Size Matters

Deqingyuan spent RMB 60 million to buy land for the plant and key generating equipment and technology, including the anaerobic fermentation technology from German LIPP, the methane power generation equipment from GE, the sand filtering technology for the treatment of chicken feces, and desulfation technology to remove sulfurated hydrogen from methane.

Construction of the methane power plant began in 2006, and in November 2007 the egg farm started to use its methane to heat chicken coops and greenhouses. The power generation milestone wasn't hit until April 9, 2009, when the plant transmitted its first supply to the local grid. This was no easy accomplishment, Gu Qing explains. Generating electricity using chicken farm waste had been unheard of in China, so it took time to convince relevant departments of the validity of the plant and to complete the licensing and certification procedures.

Deqingyuan has built the largest methane power plant in the country using chicken feces and sewage as raw materials.                             Cnsphoto

Deqingyuan sells all its power output to the Beijing-Tianjin-Tangshan grid and buys from it what is needed for its own consumption. Mr. Gu explains that two immediate considerations justify this complication. If the plant operates at full capacity, it generates 40,000 kWh of electricity per day – evenly throughout 24 hours. But the bio-garden only needs 20,000 kWh, and 98 percent of that is consumed during daytime. So at peak consumption its power supply is insufficient, while at night unconsumed output becomes a problem. The other consideration is state subsidies of at least RMB 0.25 per kWh to renewable energy generators, provided by the Renewable Energy Law (2006). "And this adds to our electricity revenues. Actually it totals RMB 7-8 million annually," says Gu Qing.

The rewards of membership in the circular economy don't stop there. According to the Kyoto Protocol, developing countries are entitled to sell emission quotas to developed countries by reducing carbon dioxide emissions. Deqingyuan's operation reduces carbon dioxide emissions by 90,000 tons per year. Purchase of that by the Dutch government adds another RMB 7-8 million to Deqingyuan's coffers. "If we had not built the methane power plant, we would have had to build a sewage and garbage disposal plant, and the cost of building and running that would have been no less. Seen from this angle, building a methane power plant is more than cost-effective," concludes Mr. Gu.

Despite all its success, it will be difficult to popularize the Deqingyuan model, however. Chinese poultry production is dominated by family operations, and the estimated 700,000 chicken farms around the country are mostly small. Last year Deqingyuan produced 330 million eggs, while the nationwide output was 380 billion, mostly produced by family-based operations and small farms. "Small operations are incapable of building methane power plants, which are costly, so their chicken feces become a serious source of pollution," says Gu. Wang Jun admits that this is the general situation with the biomass sources, whose collection is difficult and costly. This thorny situation has severely hindered the development of methane power generation.

Nevertheless, Deqingyuan is pushing ahead with another bio-garden in Huangshan, Anhui Province. Construction began in 2008, with a completion date set for 2010.

Biomass Gas Stations

Methane is also a by-product of straw and stalks – a traditional source of fuel for villagers despite the fact that burning it pollutes the air. Concrete targets set by the Ministry of Agriculture in its agricultural biomass energy industry development plan (2007-2015) assert that by 2015, 60 million rural households will use methane as fuel. For this, China's annual methane production must reach 23.3 billion cubic meters, so 8,000 sizable methane projects will be built on breeding farms. Meanwhile, energy crops must be developed to meet the need for biomass liquid fuels. By 2015, the annual production of stalk pellet fuel will reach 20 million tons, and 2,000 methane supply stations using stalks as raw materials all scheduled for construction.

The implications of the goals are significant for rural residents. "In the past, we used firewood or liquefied gas as fuel for cooking. In one year we would consume about four cylinders of liquefied gas. Now we use biomass gas to cook, at a cost averaging RMB 30 a month," said Pan Hu of Jiangjiatai Village in Yanqing's Dayushu Town. Pan Hu is a worker at the village's biomass gas station. To date, Dayushu has built seven biomass gas stations run on stalk waste, including the one in Jiangjiatai. These stations supply cooking gas for 1,400 rural households.

Lu Baoqing, deputy chief of Dayushu, told this reporter that the town's biomass gas program is a part of the new energy ecological demonstration project, kicked off early in 2005. Since the standards for environmental quality are increasingly more stringent, Yanqing County, as a supplier of drinking water for downtown Beijing, should keep step. The town administration, after investigation, identified the burning of firewood and stalks for cooking and heating as the main source of local pollution.

Yanqing amasses large quantities of stalks, according to Lu Baoqing. Its cornfields, totaling 20,000 hectares, produce 150,000 tons of stalks annually. Of these, 90,000 tons are used as feed for its 30,000 milking cows. Of the remaining 60,000 tons, half is used for cooking fuel, and half burned in the fields. "It's too troublesome to transport stalks from fields, and their storage takes up space, so farmers just burn them in the fields," explains Lu Baoqing.

Before the biomass gas stations were built, the town government calculated the volume of stalks available and the cost of the biomass gas stations. They found that an average household cooking three meals used at least 10 kilograms of stalks per day. A household run entirely on this type of biomass fuel consumes 4 to 5 cubic meters of gas or only 2 to 3 kilograms of stalks per day.

The Jiangjiatai Village biomass gas station has been in operation for two years. The useless corn stalks sold to them by farmers required the station to build a storage warehouse. "Last year we purchased 100 tons of stalks at the price of RMB 0.3 per kilogram," Pan Hu confirmed.

According to Lu Baoqing, farmers sell the stalks at the going market rate, but are supplied with biomass gas at low rates. In a sense, these biogas stations are a rural welfare project. Investors don't profit from them, each of which cost RMB 1.3 million to build. Those built in 2005 were jointly funded by the town government and the beneficiary village. Beginning in 2006, the municipal and county governments also joined in sharing the financial responsibility.

Although the gas station is non-profit, its social and environmental benefits are obvious. "In the past, smoke rose from the chimneys of every rural home here. But last year Yanqing County had 280 days of grade-I and -II air quality, the highest among Beijing's suburban districts and counties," says Mr. Lu.

The energy revolution has reached rural kitchens thanks to biomass gas stations. Firewood used to choke kitchens with smoke and leave them sooty. In the beginning, farmers knew nothing about methane. At best, they took a wait-and-see attitude; at worst they were sure it had nothing to do with their real interests. They neither supported it nor opposed it, until the autumn of 2005 when two biomass gas stations were built in Dongsangyuan and Dongxingyuan villages. The town government organized nearby villagers to pay a visit to the operation. "Farmers found that methane is really convenient for cooking, and the cost reasonable," says Lu Baoqing.

Lu Baoqing is thinking about the future. This year the town has decided to build two more methane stations. By 2012, 15 of its 25 administrative villages will have biomass gas for fuel. The town is also courting a factory to settle in the town, a manufacturer of biomass gasification stoves. "This will certainly help to popularize biomass energy projects in Yanqing County, and promote our operation from a scale for self-consumption to a status as a new energy producer and supplier," concludes Lu Baoqing.