Very complex puzzle, so not one solution

Infrastructure builders pioneering plenty of emission-free equipment

ENI (Emission-free Network Infra) is working in a unique ecosystem of frontrunners to develop the emission-free construction site.
Of the 42 members, half are contractors; the remainder are suppliers, machine lessors, energy companies and educational institutions. The social urgency to quickly achieve zero emissions is great. By bringing clients and contractors in the construction industry together, ENI seeks to accelerate the transition. The goal is not 2030 but 2026, with a focus on zero emission equipment from 20 tons/125 kW.

The infrastructure sector and its clients cannot and should not want to do without each other when it comes to the energy transition in construction, is the firm belief. The task is large, but a growing group of clients and contractors have already had their first experiences. The market is dominated by public clients such as provinces, municipalities, water boards, Rijkswaterstaat, Staatsbosbeheer and ProRail. At the end of September, ENI hosted a live webinar to inform the international construction community from a Dutch perspective about the latest state of the art of ZE machines from OEMs. Presenter Tobias Stöcker, Manager of Sustainability at GMB, hosted some interesting guests in the studio.

For example, director Erik Wagner of the High Water Protection Program (HWBP) calculated that the infrastructure sector receives between 10 and 12 billion euros annually from the government through tenders. To protect our country from flooding, about 40 billion euros will be invested until 2040 to reinforce 1,500 km of dikes and over 400 locks or pumping stations. "That is the largest investment since the Delta Works in the 1960s and 1970s," Wagner says. Arjan Walinga of Bouwend Nederland adds: "The Netherlands has the strictest rules in Europe when it comes to NOx emissions; 0.6% nitrogen emissions are already too high and the target is 0%. Without ZE machines, this is actually impossible to achieve. Currently, 1% of all the equipment in our country (roughly 300,000 to 400,000 units) is emission-free. When you consider that the Netherlands is a relatively small player in Europe, which in turn represents 16% market share of the global population of construction equipment, there is still a long way to go."    

Pooling knowledge

According to Walinga, there are many arguments for eventually achieving emission-free construction sites, but the big question is: HOW do we get there? The SSEB roadmap provides a good guideline in that regard, and €1 billion in subsidy funds are available until 2030. "It is important to combine all the knowledge gained during pilot projects, to arrive at manufacturers' products. Not only when it comes to zero-emission equipment, but also in terms of battery solutions and charging infrastructure. In that respect, we as Bouwend Nederland are more in favor of investing subsidies in knowledge than in projects. Ultimately, the whole sector benefits from that." ENI believes that SSEB funds should be invested in machines that provide the most benefits in terms of emission reduction per euro invested.

At the initiative of Bouwend Nederland and ENI, further economies of scale are also being considered. Can OEM development keep up with the growing market demand? "Frankly, we doubt it," Walinga echoes skeptically. "Manufacturers will have to be even more actively engaged, especially when it comes to larger machines starting at, say, 20 tons." Safety is and will remain a hot issue in this regard. "Changing batteries on site, is that safe? And where does responsibility ultimately lie with non-OEM products? Maintenance of electrically driven machines is also still in its infancy. Hence Bouwend Nederland maintains short lines of communication with manufacturers."

Complex puzzle

Wagner (HWBP) hooks up: "The focus right now is still on battery-electric, but hydrogen solutions are becoming more available. That development is taking longer, but is promising." Walinga speaks of a complex puzzle. "There is never one solution. It can be a combination of techniques. Moreover, we reason from what we know now. It may well be that an entirely new solution emerges in the short term." The stage of experimentation has now passed, according to Wagner. "Whether you want to or not, believe in it or not, everyone has to go along with this development. It is our common goal to achieve emission-free construction."

Next, Gerard van der Veer on behalf of GMB and Dick van de Laar from VolkerWessels take a seat at the table to talk with Baerte de Brey (ElaadNL) about how things work in practice. "The normal reasoning is that 1 liter of diesel per hour equals 4 kW of electricity," said Van der Veer. "Experience shows that an electric machine is more efficient, so that a 30-ton crawler excavator that normally consumes 20 l/hour can now move forward with 55 kW of power. Based on a 300 kWh battery pack, the machine can thus run for 5 to 5.5 consecutive hours."

More uniformity

Van de Laar: "In the past, it was just a matter of turning the key and getting to work. Nowadays, as a contractor, you have to take stock early on of what power connection is available on site and how best to charge ZE machines." Which cable do you use: AC or DC (fast charging)? What about safety? Can you use Smart Charging Solutions and open source data? Van der Veer: "The solutions are there, but we work throughout the Netherlands and have to keep discovering how it works locally." Van de Laar concurs: "More uniformity would certainly be desirable from the contractor's point of view." To which De Brey says, "Give us time. A lot is being invested in public charging networks from ElaadNL, but the 'problem' in construction is that it has to come on projects where there is no infrastructure at all. That is why it is important to take stock immediately after the award and involve us at an early stage. Engineering takes time, but eventually we will get there."