ALGUNES DADES

Table 3.2: Scoring for Household Biogas Systems

Criteria Score Comments

Technical Evaluation ★★★★★

Especially applicable to less developed rural areas for supplying farmers with clean energy for cooking and lighting. Not appropriate for farmers: (i) in regions rich in coal, solar, wind, and hydropower resources; (ii) who lack stable supplies of raw materials, such as in nomadic areas; (iii) in developed regions with access to modern energy; (iv) in underdeveloped areas lacking support for building and maintaining digesters; and (v) in regions that experience severe cold.

Economic

Assessment ★★★★★

Biogas digesters have a low investment cost. In addition to cooking gas for household use, another valuable output is high-quality fertilizer, which can be used to enhance the output and quality of a variety of agricultural products, resulting in high economic and financial returns.

For a sample village with 200 households, 200 biogas digesters are constructed with an investment of CNY1,420,000, a cost in annual operation and main- tenance of CNY3,942,000, and annual economic benefits of CNY6,812,780; therefore, its financial internal rate of return (FIRR) is 54% and economic inter- nal rate of return (EIRR) is 55%.

Environmental

Impact ★★★★★

Utilizing livestock manure in a household digester can improve the local envi- ronment by avoiding wastewater pollution, providing clean cooking gas (which reduces indoor air pollution from traditional cooking stoves), and reducing chemical fertilizer use when the digester effluent is used as fertilizer.

Social Impact ★★★★★

Project household income rose by 86.4% compared to non-project households through increased income from pig and fruit sales and reduced expenses on fertilizers, pesticides, and fuel.

Time for house chores also decreased for project households (77.8% for cook- ing and 67.5% for boiling water).

Household sanitation and household health were improved due to improved cooking and sanitation facilities.

Job opportunities created by biogas development mainly occur in digester unit construction and biogas-related enterprises.

Comprehensive

Result ★★★★★

Table 3.3: Cost–Benefit Analysis for Household Biodigesters for Cooking and Heating Application (200 Households) Initial Investment (CNY) Annual O&M Cost (CNY) Annual Economic Benefit (CNY) Net Benefit (CNY) EIRR (%) FIRR (%) Benefit– Cost Ratio Payback Period (years) 1,420,000 3,942,000 6,812,780 2,971,532 55 54 1.56 0.5

Box 3.2: Environmental Benefits of Rural Household Biogas Systems

Cofinanced with the Global Environment Facility grant, Loan 1924-PRC undertook an energy and environmental monitoring and assessment program that included over 340 farm households in the provinces of Shanxi, Hubei, Henan, and Jiangxi. Over two years, household energy and material use were measured and samples of soil, biogas yard water, fertilizer, and agriculture products were gathered and tested and comparative measurements were made on indoor air quality. The findings provided important quantification on the economic, environmental, and health benefits of rural biogas systems.

Compared to non-project households:

• Crop production increased 42% and

production value increased 25%.

• Chemical fertilizer use decreased 37.1%

and fertilizer cost decreased by 39.3% per household.

• Pesticide use decreased by 33.7% and

pesticide cost by 98.6% per household.

• CO2 discharge decreased 53%, SO2 by 39.4%,

NOX by 47%, and TSP by 52%.

• CO2 decreased 80%, PM10 by 55%, SO2 by

7.8%, NH3 by 7.8% and Fluoride decreased by

24%.

Based on these results, the overall impacts on the environment are considered to be significantly positive. The project is expected to reduce about

84,429 tons of CO₂ annually.

Ethnic minority regions could be targeted, building on recent efforts by the State Ethnic Affairs Commission. Weather conditions in the southwest, where many ethnic minorities live, are suitable for biogas development.

The government, however, should revise its subsidy policy for rural biogas. Under the current program, subsidy levels are based on regional differences when they should be based on household income levels within the community. Substantially higher subsidies should also be supported for especially poor farmers. This affordability issue is discussed in more detail in Chapter 5.

The PRC could further improve its already successful industry framework for household biogas systems (Figure 3.1). This framework includes:

(i) construction of biogas digesters at the county level, dependent on trained technicians and small-scale industries; (ii) supply of auxiliary products, such as biogas

stoves, which is mainly dependent on mid- to-large-scale industries with procurement at the provincial level and distribution at the county level; and

(iii) technical support and service centers at the county level, with training of technicians at the provincial level and carried out at the county level (some 150,000 farmer technicians have received professional certificates for biogas production, issued by the Ministry of Agriculture).

Two main improvements can be made to this framework. First, the availability of technical support service centers should be strengthened, as it is currently inconsistent between counties. As a result, many rural households have stopped using biogas because technical support was not available after their systems were constructed and problems occurred. To address this problem, a tertiary service network at county, township, and village levels should be set up.

Secondly, household biogas systems are of special significance to women, children, and ethnic groups,

Recommendations. Given their significant

advantages, the government should continue to support and promote the household biogas systems in rural villages. It will continue to be the main approach for upgrading and improving the cleanliness of residential cooking fuel and improving rural household sanitation.

and the design and implementation of these systems need to be more sensitive to their special needs. Consultancy services from sociologists can help feature more participatory and relevant project designs for communities.

Figure 3.1 illustrates how several stakeholders could be more involved: government implementation and executing agencies; rural grassroots coordinating and organizing agents; major beneficiaries in households; special interest groups (e.g., rural biogas technicians, women, and ethnic minorities); and technology extension institutes, biogas research institutions, and associations for rural biogas service providers.