Panels & Pipes: How Hybrid Designs Can Boost Efficiency

With the winter season quickly approaching, many building engineers are starting to get concerned about heating their buildings and the energy costs associated with that heat. Solar panels have a lot of potential, but even in 2015, they’re still not used as much as some experts would like.

So a group of scientists at Brunel University in London recently began experimenting with hybrid designs that put both solar panels and hot water pipes to use together to make heating more efficient and affordable. Their hybrid roofing systems mixes several different technologies using heat pipes that are super conductors of heat energy.

The Need for Change

In the UK, where the researchers are based, over half of domestic energy usage goes to heat water. Hot water is used for radiators, showers, and to generate electricity; and heat pipes can be found in all sorts of high tech devices and computers.

“Until now there was no system which fully addressed all the technical and practical issues that face making an entire building’s roof a solar-powered generator of both heat energy and electrical energy,” said Dr. Hussam Jouhara of Brunel’s Institute of Energy Futures.

The Research

The university researchers cooled photovoltaic (PV) cells and these worked better than other panels by about a 15 percent margin. Their methods use more of the sun’s targeted energy without wasting it, like other methods have in the past.

“Currently the panels would get hottest in the summer and roofs need to be designed to dissipate that heat,” said Dr. Jouhara, who led the scientific team. “Simply insulating the house below is not a good solution as that simply traps it driving up the PV panel temperature and further lowering its performance. With our system there is no waste heat.”

The Challenges

Until now, heat pipe engineers have run into road blocks with solar cells and panels when trying to get them to generate electricity. Even when solar panels are located in direct sunlight, only a portion of the sun’s energy will be transformed into electricity.

“So the sunnier it is the more of that unusable energy hits the cell which, in turn, heats it up,” Dr. Jouhara explained. “As PV cells heat up their electrical generation ability is degraded. Heat pipes, in this case, constructed in flat panels 4m x 400mm, will whisk that away to heat domestic hot water.”

It has been difficult to combine the techniques of conventional roofing and solar panel installation. But as Dr. Jouhara explained, “Our solar panels are PV coated for the most southerly-facing aspect of the roof and are designed to clip together as a weather-tight roof as simply as clicking together laminate flooring.”

Potential Applications

This promising research shows numerous benefits to use this technology for efficient and renewable energy systems. More testing is underway in a three-bedroom detached house in the UK.

The researchers’ initial testing was done in relation to residential homes, but this hybrid roofing system could be applied to commercial buildings as well. Flat heat pipes like these are easy to install and use nature to their advantage – the pipes actually collect and can utilize energy from the evaporation of morning dew!