| 摘要 | ABSTRACT
1. Research Purpose
In the Korean electricity market, the electric power generated by large-scale power generation plants has been transported through large-scale transmission facilities. Since stable supply of electricity is the overriding policy objective to meet ever-increasing demand for power, large-scale power generation and transportation facilities will probably be the best means to consider efficiency. However, due to the nature of the large size, it is difficult to install near the demand areas. Thus, nuclear power and coal-fired power plants, which are base power generation, have been formed in coastal areas with low population and low price. The large amount of electricity developed in the local power plants was transported to the metropolitan areas with high power demand through large power transmission facilities.
However, electric power supply systems that depend on large-scale power generation and transmission facilities have caused various social conflicts in recent years. Such conflicts include the Milyang transmission tower case which made conflicts with local residents caused by large-scale transmission facilities, and the environmental problems surrounding the thermal power generation facilities, which is presumed to be the main cause of fine dust generation. Furthermore, after the Great East Japan Earthquake and the Gyeongju Earthquake, concerns over the stability of the domestic nuclear power plant, which is concentrated in a small area will continue to be a major issue in achieving the policy goal of building a stable power supply system. These issues are major obstacles to the plan to build large-scale power production and supply facilities.
As the uncertainty about the continuous expansion of large-scale power production facilities is growing, the expansion of the distributed power supply facilities can be seen as an alternative to the major problems mentioned above. Distributed power generation facilities are advantageous in that it is easy to install a small scale power generation facility near the demand areas with high demand for electricity and large-scale transmission facilities are not needed because of the small power generation scale. In addition, since new/renewable energy generation, which is a representative distributed power generation facility, is an environmentally friendly facility, it is a facility with high residential acceptability that the major problems caused by large scale power generation facilities do not occur. The renewable energy generation business is developing beyond the power supply to the energy new industry, and the future of the electric power industry. However, the expansion rate of distributed power supply facilities are lower than the one of large-scale power plants due to the its expensive power production cost.
The purpose of this study is to investigate the activation plan of distributed power sources which use a fuel cell generated by the combination of hydrogen and oxygen. Unlike other renewable energy sources, fuel cells have advantages of being able to operate all year round without restriction of natural environment. Also, the installation area is also small, so it can be said that it is the best eco-friendly distributed power supply facility that can be installed in a large city with high electricity demand. Fuel cell power generation, which uses hydrogen, can be utilized for power generation, building use, and transport. Therefore, fuel cell power generation is a very important renewable energy source in terms of preparing for the future new energy industries. This is why we are studying distributed power sources.
2. Summary
Although there are many ways to produce hydrogen for fuel cell power generation, it is ideal to use hydrogen produced by water electrolysis and to produce hydrogen by reforming the biogas. In this case, the fuel cell will be a very environmentally friendly generator. However, hydrogen currently used for fuel cell power generation is mainly produced, by reforming water and natural gas which is fossil energy in consideration of economical efficiency. Because hydrogen production using natural gas as a raw material generates carbon dioxide, questions about reduction of carbon dioxide and eco-friendliness have been continuously raised.
Among the various benefits obtained from the fuel cell, the benefit provided by distributed generation resources is considered to be the greatest. First, assuming that the same capacity is installed, the fuel cell occupies a relatively small installation area as compared with other renewable energy sources, so it is very easy to install the fuel cell near the demand site. Moreover, unlike other renewable energy sources, which are sensitive to natural environment conditions, they have a high utilization ratio and can supply electricity and heat to consumers in a stable manner. The fact that a large power transmission facility is not required and that it can be used directly connected to the existing distribution network can meet the fundamental purpose of the distributed power source activation aimed at minimizing the power grid facility. In addition, if producing hydrogen energy by technological development such as biogas, water, and electrolysis becomes easier than importing fossil fuels, it can contribute to the benefits of renewable energy and energy self-sufficiency. This can be considered as an important power source for national energy security.
However, a negative point is being steadily raised about the fuel cell power generation business. In order to secure the economical efficiency of fuel cell power generation, the government issues a renewable energy supply certificate through the renewable energy duty quota system and applies weighted value 2. Fuel cell power generation classified as new energy is constantly being criticized as a power generation source does not fit the basic purpose of the renewable energy support system because of the carbon dioxide generated in hydrogen production. Also, there is a high possibility that it will shrink the development of other renewable energy sources because it is a power generation source that is not affected by changes in the natural environment. Another problem with the fuel cell business is that the domestic supply is mostly a large-scale power generation business using natural gas, and thus, from a big point of view, it is not different from large LNG power plants.
