By now most all Americans are familiar with solar panels, the large gray squares that adorn rooftops, collecting solar energy to supply electricity to homes. According to the Solar Energy Industries Association, the present “cumulative solar electric capacity operating in the U.S. [is] enough to power more than 4 million average American homes,” and that number is expected to keep growing. People love the idea of no electric bills.
But—realistically—solar panels can only work when the sun is shining on the panels, meaning no direct sun = no electricity. While panels can be installed in a direction that maximizes sun exposure, there will always be hours when the sun is not supplying power for a home. In addition, panels can also be prohibitively expensive and many people do not find having solar panels on the roof to be an attractive architectural feature.
Harnessing the power of the sun for heating is not a 21st- or even a 20th-century idea. Solar walls, built on the side of a structure that gets the most sun, have been around since at least the late 1800s.
Over the years, solar walls have utilized a combination of glass, air space, possibly water, and a wall made from stone or concrete or another material that can store heat. With the advent of modern technology photovoltaic solar walls, made of solar bricks, not only keep a building warm but also make electricity for other uses.
Sohail Anwar, professor of engineering at Penn State Altoona, is currently involved in a solar energy research collaboration with researchers from LGCgE Laboratory and Institut Universitaire de Technologie (IUT) Bethune in France. The very first project, known as International Collaboration in Engineering Education (ICEE), involved undergraduate students at partner institutions in the United States and Europe. According to an early paper on the ICEE, its objectives were to help the participating students understand the impact of engineering solutions in a global context, face the modern reality that the various subsystems of an engineering application may be developed in different countries, and gain valuable experience in teamwork and project management.
The initial cohort of students—from Bethune, Altoona, Romania, Ireland, Poland, and Hungary—worked on “A Renewable Energy System for an Agricultural Farm.”
Two more projects followed. The first, conducted in 2011, involved designing and implementing a protection system for solar walls. The second involved a Trombe solar wall and showed that more efficient energy management for solar walls can be developed using automatic controlled ventilation.
Future research activities to be conducted as a part of this international collaboration will focus on devising the most efficient energy management of the solar walls. According to Anwar, “experimental investigations will involve the design and construction of a programmable control system to limit the overheating of the PCM (phase change material) -based solar bricks. Programmable electronic control systems will be designed and built, using different approaches, at Altoona College and at IUT Bethune, and then the experimental testing will be done at LGCgE Laboratory using two in-situ solar walls.”
In addition to publishing articles about his research, Anwar is also a volume editor for a book on green building. Due to be published in 2017, the book “will cover all aspects of green building,” Anwar says, “including design practices, materials, technologies, and economics. It will serve as an excellent source of up-to-date information for individuals who want to gain the body of knowledge associated with green building and sustainable design principles.”
Anwar says the main goal of his research is “to minimize risks associated with the overheating of the solar bricks which constitute solar walls.” He hopes that the collaborative research with the French researchers will lead to the development of more efficient energy management systems for different types of solar walls, which could lead to less expensive solar-heating systems and more people using solar energy to power their homes.
A version of this story was originally published in Penn State Altoona’s Research and Teaching magazine.