Electric excavators are no longer a future scenario

Electric excavators are no longer a future scenario

Manufacturers such as Volvo CE, Caterpillar and Liebherr have increasingly developed electric excavator models in recent years and brought them to market maturity. This development is being driven by several factors, including stricter environmental regulations, rising fuel costs and the growing pressure to reduce CO2. Electric excavators offer decisive advantages over their diesel-powered counterparts. They work almost silently, which is a huge advantage, especially in urban areas and on night-time construction sites. Local emissions are zero, which not only benefits the environment but also significantly improves working conditions for the machinists. Additionally, electric motors offer more precise control and better torque response, resulting in more efficient operation.

Diversity of technology

“For us, only electric drives play a role,” emphasizes Wolfgang Rigo, Managing Director at Huppenkothen, when asked whether alternative drives play a role in excavator development. "With the models TB2126E, TB20e and TB260E, we have three electric excavators in our range, both for sale and for rent. These are particularly used on inner-city construction sites and for (indoor) demolition."
Zeppelin relies on various technologies to make excavators more efficient. “We, Zeppelin and Caterpillar, are open to technology on this issue because we assume that there will not be ‘one’ type of drive for construction machinery,” emphasizes Dominik Dam, Head of New Machines & Product Development at Zeppelin Austria. “In our view, different forms of drive – diesel, diesel-electric, battery-electric and hydrogen with and without fuel cells – will coexist in the future.”
The decisive factors for the type of drive chosen are both the energy intensity of the task to be completed and the charging and infrastructure on the construction site. “Alternative forms of drive such as battery technology will continue to develop and have great potential.”
“Alternative forms of drive, especially battery-electric machines, are increasingly coming to the fore,” emphasizes Jörg Breuer from Volvo CE. “The decision in favor of this form of drive is motivated by various reasons, such as the requirement for one's own company to use climate-friendly machines, tenders that require the use of climate-friendly machine operations or a cost/benefit calculation, which, when taken as a whole, can speak in favor of electrically operated machines.”

Diesel particulate filters and SCR have primarily increased costs, both in terms of purchase and maintenance.

Wolfgang Rigo,Huppenkothen

"We have seen a steady increase in demand from our customers since the introduction of our 'zero emission' series. We have found that renting zero emission construction machines and equipment is a particularly effective way to dispel concerns about battery-operated machines: In operation, the electric machines are just as powerful as their conventional counterparts and the battery life is designed to meet the construction site requirements. Remember that our customers as soon as they work with it themselves,” explains Christian Chudoba, Managing Director of the Austrian Wacker Neuson sales company.
However, there are still a variety of challenges standing in the way of the widespread introduction of alternative forms of drive. The limited range of electric excavators - currently between four and eight hours depending on the manufacturer's model and intended use - makes them impractical for many large, continuous construction sites, for example. In addition, the charging infrastructure often requires significant investments. In addition, the acquisition costs of electrically powered excavators are still “significantly higher than those of comparable diesel models,” as Stefan Kuhn, managing director of Kuhn Holding, points out. Especially in economically tense times, customers are more likely to opt for the cheaper diesel models rather than the more expensive models with electric drives, as the industry expert emphasizes.

Energy efficiency and environmental protection are essential parameters of our development work.

