Dean Kamen, an inventor from Manchester, New Hampshire, and founder of DEKA research, has modified an electric car by installing a Stirling engine to supplement the power. Much like today’s hybrid vehicles combine power from an electric motor with an internal combustion engine, Kamen’s invention uses a Stirling engine instead.
The Stirling engine sits at the back of the vehicle, and is used to power the defroster and heater, allowing the battery to be used solely for propulsion. This extends the driving range of the vehicle between charges. The engine can also be used to charge the battery in emergencies.
Although the article doesn’t mention it, I get the impression that the waste heat from the Stirling engine is used for heating, and the engine also runs a generator that produces electricity to power accessories such as the defroster and air-conditioner.
The car is a modified electric model, the Ford Think, which discontinued production in 2000. It can go 60 miles on a single charge.
The Stirling engine is unique in that it can be powered by any heat source. This heat source can be biomass, biofuel, or ordinary fuel.
The particularly nice thing is that you can use a fuel like biomass to power the engine. This is especially handy in emergency situations. Let’s say you were stranded in the middle of nowhere, with a dead battery. Assuming there are trees around (there often is), you can gather up some branches, burn them in the engine combustion chamber, and charge the battery. This would be the perfect car for camping.
If you wanted you could take a cross-country road trip without ever having to stop at a refueling station.
Biomass is certainly more abundant and available than fueling stations. No distribution infrastructure is needed. This flexibility opens up many possibilities. You no longer have to be at the mercy of the pump.
Environmentally speaking, biomass is carbon neutral, meaning that the only carbon emissions that result from burning it, were captured during its growth. This results in zero net carbon emissions.
The Stirling engine is known for its high theoretical efficiency. In practice its efficiency is higher than an Internal Combustion engine. But it has never been incorporated into vehicles because of its bulkiness relative to power output, and slower ability to change speed. But that is changing as we are slowly shifting away from fossil fuel dependence.
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