Many attempts have been made at developing commercial solar desalination systems but no such system has materialised. The reason for this is that while technical options have been demonstrated they are too complicated or too expensive to compete with fossil fuel systems.
The objective of this project is to design and build a prototype solar desalination plant that will be commercially viable and produce water at less than $2/m3. The plant will have a capacity of 750 m3/day.
The approach taken is to use a desalination technology that has the lowest energy consumption and combine it with a solar thermal system that produces the least cost energy that is compatible with the desalination technology:
- a commercially available vacuum vapour compression (VVC) desalination system which is normally electrically powered will be converted to run on steam at 25 bar pressure. Mechanical energy consumption can then be reduced to below 10 kWh/m3
- a fixed mirror concentrator and a tracking receiver will provide thermal power for the desalination unit. An annual solar-steam energy efficiency of 43% is predicted.
EXPECTED ACHIEVEMENTS AND EXPLOITATION
The system can operate in solar only or hybrid mode. The project tasks comprise: 1) Modification and testing of VVC unit to operate on steam 2) Design and testing of the heat transfer system (receiver, storage and boiler), 3)System Optimisation 4) Final Design and Construction 5) Commissioning and Monitoring and 6) Integration Issues. The most risky task is the design of the solar receiver.
There are five milestones:
- VVC desalination unit achieves an energy consumption less than 10 kWh/m3 - Solar receiver achieves target efficiency of 65%
- Prototype is completed and produces 750 m3/day of clean water under solar only conditions.
- Prototype achieves an availability of 80%.
Funding SchemeCSC - Cost-sharing contracts
35003 Las Palmas De Gran Canari