Study on the application potential of solarwall system in northern China

There is a growing, government-led trend of applying renewable energy in China. One area of interest lies in the wider use of solar energy systems. Solar air heating system based on unglazed transpired collector (UTC, also known as solarwall) is a simple and inexpensive technique that results in reduced energy consumption and operating costs resulted from outdoor air ventilation requirements. Solarwall is easy to be integrated in building. This paper establishes the mathematical model of solarwall systems and presents an evaluation of the application potential of solarwall in five northern cities of China. Simulation results showed that energy savings rate for the subject building in Beijing, Shenyang, Changchun, Harbin, and Lanzhou is 22.9%, 19.3%, 18.8%, 16.4%, and 20.8%, respectively. The payback period is 9.3 years, 7.8 years, 6.4 years, 7.1 years, and 10.7 years, respectively. The actual payback period will be even shorter if the energy savings resulted from the reduction of heat transmission through the building envelope due to the increase of R-value of the exterior walls is taken into account. Solarwall system is viable for China to reduce heating energy consumption and improve indoor air quality in winter.