Hybrid heavy-duty truck concept could mean greener big rigs

MIT engineers are working on methods that will help heavy-duty trucks, like big rigs, to reduce emissions and use less fuel. The majority of heavy-duty trucks out there are powered by diesel engines and a new way of powering the trucks that MIT has developed promises to significantly reduce pollution, increase efficiency, and reduce or eliminate net greenhouse gas emissions.The concept involves a plug-in hybrid engine system primarily powered by batteries and a spark ignition engine rather than diesel. The engine would also the trucks to drive the same distances as conventional trucks can. However, there would be a flex-fuel model that would run on gasoline, pure alcohol, or blends.

The end goal is to power semi trucks with batteries exclusively according to the researchers. The flex fuel hybrid would allow trucks to gain early entry into the market and overcome worries about range. The concept was developed by the MIT Energy Initiative and Plasma Fusion and Science Center scientist Daniel Cohn and a research engineer called Leslie Bromberg.

The researchers say that using flex-fuel configurations that run on gas, ethanol, methanol, or blends give the potential to emit less greenhouse gas. Cohn notes that big rig will be "very challenging" because of the cost and weight of the battery packs.

The combustion engine that the team sees in the plug-in hybrid would weigh far less and be much more fuel efficient than the diesel engines used today. Cohn admits batteries aren't where they need to be today for an all-electric semi truck. He says of batteries "let's be realistic about what they can provide."