RIYADH, Saudi Arabia – The world's largest solar-powered microgrid with battery energy storage has entered full commercial operation in Saudi Arabia, marking a milestone in the global transition toward renewable energy and off-grid utility systems.
The Red Sea multi-utility project, developed for Red Sea Global's tourism destination on Saudi Arabia's western coast, operates entirely independently of the national transmission network. The facility brings together a 358 MWac solar photovoltaic plant and a 1,225.4 MWh battery energy storage system (BESS) , alongside 112.5 MW of backup internal-combustion generation to ensure 24/7 reliability.
In May 2025, Guinness World Records certified 1,125.18 MWh of the installation as the world's highest-capacity off-grid battery-based energy storage facility. The project has also received the Renewable Energy Innovation of the Year Award and the Sustainable Construction Project of the Year Award in 2026, along with the 2022 MUSE Design Gold Award.
Engineering and Partnership
The project was carried out by SEPCOIII, which is a PowerChina subsidiary and the contractor who has signed contracts with ACWA Power in February. This project has been taken to be the biggest overseas project taken by any Chinese firm in developing power-based infrastructure.
Chinese companies were very important in carrying out the whole project as Huawei provided the inverters of the PV system along with the battery systems while Longi supplied solar panels. Earlier documents of the project mentioned around 340MW of solar energy along with 1.2GWh of storage; Huawei says that in their proposal they have given 400MW of solar power generation along with 1.3GWh of storage capacity.
This project was carried out using a public-private partnership structure while Saudi Arabia's Public Investment Fund (PIF) helped in the long-term offtake agreements.
Beyond a Conventional Solar-Plus-Storage Project
What sets the Red Sea microgrid apart from conventional solar-plus-storage projects is the extraordinary range of infrastructure connected to it. The multi-utility system integrates:
Three reverse-osmosis desalination plants with a combined capacity of 32,500 cubic meters per day
Wastewater treatment capacity of 16,000 cubic meters per day
District cooling with 32,500 refrigeration tons of capacity
Solid-waste management and communications infrastructure
The renewable-powered utility infrastructure supplies operational resorts, the airside facilities at Red Sea International Airport, employee accommodation, electric-vehicle charging, 5G infrastructure, district cooling and the destination's water systems.
Grid-Forming Technology in an Isolated Network
The battery system performs functions far beyond those typically required of storage connected to a conventional transmission grid. Because the Red Sea network is isolated, the microgrid must establish and maintain its own voltage and frequency while balancing variable solar generation with demand.
Grid-forming battery storage provides voltage and frequency support and supplies electricity when solar generation is unavailable. Project disclosures indicate that the system has also demonstrated black-start and fault-ride-through capabilities during operation, providing a utility-scale example of grid-forming storage deployed in an isolated network.
Construction Timeline and Commercial Operation
Construction on the facility began in October 2021. The storage unit started operating in September 2023. The transition to full commercial operation, announced by SEPCOIII on August 21, 2026, marks completion of the wider multi-utility package rather than the start of operations for the solar and storage assets, which have been progressively commissioned since 2023.
Strategic Significance for Saudi Vision 2030
The project forms part of Saudi Arabia's Vision 2030 development initiatives and supports the kingdom's objectives to expand clean energy infrastructure, reduce environmental impacts and develop sustainable utility systems.
The Red Sea development provides a large-scale operating example of solar and grid-forming battery storage supporting an isolated utility network rather than supplying electricity to an interconnected grid. Its performance could offer technical and operational lessons for similar systems on islands, at remote industrial sites and in new developments where grid extension is not feasible.
A Blueprint for Off-Grid Renewable Infrastructure
The project serves as a proof-of-concept for developers of renewable energy as well as EPC contractors across the globe. The successful execution of the project creates an example of how partnerships between public and private entities can help eliminate risk for large and off-grid renewable investment ventures.
Completion of this project also helps change the way remote regions achieve energy independence without having to depend on fossil fuel reliant national utility grid systems. At a time when more and more focus is placed on making the world greener and providing more access to green energy, the Red Sea microgrid also becomes a striking example of how solar energy combined with advanced battery storage can provide completely off-grid communities with energy resources.
