Open Access

ARTICLE

Optimal Capacity Planning of an Offshore Multi-Energy Complementary System Considering Seawater Desalination

Xiaozhuo Wang¹, Zhaohong He^2,*, Jun Li², Ruibing Li¹
1 School of Mechanical and Power Engineering, Shenyang University of Chemical Technology, Shenyang, China
2 Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou, China
* Corresponding Author: Zhaohong He. Email:

Energy Engineering https://doi.org/10.32604/ee.2026.080515

Received 11 February 2026; Accepted 24 March 2026; Published online 09 May 2026

Abstract

Floating offshore platforms facilitate the integration of multiple forms of renewable energy generation and exhibit notable advantages in harnessing offshore wind and solar resources, positioning them as a strategically viable and sustainable solution for meeting the energy needs of island communities. A multi-energy complementary power generation system based on floating offshore platforms is proposed for a specific island off-grid, designed to simultaneously meet the electricity and freshwater supply requirements of the island. HOMER software was employed to design a multi-energy complementary power generation system for floating offshore platforms. Given the island’s electricity and water consumption profiles, seawater desalination was integrated as a controllable load within the energy management framework. The optimal capacity planning is determined by minimizing the levelized cost of electricity (LCOE) over the entire system lifecycle, serving as the primary optimization objective. The results demonstrate that the system achieves favorable economic performance. The optimal capacity configuration yields a levelized cost of electricity (LCOE) of 1.40 CNY/kWh, enabling it to meet 70% of the island’s electricity demand and produce 77,100 m³ of freshwater annually. The integration of seawater desalination loads can be effectively coordinated with the existing power system capacity configuration. Without requiring additional investment, this approach ensures a stable supply of freshwater to islands while enabling low-cost desalination. Furthermore, the load characteristics of desalination processes contribute to mitigating overall system load fluctuations.

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Keywords

Renewable energy; multi-energy complementary system; seawater desalination; capacity planning; economic analysis

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