PVT Systems: Generating Electricity and Heat from the Same Roof

PVT modules make double use of roof space: they generate electricity while collecting heat for a heat pump. This can be particularly useful where a conventional outdoor heat-pump unit is difficult to install.

How PVT works

A PVT (photovoltaic-thermal) module combines two functions:

• Front: Solar cells generate electricity like a conventional PV panel.
• Back: A heat exchanger collects energy primarily from the surrounding air and additionally from solar radiation.
• Heat transfer: A water-based fluid containing antifreeze carries the collected heat to a heat pump.

Because ambient air is the main heat source, thermal energy can also be collected at night and during winter.

Why combine PVT with a heat pump?

Unlike a typical air-source heat pump, the roof-based collector operates without a fan. Natural airflow provides heat exchange, allowing silent operation without mechanically moving parts on the roof.

PVT can therefore be particularly attractive for terraced houses, densely built areas, or properties with limited space for an outdoor unit.

The required number of modules depends primarily on the building's heating load and system design.