A hybrid-electric groomer has a diesel engine that powers an onboard generator and also the hydraulic pumps. The generator charges a high-voltage battery, which is what runs the drive motors. In downhill operation, the electric motors recover energy to help recharge the battery and power the hydraulics, reducing overall fuel consumption.
This arrangement results in some advantages over conventional machines:
Hybrid-electric drive is relatively new to the snow grooming business, with only one manufacturer currently offering a production model – Kässbohrer’s PistenBully 600 E+ alpine groomer. That said, the 600 E+ has been on the market since 2015 and is in service at several US resorts (none so far in Colorado, though). Hybrid-electric technology is of course well established in the automotive sector, and it’s reasonable to expect that it will follow the same trajectory in snow grooming applications.
Other than producing a bit better torque at low speed, hybrid drive technology doesn’t make any significant difference to specs, features or operation. A hybrid snowcat still fills up on diesel and doesn’t require any extra electrical or charging equipment.
Don’t hold your breath. Groomers use a lot of energy, so it will be a while before full-size all-electric versions enter the market. PistenBully and Prinoth are testing the waters at the small end with concept trail groomers – see info here and here. Given their battery specs, these machines could be expected to run 2½-3 hours on a charge, and they would require dedicated charging infrastructure.