All-electric operation of mobile crushing and screening plants
1 Interlinked Kleemann plant train with an external power supply option
© Wirtgen Group
Prerequisites for electric operation
“Our mobile plant train in the sample calculation consists of a jaw crusher MOBICAT MC 120 PRO, cone crusher MOBICONE MCO 110 PRO as a secondary crusher and a downstream screen machine MOBISCREEN MSC 953 EVO. The plant train consumes an average of approx. 77 l of diesel per operating hour. In the electrified version, it has an average current consumption of 302 kW per operating hour. The maximum power requirement is 542 kW“, says Tobias Böckle, head of Product Management at Kleemann. “The energy requirement must first be provided by the infrastructure and is ideally met by electricity from renewable sources. A sustainable and quickly cost-efficient solution is to use an in-house photovoltaic power supply,” says the expert.
A suitable design of the infrastructure in advance is of decisive important for efficient use. Tobias Möß from Wolff & Müller GmbH explains: “First of all, the actual energy requirements of the plant and the demand of all already existing consumers should be determined. How much power is needed on the entire company premises? The load profile must also be taken into account. When are the power peaks, when are the times with lower consumption? The individual load profile can be obtained from the energy supplier or network operator.
2 All-electric operation incurs initial investment costs, but these pay off for the operating company in the medium term
© Wirtgen Group
Many companies already have a transformer on their premises that adapts the voltage to requirements and, for example, provides low voltage for systems. Once the required power has been calculated, it is necessary to check whether the available transformer is sufficiently dimensioned. Does it deliver the required power? The amount of power that can be drawn from the transformer is indicated on the type plate.
It is also important to consider where the main distribution is located on the site and where the system will be used. Good planning here is a precondition for efficient operation. Example: The electrical energy required to supply the plant is not transformed to low voltage directly at the transfer station, but is instead routed over the medium-voltage level across the site to the plant – the cable cross-section can therefore be much thinner, making the cable easier to handle and significantly cheaper. At the mobile plant, a second transformer converts the current into low voltage in order to operate the mobile crushing or screening plant. The aim here is to develop a suitable individual concept.
Rapid amortisation of the investment costs
With a solid foundation, the investment costs are amortised after around six years – or even sooner, depending on the energy concept. From this point on, all-electric operation will save considerable operating costs year after year.
Here is an overview of the switch to electricity as an example: With the diesel-powered plant, there is no need for additional investment in the infrastructure apart from the fuel costs. The cost of diesel fuel varies greatly depending on the country and region, so any savings depend on the difference in price between diesel and electricity. Electrically operated crushing and screening plants are initially more expensive due to their special equipment, plus the cost of cables (depending on the length of cable required) and a transformer.
All-electric operation incurs initial investment costs, but these pay off for the operating company in the medium term. On closer inspection, the one-time costs quickly turn into a worthwhile investment. In many cases, climate protection regulations lead to stricter requirements. The electric drive is a decisive competitive advantage, for example when local authorities demand emission-free operation in city centres. “Especially in combination with your own PV system, electrical operation becomes a climate-friendly, cost-efficient concept in just a few years, which not only provides the operating company with financial benefits, but also reflects the company’s efforts to achieve greater sustainability,” Tobias Böckle is convinced.
Environmentally friendly operation is also possible at locations where electricity cannot be supplied due to a lack of infrastructure. The electric version of Kleemann plants can also be operated autonomously with sustainable HVO diesel.
