DHL Freight Sweden and Danish energy company Green Energy have launched a pilot involving ten trucks running on alternative fuels—four using HVO (hydrotreated vegetable oil) and six powered by liquefied biogas—equipped with solar panel systems. Operating across Sweden from Luleå to Skåne, the vehicles will be monitored over twelve months to assess the panels’ energy efficiency under different climate conditions.
The solar energy generated powers on-board components such as tail lifts and cooling systems, reducing the load on the alternator and thereby cutting fuel consumption and CO₂ emissions. The technology, already successfully tested by Green Energy on diesel fleets, achieved reductions in fuel use and emissions of between 4 and 7%. The current goal is to demonstrate that these benefits can be maintained with vehicles running on lower-impact renewable fuels.
Each truck is fitted with a photovoltaic system of either 240 or 320 Wp, depending on the model, and a control unit that gathers real-time data through the Fleet Tracker software. Joint analysis of the results will help evaluate the operational, economic and environmental benefits of solar energy in road freight transport. As Ylva Öhrnell, head of sustainability at DHL Freight Sweden, noted, the project represents “another step towards reducing freight transport emissions by combining solar energy with the renewable fuels already in use across the company’s network.”
The panels use CIGS thin-film technology, designed by Green Energy for the transport sector. Lightweight, flexible and resistant to shocks and weather conditions, they integrate seamlessly onto vehicle roofs without affecting aerodynamics. According to Anders Mikkelsen, head of strategic sales at the company, the trial aims to measure the impact of solar technology not only in terms of fuel savings but also operational reliability and the durability of on-board electrical components.
The Swedish project forms part of a broader trend spreading across European transport. Several companies are adopting solar technology as a complementary tool in their decarbonisation strategies. Among them, Samat International AB was recognised in 2025 by Danish daily Børsen as a sustainability case study for integrating solar panels into its long-haul fleet, with proven benefits in both costs and emissions. MD Logistika uses photovoltaics to reduce engine idling and unproductive fuel consumption, while FlixBus has installed solar panels on its biogas and HVO-powered vehicles as part of a wider emissions reduction plan presented in its annual Sustainability Report.
According to data released by Green Energy, fleets adopting this technology can save up to one litre of diesel per 100 kilometres, with payback times ranging from one to three years. Beyond the economic benefits, advantages include fewer electrical failures and improved driver comfort thanks to more efficient on-board energy management. The use of solar panels in road transport also enables the creation of verifiable sustainability indicators, relevant for ESG reporting and environmental criteria in public tenders. Data collected by tracking systems can be integrated into reports on direct and indirect emissions (Scope 1 and Scope 3), providing logistics companies with a transparent and credible tool for clients and investors.
