An international research group has created a closed-loop, transparent energy platform based on PV power generation and hydrogen production from photo-electrochemical cells. The system is claimed to supply power without interruption and to be transparent enough to be integrated into buildings.
A Korean-U.S. research group has created a system to produce and store green hydrogen via transparent PV (TPV) cells and transparent photo-electrochemical (TPEC) cells that could be integrated into buildings.
“We proposed a transparent, sustainable energy platform,” the research's corresponding author, Joondong Kim, told pv magazine. “Our proposed system benefits the levelized cost of solar hydrogen by on site production and building integration and offers affordable solar hydrogen for domestic applications.”
The system is claimed to have a high average visible transmittance of around 64% and remarkable color neutrality, which the scientists said has a close chromaticity to the light source. “To ensure its suitability in building-integration, especially for windows, the visual appearance of TPV and TPEC is a fundamental issue,” the researchers noted.
The system's solar power generator is based on 1.47%-efficient transparent metal oxide solar cells built with n-doped zinc oxide (N:ZnO) and p-doped nickel(II) oxide (p-NiO) on a glass substrate made of indium tin oxide (ITO). These cells are able to generate a high photovoltage of 0.546V and work as a photoanode to provide a stable photocurrent density of 2.28mA/cm2 in the TPEC system.
The PEC cell was fabricated with a TPEC photoanode as the positive terminal and platinum wire as the negative terminal. “Short wavelength UV with highly-energetic photons was mostly absorbed in the photoanode, with an efficiency as high as 82%,” the academics emphasized.