Comprehensive Utilization of Temperature Difference Energy and Low-Temperature Seawater Resources

Abstract

China has a huge amount of ocean temperature difference energy resources that are primarily distributed in Guangdong Province and the South China Sea. These resources are crucial for optimizing the energy structure of Guangdong Province and for ensuring the energy supply of islands in the South China Sea and along the 21st Century Maritime Silk Road. Currently, the ocean thermal energy conversion (OTEC) technology and equipment are still in the experimental stage worldwide. The construction cost of megawatt-level experimental power stations is huge, and its overall technologies are not mature enough for commercial utilization; therefore, breakthroughs in related technologies and equipment are urgently needed. In this article, we summarize the development mode of OTEC and the challenges faced by related technologies and equipment in China and abroad. We propose a new approach of using low-temperature seawater—produced during the gasification of liquefied natural gas (LNG)—instead of deep seawater to generate electricity; this can help overcome the difficulties regarding the temperature difference energy development in the South China Sea and address the waste of LNG cold energy resources in Guangdong Province. Specifically, we use the Zhuhai LNG gasification station as an example to explore a development model of integrating LNG cold energy recovery with OTEC and the establishment of a low-temperature seawater comprehensive utilization demonstration base. Moreover, we demonstrate the economic and technical feasibility of the model through a preliminary estimate of the investment and revenue of the demonstration base. This case is expected to provide necessary technical references and application demonstrations for the comprehensive utilization of temperature difference energy and low-temperature seawater resources in China.

Keywords

• ocean temperature difference energy, low-temperature seawater resources, liquefied natural gas cold energy, comprehensive utilization
• temperature difference power generation