Faced with the problem of renewable-energy power curtailment, the Chinese government plans to shift the focus of no-subsidy PV power projects to populous cities in eastern China and intends to improve local power transaction markets and introduce maneuvering technology for peak-time power consumption.

Green-power curtailment refers to closure of some green-power generators to protect grid and power equipment, in case of abrupt surge in green-power output, due to lack of energy storage systems. This is a common problem plaguing various countries in their development of green energy.

The extent of PV and wind power curtailment has surged to over 10%, from 6% two years ago, with the figure even topping 30% in northern and northwestern China, where local governments cannot transmit such excess power output to big cities, due to expansive land space.

As a result, in addition to slashing of new power station projects and subsidies in the 531 new policy, unveiled in early June, the Chinese government is expected to strictly restrict development index and encourage no-subsidy projects, such as rollout of 300-500 MW quota for no-subsidy PV projects per province, which are expected to break ground in March 2019 before grid connection by the end of the year.

It is reported that as existing grid networks in northern and northwestern China cannot accommodate frequent curtailment of PV power stations, the Chinese government plans to shift the focus of PV power projects to three populous 34 areas in eastern China, thereby lowering the PV power curtailment to less than 5% for at least three years.

In addition, China has been endeavoring to alleviate the situation of excessive wind power output, thereby cutting wind-power curtailment to under 12% before attaining the level of less than 5%, similar to PV power, by 2020.

Despite continuous cost drop, PV and wind power supply is sporadic in nature and could entail major problem, should power infrastructure, maneuvering power stations, and energy storage technology fail to catch up with the development of green energy. The Chinese government also plans to develop new technology boosting maneuvering capability for peak-time power consumption and promote the development of power transaction market.

There are various methods for green-power curtailment, such as Centrica, an energy firm in the U.K., which is experimenting with the user of blockchain technology in facilitating the purchase and sale of regional excess power output, including the provision of PV cells, monitoring equipment, and smart meter. The trial plan is scheduled for completion in March 2020.

(First photo courtesy of Activ Solar via Flickr CC BY-SA 2.0, written by Daisy Chuang)