Photovoltaic-thermal window achieves 3.6% electrical efficiency, provides hot water at 50 C
A German-British research team has developed a novel building-integrated hybrid PV-thermal window (PVTW) that can simultaneously produce electricity and domestic hot water (DHW).
“The installation of common solar panels and collectors in the built environment requires access to significant roof space, which is limited. This motivates the development of high-efficiency, building-integrated technologies that can maximize space utilization and energy provision,” said the group. “In this work, a building-integrated hybrid PVTW is fabricated and tested, composed of a semi-transparent PV layer and a selectively absorptive liquid-based thermal absorber.”
The main component of the PVTW is a glass layer with an array of spaced amorphous silicon (a-Si) micro-stripes. Only a part of the sunlight is absorbed by the PV layer for electricity generation, while the remaining portion is transmitted to the 4 mm-thick water layer below it. Two brass tubes are used as the inlet and outlet gates for the water, and two polycarbonate frames are employed to clamp one standard low-iron glass layer.
Testing occurred on a London roof between July 16 and 23, 2021, when the maximum ambient temperature was measured at 34 C and solar irradiance was about 1,100 W m−2 at midday. The setup was tested at inclination angles of 30°, 60°, and 90°, and its performance was compared to that of a solar thermal window (STW) reference module lacking the PV component. The latter was identical to the PVTW, except for substituting the PV layer with a glass layer, resulting in two glass layers.
Image: Imperial College London, Advanced Science, CC BY 4.0
The testing showed that the PVTW system can achieve an electric efficiency of 3.6% and a thermal efficiency of 17.6%.
“The PVTW achieved efficiencies of 3.6% in electricity and 10.7% in heat generation at a 30° inclination. The ability to produce around 50 C hot water makes it appropriate for domestic applications, while its electricity generation supports the building’s energy needs,” the team noted. “Adjusting the PVTW’s inclination angle from 30° to 90° demonstrates the importance of orientation in system performance, with changes in output temperature and thermal efficiency observed.”
Namely, at an inclination of 90°, the PVTW system recorded an electricity efficiency of 3.3%, a thermal efficiency of 17.6%, and a maximum outlet water temperature of about 42 C. “Compared to a standalone STW, the PVTW not only provides higher temperature hot water but also shows a 10% absolute increase in thermal efficiency, along with electricity generation,” they added.
“To understand the potential impact of the PVTW in meeting a building’s thermal energy needs, we can estimate the PVTW surface required to meet the hot-water demand of a typical three bedroom terraced house in London, UK, occupied by 2 adults and 2 children,” the academics said. “Using an energy balance, an overall PVTW surface of no more than around 1.2 m2 at a 30° inclination would be needed to meet this demand instantaneously. Assuming a wider system with a hot-water storage tank, we estimate an overall PVTW surface of ≈2.8 m2 at the same inclination would be needed to meet this entire daily demand without the need for a backup boiler.”
Customized/OEM/ODM Service
HomSolar Supports Lifepo4 battery pack customization/OEM/ODM service, welcome to contact us and tell us your needs.
HomSolar: Your One-stop LiFePO4 Battery Pack & ESS Solution Manufacturer
Our line of LiFePO4 (LFP) batteries offer a solution to demanding applications that require a lighter weight, longer life, and higher capacity battery. Features include advanced battery management systems (BMS), Bluetooth® communication and active intelligent monitoring.
Customised Lithium Iron Phosphate Battery Casing
ABS plastic housing, aluminium housing, stainless steel housing and iron housing are available, and can also be designed and customised according to your needs.
HomSolar Smart BMS
Intelligent Battery Management System for HomSolar Energy Storage System. Bluetooth, temperature sensor, LCD display, CAN interface, UART interface also available.
Terminals & Plugs Can Be Customized
A wide range of terminals and plugs can be customised to suit the application needs of your battery products.
Well-designed Solutions for Energy Storage Systems
We will design the perfect energy storage system solution according to your needs, so that you can easily solve the specific industry applications of battery products.
About Our Battery Cells
Our energy storage system products use brand new grade A LiFePO4 cells with a battery lifespan of more than 4,000 charge/discharge cycles.
Applications in Different Industries
We supply customized & OEM battery pack, assemble cells with wiring, fuse and plastic cover, all the cell wires connected to PCB plug or built BMS.
Applications: E-bike, Electric Scooter, Golf Carts, RV, Electric Wheelchair, Electric Tools, Robot Cleaner, Robot Sweeper, Solar Energy Storage System, Emergency Light, Solar Power Light, Medical Equipment, UPS Backup Power Supply.
We can provide you with customized services. We have the ability to provide a vertical supply chain, from single cells to pack/module and to a complete power solution with BMS, etc.
HomSolar (Shenzhen) Technology Co., Ltd
