Four years of waste sorting leaves China’s incinerators short of fuel

Four years ago, Shanghai introduced mandatory waste sorting. The regulation changed residents’ behaviour and, as we will see, had unforeseen consequences for the waste-processing sector. Today, waste sorting is mandatory in most of China’s big cities. Meanwhile, both the number and capacity of waste-to-power incinerators have doubled. But with waste sorting reducing the amount of material being sent to incineration, some facilities are struggling to find anything to burn.

In May, Wuhu Ecology Center, for which I am a researcher, commissioned EP Map, an environmental data organisation, to compile operational data from waste-to-power plants. Monitoring information is automatically gathered from these plants and published on a public platform managed by the Ministry of Ecology and Environment, which has been updated daily since January 2020.

The data shows there were 8,499 “planned stoppages” during May, meaning at least one incinerator at a plant was not operating. In some cases, incinerators were idle for more than half the month. While other factors contribute to stoppages, such as aging incinerators kept as backup but left idle in favour of newer ones, these high numbers mean some are simply not being used.

Making use of the surplus capacity would mean burning more waste, but that would run counter to the purpose of sorting it in the first place.

Behind this situation lie contradictory government policies. Better policy coordination across ministries and regions is needed to promote waste-sorting policies.

Sorting cuts incineration

Only Shanghai publishes data on the quantity of waste that is recycled. The data shows that, since sorting became mandatory in the city, recovery of recyclables and wet (food and other organic) waste has increased, leading to a reduction in incineration.

Shanghai’s mandatory waste-sorting policy came into effect in July 2019 and caused quantities of waste sent to incineration or landfill to fall. In 2021, for example, the city diverted 6.46 million tonnes of recyclable and wet waste – 54 per cent of the total. In 2018, only 21 per cent of the total was diverted.

This had a significant impact on incinerators. Prior to the sorting policy, they couldn’t burn waste fast enough. In 2018, with all of its incinerators running at full capacity, Shanghai could in theory burn 2.81 million tonnes of waste a year. In practice, they ran at more than full capacity and burned 3.86 million tonnes. A very similar quantity, 3.87 million tonnes, was sent to landfill.

The waste-sorting policy left incinerators suddenly short on fuel and sometimes forced to shut down. By 2021, Shanghai was able to burn 7.65 million tonnes of waste a year, but only 6.652 million tonnes were burned. In May this year, the Shanghai Laogang Waste Disposal Company recorded 88 days of stoppage across its 12 incinerators, meaning 24 per cent of capacity was wasted that month. The system had reached overcapacity.

In May, the Ministry of Housing and Urban-Rural Development (MoHURD) said it aims to roll out waste sorting to all communities in prefecture-level cities by the end of 2025. As waste sorting expands, the shortages incinerators are struggling with will worsen.

Overcapacity

MoHURD has set targets for incineration since the 12th Five Year Plan (FYP) period in 2011-2015. It increased those targets in plans for waste handling during the 14th FYP period (2021-2025). Those plans stated that by the end of 2025, daily domestic waste incineration capacity for urban areas (meaning counties and towns, but not villages) will reach about 800,000 tonnes, while in cities alone capacity would be at around 65 per cent.

The targets prompted a rush to build incineration plants: in 2011, there were 130; today, there are 927. Daily incineration capacity reached 1 million tonnes at the end of 2022, hitting MoHURD’s target three years early.

Other factors besides waste sorting have contributed to overcapacity. These can include overestimating the ability to collect and transport waste; incineration firms over-building to grab market share; local governments faking data to attract investors; and a failure to share resources across local government boundaries.

To better understand the situation, the Wuhu Ecology Center has developed overcapacity figures, devised by dividing domestic waste incineration capacity by the amount of domestic waste produced. If a figure is over 100 per cent, that region has more incineration capacity than it needs.

According to our study of 29 province-level administrations, the national overcapacity figure for 2022 was 100.99 per cent, with overcapacity found in 12 administrations.

Target-driven expansion

In short, waste sorting has left incinerators short of fuel and many newly built incinerators are lying idle. Behind this predicament lies a difference over policy.

The MoHURD is responsible for the collection, transportation and disposal of waste. The MEE (Ministry of Ecology and Environment) handles the environmental oversight of this process. But with waste sorting and “zero-waste city” policies being rolled out simultaneously, in 2021 the key metric for measuring recyclables extracted from waste – the recycling rate – was replaced by a new concept – “resource recovery rate”.

In 2016, the MoHURD published plans for the “harm-free processing” of urban domestic waste during the 13th FYP period. This included two key targets for 2020: incineration capacity would stand at 50 per cent, and the recycling rate at 35 per cent or more. A year later, the ministry led drafting of a plan for waste sorting, which reiterated those targets.

However, neither document offered a clear definition of “recycling rate”.

In 2019, the MEE did provide a clear definition, in a set of “zero-waste city” targets. The term now signified the quantity of recyclable and organic (wet) waste not sent to incineration or landfill, as a percentage of total domestic waste. That meant the recycling rate for 2015 was 15.6 per cent; raising this to 35 per cent by 2020 would be virtually impossible.

Then, in MoHURD’s 14th FYP, published in 2021, the recycling rate was gone, replaced with “resource recovery rate”, with a 2025 target of 60 per cent. In accompanying documents, the resource recovery rate was defined as a calculation incorporating incineration and landfill waste, as well as the recovery of recyclable and wet waste.

If only the incineration is calculated, and not considering recovery of recyclables, the equivalent resource recovery rate for 2021 was 58.4 per cent, bringing that 60 per cent-by-2050 target within easy reach.

Urban waste management is handled by local sanitation bureaus under MoHURD jurisdiction, so the ministry’s preferred target will naturally be applied; if local governments use the resource-recovery rate, incineration can help them hit that target. This therefore provides motivation to build more incinerators and burn more waste. Meanwhile, reductions in material to burn due to increased waste sorting, and the high likelihood of the recovery of recyclable and wet waste being neglected in favour of burning, are likely to impact the quantity of waste that gets recycled.

Incineration risks

According to MoHURD figures, 210 million tonnes of domestic waste were incinerated in China’s cities and county towns in 2021, with 73 per cent of domestic waste from cities burned. This rapid increase in incineration, both in percentage and absolute terms, has helped reverse the sprawl of landfill sites encircling Chinese cities. However, it has also worsened economic, health and environmental risks.

Plants that incinerate domestic waste are heavily reliant on government subsidies. But since 2020, the industry has struggled to get the government to pay up. According to an August 2022 study, 11 incineration plants across Zhejiang, Jiangsu, Anhui, Shandong and Jiangxi were found to be owed 478 million yuan (US$65.61 million) in national and provincial electricity-generation subsidies and waste-disposal fees.

Meanwhile, increased incineration has bolstered the evidence for health impacts. A July 2022 study on safe buffer distances for Chinese waste-to-energy facilities found hazard-index and cancer-risk figures were above safe levels 1,000 metres downwind of 510 incinerators.

The study concluded that a buffer distance of at least 1,500 metres is necessary to reduce risks to an acceptable level. That is five times the current required distance of 300 metres. There are now 927 domestic waste incinerators in China and the capacity of individual facilities is increasing. This means the health impacts will continue to affect a wider area and more people.