Membrane Processes for Conversion of Solar Energy to Electricity

The world faces increasing demand for energy as the population grows and becomes more affluent. This demand poses significant challenges as the consumption of fossil fuel energy sources ultimately is not sustainable and has the potential to effect climate change.

The conversion of solar energy to electricity offers one alternative to fossil fuel use. Currently, solar energy is converted to electricity using both thermal and photovoltaic processes. We propose an alternative route that uses membrane processes.

The proposed process utilizes a combination of either reverse electro-dialysis or pressure retarded osmosis to mix two working fluids of different salinity to produce electricity. The salinity difference is restored by demixing using either membrane distillation or membrane crystallization. This demixing is driven by solar thermal energy. The overall process leads to a conversion of solar energy to electricity.

The capabilities of the proposed process are explored through simulation. The relationships between membrane transport properties, area requirements, and working fluid properties are determined from which electricity generation costs can be estimated.