On May 26, the CEC stated that the lack of electricity in some areas has been persistent in recent years. It should not be too exaggerated to exaggerate the situation and impact of power shortages, and even define it as a national “electricity shortage”.

Power gap is only 5%

In the article “Recent Understanding of the Current Power Supply and Demand Situation”, the CEC stated that partial power shortages have persisted in recent years. Compared with recent years, current power shortages are presented in advance. The characteristics of the expansion of the scope and the increase of gaps are obviously different from those of the large areas before 2004.

CEC believes that the current lack of electricity is still mainly characterized by structural power shortages. It is characterized by locality, seasonality, and seasonality. The shortage of electricity in some eastern and central China (city) is more serious, and the production in some areas is also limited. Life has a certain impact. The lack of electricity in 2003-2004 was a large-scale, long-term national power shortage. "To fully understand the current nature and characteristics of power shortages, we should not exaggerate the situation and impact of power shortages, and even define it as a national 'electricity shortage'."

In addition, for the power shortage during the summer of this year (June-August), CEC stated that the maximum power shortage at that time will account for about 5% of the maximum power load, which is far below the proportion of more than 10% in 2004. And this is exactly the same as the data published in last week's article “Electricity, Wasteland” that was questioned by the newspaper.

According to the CEC, this summer, it is expected that the entire society will use 1.25-1.3 trillion kWh of electricity, an increase of about 12% year-on-year; and the maximum electricity load will increase by about 14%. From the analysis of the balance of power supply and demand, in terms of supply, from January to May, the country’s newly-added infrastructure installed capacity was about 25 million kilowatts, and by the end of May, the total installed capacity was about 985 million kilowatts. In the newly installed capacity, the proportion of thermal power decreased further year-on-year. The effective capacity of power generation output is only 40% of thermal power, and the proportion of wind power mainly distributed in the western and northern regions continues to increase year-on-year, resulting in an increase in effective power supply capacity during the summer peak season that is nearly 3-4 percentage points lower than the maximum load growth rate. The electricity supply and demand situation in the country as a whole is tighter than in the same period of the previous two years. Regions with large supply and demand gaps are still the eastern and central regions where supply capacity is insufficient or where grid transmission capacity is limited.

At the same time, if the price of thermal coal continues to rise and the electricity shortage in some regions cannot be significantly improved, the lack of coal, the decline in coal quality, and the continuing drought in central and eastern China during peak summer peak seasons will further affect the electricity supply capacity in these regions. The play of electricity supply and demand gap will be further expanded.

CEC expects that during the summer peak season, the East China Power gap will be 15 million kilowatts, and the gap between North China, Central China, and South China will be around 5 million kilowatts; If the climate, inflow of water, coal supply and other uncertainties are added together, the peak gap may be further expanded. On a national average, the largest power gap will account for about 5% of the peak load. In 2004, this A proportion of more than 10%.

The lack of electricity in the first 4 months The article stated that from January to April, due to the rapid growth of electricity demand, power coal supply and transportation capacity shortage, hydropower output in some areas caused by drought, local power supply capacity is insufficient, the power grid cross-regional adjustment ability is limited Affected by such factors, the overall power supply and demand situation in the country is tight, and the contradiction between power supply and demand in some regions and during peak hours is indeed prominent.

According to CEC's example, during the January-March period of the “winter season” of electricity, in January, a total of 20 provincial power grids across the country experienced a power supply gap, totaling a maximum power gap of about 30 million kilowatts. These provinces basically It is the eastern and central provinces with a large proportion of hydropower, coal-fired power, and heating loads in the Midwest.

It gradually eased after February. In April, by adopting measures such as orderly use of electricity, the electricity gap dropped to about 10 million kilowatts. Hunan, Jiangxi, Chongqing, Zhejiang, Guizhou, and other places are either at the end of power coal transportation or because hydropower continues to last. Lack of dryness, or due to lack of new installed capacity, or due to the lack of local coal supply and the rigid growth of electricity consumption demand and other factors, resulting in the power gap accounted for a large proportion of the local maximum power load, the power supply situation is grim.

However, CEC said at the same time, “This kind of power shortage is completely different from the nationwide large-scale, persistent power shortage before 2005. It is generally structurally power-deficient, and through the adoption of Cross-provincial power supply support and effective coordination of coal and electricity contradictions can ease supply-demand conflicts and reduce gaps to some extent."

The CECEP said that the average utilization hours of thermal equipment in the country this year may increase to 5,300 hours, an increase of 250 hours over the previous year.

