Renewable and Sustainable Energy Reviews
Current status of ground source heat pumps in Korea
Introduction
The Republic of Korea (ROK) is one of the top 10 largest oil-consuming countries in the world [1]. Furthermore, most of the domestic energy consumed (over 85%) in the country is derived from imports [2]. To keep pace with a world wide struggle to reduce CO2 emissions and to cope with a rapid increase in oil prices, the Korean government has promoted the use of new and renewable energy (NRE hereafter) sources for various purposes, including residential heating and cooling. The Promotional Law of New and Renewable Energy Development, Use and Dissemination (revision of the 1987 Promotional Law of Alternative Energy Development) was enacted in 2004. The Law (article 12) and it is Enforcement Decree (article 15) enforced the obligatory installation of NRE systems for newly constructed and reconstructed public buildings and facilities. More than 5% of the total building constriction cost should be allocated for these systems.
Compared with many other countries such as Switzerland, Sweden, Canada, USA, and Iceland, Korea's use of NRE energy is still low [3]. The share of NRE sources in Korea's overall energy mix was 2.1% in 2004 [2]. The Korean government aims to raise this level to 5% in 2011 and 11% in 2030. To promote the use of NRE systems in public, commercial and residential buildings, the government subsidizes 30–80% of the total installation cost. Research and Development (R&D) funding for energy is relatively low (only 1.6% of the overall R&D budget), but the largest increase of funding has been found in the area of the new and renewable energy technologies, which has grown nearly fivefold during 2002–2006 [2].
In the meantime, following the enforcement of the obligatory installation of the NRE systems for public buildings and facilities in 2004, ground source heat pump systems are the first option for the public community. Over 60% of newly constructed public buildings during 2004–2007 adopted GSHP systems for space heating and cooling [4]. Because there are few sources of high-temperature geothermal energy in the country [5], utilization of ubiquitous shallow geothermal resources in de-centralized GSHP systems is an obvious option for space heating and cooling [6]. Until recently, small buildings have been the main targets for GSHP systems, but most recently the systems are being installed in very large residential and commercial buildings. Details of the GSHP systems in Korea are presented in this paper.
Section snippets
Climate and general geology
The Republic of Korea is located in the southern part of the Korean peninsular and covers 45% (99,601 km2) of the total peninsular area (Fig. 1). Korea is surrounded by the South, East and Yellow Seas, including 3200 small and large islands. The climate ranges between continental and oceanic climates and it features four distinct seasons [7]. The hottest season is in August (average 23–27 °C) and the coldest is in January (average −6 to 7 °C). The annual mean air temperature ranges between 7 and 15
Direct use of geothermal energy
Before 2000, bathing and swimming were unique forms of the direct use of geothermal energy in Korea [5]. There are a significant number of hot springs (233 geothermal wells and 452 hot spring facilities), especially in areas of granite (formed in Jurassic and Cretaceous periods), some of which can be traced to more than 1000 yr ago [5], [9]. The hot springs (water temperatures of 25–75 °C) are mainly distributed in the provinces of CN, CB and GN (see locations in Fig. 1b) [10], which coincide
Installation of GSHPs
Since 2004, ground source heat pumps have been seriously considered as one of the alternative heating and cooling systems. Starting with only 2 buildings in 2000, GSHP systems have been installed for 551 buildings and facilities for space heating and cooling as of August 2008 (among them, installation years of 99 cases are unknown). Initially, while GSHPs were mostly installed in public buildings, they were not installed in private (residential houses) or commercial buildings. With the increase
Regulations on GSHPs
Laws and regulations directly related to GSHPs include the “Promotion Law of New and Renewable Energy Development, Use and Dissemination (#8899)” and the “Groundwater Act (#9058)”. The Promotion Law designates the geothermal energy as one of the new and renewable energies (article 2(1)) and imposes the obligatory installation of new and renewable energy equipment for newly constructed governmental and public buildings and facilities (article 12(2)). The Presidential Decree (article 15(1)) sets
Conclusion
In this paper, the current status of GSHP systems in Korea was presented. In Korea, installations of GSHP systems are rapidly increasing in both private and public sectors. The GSHP systems are extremely energy efficient, clean and environmentally friendly. Recently, the Korean government announced that the share of renewable energy among the total energy use would be elevated to 11% in 2030 from 2.4% at present. In particular, dissemination of geothermal energy is scheduled to increase by 51
Acknowledgements
This work is financially supported by the Korean Ministry of Environment (Department of Soil and Groundwater). The author is grateful to Jin-Gu Yun, Su-Hyun Song, Jae-Woong Kim, Hyun-Mi Choi and Kwon-Young Moon at Kangwon National University for their collection of GSHP data in Korea.
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