Reliance on clean and renewable energy sources, especially solar power, is increasing. This is driven by their low cost, in light of the global direction to combat the effects of climate change by reducing gas emissions that cause global warming.
The main challenge is the efficient storage of this energy to ensure it is available when there is no sunlight or in different weather conditions, emphasising the importance of energy storage technologies.
Dubai Electricity and Water Authority (Dewa) is one of the leading organisations in adopting the latest and best technologies for storing clean energy, and several of its energy storage projects are among the largest regionally and globally.
Saeed Mohammed Al Tayer, MD & CEO of Dewa, said: “Energy storage is a vital aspect in ensuring energy sustainability and increasing the reliance on clean and renewable energy sources. In addition to our energy storage projects that are completed or in progress, we plan on establishing a wide-range energy storage system using electric batteries that are supplied with photovoltaic energy at the Mohammed bin Rashid Al Maktoum Solar Park. We also have a roadmap and a strategy for green hydrogen that will be implemented in phases. This supports the Dubai Clean Energy Strategy 2050 and the Dubai Net Zero Carbon Emissions Strategy 2050 to provide 100 per cent of the energy production capacity from clean energy sources by 2050.”
In December 2023, His Highness Sheikh Mohammed bin Rashid Al Maktoum, Vice-President and Prime Minister of the UAE and Ruler of Dubai, inaugurated the 950MW fourth phase of the Mohammed bin Rashid Al Maktoum Solar Park. This project will provide approximately 320,000 residences with clean energy, and it will reduce carbon emissions by about 1.6 million tonnes annually. The fourth phase of the solar park, the largest single-site solar park in the world, uses three hybrid technologies to produce clean energy: 600MW from a parabolic basin complex, 100MW from the solar power tower, and 250MW from photovoltaic solar panels. Built at an investment of Dh15.78 billion, using the independent power producer (IPP) model, the project features the tallest solar tower in the world, at 263.126 metres, and the largest thermal energy storage capacity with a capacity of 5,907-megawatt hours (MWh), according to the Guinness World Records.
The process of thermally storing solar energy in molten (liquefied) salt uses heliostats to concentrate sunlight on the solar tower, then pumping the molten salt to the steam generator, which heats the water and turns it into steam capable of moving the turbines of the electricity generator, allowing the production of electricity round the clock. Molten salt is a mixture of two or three salts, such as sodium nitrate, potassium nitrate, and calcium nitrate. Molten salt has many properties that make it ideal for use in solar thermal power plants, such as high boiling point, low viscosity, and low evaporation pressure.
Dewa is implementing a pumped-storage hydroelectric power plant in Hatta. The hydroelectric power station will utilise water from the Hatta Dam and a newly-constructed upper reservoir in the mountains. During off-peak hours, sophisticated turbines will use clean energy generated at the Mohammed bin Rashid Al Maktoum Solar Park to pump water from the dam to the upper reservoir. This is converted to kinetic energy during the water flow through the 1.2-km subterranean tunnel, and this kinetic energy rotates the turbine and converts mechanical energy to electrical energy. This system boasts high efficiency in power generation and storage, reaching up to 78.9 per cent, with a rapid 90-second response to electricity demand. The 250MW station will have a storage capacity of 1,500 MWh and a life span of 80 years. It is the first of its kind in the GCC region.
Generators are currently being assembled, and the construction of service and operational facilities is ongoing. The water upper intake structure and the associated bridge in the upper dam has been completed. Construction of the 72-metre main Roller Compacted Concrete (RCC) wall of the upper dam has been completed, and preliminary measures to commence filling the upper dam have begun. The 1.2-km-long water tunnel is presently being linked to the power generators. With investments of up to Dh1.421 billion, the project is planned for completion in Q1 of 2025.
Dewa has implemented a pilot green hydrogen project at the solar park. This is the first project of its kind in the Middle East and North Africa to produce green hydrogen using solar energy, storing it, and converting it back into electrical energy, among other uses. The plant produces about 400kg of hydrogen daily, and the hydrogen gas tank can store up to 12 hours of hydrogen. The plant uses hydrogen through a hydrogen gas motor to produce about 280 kilowatts of electrical energy. The project has been designed and built to accommodate future applications and test platforms for various uses of hydrogen.
In collaboration with Dewa, Enoc Group’s first green hydrogen station was opened within the Service Station of the Future (SSoF) at Expo City Dubai. The station uses green hydrogen, which Dewa produces at its pilot plant at the solar park. The station can fuel approximately 32 cars (FCEV- fuel cell electric vehicles) at a fuelling speed of approximately seven minutes. The dispensing facility offered by Dewa and Enoc can be integrated with any digital solution for fleet management.
Dewa is conducting experiments on several advanced experimental systems for storing energy using batteries. Dewa’s research and development (R&D) centre has filed a new patent for an innovative method for improving the performance of electrodes in lithium-ion (Li-ion) batteries, sodium–sulphur batteries, and electrolyte distribution batteries. This is achieved by treating the electrodes chemically using a polymer to increase the number of active groups on the surface of the electrodes, which leads to improving their performance. The low-cost, environmentally friendly method requires low temperatures and ensures stable battery performance. This is part of the Centre’s efforts to promote energy production and storage. The patent supports the pilot project for energy storage that Dewa inaugurated at the solar park using Tesla’s lithium-ion battery solution. The project has a power capacity of 1.21 MW and an energy capacity of 8.61 MWh with a life span of up to 10 years. This is the second battery energy storage pilot project by Dewa at the solar park. The first project was implemented in collaboration with Amplex–NGK to install and test a sodium sulphur (NaS) energy solution with a power capacity of 1.2 MW and an energy capacity of 7.5 MWh. This was the first utility-scale energy storage pilot project in the region.