Novel hybrid solar nanophotonic distillation membrane with photovoltaic module for co-production of electricity and water

Solar energy utilization and desalination are both critical needs for large portions of the world facing energy and water challenges. Direct contact membrane distillation is an attractive thermally driven desalination technique that can easily be integrated with solar energy. Here we propose and experimentally demonstrate for the first time a hybrid direct contact membrane desalination plus photovoltaic device. The system utilizes partially transparent photovoltaic cells to produce electricity and pass thermal energy to the nanoparticle doped membrane to produce thermal energy at the membrane surface. A custom lab-scale direct contact membrane distillation setup characterizes the membranes fabricated off-sun and on-sun. The doped membrane exhibited a 15–32% increase in desalination performance (compared to an undoped membrane) when exposed to solar irradiance while simultaneously producing an average of 0.36 W of electrical power (at a module area of 225 cm2 and solar irradiance values of ∼ 600 W/m2). Water production costs demonstrate a reduction of roughly 5% when the photovoltaic system is integrated directly into the desalination unit.