European roads, rails may host 403 GW of vertical PV

The European Commission's Joint Research Centre (JRC) has assessed the potential of both monofacial and bifacial vertical PV installations deployed along roads and rails across the European Union.

“This is the first systematic, pan-European investigation of the total PV potential associated with roads and railways, considering different technologies and configurations,” the scientists said, referring to the novelty of their work.

For their road analysis, the researchers used open-access spatially explicit data, a road network derived from the OpenStreetMap project, which is an open-access geographic database maintained by a community of volunteers, and highway datasets of the European Union.  They identified motorways, trunk roads, and primary roads suitable for vertical PV installations and excluded secondary and tertiary roads, as well as sections with tunnels, bridges, and intersections.

As for the rail analysis, the academics utilized data from the Geographical Reference database of the European Commission (GISCO) and discarded underground lines, junctions, and stations.

They also specified that their overall analysis reflected the limitation imposed by the road or rail direction at a given location for the orientation of the PV system. “This was in turn determined by dividing the transport infrastructure into 500m-long segments and estimating the mean direction of each segment,” they stressed. “The orientation of the corresponding PV structure was defined as perpendicular to the segment direction in both clockwise and anticlockwise senses.”

The scientists found that the EU transport infrastructure may potentially host 403 GW of vertical PV capacity, which they said would correspond to an annual energy production of 391 TWh. They also found that the annual energy potential per km of the EU's transport infrastructure is approximately 0.65 GWh/km/yr for bifacial PV.

“Cyprus and Latvia stand out as the biggest potential beneficiaries in relative terms, with the potential to cover 75% of their current electricity consumption per capita,” the academics noted.

Their findings are available in the study “European transport infrastructure as a solar photovoltaic energy hub,” which was recently published in Renewable and Sustainable Energy Reviews.

Recent research from the Netherlands revealed that vertical PV systems tend to provide unexpected yield gains compared to horizontal arrays and have found that vertical installations have much lower operating temperatures. These scientists ascertained that vertical arrays operate at a temperature difference with respect to ambient that is “nearly halved,” which they said results in a 2.5% higher annual energy yield.