From the perspective of historical experience and combining the characteristics of electricity consumption in the new period, the average utilization hours of thermal power equipment is below 5,000 hours (including 5100 hours of coal power), indicating that there is more than enough power supply and demand balance in the country; in the period of 5000-5400 hours (of which coal is In the range of 5100 to 5500 hours, it indicates that the supply and demand are tight; more than 5400 hours can be considered as being in a state of power shortage.

In the power industry, the utilization rate of power generation equipment is usually measured against the indicator of the hours of use of power generation equipment. The generating capacity of a unit (in kilowatts) is the amount of electricity (in kilowatt-hours) that the unit emits at full load within an hour. The unit is generating electricity at full load for 8760 hours throughout the year, achieving an ideal utilization rate of 100% of power generation equipment. The corresponding unit power generation equipment utilization hours is 8,760 hours.

According to the interpretation of statistical indicators for the power industry, the average utilization hours of a region's power generation equipment (including all types of thermal power, hydropower, nuclear power, wind power, photovoltaic power generation, and biomass power generation) is 5,500 hours, which is all types of grid-connected production in the region. At the end of the statistical period, the units were able to produce 5,500 hours of full-load operation at the end of the year, based on the average equipment capacity (not the geometric stacking of the nameplate capacities of all units), and the corresponding equipment utilization rate was 62.79%.

In this regard, the CEC stated that from January to April this year, the cumulative average utilization hours of power generation equipment in the country was 1,530 hours, which was 21 hours higher than the same period of last year. The rate of increase was not significant, among which was the increase in the proportion of hydropower and wind power. However, the utilization hours of thermal power equipment in the eastern, central and western provinces that are powerless are not only far higher than the same period of last year or even higher than 2007 (the starting year when supply and demand slowed down and supply capacity was released) over the same period of more than 200 hours.

For instance, Jiangsu increased 241 hours over 2007, Anhui increased 242 hours, Hunan increased 188 hours, and Chongqing and Sichuan also increased 244 and 273 hours, respectively, which is equivalent to an average increase in the utilization rate of thermal power equipment from January to April 2007. 7 -9 percentage points.

“It is expected that the utilization of thermal equipment in these provinces in 2011 will increase by 300-400 hours compared with 2010. Some provinces will even increase by 500-700 hours, and the average annual utilization of thermal power equipment in the province may increase to 5,300 hours, compared with the previous year. The increase of 250 hours, but the average number of hours of use of power generation equipment in the country is only about 100 hours more than in 2010." The article said.

Maintenance of the unit In the plan, the China National Electrical and Electronic Union (CEC) stated that the maintenance plan had been approved by November of the previous year and that the shutdowns carried out by thermal power plants were basically planned maintenance.

According to the China Electro-Optical Association, April is the traditional off-season electricity use. In April, the power shortage was caused by a combination of factors such as strong demand, reduced hydropower generation, and tight coal power. Among these factors, organic maintenance causes a decline in supply capacity.

The main content of the genset plan maintenance is that according to the characteristics of the gensets and the characteristics of the grid operation, the gen- eration companies plan to make maintenance plans for the long-term and next-year grades according to the requirements of the regulation and report them to the grid companies, and strictly implement them in accordance with the established plan. According to the operating characteristics of the electric power industry, in addition to the temporary failure of the equipment, which requires immediate maintenance, equipment maintenance of the power grid and power generation enterprises is a preventive level planned maintenance, and there are clear regulations.

Every year, the power companies must perform preventive maintenance of power generation and power grid equipment before the arrival of these two peaks. This is also done by the power grid companies and power generation companies after the previous year's power load forecast and the characteristics of the power generators. The purpose of the systematic arrangement is to make full use of the spring and autumn power maintenance equipment to actively respond to and ensure the power supply during the peak period of winter and summer electricity use. In general, the peak period of maintenance is mainly in April and May and September and October.

For example, in this year, China Southern Power Grid's regional maintenance capacity for April and May respectively reached 20.67 million kilowatts and 15.41 million kilowatts. In April, the maintenance capacity of the unit accounted for about 13% of the total installed capacity of the entire network, and compared with the same period of the year, it was normal maintenance capacity. range. Another example is that the utilization hours of thermal power equipment in Hunan from January to April are severely lower than the previous year's hydropower, resulting in an increase of 72 hours in the case of large-scale thermal power; Shanxi, Henan, Guizhou and other coal-fired resource provinces have been forced to stop due to coal shortages. As a result, the average utilization hours of thermal power equipment in January-April decreased, but this is not the root cause of power shortage.