Christian Chudoba, Wacker Neuson

Predestined for sensitive areas

Alternative forms of drive would become established particularly quickly in certain areas of application, explains Hans-Werner Eder, District Manager DACH at Develon Europe. "For example, where low-noise and low-emission work is required. This primarily includes inner-city areas, sensitive ecosystems as well as natural and landscaping." Users would benefit from several advantages in these areas; alternative drives also enable use in particularly sensitive zones thanks to their “zero emissions and noise reduction”. There are also “competitive advantages in tenders that require environmentally friendly machines”. In addition, there is long-term economic viability through lower operating and maintenance costs and an “innovative corporate image that relies on sustainability and future viability” is being built. “Devleon is of course not ignoring this development – ​​on the contrary: we are increasingly using our internal company capacities to further develop alternative drive solutions.”
Hybrid drives represent a transitional technology to combine the best of both worlds. They combine a smaller diesel engine with electrical components, enabling fuel savings of up to 20 percent while reducing noise pollution. Hybrid excavators offer an attractive alternative, especially for operators who are not yet ready for the complete switch to electromobility. Hydrogen as a drive alternative, however, is still at the beginning of development, but is already showing promising approaches. In recent months, a variety of hydrogen excavator prototypes have been tested by a wide range of manufacturers. The technology is particularly interesting for large excavators, as the weight of the batteries is a limiting factor.

EU standard as a driver of innovation

The introduction of the EU emissions standard “Stage V” has forced the excavation industry to make significant technological innovations in recent years. This standard not only drastically limits nitrogen oxide and particle emissions, but also introduced limits for the number of particles for the first time - a first in the world of construction machinery. Manufacturers responded to this with a variety of exhaust gas aftertreatment technologies. The effects of the Stage V standard go far beyond just reducing emissions. The standard led to a fundamental redesign of many engine concepts and spurred the development of intelligent engine control systems. Modern excavators now have adaptive engine controls that optimize performance depending on the work situation while minimizing fuel consumption.
It is also interesting that the stricter standards indirectly promoted electrification. Many manufacturers recognized that the complex and expensive exhaust aftertreatment of diesel engines made electrification more economically attractive, especially for smaller excavators. “Fuel consumption has fallen significantly as a result of the guidelines,” explains Dam.
"There were briefly adjustment difficulties with the Stage 3 engines - the fuel consumption even went up in order to achieve the emissions values. However, engine technology has now progressed further and there are significant reductions in fuel consumption."
"Energy efficiency and environmental protection are essential parameters of our development work. The legal requirements have become enormously stricter in recent years, especially in the area of ​​emissions legislation," says Chudoba. "Alternative drives are continuing to gain in importance. We are very well positioned here with our zero emission portfolio, because our customers can already operate an entire inner-city construction site without any local exhaust emissions."

In economically tense times, the higher costs of electrically operated excavators are a decisive factor for many customers to prefer cheaper, conventionally operated excavators.

Stefan Kuhn, Kuhn Holding

 

More complex technologies

“The engine technology is significantly more complex than in the past,” points out Breuer. "The strict requirements for reducing nitrogen oxides and particles in particular mean a relatively high level of effort in exhaust gas aftertreatment. As is already known for trucks, this requires catalytic reduction (use of 'Adblue', editor's note) and particle filters. This presents all manufacturers with additional challenges, such as investing in additional components for engine technology and electronics to achieve the specified emissions values.”
“The diesel particulate filter (from 19 kW, editor's note) and SCR (from 56 kW, editor's note) have primarily increased the costs, both in terms of purchase and maintenance,” says Rigo. Kuhn also sees customers confronted with increased costs due to the standards. But not everyone sees rising costs; Eder, for example, believes that Develon customers benefit from lower operating costs and fewer downtimes. "Compliance with EU Stage V drives continuous innovation in engine technology at Develon. Our machines are equipped with modern exhaust aftertreatment systems (DPF, DOC, SCR) and meet the highest environmental standards."

The key to electrification

Battery technology is the critical success factor for the electrification of excavators. The battery capacities of modern electric excavators vary greatly depending on the size of the machine. Compact excavators typically have 20-40 kWh of battery capacity, while larger models can reach up to 300 kWh. These capacities enable operating times of four to eight hours, depending on the intensity of the operation.
For the Austrian construction industry, these developments represent both challenges and opportunities. Companies that invest in new technologies at an early stage and train their employees accordingly will gain competitive advantages. At the same time, technological advances offer the opportunity to remain competitive even in a country with high labor costs like Austria.