A photovoltaic sheet that simultaneously produces electricity, water and thermal energy
Published on Sunday 3 September 2023 | Article n°455
British researchers have developed a concept for a photovoltaic sheet capable of simultaneously producing electricity, water and thermal energy. The system, inspired by nature, is based on a biomimetic transpiration layer that cools the integrated PV unit and uses the excess heat from the cell to produce water and thermal energy.
The 1mm-thick transpiration layer moves water passively from a separate water tank into a 10cm x 10cm solar cell on top of the structure. The water that reaches the cell reduces its operating temperature, increasing its efficiency. The excess heat is used to produce water and thermal energy. The PV sheet is protected by a single layer of 0.7 mm thick, high-transmittance glass.
The PV sheet achieved an energy conversion efficiency of 15%, an open circuit voltage of 0.63 V and a fill factor of 0.77. By comparison, the control cell achieved an efficiency of 13.2%, an open circuit voltage of 0.58 V and a fill factor of 0.75.
The capital cost of the additional components required for the PV sheet is around €1.02/m², or approximately 2% of the cost of conventional solar panels. The energy payback time for the additional components is estimated at less than six months.
PV Magazine, 29 August 2023