Curtailed Wind to Curtail Coal Heating in China: A Double Advantage?
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|BY WANQING ZHOU | APRIL 26, 2013|
In March 2013, the National Energy Administration (NEA) of China issued a Notice to urge development of wind-to-heat projects in northern China. This practice aims to reduce the waste of wind power and cut emissions from the coal-fired central heating system. Experiments have been carried out and the approach is going to be scaled up, but further innovations are needed to really shake the dominance of coal.
The niche for large-scale wind-to-heat
According to the Chinese Wind Energy Association(CWEA), China’s total installed capacity of wind power jumped to 75.3 gigawatt (GW) by the end of 2012, while the annual installed capacity was 13 GW, nearly 27percent lower than that of 2011 (See Figure 1). This may reflect bottlenecks, such as growing wind curtailment, faced by the industry.
Figure 1. China’s installed wind power generation capacity, and average operation hours of the turbines from different sources.
Since 2010, the operating hours of wind turbines have been decreasing (See Figure 1). Combined with growing generation capacity, wind curtailment in 2012 reached 20,000 gigawatt hours(GWh), nearly doubled the curtailed production of 2011.
Jilin Province is a region with one of the highest curtailment rates. Winter nights see high wind speed but low electricity demand, and the local grid’s flexibility for peak electricity management is limited. As a result, wind farms in Jilin Province, which have a total generation capacity of 3.3 GW, were generating for only 1,420 hours in 2012. This was much lower than the industry-adopted economic minimum of 1,900 hours.
Meanwhile, burdens created by coal-burning are becoming less bearable. It is estimated that 70 percent of residential area in northern China has central heating systems. Half of this heat comes from heat-power cogeneration (which is mainly coal-fired), and the other half comes from the direct combustion of fossil fuels. These coal-intensive approaches consume 160 million tons of coal equivalent each year, which translates to 108.8 million tons of carbon emissions.
The atmospheric pollutants generated from burning coal threaten human health, especially during winters when the demand for heating is at the highest. Adding insult to (literal) injury, many coal-fired heating stations are constantly losing money because the price for heat is relatively low. According to China National Renewable Energy Center (CNREC), if the profit of wind power companies could be increased by reducing wind curtailment, it would be possible to compensate for the loss in power generation and heating services.
Utilizing curtailed wind for heating could therefore mitigate some pollution impacts and be economically beneficial. As Mr. Lishan Shi, Deputy General of the New and Renewable Energy Department under NEA, said, “wind-to-heat is a key that can open two locks”.
From pilot projects to scaling up
Wind-to-heat pilot projects have been carried out by major power companies in the Inner Mongolia and the Northeastern regions. In 2011, Datang Group, one of China’s “Big Five” state-owned power companies, launched an experimental project in Taonan, a county-level city in Baicheng, Jilin Province (See Figure 2).
Figure 2. Map of Baicheng, Jilin Province, showing the city of Taonan (Source: Google Maps)
The project coupled the Datang Taonan Heating Stations with the Datang Jilin Xiangyang Wind Farm. During the off-peak hours in the heating season, electricity generated from the 200 megawatt (MW) of wind capacity is used to heat the water in nine heat storage boilers (each is designed to hold 150 tons of water), which then provide heat to 163,000 m2 of residential area, or roughly 1,630 households. The 27 GWh of wind power saved at Taonan from curtailment and converted to heat during one season is equivalent to 9,000 tons of coal equicalent, which means an emission reduction of 5,000 tons of carbon dioxide and 150 tons of sulfur dioxide.
Encouraged by the preliminary results, the NEA plans to scale up the success in Baicheng by assigning wind-to-heat projects to all the major wind power companies in the region. If all of the wind power generation capacity in Jilin Province (3,997 MW by the end of 2012) could be connected to adjacent heating systems and operate in a similar way, the would-be-curtailed wind could reduce coal consumption by 160,000 tons per heating season (a period of about four to six months).
Implementation and beyond
To utilize the off-peak wind power in a larger scale, supporting policies need to catch up with the political will. Holistic planning is necessary to allow the penetration of wind power to fit into local situations. For example, the demonstrated approach requires extensive coordination between wind farms and coal-fired heating stations, and the pricing of wind-powered heating (as well as the compensation mechanism mentioned earlier) is key to wind power companies, heating stations, and customers.
It is also important to note that wind-to-heat, without further technology improvement and innovative policies, can hardly divert China from massive coal consumption. With the current approach, even with all installed wind capacities in northeastern and northern China (eight provinces including Inner Mongolia) combined, wind-to-heat would only able to reduce coal consumption by 20 million tons per season, a mere 1.2 percent of the total annual demand for coal-powered heating in the country. For the time being, China will need to explore other alternatives to existing heating infrastructures and the utilization of curtailed wind in order to reduce coal consumption in the heating sector.
Encouraging wind-to-heat is a step forward, highlighting the diversified approach China is taking to reduce coal consumption. With more projects to follow, the country seems to be exploring all available approaches to overcome barriers to the growth of the renewable energy sector and the progress towards more sustainable lifestyles.
Wanqing Zhou is an intern with the China Program at Worldwatch Institute.