Solar cells on crash barriers: first phase of unique pilot project completed

The pilot with flexible foil and solar cells on 72 metres of double crash barrier has been running for a year along the N194 road near Heerhugowaard. The design is the first of its kind in the world. The recently completed one-year trial shows that the experiment has continued to function well in various weather conditions.

There was no moisture penetration or defects and the pilot generated energy until the end, although slightly less than expected. It also appears that the protective cover on the solar cells has more influence on the yield than expected. These new insights are useful to improve the technology and to be able to apply it in practice in the future.

Influence of weather conditions

Flexible thin-film solar cells were used during the pilot since solar panels are too rigid and dangerous in the event of a collision. Types from different manufacturers were used to determine whether they continue to function properly in a variety of situations. And this has been the case. The influences of all seasons and weather conditions were measured over the course of one year. For sustainable electricity production, the cells, electronics and connections must be well protected against external influences, including heat, cold, sun, rain and other factors. The design is a careful balance between safety requirements, energy yield, cost and aesthetics.

Further development

The pilot yielded approximately 1,200 kilowatt hours (kWh) solar energy per year whereas the expected yield was about 1,800 kWh/year, the consumption of an average 1-person household. Further development of this type of application of integrated flexible thin-film solar cells requires improvements in components, in particular the protective cover on the solar cells. Solar energy transport to the grid connection is also important due to the length of the experiment. In order to be able to generate profitable and sustainable energy with an integrated system, costs must be further reduced. When redesigning the system, the installation costs, which are often the largest cost item of a solar system, must therefore also be given a great deal of attention.

More applications of solar energy

Generating solar energy by making smart use of flexible solar foils can be done not only on crash barriers but also on noise barriers or other types of infrastructure. This contributes to a sustainable living environment. It is expected that more and more traffic management infrastructure will be used in the future as part of the transition to smart highways.

Research partners

This project 'Modular E-cover for Smart Highways' (MESH) was carried out by the province of North Holland together with TNO, Solliance Solar Research, Heijmans, Femtogrid and Amsterdam University of Applied Sciences.

Together, these partners developed the E-cover with solar foil and the system behind it:

• The Province of North Holland acted as the road authority
• TNO and Solliance Solar Research worked on the development of this application of solar foil, design of the E-cover and monitoring
• Heijmans co-developed the E-cover and was responsible for the installation at the location
• Femtogrid supplied the electrical equipment
• Students from the Amsterdam University of Applied Sciences also took part in the pilot

MESH was subsidised by the Energy top sector scheme iDEEGO (for the innovation of Renewable Energy and Energy Saving Built Environment), facilitated by the Netherlands Enterprise Agency (RVO).