Railpower Technologies of Montreal has drawn wide interest for its pioneering work to improve locomotives’ fuel efficiency with hybrid diesel-electric technology. Still, outsiders can be forgiven for wondering whether the company’s glass is half-full or half-empty.

Railpower has so far converted almost 50 shunting locomotives, known as yard-switchers in North America, into its Green Goat battery-and- diesel hybrids. Another 45 units are on order.