Korea Hydro & Nuclear Power plans world’s largest salinity gradient power plant in Donghae

South Korea’s largest power generation company, Korea Hydro & Nuclear Power Co. (KHNP), has announced its plan to develop the world’s largest salinity gradient power plant. 

A salinity gradient power plant utilizes the difference in salt concentration between seawater and freshwater sources like rivers or lakes to generate electricity. This difference in salinity gradient transports ions and ultimately generates electricity. 

The company, in collaboration with the Korea Institute of Energy Research (KIER), Petrochemistry plant machinery supplier Dream Engineering, and Donghae City officials, will construct a 100-kilowatt salinity gradient power plant in Donghae, a city in Gangwon Province. 

Additionally, the consortium will focus on improving existing renewable marine technology. 

KHNP will be incharge of 100 kilowatt salinity gradient power generation. Technological support and power plant design will be overseen by KIER and Dream Engineering respectively. Whereas, allocation of land and permit will fall under Donghae City authorities. Along with KHNP, the three parties will also provide training for professionals in the field as part of the agreement.

Donghae City aims to commercialize salt gradient power energy within the next three years as part of its efforts to mitigate climate change. The city government has set a target of achieving zero carbon emissions and aims to become a global center for marine energy by 2026. 

The Donghae city government plans to invest approximately $7.49 million (10 billion won) in the power plant’s demonstration project. Under the agreement, KHNP will showcase salt gradient power generation and ensure a clean and stable energy supply in the region.

Salinity gradient power plant

Salinity gradient power generation provides consistent electrical energy production, making it suitable as a renewable energy source for base load.

The method of salinity gradient power generation is cost-effective and environmentally friendly. Unlike batteries, it allows for longer energy storage, and it minimizes resource wastage as a clean energy source.

Salinity gradient energy can generate consistently, in contrast to intermittent renewable energy sources.

On the other hand, developing a salinity gradient power plant presents social and economic challenges. Diverting freshwater from one region to another may cause concerns among people living in water-scarce areas.

Moreover, there is limited research on salinity power generation, resulting in uncertainty about its environmental impacts. Other environmental concerns associated with salinity gradient technologies include changes in water quality and impacts on the natural habitat. The process of mixing freshwater and seawater can cause instability between organisms living in freshwater and seawater.

However, salinity gradient power generation is an emerging technology. KHNP is actively developing various new technologies to achieve carbon neutrality. It is also focusing on researching more about the less explored salinity gradient energy.