Contractors are waiting for Dubai Electricity & water Authority (Dewa) to finalise the prequalification list and issue the tender for the main engineering, procurement and construction (EPC) contract for the planned 250MW pumped-storage hydroelectric project.

MEED reported in November that contractors had been invited to prequalify for the EPC contract for the GCC’s first pumped-storage hydroelectric scheme. According to sources close to the project, as many as 10 groups are believed to have submitted prequalification entries.

In June last year, Dewa awarded a AED58m ($15.8m) contract to France’s EDF to provide consultancy services for the pumped-storage project.

The hydro project will use water stored in the Hatta Dam, near the Oman border. The existing Hatta Dam can store up to 1,716 million gallons of water. The project will involve the construction of an upper reservoir, which will be able to hold up to 880 million gallons. The upper reservoir will be located 300 metres above the dam level.

During off-peak hours, turbines will use solar energy to pump water from the dam to the upper reservoir. The project will support the AED1.3bn ($354m) Hatta development plan, which was announced earlier in November.

Dewa is planning to develop another pumped-storage hydro project as part of its plans to develop renewable energy with storage capacity to meet its ambitious long-term energy diversification targets. The emirate is planning for 75 per cent of its total energy requirements to be produced by clean energy resources by 2050.

In January, Dewa signed a memorandum of agreement (MoA) with the GCC Interconnection Authority (GCCIA) and the Belgian Dredging, Environmental & Marine Engineering Group (DEME) to conduct a study for a 400MW pumped-storage hydro power island in the Gulf area. The planned project would have a storage capacity of about 2,500MWh.

The appeal of pumped storage is that it can be integrated with different renewable energy sources such as wind and solar power, which are intermittent power supply options affected by wind patterns or when sun is covered by clouds. Pumped storage is an important source for energy storage as water is stored when excess energy is produced, and then can be used to provide electricity when energy demand is at its highest during peak hours.