An aerial drone image of Wufuling Wind Farm in Qianjiang District, Chongqing. (Photo/Xinhua)

Chongqing - In the first half of 2025, Chongqing integrated 3.18 billion kWh of renewable energy into its grid—up 34% year-on-year—with no curtailment, according to State Grid. Solar power led the growth, with distributed PV surging nearly 390% and centralized projects up 75%.

The integration of renewable electricity has emerged as a key challenge in China's energy transition. Compared to thermal and hydropower generation, renewable output, particularly from wind and solar, is intermittent, weather-dependent, and difficult to dispatch. Without adequate system flexibility and transmission support, curtailment of excess electricity becomes unavoidable.

As China advances its carbon neutrality goals and rapidly scales up renewable installations, grid integration has become increasingly urgent. Some renewable projects are approved and constructed more quickly than their associated transmission infrastructure, resulting in local delivery constraints. Meanwhile, the variability of wind and solar output puts additional stress on real-time grid balancing. There is also a geographic mismatch between resource-rich western and northern provinces and the demand-heavy central and eastern regions, where inbound transmission remains insufficient.

Power generation, grid infrastructure, end-user demand, and energy storage must be addressed together through coordinated advances in technology, market design, and policy mechanisms. Improving grid flexibility is essential to ensure that renewable electricity is fully utilized.

In Chongqing, utility and planning authorities have prioritized improving local grid capabilities. Chongqing has strengthened real-time scheduling based on daily load and generation forecasts, while upgrading weak links, particularly in areas with concentrated renewable output. Inspections now combine manual checks, drone patrols, and video monitoring to identify and resolve risks.

Chongqing is expanding its clean energy portfolio with continued investment in local wind, solar, and hydropower projects, alongside increased intake of clean electricity from external sources. By mid-2025, Chongqing's total renewable installed capacity reached 5.26 gigawatts, a 221.1 percent increase over the end of 2020. As part of the region's gas basin development efforts, natural gas output hit 17.5 billion cubic meters, up 33 percent from 2020.

Since the start of the 14th Five-Year Plan, Chongqing's renewable capacity has grown by over 30 percent annually. Major projects have entered operation, including the Panlong pumped storage plant in Qijiang District, the Gangqiao gas turbine project in Yongchuan, the relocation and upgrade of the Chongqing coal-fired plant, and the battery storage facility in Hechuan. Construction has begun on an additional 4.85 gigawatts of gas-fired generation and 5 gigawatts of pumped hydro storage.

By the end of June 2025, Chongqing had one operational pumped storage facility with 1.2 gigawatts of capacity, and 12 grid-side battery storage projects had come online, adding 1.4 gigawatts of dispatchable flexibility to support variable renewable output.

At the same time, Chongqing is scaling up non-fossil energy deployment. Rooftop solar and distributed wind projects are expanding under national programs. New models such as virtual power plants, load aggregators, and integrated source-grid-load-storage systems are being tested, while grid operations are optimized to accommodate higher levels of renewable penetration. A green power consumption framework is under development to encourage large industrial and export-oriented firms to purchase renewable electricity and green certificates. By 2027, the city aims to reach 7.8 gigawatts of renewable capacity.

The city is also advancing efforts to green its overall energy structure. Initiatives include electrifying industrial and residential heat, substituting natural gas, and phasing out inefficient coal boilers. Retrofits are underway to improve coal-fired power plants. Alternative fuels, including biofuels and sustainable aviation fuel, are also under evaluation.

Chongqing is also positioning itself as a strategic hub in the national power system, particularly within China's West-to-East transmission strategy. A proposed 1,000-kilovolt ultra-high-voltage AC ring connecting Chengdu and Chongqing is currently under feasibility review.

The city is also studying multiple interregional transmission projects, including long-distance direct-current lines from northwestern and southwestern China, a southern ultra-high-voltage AC loop, and a back-to-back interconnection with Shaanxi. Together, these would form a robust regional power system enabling secure and efficient delivery of low-carbon electricity at scale.