EDF, Oceanus, Plan Power & Desalination, By Using Pumped Storage, Renewable Energy

For Oceanus, or Oceanus Energía y Agua de Sudamerica SpA,  a unit of US infrastructure developer Oceanus Power & Water, the deal with EDF to build the world’s first integrated pumped hydro reverse osmosis clean energy system (IPHROCES) could open up a whole new path for simialr opportunities worldwide .

Like all pumped storage systems, this system will also pump seawater into a storage reservoir at an upper level using conventional reversible pump-turbines, with power provided by on-site renewable energy facilities (wind or solar) or grid electricity.

The water in the upper reservoir will be sent back to the shore, where the reverse osmosis system is located, and used to produce freshwater. The water that is not used for desalination purposes will be used to produce hydropower for between eight and 12 hours per day during peak demand periods, with fast response times. Pumped storage of course remains the oldest and most dominant technology even today to store energy and produce it on demand.

“This hydraulic pressure eliminates the need for additional electricity to be provided to drive the desalination facility, greatly reducing both the capital expenditure and operational expenditure associated with standalone desalination facilities,” Oceanus said.

This process purportedly offers better brine management, as pumped storage outflows dilute desalination waste brine. The system also has a better energy footprint, as it reduces reverse osmosis energy consumption, Oceanus claimed.

“The result is a low salinity concentration mixture that is sent back to the ocean, minimizing the impacts on marine life,” the company said.

Adding desalination to the mix, which is the big innovation here, makes a lot of sense due to the energy intensive nature of desalination plants, which has limited their effectiveness  in many water deficient areas of the world, especially in the developing world. Because these parts have tended to be power deficient as well as hosting expensive power. Now, with renewables running into issues of fresh power demand  due to over capacity as legacy power systems are phased out slowly, finding opportunities like this, or producing Green hydrogen is seen as a very important way to ensure the build out of renewable capacity does not slow.

Thus while the release from the firms does not mention the final cost of desalinated fresh water, in India for instance, the holy grail for this water seems to be a price under 5 paise per litre, something that has been limited by high energy costs so far. Corporate partnerships have helped push it in some areas, but much more needs to be done. A massive government push to bring piped water to every household by 2024, the nal se jal scheme, should help unlock similar opportunities, one hopes. The largest desalination plant remains the Minjur Desalination Plant in Chennai, that caters to over a million city residents.