Workers install photovoltaic panels at a farm in Qingdao's West Coast New Area, Shandong province, in March 2022. HAN JIAQUN/FOR CHINA DAILY

Air pollution levels drop markedly after switching to renewable energy sources

Qingdao, a key export and economic hub in East China's Shandong province, has shown substantial improvement in air quality after switching its major heating source from coal to natural gas in key urban districts and developing a network of multiple clean energy resources.

In September, its PM2.5 level fell to 18 micrograms per cubic meter, while concentrations of inhalable particulate matter — sulfur dioxide, nitrogen dioxide and carbon monoxide — had all turned first-class by national standards on air quality.

PM2.5 is the average concentration of fine particles of less than 2.5 microns in diameter and is a common measure of air pollution levels.

While Qingdao's annual average concentration of fine particles was as high as 59 micrograms per cubic meter in 2014, it had dropped to 26 by 2022, data from the city government showed.

"In the past, the 44 coal-fired boilers in the main urban areas of Qingdao often operated at full capacity each winter, causing heavy environmental problems from coal transportation, spill of cinder, chimney discharge and coal storage," said Xu Bing, general manager of Qingdao Energy Group, a State-owned large-scale energy supplier. "Today, such a sight has disappeared forever."

In its energy development plan for the 14th Five-Year Plan (2021-25) period unveiled in late 2021, Qingdao vowed to expand the scale of clean energy utilization, increase the proportion of non-fossil energy in its energy consumption structure, and reduce coal consumption.

By 2025, coal is expected to account for 23.5 percent of primary energy use. Consumption of coal-fired power, clean energy and external power transmitted to Qingdao will be optimized, to account for 21.5 percent, 27 percent, and 51.5 percent, respectively, of total electricity consumption in the city, according to the plan.

To promote the use of clean energy, the city will carry out projects to supply natural gas for heating in urban areas, and steadily promote clean heating projects such as "coal-to-gas" and "coal-to-electricity" in rural areas in accordance with local conditions, the plan showed.

The city will also continue to expand the use of clean energy, such as solar energy, geothermal energy, biomass energy, and industrial waste heat, while promoting the integration of renewable energy-based and conventional fossil energy-based heating systems.

It is estimated that the coal-togas conversion project will help the city reduce consumption of around 1 million metric tons of coal per year, thereby cutting carbon emissions by 850,000 tons annually.

Thanks to loans worth about $130 million provided by the Asian Development Bank, the company started the three-year project in 2021, together with other initiatives to promote low-carbon and digital transformation of energy supplies in Qingdao.

The total investment for the project as well as for other initiatives is planned at 1.68 billion yuan ($230 million), which also includes special local government bonds and funds from Qingdao Energy, in addition to ADB loans.

As of end-October, the first and second phases of the project had been completed, which can provide heating to an area of more than 11.43 million square meters, reducing coal consumption by 92,800 tons per year.

The project can also reduce emissions of ash and nitrogen oxide by 30,000 tons and 137.05 tons, respectively, per year.

The project, which upgrades the energy mix and improves the air quality in Qingdao, also aims to set an example for the rest of the country amid China's efforts to honor its dual-carbon goals.