The Solar Highways project has been concluded. Eighteen months after the innovative and unique solar noise barrier alongside the A50 motorway in Uden was connected to the national power grid, the monitoring phase is now over. This milestone also marks the official end of the demonstration project undertaken by Rijkswaterstaat and TNO. The green power generated by the barrier will be supplied to users via a public tender procedure.
Solar Highways objectives achieved
The most important objectives of Solar Highways have been achieved. The technical feasibility of integrating double-sided solar cells into noise barriers and their application alongside motorways has been investigated and proven. The project partners Rijkswaterstaat and TNO have demonstrated that the application is possible and viable. Rijkswaterstaat and Rijksvastgoedbedrijf (Central Government Real Estate Agency) have succeeded in making the generated energy available to inhabitants living close to Solar Highways, via a public tender procedure.
Solar Highways energy yield
After 18 months of monitoring, the energy yield equals the most positive forecasts drawn up in advance. In 2019, the installation generated a total of around 203 MWh (megawatt hours). This is sufficient to supply power to around 60 households, a year. It is also equivalent to 1 million road kilometres by an electric vehicle, or powering the lighting for 14 kilometres of motorway. Peak output of the installation is 248 kWp (kilowatt peak).
Public tender for green power
Rijksvastgoedbedrijf now plans to release the installation in the Rijkswaterstaat noise barrier for use by a party that will deliver the power to users in the area immediately surrounding the A50 motorway, via a public tender procedure. Candidates must submit their action plan to Rijksvastgoedbedrijf. The public tender procedure started on 1 September 2020. For more information about the procedure, visit Biedboek.nl.
To ensure the success of the Solar Highways project, Rijkswaterstaat and TNO (at the time still ECN and SEAC) joined forces with the Municipality of Uden and contractor Heijmans. Rijkswaterstaat was in charge of the project and monitored the noise absorbing capacity of the solar noise barriers, as the primary function. TNO (then still ECN) designed, built and tested a prototype of the solar noise barrier and submitted the reference design. This assisted Rijkswaterstaat in preparing the call for tender for the design and building work, undertaken by Heijmans.
Monitoring phase and test period for Solar Highways
Solar Highways has been in operation and connected to the power grid since 6 December 2018. The installation was monitored as a demonstration project through to 30 June 2020. Contractor Heijmans was responsible throughout the test period for maintenance and management of the barrier.
Solar Highways is a new and innovative noise barrier. This means that there was no previous experience whatsoever with the management and maintenance process. Rijkswaterstaat will make use of the experience acquired during the test period for drawing up the maintenance contract for Solar Highways for the coming years. This will include aspects such as troubleshooting and developing an adequate response to fouling, graffiti and vandalism.
Over the same 18-month period, the energy yield from the solar noise barrier was precisely measured and evaluated by TNO. Test sections were also established, each with their own cleaning regime, to ascertain the effect of cleaning on the energy yield. Based on the monitored results, an estimate will be made of the maintenance requirements, the energy performance, and the costs and benefits of Solar Highways and of potential similar solar noise barriers in the future.