Project Name: Solar Steam on Demand
Funding Opportunity: Solar Desalination
SETO Subprogram: Concentrating Solar-Thermal Power
Location: Livermore, CA
SETO Award Amount: $1,500,000
Awardee Cost Share:  $389,000
Principal Investigator: Philip Gleckman

The most efficient water distillation processes for desalination that use heat recovery require a steam source at a temperature around 180° Celsius. This project will develop and test a novel solution for generating steam by using solar-thermal energy as the primary source of heat and developing thermal-energy storage using a phase-change material (PCM). This solution will be combined with a previously developed low-cost, high-performance solar collector, creating a system that has the potential to operate water distillation equipment and meet the heat requirements of many industrial heating applications day or night.


The team will develop a cost-effective PCM to act as a thermal-energy storage material. In this system, solar energy will be transferred via the collectors to the PCM, which is stored in a tank as a molten liquid at 150°-250°C. The thermal energy from the storage tank is then used to produce steam, which can be used for water distillation in solar desalination or for industrial heat processes. To optimize solar steam storage, the team will test the PCM and a heat exchanger to transfer heat from molten material to steam. Then they will test a full-scale PCM storage tank and integrate it with a parabolic trough that was developed in an earlier SETO project. To test its viability, the team will evaluate the system’s operation over several months.


Using solar-generated steam and low-cost materials, this system could lower the cost of heat for industrial processes and desalination. While conventional CSP plants use molten salt to create energy storage, this system will use a more energy-dense PCM such as sodium formate that changes from solid to liquid and back. This system could lower operation costs and create enough storage to accommodate industrial steam applications around the clock.