ارزیابی هزینه های زیست محیطی و اقتصادی مصرف انرژی خانگی روستایی منطقه پر از تپه لس، استان گانسو، چین

Due to poverty, serious soil erosion and shortage of rural household energy in Loess Hilly Region, Gansu Province, China, excessive consumption of biofuel has become a critical factor underlying eco-environment degeneration. Data on rural household energy use was obtained by questionnaires, and based on substitutable analysis, environmental and economic costs under different energy consumption structures were estimated using a quantitative model. The results show that annual energy consumption per household is 2112.44 kgce and per capita 428.59 kgce, a low level. The total annual energy consumption cost per household is 1925.25 yuan, of which environmental cost is 621.13 yuan and economic cost 1304.52 yuan. Commercial energy has been used widely. The per household annual cash payment for commercial energy is 536.51 yuan, 8.69% of household net income. Exclusive use of solar energy and biogas obviously decreases energy consumption cost, cash payout and energy source availability being the main criteria for household energy choice. To compare with the actual structure of energy usage, there are clear differences in the total cost, environment cost, economic cost and cash payout for households among the four substitutable structures. All costs are lower when biogas and solar energy are used, so this structure is the primary direction that rural energy should adopt in the future.

Energy is the most basic material demand for human existence and development. Energy consumption level is used as the criteria to indicate the economic and social development level of a certain region [1]. Energy demand has also become a critical factor driving resource exploitation and environmental change. In rural areas of developing countries in particular, energy consumption has caused a series of environmental and economic problems. Firstly, there are complex and numerous links between energy and poverty. Not only does energy consumption increase the direct economic payment of rural households, but energy collection results in peasants losing opportunities to increase income [2]. Shortage of energy severely restricts the improvement of people's living standard. Secondly, the rapid growth of total energy consumption causes serious environmental problems [3]. Excessive consumption of biomass energy has resulted in degradation of forest and grass vegetation, accelerated soil erosion, and changed ecosystem substance cycles. Thirdly, burning of biomass and coal has caused massive CO2 and SO2 emissions, resulting in atmospheric pollution [4]. Fourthly, indoor air pollution from household energy use is a leading environmental health risk. Indoor smoke in particular produces obvious impact on the health of women and children [5]. Energy supply and demand is widely and closely connected to eco-social development and environmental protection in developing countries. This issue has received much attention internationally and many studies have probed how to solve the problem in rural areas. Evaluation of the exploitation potential of various fuel sources in different regions, especially renewable energy like solar energy, wind energy, biomass, terrestrial heat, etc. has indicated great potential, but energy utilization is restricted by the payment capability of households and lifestyle. In fact, the shortage of energy sources is still a long-standing problem [6], [7] and [8]. Exploitation and utilization of renewable energy, improvement of the technology of resource use and transformation of patterns of resource consumption are not only main approaches to resolve the problem of energy shortage, but also play important roles in improving the efficiency of resource use and reducing environmental pollution. These approaches have been put into practice in rural areas of Asia and Africa with good results [9], [10] and [11]. Moreover, some developing countries have optimized their energy structure and adjusted their energy management policies to advance rural development [12] and [13]. The demand for rural energy in developing countries is continuously increasing, while the energy consumption structure only changes gradually along with population growth and improvement of household living level. These increases impact on the ecological environment, causing shifts in the energy consumption behavior of households and government policies. The above-mentioned studies have discussed issues such as greenhouse gas emission, energy poverty and health risk, but insufficient attention has been paid to the economic and environmental benefits of energy consumption. In Loess Hilly Region, Gansu Province, China, ecological and economic problems of energy use stand out, fuel being in very short supply, rural households poor and soil erosion severe. This article takes this region as the subject and attempts to calculate the environmental and economic costs of rural living energy consumption, comparing the effect variances under different structures of energy use. The aim is to put forward an energy policy for environmental management.

5.1. Conclusions This study investigated the impact of living energy consumption on the economy and environment, using data collected by questionnaire from 336 rural households in Loess Hilly Region of Gansu Province, China. A model was constructed from the data to calculate the economic and environmental costs of energy consumption. Based on the present structure of living energy consumption, economic and environmental costs are estimated under different energy structures. The main conclusions are as follows. (1) At present, annual living energy consumption per rural household is 2112.44 kgce and per capita 428.59 kgce in Loess Hilly Region of Gansu Province. Total energy consumption is so low that it only meets the basic energy demand of rural households, such as cooking and heating. Energy consumption for improvement of living standards like recreation and sanitation is limited. The proportion of unclean energy is high, 59.66% of total energy consumption being traditional biology energy, while that of clean energy is low. The total annual energy consumption cost per household is 1925.25 yuan, of which the environmental cost is 621.13 yuan and economic cost 1304.52 yuan. Commercial energy has been used widely. The annual per household cash payment is 536.51 yuan, 8.69% of household net income. The use of solar energy and biogas has accelerated transformation of the energy consumption structure. (2) Substitution among energy sources was analyzed for four types of energy structures for existing energy consumption. The results are as follows. Electricity is clean and convenient, but the cost for rural households is too high to bear. The total cost of the traditional energy structure comprising mainly biomass energy is the highest per household, with cash payment the lowest, immolating environmental benefits. Under the structure where fossil fuel dominates, each cost is at the middle level, but the economic burden is the heaviest. Various costs are lower when biogas and solar energy are used exclusively. This is the perfect structure, and should be changed to this structure in future. (3) Currently, the primary basis used by rural households in selecting fuel for living is the amount of cash payment and how easily the energy source is obtained; followed by cleanliness in utilization, with environmental cost being the least considered. The reasons that the actual energy structure exists are that there is still an energy shortfall after peasants have consumed all biomass fuel, therefore needing to use solar stoves, coal and LPG to meet their basic energy needs. However, a lot of cash is needed – of which the peasants have little – to pay for consumption of electricity and fossil fuel. 5.2. Discussions (1) The structure transformation of household energy consumption has played a positive role in improving peasants' living standards and environmental protection in Loess Hilly Region of Gansu Province, China, but the existing measures are mainly focused on resolving cooking energy. Space heating, especially heating Kang bed-stoves, accounts for more than half of living energy consumption, which uses biomass fuel and has negative impact on the eco-environment. There are few effective substitution methods. Therefore, how to develop and use solar energy, such as building greenhouses, will be the key to solving the problem of space heating in the winter, and should be the aim of rural energy structure in the future. (2) Supply and demand of rural energy sources is a complex issue interconnecting ecology, economy and society. This study obtained useful findings through in-depth investigation and quantitative analysis. Although the sample size was limited, the environmental and economic benefits calculated represent the typical situation of energy use in Loess Hilly Region of Gansu Province. According to the above results, 6450 biogas digesters built in Qin'an County and Tongwei County during 2004–2006 could create environmental and economic benefit of 3.6969 million yuan per year, with environmental benefit of 1.2691 million yuan and economic benefit of 2.4278 million yuan. If biogas and solar stoves are used by the 208.3 thousand households of the two counties, the environmental and economic benefit created would be huge. (3) In Loess Hilly Region of Gansu Province where rural households are in poverty and water loss and soil erosion is very serious, the issue of living energy shortage must be solved firstly to improve the ecological environment. Biogas digesters and solar stoves should be popularized widely. At the same time, researchers should focus their efforts on how to solve indoor space heating in rural areas. Moreover, when expanding vegetation on hills, deposited vegetation should be protected from damage. This should be taken as the foundation of policy-making on ecological construction, environmental management and living energy guarantee. Eco-environmental and economic problems need to be addressed and resolved together in rural energy development.