In Gansu, one of China's poorest provinces, the residents of Daping Village all have two things in their backyards: biogas digesters and solar cookers.

In this barren and remote northwestern town, no energy sources could be more efficient or economical in meeting residents' daily cooking and heating needs than biogas and solar power.

"I used to burn firewood to cook. The smoke choked me to tears. After switching to biogas, the air is much cleaner, and I do not have to live with smelly animal waste," said 55-year-old villager Li Hongmei, who can now dispose of animal waste in the biogas digester.

In Li's backyard, a 15-cubic-meter biogas digester in the ground remains invisible unless a heavy stone cover is removed. A 20-meter plastic tube connects the biogas tank to a stove in her kitchen.

The local government offered her family 1,400 yuan (218.75 U.S. dollars) two years ago to fund her biogas set-up. Li spent the money on buying cement and sand and hiring construction workers.

For the past five years, the local government has provided residents with nearly 10 million yuan a year to construct these clean energy-yielding facilities.

According to data released by the Pew Charitable Trusts in April, China extended its global lead in renewable energy investment and financing by spending a record 54.4 billion U.S. dollars last year.

In the past five years, the central government alone invested 21.2 billion yuan in promoting and developing the use of biogas in rural areas, according to data from the Ministry of Finance.

Figures from the Ministry of Agriculture showed that by the end of last year, 40 million households in China, or about one-third of the nation's rural population with access to methane, used biogas, benefiting 155 million people.

Biogas and a greener development mode

The benefits of biogas extend far beyond a cleaner environment and waste disposal. The agriculture ministry figures also showed an 8-cubic-meter biogas digester can produce enough gas to meet 80 percent of the fuel demands for a family of three to five people.

According to Bai Jiming, director of the Science and Education Department of MOA, China produces at least 16 billion cubic meters of biogas a year, accounting for 13 percent of the nation's consumption of natural gas.

China aims to make its economic development model greener, an important part of its 12th Five-Year Plan for the period of 2011 and 2015.

The country has pledged to raise the share of non-fossil fuel consumption in total energy use from its current 9.6 percent to 15 percent by 2020. Non-fossil fuel sources include wind, solar, biomass, hydroelectric and nuclear power.

The use of household biogas digesters has expanded remarkably in the 10 years since the national deployment program was initiated. It is a successful example of a central government mandate that has been able to make significant impacts on social, environmental and economic issues at the local level, said Michael R. Davidson, a China Climate Fellow of the U.S.-based Natural Resources Defense Council (NRDC) in an e-mail interview with Xinhua.

But he also pointed out problems, including the high operational and maintenance costs of biogas digesters which could burden some users.

Additionally, the central government program does not provide all of the subsidies, which means provinces and local governments have to pick up a large portion of the tab. Rural service stations get limited central government support, as well.

As a result, the program runs into the same issues as other under-funded central government policies: limited enforcement of quality standards, poor follow-up and unreliable data reporting, Davidson said.

China's central government often comes into spending conflicts with local authorities, with the latter complaining about not having enough funds to implement projects ordered by the central government after giving a large proportion of their tax revenues to the central coffer.

According to the 12th Five-Year Plan, China will increase subsidies for household biogas users in the next five years, but no detailed data has been released in this regard.

Industrial applications

Another point highlighting the government's biogas development agenda is that it is looking toward enhancing the industrial applications of biogas by building more mid- and large-scale biogas stations.

Shi Yuanchun, a biogas expert with China Agricultural University, said household biogas digesters have room to yield purer fuel, requiring the participation of more industrial enterprises.

China's household biogas digesters are mostly located in 12 western provinces where economic development is slow and the ecological environment is vulnerable to outside changes, as well as another 12 provinces in the major gain-producing regions of central and northwestern provinces.

Meanwhile, large scale biogas stations have been built in the developed east coast regions where many livestock farms are based.

China has 22,600 mid- and large-sized biogas stations. It aims to add 3,000 more before the end of 2015, according to figures from the MOA.

Zhang Taolin, vice minister of MOA, said the central government will invest more in large scale biogas station projects to raise efficiency.

According to a biogas development plan mapped out by MOA, the ministry will carry out pilot programs on a number of large biogas stations with a daily output over 5,000 cubic meters each.

The pilot program will focus on implementing the desulfurization and decarbonation processes to purify the biogas for greater efficiency.