Chevrolet Volt at the 2007 Chicago Auto Show. Click image to enlarge
By Jim Kerr
When GM introduced the Volt concept car at the Detroit Auto Show this past January, it captured the imagination of people from around the world. This sporty-looking vehicle features electric motor propulsion and state-of-the-art battery technology with an internal combustion engine to drive a generator. This vehicle isn’t a hybrid; it operates only on electricity. It can even be plugged in, so short-trip driving can be done entirely on electricity from a household power grid. Now, less than a third of a year later, GM has introduced the next version of the Volt at the New York Auto Show. Will this one be the vehicle of the future?
Like the first Volt, this Volt E-Flex concept uses an electric motor to propel the vehicle, but a hydrogen-fueled fuel cell provides much of the electrical power instead of an internal combustion engine. The fuel cell can recharge the battery pack, or it can provide power directly to the electric motors to provide extended driving range. The vehicle can still be plugged in to charge the battery and it will operate on battery power only, but when combined with a fuel cell that also provides electricity, the battery pack needs to be only half the size of one used on a typical hybrid vehicle.
Why a fuel cell? Larry Burns, Vice President in charge of GM’s research and development team (including alternative energy vehicles) says that even though battery technology is improving, it is still not a proven alternative. Batteries by themselves provide a limited range. Thirty-five per cent of the world’s energy currently comes from petroleum, and with the expected demand for oil increasing 70 per cent by 2030, and countries like China and India developing auto industries quickly, we need to look at alternative energy sources. According to Burns, now is the time to face reality and look for alternative energy. There are currently 850 million vehicles in the world. “If the world waits till every question has an answer, then it will never happen.”
GM is now working with its fifth-generation fuel cell. As hydrogen gas passes through a polymer membrane inside the fuel cell stack, it creates electricity. The only byproduct is water. This fifth-generation fuel cell is about half the size of the forth-generation unit; efficiency has been increased by designing stacks that expose more of the membrane to the fuel, and by improved control systems. With four kilograms of hydrogen stored on board as a high-pressure gas (10,000 psi), the Volt E-flex would have a 300 mile (483 km) range, with about 20 of those miles powered by the battery pack.
There is one-tenth the number of parts in a fuel cell powertrain versus a hybrid vehicle, but the cost of building efficient fuel cells is still a limitation. Burns says that if production costs of $50 per kilowatt energy produced can be achieved, then the cost of a fuel cell-powered vehicle can match that of today’s gasoline-powered vehicle. Burns is confident that his team will be able to achieve this target, including a 150,000 mile (241,401 km) life cycle and a 300 mile range by 2009, and that these vehicles could be on the road in the 2015 to 2018 time frame. That sounds far away, but it is only eight years!
Hydrogen may be the fuel for the future. Burns sees hydrogen and electricity as interchangeable: hydrogen can produce electricity and electricity can produce hydrogen. Current world hydrogen production is 50 million tons per year, enough to fuel 200 million vehicles. Gasoline production alone uses about 35 per cent of world hydrogen production to enhance gasoline quality. That is enough to fuel about 60 million vehicles. The cost of producing hydrogen can be competitive with producing gasoline, and a fuel cell vehicle has the potential of reducing operating costs on a per-mile basis.
The Volt E-Flex is a front-wheel drive vehicle, but could become all-wheel drive with the addition of another electric motor at the rear. Flex is the word: vehicles with the same architecture, same electric motor propulsion and same battery, but with different fuel tanks and different motor units. GM has shown the Volt with a gasoline motor generator, a fuel cell and, recently, with a biodiesel-fuelled diesel generator. Perhaps the future will see all of these concepts on the road. I am looking forward to the hydrogen-fueled fuel cell model.