One way to reduce the cost of cooling the buildings is to equip them with their own photovoltaic panels. This would increase the production of electricity during the day. Even more importantly: the installation of solar panels on roofs and walls reduces the need for cooling by shadowing the buildings.

When the house does not have its own solar panels, its roof and walls become very hot in the direct sunlight. The heat is then conducted inwards and inside the building relatively efficiently, because most buildings in the tropics have not been equipped with any heat insulation. We then need to use electricity and air conditioners to channel heat out from our apartments.

However, when photovoltaic panels are installed on the roof or on the southern, western or eastern walls of a building, solar radiation no longer reaches the surfaces that are under or behind the solar panels. Because solar panels are installed on the surfaces that receive most of the sunlight, this shadowing effect can be even more valuable than the electricity produced by the photovoltaic panels.

Besides this, a 10-centimeter-high gap is typically left under the panels or between the panels and the wall. This is done to prevent the overheating of the photovoltaic panels, but the air current thus induced under or behind the panels also provides a secondary cooling service for the whole building.

When the economy of installing solar panels on the roof is calculated, these cooling impacts are often forgotten. Solar panels can also protect the coatings used in the roofs and walls from the sun’s ultraviolet radiation and rain, lengthening its lifespan in an economically meaningful way.

The PVT panels, producing both electricity and heat, or electricity and hot water, can provide an even stronger cooling impact than ordinary photovoltaic panels. *Illustrative Image.