The International Energy Agency recently published a striking finding. A single container ship carrying solar panels can provide the means to generate as much electricity as the coal carried by more than 100 ships of the same size.
The reason is simple. Coal gets burned once, and then it is gone. Solar panels, once installed, keep generating energy for decades – with no additional input and no ongoing cost. For fleet operators managing trucks and trailers across Europe, the same logic applies.
The real cost of diesel is what you keep spending
Fuel is one of the largest operating costs in road transport. For most fleets, it represents 25–35% of total running costs.
And unlike fixed costs, it fluctuates. Sometimes sharply. Diesel prices rise and fall with global events outside any operator’s control – and right now, that volatility is hard to ignore.
Every kilometre driven burns fuel that has to be purchased again. Operators cannot control what the price is at the pump. But they can control how much fuel their vehicles need.
That is exactly what a vehicle-mounted solar system does. It generates power while the vehicle is on the road. That power feeds directly into the vehicle’s electrical systems, reducing the load on the alternator. Less alternator load means the engine works less hard – and burns less diesel.
The improvement per vehicle is not dramatic. But it is consistent. And it repeats every year the system is installed.
Small gains, compounding value
Our WiVA (Within Vehicle Analysis) data covers 4.2 million kilometres across 370 vehicle months, measured to a 95% statistical confidence level. It shows:
- Trucks save between 500 and 1,000 litres of diesel per year
- Savings of 0.6–1.0 litres per 100 km
These are verified, real-world numbers from actual fleet operations – not projections or estimates.
For a fleet of 50 trucks, that translates to between 25,000 and 50,000 litres of diesel saved every year. At current European diesel prices, that is a meaningful reduction in operating costs – year after year, from a single upfront investment. And when prices spike, those savings grow with them.
What this looks like in practice
Fogtmann Group, a Danish logistics operator serving major national retailers, ran a four-month pilot with four trucks fitted with Green Energy solar systems. Results were measured to a 95% statistical confidence level.
Each truck saved 1,019 litres of diesel per year – with a payback period of under 12 months. Drivers reported more stable power and better battery reliability. Fogtmann now plans to roll solar out across its full 70-vehicle fleet.
As Klaus Fogtmann, CEO, put it: “When a solution delivers clear fuel savings and a payback in under a year, you act.”
That is the nature of this investment. You pay once. It keeps delivering – regardless of what happens at the pump.
Fuel efficiency and decarbonisation – the same investment
Reducing fuel consumption and reducing CO₂ emissions are the same thing. Every litre of diesel saved removes approximately 2.68 kg of CO₂ from a vehicle’s emissions profile.
For fleets with CO₂ reporting obligations – whether under CSRD, customer contracts, or national regulations – vehicle-mounted solar provides a straightforward way to deliver verified, measurable Scope 1 emission reductions. Our systems save 1.3–2.7 tonnes of CO₂ per truck per year.
These are not projected figures. They are recorded outcomes from vehicles already on the road.
As pressure on road transport decarbonisation increases across Europe, operators who have already taken steps to reduce fleet emissions will be better placed – with customers, with regulators, and with their own bottom line.
An available solution, today
Much of the conversation around fleet decarbonisation focuses on technologies that are still developing – electric trucks, hydrogen powertrains, alternative fuels. These will play an important role. But widespread adoption is still years away for most operators.
Vehicle-mounted solar systems – also referred to as VIPV, or Vehicle-Integrated Photovoltaics – work on existing diesel vehicles. They require no changes to how vehicles are operated or maintained. Installation typically takes less than a day. And they start delivering fuel savings from day one.
There is no single answer to reducing fuel costs and cutting emissions in road transport. But for fleets looking for a practical, proven step they can take now – the maths on solar is straightforward.
The same technology is also proven on buses and coaches, where annual diesel savings reach 1,600–2,100 litres per vehicle.
You invest once. It saves every year.
Want to see what this looks like for your fleet? Try our savings calculator at greenenergy.pro/savings-calculator
