SolarWall^® Photovoltaic / Solar Thermal (SolarWall PV/T^TM) – A Total Energy System

Adding SolarWall® to photovoltaics dramatically reduces ROI timeframe

Top, SolarWall PV/T being installed at the Beijing Olympic Village (PV modules not mounted)
Bottom, SolarWall PV/T on the roof of the completed building

SolarWall PV/T (photovoltaic + solar thermal) is a total energy system that is setting a new standard in the solar industry.  Combining the advantages of solar photovoltaics with solar thermal in one renewable energy solution is one of the most exciting forms of technological convergence to occur in the renewable energy sector.  Pairing the electricity producing PV panels with the SolarWall thermal component (for solar heating) creates a solar-cogeneration system in which PV efficiency is optimized, and two types of energy - heat and electricity - become available from the same surface area.

Conserval Engineering originated the concept of combining PV with SolarWall. The goal was to address some of the problems inherent with conventional photovoltaics, and to develop a solution that would further enhance PV as a viable renewable energy solution. Two problems that make PV unattractive are the long payback periods and the low efficiencies.  These occur because of the excess heat accumulation on the PV panels. For every 1ºC rise in PV panel temperature, there is a 0.4% - 0.5% drop in the electrical output efficiency, and this is why the concept of “PV cooling” has become so important.

Combining SolarWall with PV provides a solution to both of these problems.  The solar thermal SolarWall panels cool the PV modules and enable the "waste heat" to be removed and utilized for practical heating purposes. The addition of this thermal component also guarantees that the PV panels function at their optimal output efficiency. The ability to displace this heat build up, and use it for solar air heating (to warm  buildings) in addition to the PV panels electricity generation, lead to significant decreases in greenhouse gas emissions.

Testing at the National Solar Test Facility
The SolarWall PV thermal (PV/T) co-generation system was recently tested at the Canadian National Solar Test Facility in conjunction with the International Energy Agency Task 35.  The results documented that adding a solar thermal component to a PV array boosts the total solar efficiency to over 50%, compared with 10 to 15% efficiency for most PV modules alone. The heat from the PV panels, captured by the SolarWall perforated absorber, was documented to be three times more than the electrical energy generated from the PV modules. This means that by utilizing the excess heat, it becomes possible to realize a solar capture efficiency improvements of up to 200-300%.