Diesel prices are rising again. Why Solar is an efficient solution for fleets

Diesel prices across Europe are rising again as geopolitical tensions disrupt global oil markets. In recent weeks, prices have increased by around 0,30-0,40 Euro per litre in just days. For fleet managers, this volatility directly impacts operating costs.

A typical long-haul truck consumes roughly 30.000–40.000 litres of diesel per year. This means that a €0,30 increase per litre raises costs by €9.000–€12.000 per truck annually. For a fleet of 100 trucks, this translates into €900.000–€1.2 million in additional fuel costs per year.

To reduce this exposure, transport companies are looking for solutions that lower diesel consumption and stabilize energy costs. This is where solar technology for trucks and trailers offers a practical alternative.

SolarOnTop: Generating energy directly from the sun

SolarOnTop reduces exposure to fuel volatility by generating electricity directly on the truck using a free and stable energy source: The sun. Solar panels installed on the roof of trucks and trailers produce electricity while the vehicle is driving or parked. This energy powers auxiliary systems such as:

• • Heating, Ventilation, and Air Conditioning units
• • Liftgates and tail lifts
• • Cabin electronics
• • Onboard batteries

Normally, these systems rely on electricity generated by the engine through the alternator. SolarOnTop replaces part of that demand with solar energy, reducing the load on the engine and lowering diesel consumption by up to 1.000–3.000 litres per truck per year.

At a diesel price of €1,70 per litre, this represents €1.700–€5.100 in fuel savings per truck annually. For a fleet of 100 trucks, this can translate into €170.000–€510.000 in annual fuel savings.

Real-world results

Our customers are already seeing the impact:

• • Van Rijnsbergen: SolarOnTop supplied 53% of onboard electrical energy, saving 1.672 litres of diesel per year per truck. ➡️ read full case study
• • Rhenus Logistics / Hitachi Vantara: Solar provided 52% of electrical energy, reducing diesel consumption by 1.284 litres per year per truck. ➡️ read full case study

Key benefits for fleet managers

SolarOnTop delivers several practical advantages:

• • Lower fuel consumption: reducing diesel use by up to 1.000–3.000 litres per truck per year
• • Reduced operating costs: every litre saved directly improves margins
• • Energy cost stability: solar energy is not affected by fuel price volatility
• • Works with existing fleets: no need to replace vehicles
• • No infrastructure dependency: trucks generate electricity independently

Why Solar matters in a volatile fuel market

The real advantage of solar is not only fuel savings, it is energy stability.

Diesel prices fluctuate constantly due to global energy markets and geopolitical developments. Solar energy works differently. Once installed, solar panels generate electricity every day with no fuel cost and no exposure to oil price volatility.

This creates a fundamentally different energy model for fleets:

Diesel-based energy

• • Price fluctuates with global markets
• • Exposed to geopolitical risks
• • Continuous fuel purchases required
• • Increasing operating costs

Solar-generated energy

• • Energy cost fixed after installation
• • Independent energy source
• • Electricity generated on the vehicle
• • Predictable long-term energy cost

Solar technology will not replace diesel propulsion. However, it allows fleets to reduce diesel consumption and gain greater control over their energy costs today.

For fleet managers operating in a market where fuel prices can change overnight, generating part of a truck’s energy directly on the vehicle provides a clear advantage: more efficiency, more predictability and less exposure to fuel volatility.