Andreas Cremer is the Vice President of Product Management at Manitowoc. He shares the responsibility for the Project Management Group, Product Management and the Marketing Department, determining what the design and engineering teams are working on. Andreas provides an update on the Grove Hybrid project.
“During bauma 2022, we showcased a GMK4100L-2 ‘concept crane’. Prior to the event our team worked on electrifying the maximum functions we could imagine,” said Andreas. “We took all the rotary functions, which includes the hoist and the slew drives, and equipped them with electric motors, and we installed batteries. We had an electric motor to drive the remaining linear, hydraulic functions. In the carrier, we had a generator so if there was no battery power available the crane could still work from the engine.
“Before, during and after bauma, we used the ‘concept crane’ as a discussion point with many customers and recorded their input and feedback as ‘Voice of the Customer’.
“After the show, we took the crane back to our test centre. We tested the hoist function and recorded how much energy we consumed hoisting a certain load, and how much energy we could recoup when lowering the load from a given height. With most lifts we were able to recoup about two-thirds of the energy being used to lift up a load when bringing the same load down.”
Electrifying the crane’s super structure has a number of benefits, said Andreas.
“Practically speaking, a crane is usually lifting a load up or putting it down and at this practical level electric hoists offer significant benefits. We examined other functions to monitor how much energy or how many kilowatts we used compared to using a diesel engine and how much fuel we burn for the same operation.
“We were able to get an indication about efficiencies and understand how much more efficient electric drives and electric driven hydraulic systems are compared to the traditional driven systems. In effect, the ‘concept crane’ was a learning crane for us.
“Another interesting test with the GMK4100L-2 Hybrid was the use of battery power to support the drive line when accelerating. We went from two kilometres to 70 kilometres and shortened the acceleration time by 15 seconds.”
Andreas said that based on the customer input, plus the results from the testing, the team decided to look at the largest taxi crane Manitowoc has, the GMK5150XL and the L version, and converted that machine to a hybrid machine. A number of learnings were implemented into the new 5-axle crane.
“At the moment we are testing the first unit and there will be another unit built for testing. The hybrid GMK5150XLe will be on display at bauma 2025 and we are expecting to supply the first units throughout next year, so we’re pretty close,” said Andreas.
Manitowoc is quite advanced with the whole hybrid plan, but does it see the hybrid model as the answer to a more sustainable future or rather as a stepping stone towards the implementation of other technologies? Andreas explains more.
“It’s both. Our engineering team is on a learning curve, and they enjoy working with new technologies. But it is also a learning curve for our organisation because once these machines are in the market, the requirements for our service technicians to be able to work with higher voltage systems increases significantly.
“We are also faced with the challenge of customers requesting more sustainable products but not prepared to pay a premium for the technology and there is an additional incremental price for hybrid cranes.
“Our customers are trying to justify the additional cost. You always have ‘pioneers’ who want to try it first and we have a few of them. At this stage, we are not expecting hybrid cranes to take the majority of our production, rather we expect demand to stay at a lower level with an increase highly dependent on a change of opinion and potential ROI towards hybrid machines.”
The results of testing the hybrid cranes have been impressive said Andreas.
“When you examine the overall fuel consumption of a normal taxi machine, a hybrid crane can reduce the carbon dioxide (CO²) footprint by one third when it comes to the operational element of the crane. Obviously, getting the crane to site is where the majority of the diesel is consumed. Once on site the crane’s superstructure is powered by the battery and this can be recharged using renewable energy making it carbon neutral,” he said.
“With hybrids, there will be savings in energy consumption but that by itself will not offset the price difference compared to a diesel-powered crane. Diesel is still too cheap, but it will certainly look different as the world moves forward and there is a price for carbon dioxide emissions.
“If the cost of diesel goes up, it will make hybrids more attractive providing a better return on investment. We have customers asking about the hybrids and they want to invest in greener technologies to be more compliant in reducing carbon footprints.”
Andreas said countries in Europe are focused on the reduction of emissions and Manitowoc is seeing this increasingly in the US as well. But he said it is not enough for customers to think about investing in hybrids.
“When you start to invest in hybrid technology you also have to invest in the charging technology infrastructure.
“Having one hybrid crane in a depot and charging that is one thing, but if you look at the capacities of the batteries, and we will have a 180-kilowatt-hour battery on our machine, imagine if you have 10 hybrids and the infrastructure required to charge all 10 overnight.
“Our friends in Australia do have a special feeling about our hybrid and with all the mineral and infrastructure projects now requiring carbon reduction efforts, several customers are eager to get a few cranes into the market. As we all know, mining companies are putting a huge emphasis on solutions like our GMK5150XLe and we are working closely with a number of Australian companies to ensure we are providing the right solution,” he said.
Manitowoc manufactures the Potain range of tower cranes, rough terrains under the Grove brand and Manitowoc crawlers. There are unique challenges with electrifying all-terrains compared to the other types of cranes, explains Andreas.
“Manitowoc has manufactured electric tower cranes for years, so it is not new for us to handle electric drive functions on cranes and we have exchanged information with our colleagues. But electrifying all-terrains is very different compared to tower cranes or crawlers.
“Because a tower crane is onsite for an extended period of time it receives its own infrastructure or line of power. If you look at crawler cranes, you know they are going to be on site for a number of weeks or months and you can plan the infrastructure for an electric crawler crane.
“But all-terrain cranes are most likely used as taxi cranes, managing two or three different jobs a day. Moving from site to site, there will be some days when you don’t know if they will stay out overnight or return to the depot for charging. On a job site, you’re not necessarily able to access a power point to plug in and charge your machine.
“So, there are challenges with all-terrain cranes and you have to build something very flexible that can work either with access to electricity or without. Our concept is flexible for all the challenges the current infrastructure provides us today, and I think for this time, it’s the right thing. And if our environment changes, if infrastructures change, if accessibility to sufficient energy gets better on job sites, then I think we also will see cranes and hybrid cranes progressing in a different direction.”