Based on the assumption that low oil prices will continue for the time being, it is analyzed that the current fuel cell power generation business can secure economical efficiency of power generation companies. However, if we analyze the cost and benefit from the national perspective, as it is considered that the benefit of avoiding the transmission / distribution facilities and the congestion of transmission is included as a benefit of the fuel cell power generation business, it is expected that the benefits to new energy will be reduced to a considerable extent. Therefore, the total benefits will be relatively small compared to the total related costs. To conclude, fuel cells are an important source of power for expanding distributed power sources in preparation for the future energy age. Nonetheless, there is a problem such as the environmental problem of fuel cell caused by hydrogen production which uses fossil energy and the reduction of distributed power supply benefit due to large-scale power generation. This problem seems to need improvement as soon as possible.
3. Research Results and Policy Suggestions
In this study, we propose the following policy for the activation of distributed power supply and environmental friendliness using fuel cell.
First, the issuance of the fuel cell REC in the current RPS applies a constant weighted value irrespective of the hydrogen generation fuel. In this case, it is the most reasonable way for the operator to use natural gas that can easily produce hydrogen because the environmental benefit of byproduct hydrogen or hydrogen production using biogas is not compensated. However, in order to raise the environment-friendliness, which is the most fundamental problem of current fuel cell power generation, it is necessary to provide a higher economic benefit to the fuel cell power generation using hydrogen that does not discharge carbon dioxide during the production process. This can be understood as a supportive measure to promote interest in the production of environmentally friendly hydrogen that does not emit carbon dioxide, and to promote technology development and investment.
Furthermore, support for fuel cell power generation using natural gas, which is currently being implemented, should be promoted in a direction to be gradually reduced in consideration of future environment friendly hydrogen production technology and fuel cell facility cost reduction. It is believed that fuel cells that use natural gas can secure economical efficiency only under the assumption that the low oil price era will last for a long time. If a sunset system that gradually reduces the RPS support for fuel cell power generation using natural gas is implemented, it will be a way to reinvigorate the revenues generated from the fuel cell business back to environmentally friendly hydrogen production. If the cost-benefit analysis is performed from the national standpoint, unlike the economic analysis analyzed from the viewpoint of the operator, it is difficult to judge that the benefit of the fuel cell power generation business exceeds the cost. Therefore, in the long run, the direction of the fuel cell power generation business should be determined so as to increase national benefits.
Second, as in the case of California, USA, Fuel cell power generation using environmentally friendly hydrogen should be included in the renewable energy support system. Moreover, the fuel cell power generation business itself should consider a distributed power support system that compensates for the benefits of generation by distributed power without fuel classification. In other words, it is necessary to establish a support system that meets the benefits offered. As mentioned earlier, it will be important to establish a system considering the social benefits created by decentralized power sources such as the benefits of evacuation and transmission congestion, and make appropriate compensation for the benefits generated by fuel cell power generation.
Thirdly, it is possible to consider compulsory new/renewable energy generation projects that combine fuel cell power generation with renewable energy generation such as solar power and wind power at the fuel cell power generation site. Similar to the Japan's fixed price purchase system, there is a way to generate fuel cell, solar and wind power together and include the RPS support target. In this case, it is possible to solve the feasibility problem of RPS support for fuel cell power generation in which the method of assigning appropriate weight to co-generation of renewable energy and fuel cell is continuously being raised. The system that supports the mixing of the fuel cell and the solar power as described above can be equally applied to the existing small-scale solar rental business. If a renewable energy production certificate (REP) is issued by combining the small-scale solar chartering business and the household / building fuel cell power generation, the decrease in the economic efficiency of the solar power rental business caused by the relaxation of the electricity progressive stage system for households will also be relatively complemented.
Finally, there is a need to consider stronger policy measures to enable distributed power sources, including fuel cells. For example, it is a system that allows a fixed percentage of the power to be used as the self-produced power, or to install a distributed power facility in the main electricity demand place. Approximately 50% of the electricity used in Korea is used for industrial purposes and the number of major industrial complexes in Korea shows that the number is increasing rapidly every year. If the obligation to generate a part of the power used for large-scale industrial complexes by using distributed power sources, the peak load reduction and the reduction of the transmission and distribution cost can be achieved. In particular, if fuel cell power generation projects are conducted in large industrial complexes, even if relatively large-scale power generation projects are carried out, it will contribute to distributed power generation benefits and stable supply of power to large-scale demand areas. |
