Daniel Gross:

But it’s a much different calculus for industrial workhorses. Imagine you could somehow take a regular cargo van that guzzles gas and will be driven for 200,000 miles over its long lifetime—and then install equipment (a battery pack, an electric motor) that makes it run like a hybrid. If you could offer it at a reasonable upfront price, economically rational fleet managers would take a look, even if there was no subsidy or tax credit.
 That’s precisely what XL Hybrids, a startup in Brighton, Massachusetts, has done during the last several years. Some car owners pimp their rides by adding spoilers, rims, or sound systems. XL Hybrids asks its calculating customers to pimp theirs by adding inconspicuous fuel-saving systems that cost about $8,000. Coca-Cola has already bought 100.
 XL Hybrids was started in 2008 by clean-tech veterans who wanted to avoid having their businesses rise and fall with subsidies and tax credits, which have a way of coming and going. They thought a hybrid power train pitched at people who own gas-guzzling vehicles that rack up a lot of city driving miles might be a winning proposition, especially if they could show that the $8,000 investment would pay for itself in three years or less. Their targets: the delivery and utility fleets that rely on General Motors light-duty vans.