The Seoul Metropolitan Government has completed the construction of the Tancheon Heat Supply Facility, which will recycle the sewage heat discharged from the Tancheon Sewage Treatment Facility to the Han River. It will supply heating to about 20,000 households annually. As part of the Build-Own-Transfer (BOT) project, the facility took about 14 months to complete, after work commenced on October 2013. This is the largest heating supply facility of its kind in Korea, and the first in Seoul to use heat from sewage.
The technique of transferring heat from sewage is widely used in countries in Northern Europe, such as Sweden and Norway, since the first and second Oil Crisis, but, in Korea, it was an energy source used mostly for heating and cooling systems in small-scale buildings.
The Tancheon Sewage Treatment Facility is a domestic facility that manages about 800,000 tons of sewage generated from four districts in the Gangnam area, Hanam-si, and Gwacheon-si every day. The recently constructed heat supply facility was established in the underground floors–about 1,434 square meters–of two nearby sewage treatment facilities.
The main components of the heat production facility include seven heat pumps, which can generate up to 9Gcal per hour, heat supply pipes, and electrical pathways, enabling it to produce a maximum of 63Gcal per hour.
The new facility is expected to provide various benefits. First of all, it is an alternative to the export of oil, amounting to the conservation of KRW 15 billion or the equivalent of 20,000 tons of oil per year. It will also have a positive effect, equivalent to the planting of 316,000 pine trees, by reducing emissions by 44,000 tons of greenhouse gas.
The Magok Sewage Heat-based Heat Supply Project will be built in the Seonam Sewage Treatment Facility in the first half of 2015
The Seoul Metropolitan Government made an announcement regarding the recycling of effluent from the sewage treatment facilities in Seonam, Nanji, and Jungnang for the purpose of producing heat and supplying it to the local heating system. Currently, the sewage treatment facilities in Tancheon, Seonam, Nanji, and Jungnang discharge an average of 4,390,000 tons of sewage water into the Hangang (River) on a daily basis. As effluent water retains enough latent heat to keep its temperature around 11°C in the winter, it should be used actively.
In the second stage of this project, a heating supply facility that uses heat from sewage will be constructed in the Seonam Sewage Treatment Facility in the first half of 2015, supplying 190,000Gcal of heat water annually to the Magok Urban Development District.
Starting from the Tancheon, the Seoul Metropolitan Government is planning to actively conduct the water temperature energy development project using facilities in the Seonam Sewage Treatment Facility and underground water, which is generated from the subway stations. Eco-friendly energy will be used and developed with the goal of achieving an electricity self-reliance rate of 20 percent by 2020.
※ Use of sewage heat: sewage shows slight fluctuations in water temperature every year and maintains an average temperature of 11°C in winter, making it possible to generate hot water for local heating by increasing the temperature of latent heat in the sewage water, through a heat pump, a device that conveys heat from a heat source of low temperature to a heat source of high temperature by using the evaporation and condensation heat of a refrigerant.
A Bird’s-Eye View of the Tancheon District Heating Supply Facility Using Sewage Heat
A Diagram of District Heating Supply Using Sewage Heat