How to Cool an Electric Bus Without Draining the Battery
The electric revolution has introduced many innovations in the transport sector, but if there is one aspect that often complicates the life of zero-emission vehicles it is climate control in the interior.
A traditional air conditioner either relies on belts connected to the internal combustion engine or, alternatively, draws a large amount of power from the battery, compromising the vehicle’s range. And when the vehicle in question is a 30-seater bus, the challenge becomes even more serious.
The problem to solve
An air conditioning system that puts too much strain on the battery risks undermining the whole point of designing environmentally friendly electric vehicles. A number of manufacturers had tried to solve the issue by installing a small combustion engine dedicated solely to powering the air conditioning system. Unfortunately, this completely defeats the purpose of having a fully electric, zero-emissions vehicle!
Another possible solution involved the addition of larger, bulky and expensive battery packs, not to mention the additional weight, ultimately increasing energy consumption. In short, a new, sustainable approach was needed – one that could keep both costs and battery impact to a minimum.
Our idea
When Iveco, a leading Italian company in the commercial vehicle sector, approached us to find a practical, efficient way to cool a passenger bus, we immediately turned to eutectic technology: a system that allows the “cold” to be stored while the vehicle is stationary, using mains electricity instead of draining the on-board batteries. How did we do it? We started with an idea that was as simple as it was effective:
We basically used luggage racks to install tubes filled with distilled water. During the night, when the bus is connected to the power grid, the water is cooled significantly. Then, during the day, the vehicle’s internal ventilation system circulates air through these tubes, cooling the interior. In this way, the only additional energy use is for the fans – without putting any strain on the main battery.
A project in collaboration with Iveco and the university
This system was the result of a collaborative effort involving Iveco, The University of Eastern Piedmont and ES Frigo. European funding has made it possible to explore innovative solutions, bringing together research, engineering and sustainability. The first tests were a success – so much so that the prototype was sent to a major testing facility in Madrid, where Iveco operates cutting-edge infrastructure to test vehicle performance under extreme conditions.
How the testing went
At the Spanish test site, a team of researchers and technicians measured the energy needs of our air conditioning system with extreme precision. Thanks to this data, we were able to determine the number of kilowatt-hours that were needed to keep a medium-sized electric bus cool, while minimising the loss in driving range.
The feedback was positive across the board:
- Energy savings: much of the thermal energy was already “stored” overnight.
- Cost reduction: no need for auxiliary engines or oversized battery packs.
- Passenger comfort: interior temperatures remained pleasantly cool even during the hottest hours.
Why this was a special project
Creating a eutectic air conditioning system for a 30-seater bus was a real leap into the future. We brought our expertise in refrigerated transport into a rapidly evolving sector: electric vehicles.
It’s not every day you get to contribute to a project that reduces CO₂ emissions while maintaining passenger comfort – all without compromising the vehicle’s range. Working closely with Iveco and university researchers allowed us to tackle unique technical challenges and gather valuable data for future developments.
This electric bus with cold storage technology is a tangible example of how innovation can open up new pathways for sustainable mobility. And we at ES Frigo are proud to have brought our expertise to the table to help solve a real-world challenge with a practical, forward-thinking solution!
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Keen to learn more about our technologies for green mobility? Visit the section on solutions for the electrical world on the ES Frigo website and get inspired by the sustainable revolution!
