Researchers conduct first study of passive solar energy as a residential heat source

Space heating is one of the largest contributors to climate change produced by industrialized nations, creating an urgent need for carbon-free heating. Recent advances suggest that passive solar energy as a heat source can and should be part of a sustainable solution.

Researchers at the University of Oregon, funded by the U.S. National Science Foundation, measured the scale and scope of unused passive solar energy and compared the data to residential space heating needs. Among the noteworthy findings, the researchers discovered that cold and cloudy climates are abundant sources of solar energy and estimated that this untapped passive solar energy could provide one-third of residential heating. The group published the research in Renewable and Sustainable Energy Reviews.

"In the course of studying sustainable architecture, it became clear that there were lots of resources we weren't tapping into," said Alexandra Rempel, one of the study co-authors. "People were dismissing the possibility that there could be enough solar energy available in cold climates." As a result, passive solar heating has been overlooked as a component of sustainable architecture and design.

Passive solar heating systems collect natural light to provide heat without converting the light to electricity. In this approach, solar radiation is collected through windows and skylights. Some is used immediately for heat, and some is stored for later use. Capturing, storing and distributing solar energy for heat without converting it to electricity is a feasible option even in cold and cloudy climates, the researchers found.