Hybrid electric vehicles represent a growing percentage of vehicles purchased by corporate and government fleets worldwide, according to a recent report from Pike Research, which found that cumulative sales of hybrid vehicles in the fleet sector will total nearly 4 million worldwide between 2009 and 2015.

The market intelligence firm forecasts in its "Hybrid Electric Vehicles for Fleet Markets" report that hybrid fleet sales of HEVs and PHEVs will increase from 300,000 in 2009, to more than 830,000 in 2015. The increase in hybrid fleet sales is due in part to a new segment of hybrids, the PHEV, which will be more widely available for fleet purchases after 2010.

The study found that PHEV programs will initially fall into the small car segment (82 percent of sales in 2013), which will not match the greatest needs of fleet customers. But medium/heavy duty trucks are also receiving PHEV treatments, and sales in that category are expected to grow.

"The biggest growth categories for fleet hybrids are medium/heavy duty trucks and buses," says managing director Clint Wheelock. "Manufacturers are beginning to turn their attention beyond light duty vehicles to the efficiency opportunities for hybrid drive in heavy trucks. For example, in North America nearly 10 percent of buses sold in 2015 will be hybrids."

However, costs remain an issue because the trucks will require much larger capacity batteries, thereby increasing the total vehicle costs.

The study said fleet managers in the United States don't expect to purchase the quantity of PHEVs they require within the first few years of their production. Fleet managers generally haven't been able to purchase the number of HEVs they would like, and those vehicles require a longer wait for delivery after ordering than ICE vehicles.

In addition, as the fuel economy of ICE vehicles increases, it will be more difficult for fleet managers to justify the purchase of PHEVs with higher acquisition costs. There also are concerns that the expected 40 miles of electric driving range announced by OEMs will not be enough for fleets and will therefore result in worse fuel economy than publicized.

The study found that the overall number of commercial vehicle registrations and fleet sales fell in 2008 and will continue to fall during 2009 in most regions (China being an exception). However, as a result of increasing government restrictions on corporate emissions and vehicle fuel economy in many regions, hybrid fleet sales will not see the same level of decline as ICE fleet sales.

Wheelock adds that North America will be the leading region in terms of hybrid fleet penetration, with hybrids reaching 8 percent of all fleet sales in the next five years. Early adopters will include government, university, and utility company fleets. Asia Pacific will be the leader in terms of unit volumes by that time, reaching 420,000 fleet hybrids sold per year, though the hybrid penetration will be somewhat lower than North America's.

An executive summary of Pike Research's report is available for free download on the firm's website.