Reviewed by Lexie CornerMar 18 2025
The first photovoltaic guardrail in history has the potential to turn highways and roads into energy sources. This invention, designed to improve sustainability, could contribute to the decarbonization of Europe’s transportation system. However, experts caution that “for such solutions to become reality, we need more opportunities to implement our innovative approaches."
Image Credit: bombermoon/Shutterstock.com
Not far from the small Italian town of Erbusco, along the route from Turin to Trieste, travelers might soon notice not only the medieval castle and the 16th and 17th-century residences but also a motorway service center.
However, what might be overlooked is a groundbreaking technological development. At first glance, it may look like a regular guardrail, but upon closer inspection, one will find it partially covered with an incredibly thin solar panel.
This is the first photovoltaic guardrail in history.
Its estimated annual production is about 623 kilowatt-hours per kilowatt peak, which translates to approximately 25 megawatt-hours per kilometer. A family of three consumes about 100 kilowatt-hours per month on average. So, with that amount of energy, we could power around 20 such households.
Eduardo Román, Head, Photovoltaic Team, Tecnalia
The concept was inspired by the vast potential of European road networks, which span approximately 136,700 kilometers. These roads could potentially be converted into energy sources capable of powering more than 8 million people.
In Europe, guardrails line thousands of kilometers of roads and highways. These vast, unused surfaces seemed like a valuable opportunity to promote sustainability, so we thought of using them to generate energy. Compared to traditional guardrails, ours includes an additional safety feature for motorcyclists in the form of a flat sheet slightly tilted upward, which is where we mounted the photovoltaic panels.
Irina Mella Burlacu, Founder, Vita International
This innovative technology is primarily aimed at improving road safety and decarbonizing transportation infrastructure, although its full potential is still under evaluation.
“Amongst other benefits, the photovoltaic guardrail will produce clean energy to power streetlights, traffic signals, and tunnel ventilation systems, leading to significant savings for road operators. But it will also enable the addition of signage and lighting in areas without access to the electrical grid,” Burlacu added.
The photovoltaic guardrail was developed as part of Liaison, a European initiative that promotes sustainability and circularity in transportation infrastructure. It is expected to be tested on a 100-meter section by the end of the year to evaluate its performance across all seasons.
Europe has more than 136,000 kilometers of roads and over 234,000 kilometers of railways. This transport infrastructure network is continuously upgraded through construction and maintenance activities, such as pavement replacement and ballast maintenance.
David Garcia Sanchez, Coordinator, Liaison
In 2020 alone, the European Union used more than 208 million tons of asphalt, approximately 44 million tons of cement, and over 600 million tons of aggregates for infrastructure projects.
“Civil engineering solutions for transport infrastructure have traditionally been carbon sinks. That’s why we need to not only extend their lifespan as much as possible but also develop circular solutions,” he emphasized.
The photovoltaic guardrail represents an unprecedented attempt to integrate photovoltaics with road safety regulations, aligned with Liaison's goal to reduce emissions from road and rail infrastructure.
“Its impact resistance is equivalent to that of a regular guardrail. However, in the event of a crash, the solar panels along the affected section would obviously need to be replaced,” Burlacu explained.
The unique design of the guardrail allows for easy cleaning, removal, and replacement, and includes special coatings and protective layers to reduce damage and abrasion. A challenge for the developers was assessing the impact of shadows cast by passing vehicles on energy output.
“There are two ways to tackle this issue. One approach is to use advanced power electronics to isolate the shaded panel without affecting the performance of the others it’s connected to. Another option is to design the PV panel in a way that minimizes the impact of shadows by strategically connecting the cells in series-parallel connection schemes,” Román added.
The Liaison project emphasizes promoting these sophisticated technical solutions while assisting stakeholders with procurement and contract processes.
“We are developing a new type of concrete slab for roads made with eco-friendly geopolymers instead of cement, as well as using 3D printing to create beams from recycled materials,” added Garcia Sanchez.
When recycling isn’t possible, technologies like blockchain and digital twins help track materials and components.
“The most impactful ones, from an environmental perspective, are concrete, steel, and asphalt. Since our goal is to reuse them as many times as possible, we also collaborate with ‘banks of materials’—repositories where you can both find and contribute materials when you no longer need them,” Garcia Sanchez stated.
However, technology alone will not ensure success. A 'holistic approach,' as he describes it, is critical to making these methods effective.
He added, “We need to ensure resilience to climate change, while also considering the safety of workers and citizens, durability, and public acceptance of new technologies.”
Despite the available solutions, the biggest challenge is convincing administrations and other stakeholders that “circularity is the way forward.”
“Engineering and transport infrastructure are highly segmented sectors, characterized by strong inertia and resistance to change. Shifting this mindset is very challenging,” he further added.
His message to industry stakeholders and policymakers is clear, even as the photovoltaic guardrail undergoes real-world testing in the coming months.
He concluded, “We are creating new opportunities for circularity, sustainability, and resilience in terrestrial transport sector. We are not here to create problems but to provide decarbonized solutions. Yet, for them to become reality, we need more opportunities to implement our innovative approaches.”