Joining Efforts at Power Sources, Grids and Loads to Ensure Reliable Power Supply

Due to cloudy weather on December 7, some areas in Gansu Province saw power shortage as the photovoltaic generation output remained low during the morning peak hours. Northwest Power Dispatching & Control Center immediately made three inter-provincial mutual complementary transactions with a total of 1.9 GWh electricity to ensure electric power balance for Gansu power grid. Since the beginning of winter, State Grid Corporation of China has made advance plan in response to the combined impact of peak power consumption in winter, the heating period in northern China, the Yellow River ice flood prevention period, and the winter breeze period. State Grid capitalizes on the role of the large power grid in optimizing the resource allocation, puts in efforts at the power source, grid, load to enhance lean regulation, and supports the power supply in the central and eastern regions while ensuring power supply in northwest China.

Employees of Qilian Converter Station of State Grid Gansu Electric Power brave the wind and snow to inspect equipment.

The grid load in five northwestern provinces (autonomous region) reached new highs 13 times with the onset of winter. The load of Gansu power grid hit new highs twice, peaking at 17.66 GW, while that of Qinghai and Xinjiang hit 7 and 4 times, peaking at 11.23 GW and 37.85 GW respectively. The maximum load of Northwest Power Grid reached 109.34 GW, an increase of 2.02 GW compared to that in summer this year. Northwest China is a major energy base in the country. Whilst ensuring power supply in the five northwestern provinces (autonomous region), State Grid tapped the potential of outbound power transmission and strengthened the regulation of power resources. In November, the maximum outbound electricity delivered via DC transmission lines reached 37.62 GW.

In terms of power sources, management has been strengthened, generating capacity increased, and coordination of thermal coal supply enhanced among the parties. By the end of November, the thermal coal stock of power plants in Northwest China was nearly 18 million tons, with a year-on-year increase of 1.35 million tons. Moreover, a special program was launched to increase thermal power generation capacity, efforts stepped up to assess the non-planned shutdown and restricted generation of thermal power units during peak hours, and potential of hydropower generation capacity tapped to ensure that all types of power sources were "put into operation and connected to the grid to the greatest extent". By the end of November, Ningxia Power Grid transmitted outbound electricity totaling 80.6 TWh in 2021, breaking the 80 TWh mark and hitting a new annual high. It achieved the annual outbound power transmission target one month ahead of schedule. State Grid Shaanxi Electric Power stepped up efforts to monitor the status of generating units and mobilized its power generation capacity to the maximum. State Grid Gansu Electric Power lowered the water level of Liujiaxia reservoir to 1,715.83 meters on November 15 and reserved a reservoir capacity of 2.1 billion cubic meters for ice flood prevention. State Grid Qinghai Electric Power expanded hydroelectric power generation potential to 3.9 TWh during the ice flood prevention period, an year-on-year increase of 200 GWh. Cascade hydropower stations in Xinjiang have carried out water and energy conservation work to ensure that key hydropower plants have the capacity to cover the winter peak demand.

State Grid Shaanxi Electric Power's Power Dispatching & Control Center strengthens the monitoring and analysis of power grid operation.

In terms of power grid, the scheduling of power grid operating mode has been optimized, inter-provincial mutual complementarity reinforced, and monitoring and analysis of power grid operation strengthened. In November, 1,157 inter-provincial power support transactions were made, with a maximum of 4.28 GW, and a cumulative total of 2.221 TWh. Leveraging the three-level daily consultation mechanism involving the national, regional, and provincial power dispatching & control centers, and the platform of a large power grid in optimizing resource allocation, State Grid Shaanxi Electric Power enhanced the integrated grid-wide power balance. Focusing on the areas prone to ice and snow disasters in the central and eastern regions of Gansu, State Grid Gansu Electric Power made full use of the integrated safe and intelligent management and control platform, issued a total of 13 early warnings on low-temperature ice-covered lines, and completed 5 anti-accident plans for equipment failure. State Grid Xinjiang Electric Power cleaned equipment operation environment, shortened equipment inspection cycle, stepped up efforts in patrol inspection of projects and equipment that were put into operation this year, gave priority to guarantee power supply for heating, and intensified efforts in identifying hidden dangers in power supply equipment for heating as well as customer-side equipment.

A wind farm of State Grid Ningxia Electric Power

In terms of load, State Grid Northwest China Branch petitioined the government of the five northwestern provinces (autonomous region) to complete the submission and approval of plans for orderly power utilization; organized the formulation of an intra-day emergency control plan for large-scale industrial load, with the first controllable load totaling 7.53 GW; improve the on and off grid interaction efficiency of self-owned power plants to improve the flexibility of load control. State Grid Shaanxi Electric Power revised the two sequence tables of Shaanxi Grid's unplanned power utilization and accident-related power rationing, improved emergency plans, and comprehensively improved the emergency response ability. State Grid Qinghai Electric Power leveraged the peak-load shifting of demand-side to optimize the peak, flat and valley hours of electricity consumption in the ferroalloy industry in the province, to alleviate the imbalance between supply and demand for photovoltaic power characterized by "generation in daytime and zero at night", and to help businesses cut costs and increase efficiency.

State Grid Northwest China Branch has recently carried out negotiation and adjustment of prices for existing Nov. - Dec. contracts for inter-regional and inter-provincial thermal power tradings in 2021, to implement market-oriented reform measures for the feed-in tariffs of coal-fired power generation, and to enhance the enthusiasm of thermal power enterprises in power generation. It carried forward the optimization and adjustment of the contract curve for annual electric power transactions from Northwest Power Grid to Southwest Power Grid, and achieved inter-provincial mutual complementation across regions to ease power shortage in the morning and evening peak consumption period in winter in Northwest Power Grid. In view of the characteristics of power loads in Xinjiang and Shaanxi as well as the difference of peak load hours of the east and west parts in the Northwest Power Grid, the Branch leveraged the peak load shifting to achieve mutual complementation between provinces, and to ease the pressure of balancing the Xinjiang power grid during evening peak hours. It also leveraged the forecast of new energy power to make short-term adjustments to the medium and long-term contracts.

The Changji-Guquan UHV Transmission Project boosted Xinjiang's outbound power transmission capacity.

According to the forecast, northwestern China will see frequent extreme weather this winter-spring period and a variety of adverse factors, which will pose serious challenges and complication to Northwest Power Grid. All relevant affiliates of State Grid will diligently fulfill their responsibilities, conduct lean management and control, adopt innovative management methods, and improve emergency response capabilities to ensure the safe and stable operation of the power grids, and secure a decisive victory in ensuring power supply.