China’s cities have long struggled with the challenge of being overwhelmed by trash.

In early 2020, the country’s largest landfill site — Jiangcungou Landfill in Xi’an, capital of the northwestern Shaanxi province, which is almost the size of 100 soccer fields — had to be “retired” just halfway into its designed 50-year lifespan due to the acceleration in urban waste generation.

However, in recent years, many cities have reduced their reliance on landfills for disposing of municipal solid waste. Instead, they’ve turned to incineration.

In the same year Jiangcungou was closed, incineration plants became the primary method for treating urban household waste. By 2023, more than 78% of waste was being treated through non-hazardous incineration, while use of sanitary landfill sites had decreased to 13%.

However, many plants are facing a new dilemma — not enough trash.

Growth in plants

China’s waste-to-energy incineration industry began as early as 1985, when the southern city of Shenzhen imported two waste incinerators from Mitsubishi Heavy Industries for its municipal sanitation integrated treatment plant. However, as household waste at the time had such low calorific value — the amount of heat released when it undergoes combustion — the project ran into operational difficulties.

It wasn’t until the early 2000s, as the economy developed and living standards improved nationwide, that the calorific value of domestic waste increased significantly.

The build-operate-transfer, or BOT, model was introduced to the waste incineration industry in 2005, allowing private enterprises to participate in infrastructure construction and provide related public services. To attract investment and accelerate the construction of waste-to-energy plants, enterprises received preferential grid-connection policies and feed-in tariffs, with power companies required to purchase all the electricity generated by incineration projects.

A decade later, the country began building a stronger regulatory framework.

This first came in the shape of monitoring policies imposed on waste-to-energy plants, helping strengthen information disclosure and social participation. The Ministry of Ecology and Environment ordered all facilities to install automatic pollution monitoring equipment, display emissions data in prominent public locations, and integrate their systems with those of environmental authorities.

On Jan. 1, 2020, the ministry launched the National Online Platform for Waste-to-Energy Plant Monitoring Data, providing public access to real-time emissions data from incineration facilities, including important indices such as nitrogen oxide and sulfur dioxide levels, and furnace temperatures.

With these measures in place, incineration was established as the primary method of treating household waste, leading to a rapid proliferation of projects nationwide.

According to the monitoring platform, the total designed processing capacity of China’s waste incineration plants was 1.17 million tons a day last year, up from just 238,000 tons daily in 2016.

Yet, with incineration capacity now greater than the volume of urban domestic waste being generated, some waste-to-energy plants have had to unexpectedly suspend operations due to insufficient supply.

In 2024, the monitoring platform showed that of the 2,138 waste incinerators nationwide, 1,267 had an uptime — the period during which they were available for operation — of more than 90%.

However, this operating time does not directly reflect load capacity. For instance, Shenzhen’s largest plant, Bao’an Energy Ecological Park, processed an average of 8,985.4 tons a day last year, exceeding its designed capacity of 8,000 tons, according to a report by the city’s Ecology and Environment Bureau.

Yet, some 107 incinerators — about 5% of the total — remained idle for more than six months.

Some plants have faced substantial waste shortages. In July 2020, when an urban-rural waste-to-energy incineration project in Xianyang, Shaanxi province, went into operation, the state broadcaster CCTV reported that the facility was designed to process 1,500 tons a day, although the main urban area produced only about 800 tons, making continuous operation a challenge.

Aged waste

In the summer of 2021, China’s fifth Central Environmental Protection Inspection Team visited the central Henan province and reported that some new waste-to-energy plants were operating far below capacity, highlighting a project in Hebi that was operating at only 50%.

In response, the following year, the Hebi government implemented measures including transporting all household waste from affiliated counties and townships, coordinating the transfer of 90,000 tons of municipal solid waste from neighboring Anyang, and excavating 91,000 tons of aged waste — material that has decomposed over years in landfill — to make up the capacity gap.

Hebi was not the first city to consider utilizing aged waste. In 2021, Jinhua in the eastern Zhejiang province announced plans to excavate and incinerate 260,000 tons over three to four years, aiming to address landfill capacity shortages while achieving both emissions reductions and power generation.

However, the excavation of aged waste is not solely driven by waste shortages.

Last September, authorities in Guangzhou, capital of the southern Guangdong province, revealed plans to reopen the Xingfeng Landfill, one of the largest in China. Over the next four years, the city will excavate and incinerate aged waste from the site in response to dwindling landfill space.

After waste incineration, residues such as fly ash cannot be fully recycled due to technical constraints and must be placed in landfill. By the end of 2023, Guangzhou’s landfill sites had 3.02 million cubic meters of remaining capacity for fly ash disposal. According to assessments, this will last only until 2030 unless aged waste can be excavated and incinerated to reduce volume.

In fact, some waste-to-energy plants in major cities were initially built to address the accumulation of aged landfill waste.

Rate of change

Although China’s domestic waste incineration capacity exceeds the urban waste collection volume, about 10% of waste still needs to be placed in landfill. This issue is most pronounced in counties.

According to a paper written by researchers at the Ministry of Ecology and Environment and the Chinese Research Academy of Environmental Sciences, more than 75% of counties have insufficient waste incineration capacity. However, some also have incineration plants that face overcapacity and a limited waste supply.

The waste incineration plant in Xinshao County, central Hunan province, for example, has been maintaining full operational capacity by processing not only its own waste but also that from Shaoyang, the nearest large city. Meanwhile, about 110 kilometers away, the incineration plant in Dongkou County processed just 22,900 tons of waste last year, a fraction of its designed capacity of 213,600 tons.

This disparity is reflected in the reliance on sanitary landfill sites. While the number of city-level sites fell from a peak of 663 to 366 in 2023, a reduction of almost 45%, usage of landfills among county authorities decreased by just under 30%, showing a much slower rate of change.

Reported by Chen Liangxian.

A version of this article originally appeared in The Paper. It has been translated and edited for brevity and clarity, and is republished here with permission.

Graphic designers: Wang Yasai and Fu Xiaofan; editors: Wang Juyi and Hao Qibao.

(Header image: The Paper)