Growing potential for solar energy on buildings and infrastructure

TNO strives for an optimal combination of yield, economic feasibility, aesthetics and integration into multi-functional end products.

Roads that generate energy

Following the first successes of SolaRoad – cycle paths fitted with solar cells – TNO and partners are now conducting practical trials on provincial roads used by heavy traffic. As with other applications, the primary function of the infrastructure must be fully preserved. In concrete terms: the generation of energy via roads must be reliable and economically viable without endangering traffic safety. Our road network covers some 140,000 kilometres, a significant proportion of which can be fitted with this technology. A third of this can already produce enough energy to power nine million electric cars.

Utilising noise barriers

Another part of our infrastructure that can be utilised for solar energy is noise barriers alongside motorways. TNO is working with partners on various designs for solar noise barriers. A successful example is a technology for integrating two-sided solar panels in noise barriers. This has the potential to cover many hundreds of kilometres. In collaboration with Rijkswaterstaat and Heijmans, the first 400-meter-long noise barrier has been realised near the Dutch town of Uden. These bifacial panels no longer require south-facing installation as they capture sunlight from every direction. TNO is now developing the same application in noise barriers along railways. Some 700 kilometres are potentially available for this.

Roof surfaces

The load-bearing capacity of many large, flat roofs is not adequate for the application of today’s standard technology. The Netherlands has more than 2000 distribution centres with large roofs, as well as many industrial buildings in the agricultural sector. This adds up to more than 100 square kilometres of roof surface that can potentially accommodate at least 10 gigawatt-peak (GWp) of PV. In order to make the most of this potential, TNO is working with companies to find out which lightweight materials and structures can be used. Most solar panels currently contain glass, making them too heavy for this application. A new type of plastic-based solar panel can be used to create lightweight PV systems for these roofs. The utilisation of all these roofs may provide a wealth of sustainable energy without prompting any aesthetic objections.

BIPV: variety in shape and colour

In the summer of 2020, some very special solar panels were installed on the facade of the headquarters of the construction company BAM in Bunnik. The shape, colour and pattern of these panels nicely complement the appearance of the building. Such new forms of coloured or patterned PV module in BIPV, form an alternative to the standard PV panel available in one dark colour and fixed format. This allows architects to design buildings in aesthetic freedom and still capture solar energy as needed for meeting the norms of near zero energy buildings. In the future, windows will also be able to generate solar energy.

Reducing societal costs

The large-scale utilisation of roofs and facades has the additional advantage that the solar energy is generated where the demand is. This reduces the need for transportation of electricity via expensive cables and other infrastructure. Utilizing the roofs and facades increases the sustainable energy capacity and provides society with a substantial cost advantage.

It is still relatively expensive to manufacture tailor-made solar panels in any desired colour. TNO is developing a technology that could bring about a cost breakthrough: ‘mass customization’. Mass customization focuses on cleverly designed semi-finished products that can be made in a cost-effective way. These can then be ‘tailor-made’ and integrated into a wide variety of components and end products.