing huge power shortages , a situation that led to a boom in construction of coal-fired thermal plants. But as those plants began to come online, China’s economy was slowing rapidly and capacity growth is now far outstripping growth in electricity demand . Through the first six months of 2016, demand rose 2.7% year-over-year even as installed capacity grew by a blistering 11.3%.

That’s led to a dramatic drop in operating hours for China’s thermal plants. In 2015, the average utilization nationwide of 4,300 hours was the lowest since 1978 (equating to a 57% capacity factor), and utilization has continued falling in 2016—9% year-over-year so far.

Plummeting utilization has also meant big drops in profits for power producers. The SCMP report estimated that major firms are likely to see profits decline as much as 26% this year—this despite significant drops in the price of thermal coal .

Policy Moves Face Development Inertia

The central government has moved aggressively to slow capacity growth, at least from a policy standpoint. Earlier this year, the National Development and Reform Commission and National Energy Administration ordered provincial governments to suspend or slow plans for around 200 new plants comprising more than 100 GW of capacity and to accelerate retirements of older units. Then, last month, reports emerged that the 13th Five-Year Plan may impose a nationwide ban on new coal plant construction at least through 2018.

Yet, despite these moves, the Greenpeace study found that exemptions in the policy announced this spring have allowed numerous projects to continue development. These exemptions cover “coal power bases,” regions in the west and north close to coal resources where an array of new ultra-high-voltage transmission lines are planned. Around 200 GW of new capacity is currently under construction because of a “permitting binge” in 2015, the study says, and another 160 GW could still be permitted in 2016 under the current exemptions—30 GW of which have in fact received permits. Nationwide, China is still seeing around two new coal plants begin construction each week.

Just how much new construction China has seen is encapsulated in one startling statistic: After planned and likely retirements by 2020, the average age of China’s coal fleet will be a mere 10 years.

More to Come

The official 13th Five-Year Plan for Energy has not yet been published (but is expected very soon). It is still widely expected to include at least a two-year freeze on new coal plant construction , but the precise form that will take is not yet known. Meanwhile, the Five-Year Plan for Economic and Social Development, released in March, contains a number of provisions, such as a 15% target for renewable generation and an 18% cut in carbon intensity, that seem certain to further depress coal plant utilization.

—Thomas W. Overton, JD is a POWER associate editor (@thomas_overton, @POWERmagazine).