Converting coal-fired boilers into heat-accumulating electric boilers will help solve the problems of haze pollution as well as wind curtailment, according to Shi Lishan, deputy director of NEA's new renewable-energy department.
In recent years, northern China has frequently been enveloped in thick hazes, largely a result of coal-fire discharges, combined with emissions from motor vehicles and industrial plants, plus dust from construction sites.
China relies heavily on coal for energy generation. In 2012, it consumed 3.62 billion tonnes and its average consumption is rising by 200 million tonnes a year, against the international tide.
China is rich in wind energy resources, however — sufficient to host up to 2,500GW of installed projects according to industry estimates. About 90% of the resources are located in northern China. At the end of June, China's grid-connected wind installations reached 66.5GW, making wind the country's third-largest renewable energy source, behind thermal and hydro power.
But China's energy management systems cannot cope with the fluctuating nature of wind power, which has caused intense bottlenecks in wind-power consumption.
According to the China Wind Energy Association (CWEA), China gave up the opportunity to generate 21.8 million megawatt hours of wind power in 2012. The hardest-hit area was Jilin province in the north-east of the country. Jilin's provincial grid last year managed 19.32GW of power installations, with 12.78GW from heat-supply units. The province's electrical load maximised at 8.75GW and minimised at 3.97GW, leaving no running space for wind power at the low ebb of power consumption. Wind turbines operated only 1,420 hours annually on average in the province, meaning about one-third of wind-generation capacity was wasted.
In northern China, wind energy features in "large quantity in winter and small quantity in summer, and large amount at night and small amount in daytime", says Shi. This means resources are at their richest during winter nights, but that coincides with the low ebb of power load and the peak of heating to warm houses.
Forerunners
Datang Renewables, a leading Chinese wind-power developer, has put into trial operation a heating station in Taonan city, Jilin, the first national-level demonstration project for heating with wind power.
Nine high-temperature, pressure-bearing, heat-accumulating electric boilers and supporting facilities replaced one 20-tonne coal-fired boiler. Two 10kV power supply lines, from the Liming transformer substation, supply power to the boilers. The Taonan heating station buys electric power from the grid, mainly the low-ebb power from 10pm to 5am and sells the clean heat energy to local power companies.
According to Cui Jian, deputy director of the comprehensive planning section of Datang Renewables, replacing coal-fired units with heat-storage electric boilers could increase electricity consumption in the low-ebb period at night, expanding wind power connection to the grid.
"Our demonstration project in Taonan is significant in that it has proven heating with curtailed wind power is feasible technically," a senior Datang executive said.
In May, Longyuan Power, China's largest developer, signed a deal with the government of Faku county, Liaoning Province, to supply heating with wind power to 200,000 square meters of houses this winter.
Longyuan has submitted the plan for the demonstration project to the provincial authority for approval. It is negotiating an agreement with local heating companies.
Longyuan expects to generate 20 million kWh of wind power that would otherwise be curtailed, cutting 7,000 tonnes of coal consumption and 16,000 tonnes of CO2 emissions.
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