Renewable energy is an important element of the Thermal Road Repairs; it uses solar power to charge up the heaters we use in the repair process, which is one of the reasons why our technology is so low carbon compared to other methods.
We are not alone in our interest for renewable energy. In National Highways’ roadmap to net zero by 2050, published in July this year, it set itself a target of generating 10% of its energy from renewable sources by 2030. At a local level, several authorities are investigating the use of renewable energy such as wind, solar and kinetic as a way of reducing their demand for fossil fuels and hence carbon emissions.
The idea of using robust solar panels as a road surface has been around for years if not decades, and there are many trials underway. France committed to the idea early, with plans to pave 1,000km of roads with PV panels over five years. However, in 2019, just three years after a trial 1km-long section was installed in Tourouvre-au-Perche in Normandy, those plans were disrupted because the panels had generated far less electricity than expected and deteriorated at a greater rate than predicted too.
A more feasible system might be to install solar panels in canopies above motorways and major roads. In 2020, a three-year project to investigate the installation of PV canopies over Germany’s Autobahn’s got underway. This is a concept that has been proven in South Korea, where a 32km-long cycle way that runs down the middle of a highway is covered in solar panels to shade cyclists and generate energy.
As part of the Department of Transport funded ADEPT Live Labs programme, Central Bedfordshire Council is installing 216 solar carriageway modules at its Highways Depot at Thorn Turn in Houghton Regis.
Solar lights and signs
Solar energy is already being used to power lights and signs, both temporary and permanent, in the UK. And solar powered ‘cats’ eyes’ or studs are becoming more commonly used.
National Highways installed 4,500 solar road studs on the A38 between Ripley and junction 28 of the M1 back in 2018. The studs absorb and store energy during the day and then power their LEDs during the night. Other authorities have followed suit; Lancashire County Council recently installed them on two sections of the A682.
Buckinghamshire County Council is installing solar panels and mini wind turbines on its taller lamp posts, to power streetlights and sensors, also part of the ADEPT Live Labs.
Geothermal energy for de-icing
There are currently several research programmes underway around the world looking at how the energy generated by the sun heating up roads in the summer can be stored and then used to de-ice them in the winter. The systems work in a similar way to geothermal heat systems.
However, one of the first such systems was installed in the UK back in 2006 and 2007 on a road next to the M1 in Bedfordshire by ICAX. The Interseasonal Heat Transfer (IHT) system was reported to work well, maintaining the road temperature above 0 degrees C even at very low temperatures and when snow fell.
Perhaps due to the expense of installing the pipework, this is probably only a viable solution for airfield, bus stations or car parks. Central Bedfordshire Council’s Thorn Thurn depot will also be benefitting from a geothermal system to heat and de-ice it, again as part of the ADEPT programme.
Researchers at the Federal Highway Research Institute (BASt) In Germany are also looking at creating pathways within the road layers themselves to carry the water. This could make such a system simpler and cheaper to install.
Lancaster University is working with both Central Bedfordshire and Buckinghamshire Councils on projects to use kinetic energy. One looks at using human footfall to power advertising boards, using tiles made by technology company Pavegen, the other aims to create electricity from the movement of vehicles on roads. Whereas Pavegen can claim projects and partners around the world, systems to extract kinetic energy from vehicles driving on roads is perhaps more experimental at this point.
It is encouraging to see so many different uses of renewable energy already developed or in development. With more and more local authorities committing to climate change targets and seeking new ways to reduce carbon emissions, perhaps applications such as those mentioned above will become more commonplace.
Thermal Road Repairs is a green technology company which supplies systems to improve the quality, cost and time efficiency of road repairs and paving – at a far lower environmental cost than traditional methods. We invest significantly in R&D, to create new technologies and to continuously improve our existing ones.
High output. Low emission. Permanent solution.