As fuel prices keep climbing, the business case becomes stronger for hybrid power on heavy equipment. But the payoff period for heavy-duty hybrids is still fuzzy, and equipment designers face the tough decision of which technology to pick.
Some hybrid excavators have followed a similar path as have hybrid cars: An internal-combustion engine drives one or more electric motors; during braking, the motor reverses to serve as a generator. Some hybrids also use batteries or capacitors to store energy. These electric systems take a load off the engine, reducing fuel consumption and emissions.