100% emission-free concrete mixing

Concrete is, after water, the most widely used material in the world. Our construction processes about 14 million m³ concrete. Not surprisingly, because concrete is strong, offers high insulation value and is easy to work with. But concrete use also results in annual CO₂-emissions of about 3.5 megatons. About 80 percent of these emissions are related to the production of cement; an important concrete raw material. And transport to the construction site is also polluting. Especially when still using Euro 3 diesel engines. The electric concrete mixer trailers of P. van der Velden Lease b.v. offer a solution for this. Jos Leurs Automotive, Top Systems and MG Energy Systems have explained the energy system of the concrete mixer semi-trailers so that the drum can run emission-free all day.

P. van der Velden Lease b.v. is a leasing company for MAN trucks and other commercial vehicles in particular. "We lease hookloaders, dumpers, concrete mixers and other versions for the construction industry," says director Casper van der Velden. "In addition, we are a MAN service dealer. We are happy to take maintenance and repairs off your hands so that the high quality of the fleet is maintained. To keep up with the trends and developments in construction and society, we continuously develop our products. Our electric fleet is a great calling card for this."

100% electric transport fleet

The move toward electrification was initiated back in 2014. "I am an avid cyclist," Van der Velden explains. "On my way from the city to nature, I regularly crossed diesel trucks. Couldn't that be different? At the same time, I purchased a hybrid car and found myself riding electric as much as possible. A 100% electric car followed and I was so excited about this that I started exploring the possibilities for the transport fleet." Together with a partner and as a first project, a number of terminal buses were electrified. "With another partner, we additionally electrified a concrete mixer truck and crane truck. But we also wanted to be able to do this ourselves! Jos Leurs, owner of Jos Leurs Automotive, saw fit to take this on together."

Jos Leurs Automotive specializes in vehicle modifications and motorhome modifications. The company also provides design and engineering of battery systems for RVs, ships, machinery, ESS systems and other applications, among others. Leurs: "Traditionally, a concrete mixer trailer has a diesel engine that drives a hydraulic pump to turn the drum of the concrete mixer. Given the current developments around sustainability and CO₂-reduction, I was asked to engineer, develop and realize a sustainable alternative for this. The goal was to replace the diesel drive with a 100% electric drive, without changing the controls. In addition, good service and maintenance must be able to be provided." Van der Velden: "Partly for this reason, the power system is modular. The moment an unexpected failure occurs, the complete power system can be disassembled in 15-30 minutes."  

Charging at night, running during the day

The decision to electrify precisely the concrete mixer trailers was a logical one, according to Van der Velden. "After all, many of these trailers still use Euro 3 diesel engines. Only since half a year is the Euro 5 emission standard in force for new trailers. However, most concrete mixer trailers are still so polluting that the gain of electrification is huge. The energy system is laid out so that the drum/semitrailer can run all day, without charging in between. It's charging at night and using it during the day, with no restrictions." Leurs: "To make this possible, we made the excesses in use transparent in advance. One drum can hold a maximum of 15 m³ transporting concrete. How much power should the system be able to deliver at most to mix this quantity without restrictions, as the user is used to? We then searched for a suitable DC electric motor and power system to match this. The power system was supplied by Top Systems, which put together a very neat package of battery modules and a Battery Management System (BMS). Because all components are precisely tuned and communicate flawlessly, optimal operation and safety are guaranteed. In accordance with current requirements and for both the machine and its users."

High voltage battery system

Leurs already had experience with Top Systems' systems, which are regularly used in RVs, caravans, boats and ESS systems. "I knew that Top Systems could also supply high-voltage battery systems. At the table with Top Systems and MG Energy Systems, we explored the possibilities for this particular project. I created a mechanical drawing of the enclosure, for which Top Systems and MG Energy Systems also provided their installation information. Moreover, they shared useful tips & tricks, based on which the system could be optimized. Also with regard to the electrical connections. A commissioning engineer from Top Systems supervised the commissioning and inspected the installation: is everything connected properly? And are all the safety devices functioning?"

The energy system is built into an e-box on the back of the concrete mixer trailer. "At the basis of the energy system are 14 MG LFP lithium-ion batteries of 7.2 kWh (total: 100.8 kWh)," says Ronald van den Berg, sector specialist Construction, Installation and Infrastructure at Top Systems. "The 24 Volt batteries are connected in series, creating a high voltage of 358 Volts. This corresponds to the desired DC voltage required by the electric motor. The lithium-ion battery modules are connected to an MG Master 300A High Voltage Battery Management System (BMS), with a DC voltage range of 144 to 800 volts. The BMS controls, protects and monitors the connected batteries against overcharging, over discharging, over or under temperature. In addition, this system controls the balancing of the battery cells and makes important parameters such as battery status and energy consumption transparent."

Payback within four years

"For the electrification of our transport fleet, we started a DKTI (Demonstration of Climate Technologies and Innovations in Transport) trajectory, in cooperation with Vlot Logistics," says Van der Velden. "We received a subsidy from the RVO, which we are spending on the electrification of the concrete mixer trailers, among other things. Soon we will also start the electrification of a dump truck. We have also purchased an electric tractor and are busy developing mobile charging infrastructure." The first concrete mixer trailer was put into service at the end of May, followed in August by number 2. "Number 3 and 4 are currently under development," Leurs says. "Their realization is planned for the end of this year. Unique to our system is that we can electrify not only new, but also existing trailers. Companies benefit in this case from a huge CO₂-profit. In addition, maintenance of an electric drive is much easier, which also allows concrete builders to reduce their Total Cost of Ownership." Van der Velden: "With current energy prices, electrification of a concrete mixer semi-trailer can pay for itself within as little as four years. Companies that have solar panels or other renewable energy generators can also 100% sustainably charge the machines. Partly because of this, we expect electrification in construction to take off in the coming years. We are ready for it."