Ministry of Climate, Environment and Energy, Sejong city and Korea District Heating sign MOU on energy use at sewage treatment facilities

Gwangju's No. 1 sewage treatment plant [Gwangju Environment Corporation]
Gwangju's No. 1 sewage treatment plant [Gwangju Environment Corporation]

South Korea's Ministry of Climate, Environment and Energy signed an MOU Monday with Sejong city and Korea District Heating at Sejong City Hall in Boram-dong, Sejong, to build an energy self-sufficiency framework at sewage treatment facilities through the use of biogas and sewage heat.

The agreement aims to boost the use of untapped energy sources — including sewage heat and biogas — at Sejong Water Quality Restoration Center A, the city's sewage treatment facility.

Under the MOU, Sejong city will provide the demonstration site, biogas and treated sewage water, and offer administrative support for permits and project approvals. Korea District Heating will connect sewage heat and waste heat from biogas power generation to the district heating network and provide the necessary equipment and technical support.

The two organizations plan to work out specific project details through operational agreements as needed. The ministry will provide policy and regulatory support to expand the use of sewage heat.

If the facility's average daily discharge of about 59,000 tons last year were fully utilized, approximately 105,000 gigacalories (Gcal) of heat could be recovered annually — enough to supply heat to about 17,000 households for a year.

The project will initially generate electricity from biogas, then combine the resulting waste heat with sewage heat to supply 1 Gcal of heat per hour to the district heating network. Sejong city and Korea District Heating expect annual direct and indirect benefits of approximately 450 million won ($333,000) and about 200 million won, respectively.

Earlier this year, the ministry revised its guidelines for establishing basic sewage system improvement plans, making it mandatory for public sewage management authorities to assess the feasibility of using sewage heat at treatment facilities with a daily processing capacity of 5,000 cubic meters or more.

The revision also requires that when setting energy self-sufficiency targets — defined as the ratio of renewable energy output from biogas, solar and small hydropower to total energy consumption at a facility — authorities must factor in not only the facility's own energy use but also the amount supplied externally, including to district heating networks.

The ministry is also pursuing an amendment to the enforcement decree of the Act on the Promotion of the Development, Use and Diffusion of Renewable Energy to include sewage heat within the definition of water-source thermal energy, a recognized form of renewable energy.

"Sewage heat can be obtained close to urban centers and maintains a relatively stable water temperature throughout the year, making it an important heat source for achieving carbon neutrality," said Geum Han-seung, first vice minister of the Ministry of Climate, Environment and Energy. "We will continue to provide policy and regulatory support so that sewage heat can play a key role in building energy self-sufficiency at sewage treatment facilities."


thlee@heraldcorp.com