| 摘要 | ABSTRACT
1. Purpose of research
Many countries in the world have been making efforts to solve the problems related to the growth of energy demand and climate changes. South Korea, which depends most of its energy demand on imports, faces difficulties in ensuring energy supply security due to persistent high oil prices, lack of nuclear power capacities, and difficulty of expanding renewable energy supply.
Buildings account for about 21% of all energy consumption in Korea (Park 2013). Korean government has strengthened energy regulations and standards in new buildings, whereas rarely having applied them to existing buildings, which account for the dominant share of buildings in Korea. Even though Korean government has implemented various energy efficiency policies and programs in every area, energy consumption in building sectors has continuously increased (Yearbook of Energy Statistics 2013).
Since heating and cooling systems using electricity have been adapted in primary and secondary schools in accordance with school facility renovation policies in Korea, there has been a noticeable increase in electricity consumption in schools. Especially, it is caused partly, by new construction of library and expansion of food service facilities, modernization of school equipments, and operation of various programs such as after-school care classes and after-school programs. On top of that, the average annual growth rate of electricity tariffs from 2007 to 2012 has reached 8% (Korea Energy Statistics Information System). Consequently, the expenditure for energy consumption in schools has gradually increased due to modernization of school facilities and a rise in electricity tariff. Most schools have no choice but to diminish operation hours of heating and cooling to save the energy use expenditure, which ended up taking a toll on their students.
Energy saving technology can be easier to be applied to school buildings than commercial buildings such as hospitals and hotels in that 1) the structure of buildings are simple, and 2) the building usage schedule and the number of people using buildings are similar across schools in the nation. More than half of 11,000 primary and secondary schools nationwide have deteriorated buildings more than 30-40 years old. For the case of elementary and middle schools, the percentage of public schools is fairly high. Considering this fact, Korean government is feasibly able to implement energy-saving retrofitting of public primary and secondary school buildings. In this context, this research explores the status of energy consumption of primary and secondary school buildings, and suggests the policy implication to improve energy efficiency of school buildings.
2. Results and Policy Implication
This paper firstly reviews the domestic and foreign programs and policies for enhancing energy efficiency of buildings in primary and secondary schools. One of representative energy efficiency programs is the Green-School Project, which has been being promoted by Ministry of Education, Korea. Korean government has undertaken this project to create environmentally friendly schools by renovating deteriorated school buildings since 2009. Currently, the limited budget binds only fifty schools to this project. The U.S., Europe, and Japan have been implementing energy retrofitting programs such as EnergySmart School in U.S., ECBCS(Energy Conservation in Building and Community Systems Programme) Annex 36 in Europe, and the Eco-School program in Japan in order to improve their educational environment. Specifically, the U.S. and Europe have set the systematic guidelines about the school retrofitting. The guidelines include the specific instructions of step-by-step retrofitting processes.
In this paper, we have collected the data on energy consumption in entire primary and secondary schools, and have conducted the basic statistical analysis. The number of primary and secondary school has consistently increased in Korea from 1970 to 2013. By contrast, the number of students in those schools has decreased during the same period. Since 2000, the number of students per class has gradually decreased and reached 23.2, 31.7, and 31.9 students per class for an elementary school, a middle school, and a high school, respectively. We analyzed the energy consumption data of elementary, middle, and high schools nationwide from 2012 to 2013. The data has been collected from education basic statistics 2013. Total energy consumption in schools has increased by 8.7% from 2012 to 2013(778,628TOE in 2012 and 847,002TOE in 2013). Energy consumption not only per area but also per the number of students has increased.
High schools took the top position in energy consumption among schools. Elementary schools turn out to take the second position, and Middle schools ranked the last. Energy consumption per area tends to increase proportionally as school buildings get old. In terms of type of founder, energy consumption of private schools is the most, and national schools and public schools are followed. The schools in the northern region of Korea, which are relatively colder than the southern region, tend to consume more energy than those in the southern region.
After selecting schools of which energy consumption is close to the national average, we investigate the current status of their energy consumption, and conduct simulation analysis by using EnergyPlus program. Considering the usage of energy in analyzed middle schools, hot water supply takes the biggest share (23.3%) of total energy consumption. Heating, electricity, cooking system took the second, third, and fourth shares, respectively. From the aspect of energy saving technology, thickening thermal insulation materials from 50mm to 400mm results in saving 3.8% of energy consumption, which is not bigger than expected. Using all applicable energy saving technologies to heating and cooling systems turns out to decrease total energy consumption in school by 10.4%, and reduces energy consumption for heating and cooling in school by 13.8%. This result is attributed to the fact that the share of energy use for heating and cooling out of total energy consumption is just 34.3%, which is not that big.
But, in the case where applying a 100m2 of solar heat collector to the hot water supply system has the energy saving effect of 16.2%. In the case of photovoltaic, energy saving rate reached to 18.5%. As free school meals system has been adapted to elementary schools across the nation, energy consumption for hot water supply has increased. In order to save energy consumption in school, adapting the solar energy systems for hot water supply should be preferentially considered rather than the adapting of energy saving technologies for heating and cooling systems.
Introduction of the system of photovoltaic should be considered to save not only electricity use in schools but also nationwide electricity use. In the case of schools, the building-to-land ratio and floor-area ratio are low, and long term usage and rent are possible. Therefore, rental fees obtained from renting a roof of the school to solar system company can be transferred to the school budget. It also contributes to expansion of national renewable energy supply. Korean government recommends that solar system companies should install the monitoring room in school for the publicity and educational purposes of schools. This enables students to face renewable energy facilities in a daily life of renewable energy facilities and expand awareness of renewable energy.
Finally, we present the result of the economic analysis of the applicable construction type in school and the technical elements in energy sectors after calculating the payback period using the input costs and LCC techniques based on energy consumption costs of existing schools. The result shows that for solar hot water system, the investment payback period is 7.7, and solar power system is about 13 years.
To conduct the retrofit projects of buildings in national&public elementary and secondary schools, funding is urgently needed. One way to obtain necessary funds for school retrofitting projects is to use the funds available in the public sector such as ��Power Industry Promotion Fund. If necessary, modification and supplementary revision of related Act or Decree is needed to get funds for school retrofitting. The usage of Energy Use Rationalization Fund is worth being considered as well.
In order to facilitate the promotion of Building Energy Retrofit Project, the most important thing to be done is the energy audit and performance assessment of buildings in schools. Each of these energy assessments and retrofit projects should be conducted after reflecting the circumstances of each individual school. Moreover, the retrofit projects that satisfy schools, government, and participating company should be carried out. All types of retrofitting including school buildings should carefully reflect what consumers need in the projects. The system for consumers to access easily to all retrofit information should be essentially provided. of this study provides some important insights for policy design. |
