Solar panels on windows, façades, and roofs

The variety of sizes, shapes, colours, and transparency of solar panels we’re working on may reduce the yield per panel. But on the plus side, many more surfaces in the built environment are suddenly able to generate solar energy. This can significantly boost the total amount of energy generated.

The next step in large scale implementation of PV in buildings is the industrialisation of (custom) PV panels for façades. TNO contributes to the project Circulaire Multicolour gevel PV-fabriek by co-development of more sustainable module technology in the PV panels and quality control for PV functionality depending on the customisation of the PV façade panels. For more information, check out the website of the project.

We do those innovations together with multiple companies. For example, in the development of an approach that ensures solar cells can be incorporated flexibly and affordably into surfaces and objects. From solar roofs and facades to cars. We have built a research pilot line for this purpose. This is a model for a new generation of factories that will produce flexible semi-finished products with solar power.

Variations in shape, size, and colour are also important for the wider acceptance of solar panels. And to ensure that using solar power doesn’t undermine an architect’s creative freedom. Moreover, these innovative solutions create new market combinations and business activities. There are opportunities for construction companies, suppliers, machine manufacturers, and installation engineers.

For solar windows, we use thin-film solar cells or striped crystalline silicon solar cells. The goal is to create glass that lets in at least 20% of sunlight, while converting at least 10% into solar power. In this way, the windows can help make buildings energy-neutral, for example.

We have developed an innovative working prototype glass window semi-transparent module based on the material perovskite that generates solar energy. The prototype is 10 by 10 centimetres, with 5% efficiency. If we remove 50% of the material, 40% of the yield remains.

We are working with market participants on innovations in photovoltaic-thermal (PVT) systems. These systems generate both heat and electricity. Among other things, to make them better and more affordable. PVT systems on roofs in combination with a heat pump can contribute to an energy-neutral built environment.

Solar heat can supply a quarter of the total heat demand of the built environment, utilities, agriculture and industry. We conducted research into the use of solar energy as a heat source. The bottlenecks and concrete recommendations to make optimal use of solar heat can be read in an exploratory study (in Dutch) (pdf).

Previous research (pdf) (pdf)shows that PVT modules can optically match the building in terms of colour format. We demonstrated this on aesthetic facades with solar modules and with solar collectors with a heat-absorbing paint.

At our research site SolarBEAT we conduct tests on various PVT and solar thermal collectors.