For more than a year, Emons Cargo 2WIN has been testing solar panels on the top of some trailers. Results are really encouraging. The new 2WIN ‘solar powered’ promises to be a strategic step in logistics and especially in our path towards Net Zero.
Since the first commercial solar panel was constructed by the American Charles Fritts in 1881, photovoltaic technology has progressed by leaps and bounds to conquer the power of the sun. Today, solar panels can be seen on the roofs of buildings, covering large patches of land, or on parking covers at gas stations. Smaller versions are used to power street signs and there are portable solar panels that everyone can use to charge smartphones or other electronic devices on the go.
Also in logistics, the use of solar energy is increasing. Companies are eager not only to save costs on their energy bills but also to improve their carbon footprint by turning to renewable sources of energy. Therefore, the use of solar panels on warehouses’ roofs or, in the case of the Emons Group headquarters, covering the façade of the main building.
Solar panels on the 2WIN trailers
The next logical step, at least for transport companies like ours, was to put solar panels on the roofs of trailers. This is, in fact, what a few companies, in Europe and in the USA, are now working on. Emons Cargo is among the first companies in Europe to develop and start testing its first prototype in August 2021.
‘Endless innovation’ is one of the Emons Group keywords. Trying new technologies and alternative solutions is in our DNA. The idea of being able to use clean, solar energy for our 2WIN trailers was so appealing that we had to immediately embark on this new technological development.
Apart from the thrill of innovation, however, the practical issue driving us was the need for energy to power both the tail-lift of the trailers and the EPT (Electric Pallet Truck) used by our drivers for the operations of loading and unloading.
The 2WIN double-deckers are equipped with two battery packs. One is needed for the tail-lift, the other for the EPT. At the time the 2WIN concept was created, the freight industry required long trips. The two batteries on the trailers only charge when the tractor engine is running, and these long distances were enough to charge them.
Nowadays, however, the transport industry has changed. Trips are shorter; therefore, the charging time is no longer sufficient. It happened sometimes that the batteries needed to be recharged in the middle of loading or unloading operations.
Now, with our standards of efficiency and agility, we surely could not stand it! We needed an improvement, and what could be better than clean and sustainable solar panels on the top of our trailers to get more eco-friendly energy?
Just to give an idea, let’s see in a few simple words what solar panels are and how they function.
How do solar panels work?
Sunlight is made of photons, elementary particles generated through a process of nuclear fusion in the sun’s core. The solar panels are made of solar cells, electrical devices that convert the energy of light directly into electricity. The process of this transformation is called the photovoltaic effect and is a physical and chemical phenomenon that occurs in a material when it is hit by light.
In short, when photons hit the solar cells of a solar panel, the material of which they are made generates electricity through the photovoltaic effect. This energy can be stored in batteries.
Phase 1: How did we start?
A first test helped us to realize that the existing systems on the market, though really well advanced in technology, were still way too much expensive to satisfy our cost-benefit balance. Therefore, we decided to develop our very own system. Our technical consultant for the Research and Development department Markus Ebben took the matter into his hands. After an in-depth analysis of the market and endless discussions and brainstorming, we created our circuit diagram, the graphical representation of the electrical circuit we were going to use. Then it was time to order the necessary materials, assemble the prototype, and test it for what it felt like a million times.
We improved the system and managed to use fewer components thus lowering the costs. In the end, we created our solar panels system with a capacity of 2960wp (Watt Peak: maximum electrical power under standard conditions). Charging, control, and regulation of the voltage are integrated into a powerbox, the heart of the entire system, also devised and developed by Emons. We also installed a monitoring system to constantly check our solar panels and obtain data on the quantity of electricity we can generate and consume.
By the beginning of 2022, we had enough data to draw some conclusions.
Phase 2: What did we achieve?
The first thing we immediately realized was that not only we were able to keep both the batteries of the trailer in optimum status, but we could also generate much more power than, apparently, we needed. We equipped several vehicles with the same system to confirm these data.
It was actually so! We were consuming only a little amount of the energy we were generating.
The figure above illustrates a few simple data of a normal 2WIN (on the left) and a 2WIN ‘solar powered’ (on the right).
The data in the figure show the daily status (maximum, average, minimum) of the battery packet for the tail-lift in the two trailers. From the first two line charts, we can see that in the 2WIN ‘solar powered’ the maximum level never drops below the value of 27V. The middle chart shows that the average voltage is higher in the 2WIN ‘solar powered’ than in the normal 2WIN. The last chart represents the daily minimum status of the battery. At a first sight, the ups and downs of the yellow lines do not seem too different. But if you look closer, you will notice that, in the 2WIN, the minimum voltage of the battery falls under the value of 24V almost every day. In the 2WIN ‘solar powered’, this hardly ever happens. A battery should drop below 24V as little as possible. With our solar panel system, therefore, we achieved the added value of extending the service life of the batteries by 25%. By doing so, we also manage to reduce maintenance costs.
We continued to develop and improve our system until we managed to make the trailer completely independent from the truck. In March 2022 we installed the system on the trailer TLN2170. In case of bad weather conditions, the charging power of the truck’s engine could automatically take over but, in all respects, the trailer was self-sufficient and entirely charged through the solar panels on its roof.
The 2WIN ‘solar powered’ was born.
Phase 3: What are we planning for the future?
Loyal to our reputation as innovators, we cannot stop at this achievement. We have plans for the future.
First of all, we want to use the 2WIN ‘solar powered’ to provide energy also for the tractor unit’s battery.
To start this new testing, we just need to keep the same tractor coupled with the trailer carrying our solar system. The challenge, this time, is not technological but organizational because for logistics reasons we often have to change the combinations of truck and trailer. We are quite positive, however, that we will soon find a solution and will be able to test our photovoltaic system and employ it to its full potential.
What we have created with our 2WIN ‘solar powered’ is nothing less than a driving energy station and as such we are also planning to use the extra energy we produce for different uses. One example is to charge external battery packs that can be used in several different ways.
However, our most ambitious plan is to be able one day to supply warehouses with the extra energy our 2WIN ‘solar powered’ can generate. This way, we will be able not only to be more sustainable ourselves and help improve the carbon footprint of our customers’ companies, but we will also contribute even further to the global effort toward Net Zero.