CES 2025: Cat Debuts Hybrid-Electric Retrofit on 972 Wheel Loader

January 14, 2025

Kami Buchholz

The centerpiece of Caterpillar’s CES 2025 exhibit was the hybrid technology demonstration retrofit of a 972 wheel loader. The machine highlights the exhibit theme of “The Next 100 Years: Experience What’s Possible.” Caterpillar was founded in 1925. (SAE/Kami Buchholz)

A 55,000-lb (24,948-kg) front end loader with substantial field usage time underwent a 12-week hybrid-electric conversion in advance of its CES 2025 debut. “This retrofitted hybrid machine demonstrates Caterpillar’s flexibility in being able to accommodate different customer needs,” Paul Schmidt, engineering team lead for power electronics at Caterpillar, said in an interview with SAE Media.

Caterpillar’s Paul Schmidt points to the under-hood area of the 972 front loader where the conventional diesel engine and related components were replaced in a hybrid-electric retrofit. (SAE/Kami Buchholz)

Caterpillar kicked off its year-long centennial celebration at CES 2025 via showcasing the hybrid 972 wheel loader fitted with an extended range electrified machine (EREM). This powertrain technology demonstrator serves as Caterpillar’s alternative to full battery-electric machine power.

The Irving, Texas-headquartered company’s electrification ambitions publicly began with the unveiling of four battery-electric machine prototypes – the 301.9 mini excavator, 320 medium excavator, 950 GC medium wheel loader, and 906 compact wheel loader – at Bauma 2022 in Munich, Germany. Select all-electric machines are available.

For the hybrid-electric conversion of the 972, a small team of engineers completed a number of huge tasks, including the removal of the machine’s 9.3-L diesel engine as well as the turbo, air intake and engine cooling systems. The original fuel tank also was removed.

“Basically, everything behind the transmission came out,” said Noah George, a mechanical design engineer who worked on the 972 loader.

The 972 demonstrator’s hybrid-electric configuration features an electric motor, two strings of lithium-ion batteries, an inverter, high-voltage components, power electronics and an onboard diesel generator.

No DC charging is required for the 972 technology demonstrator. A 3.6-L diesel generator set runs AC power to a rectifier that converts energy from AC to DC. The energy created can be used to charge the battery. “The diesel gen-set really helps to extend the range of what this machine can do,” George said.

During mining, construction or other machine in-field applications, the 972 wheel loader demonstrator can be in-use for several hours at a jobsite. “On a typical emissions load cycle, the hybrid can run for more than eight hours,” said Dr. Saravanan Duraiarasan, Caterpillar’s senior controls engineer for electric powertrain optimal controls.

“The hybrid can operate at similar productivity and performance as its diesel mechanical counterpart,” Schmidt added.

Sobhi Alowdi, a battery-electric sales representative, said that feedback from customers of Caterpillar’s all-electric machine prototypes “has been really positive.” But not all jobsites have the charging infrastructure to support full battery-electric vehicles, so a hybrid-electric machine might be a preferred option.

“It’s emissions-free work until the battery depletes, then the generator charges the battery and the work continues,” Alowdi said. The hybrid version can charge overnight on a 240V utility grid connection.

The nearly 12-ft (3.6-m) tall front loader weighing 27.5 tons may be the perfect choice for Caterpillar’s hybrid technology demonstration premiere. “At the end of the day, it’s just a way to prove that we can do hybrid technology,” Alowdi said. “If we can do it on this model, we can do it on any model.”