Power plant - Cheong Soo - South Korea

Cheong Soo + Wärtsilä

Introducing trigeneration in Cheong Soo

In May 2007, Wärtsilä was awarded a contract from JB Enertek Co., Ltd., South Korea, to deliver engineering and equipment (EEQ) in two phases for a 25.3 MWe combined heat and power plant (CHP).

The plant is located in Cheong Soo community in Cheon Ahn City, approximately 100 kilometres south of Seoul, Korea. The purpose of the Cheong Soo trigeneration plant is to provide district heating and electricity to a suburban area covering approximately three square kilometres with about 6400 households and public buildings. The first phase of the project comprised two Wärtsilä 20V34SG natural gas-fuelled generating sets equipped with a heat recovery system for district heating purposes. Phase 1 was commissioned and handed over in February 2010. The second phase consists of an identical genset to the previous and is scheduled to be completed in 2015. The three gensets generate electricity in parallel with the electrical grid and supply district heating to the town network.

During the warm summer periods the plant provides district cooling as well. Due to tariff policy in South Korea, selling only electrical power to the grid is not feasible. At night, the electrical load in the suburban area is so low that the amount of heat generated by the engines at this time is significantly reduced compared to daytime. Unfortunately, the amount of heat needed by households during this period of time in the 24-hour cycle is at its maximum. This is why installing a heat accumulator comes into question: it allows the Cheong Soo plant – operating essentially in island mode – to run continuously on high load and thus, at high levels of total efficiency (more than 85% in this case). The additional heat generated during daytime is partly stored in the accumulator for use during the following night.

This was the first CHP project delivered by Wärtsilä in South Korea under the CES (Community Energy System) concept which is based on South Korean legislation to encourage decentralized energy production. The objective of the CES concept is to supply electricity and heat from independent power production facilities to commercial, residential, business and hospital buildings in specific areas.

After the completion of the second phase, the total electrical output of the plant will be raised to 25 MWe and thermal output to 21 MWth. Wärtsilä designs, procures and delivers the equipment as well as provides technical advisory services at site during the installation and commissioning works. The erection and installation of the equipment is carried out by JB Enertek and local contractors.

WHOJB Enertek Co., Ltd
WHAT 2 x Wärtsilä 20V34SG & 1 x Wärtsilä 20V34SG Flexible Baseload
WHERECheong Soo, South Korea
HOWEEQ (Engineered equipment delivery)


This is what we achieved


MW of electrical output


MW of district heating output


Total operating efficiency

Cheong Soo CHP is the most successful engine plant in South Korea and we are very proud to supply power and heat to our customer by using Wärtsilä 20V34SG engines.

Mr DP Lee, Gas Equipment 1 Team, Sales Manager, JB Enertek Co., Ltd.

How we did it

Challenge icon


  • Electrical load minimal but head demand maximum at night
  • Electricity generation parallel to the grid
  • Meeting the noise level and emission requirements set by Korean legislation
Solution icon


  • Charging of heat accumulators during daytime and consumption of heat at night
  • Wärtsilä 34SG gensets provide continuous and reliable energy
  • Advanced emissions and noise reduction equipment were installed
Benefit icon


  • Minimum 85% efficiency 24 hours a day
  • Avoiding the costs of installing external site connections 
  • Compliance with regulations allows plant to operate efficiently and avoid potential penalties

The main details

   Customer  JB Enertek Co., Ltd (IPP)
   Type  Wärtsilä 34SG gas trigeneration power plant
   Operating mode  Flexible baseload
   Gensets  2 x Wärtsilä 20V34SG & 1 x Wärtsilä 20V34SG
   Total output  25 MWe + 21 MWth 
   Fuel  Natural gas
   Scope  EEQ (Engineered Equipment Delivery)
   Delivered  2010 & 2015
Cheongsoo map

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Related press releases

Wärtsilä and JB Corporation sign a 9-year optimised maintenance agreement to ensure operational reliability of South Korean power plant

Oct 28, 2020, 10:00 AM by Wärtsilä Corporation

The technology group Wärtsilä has signed a long-term Optimised maintenance agreement with South Korean energy provider JB Corporation. The agreement covers three Wärtsilä 34SG engine generating sets providing electricity and hot water for consumers served by the JB power plant in Cheongsu. The 9-year agreement was placed in August.

The Wärtsilä engines operate on liquefied natural gas (LNG) and have been in operation for a number of years. The long-term agreement will ensure their continued operational efficiency and reliability, while providing JB Corporation with budgeted maintenance costs. Under the terms of the contract, Wärtsilä will provide scheduled spare part deliveries, as well as field service, maintenance planning, and Asset Diagnostics of the engines for a bi-annual fixed fee.

”A reliable supply of power and heat is extremely important to our consumer customers, and this agreement with Wärtsilä will ensure that the engines are efficiently and professionally maintained for this purpose. We very much appreciate Wärtsilä’s support and look forward to many more years of successful operation from their generating sets,” commented Mr Jae Hwa Woo, Executive Director of JB Corporation.

“Being able to accurately predict and calculate the maintenance budget is a significant benefit for power producers, and this can best be achieved with a maintenance agreement. Furthermore, our optimised maintenance offering allows the customer to concentrate on the core business of selling power and heat, while knowing that the plant’s operational performance will be maximised with the support of Wärtsilä South Korean Agreement Manager. The Agreement Manager will work closely with the customer to plan for the optimum time for maintenance work and address any technical issue. The Asset Diagnostics gives valuable data on the engines’ health, and reduces the possibility of unplanned shutdowns,” said Mr Nicolas Leong, Energy Business Director, North & South East Asia, Wärtsilä Energy.

The combined output from the three Wärtsilä engines is 25.2 MW. The fast-starting flexibility and grid balancing capability of the engines will facilitate possible future integration of energy from renewable sources, such as solar and wind. The South Korean government plans to have 40 percent of the country’s energy supplied from renewable sources by 2034.  

Read more:

Wärtsilä Lifecycle solutions
Wärtsilä 34SG gas power plants

Media contact for more information on this release:

Mirja-Maija Santala
Manager, Marketing & Communications
Wärtsilä Energy
Mob: +358 400 793 827

Caption: Local Wärtsilä Agreement Manager will work closely with JB Corp. to plan for the optimum time for maintenance work and address any technical issue in the South Korean power plant. © Wärtsilä Corporation

Wärtsilä Energy in brief
Wärtsilä Energy leads the transition towards a 100% renewable energy future. We help our customers unlock the value of the energy transition by optimising their energy systems and future-proofing their assets. Our offering comprises flexible power plants, energy management systems, and storage, as well as lifecycle services that ensure increased efficiency and guaranteed performance. Wärtsilä has delivered 72 GW of power plant capacity in 180 countries around the world.

Wärtsilä in brief
Wärtsilä is a global leader in smart technologies and complete lifecycle solutions for the marine and energy markets. By emphasising sustainable innovation, total efficiency and data analytics, Wärtsilä maximises the environmental and economic performance of the vessels and power plants of its customers. In 2019, Wärtsilä’s net sales totalled EUR 5.2 billion with approximately 19,000 employees. The company has operations in over 200 locations in more than 80 countries around the world. Wärtsilä is listed on Nasdaq Helsinki.

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