Vehicle Electrification: More than Fuel Economy by; William G. Rankin
With oil again approaching $70 a barrel and gasoline prices at the pump over $3.00 per gallon, vehicle owners are feeling increased economic pain and looking for relief. The solution offered by most vehicle manufacturers is the incorporation of efficient electric motors to displace conventional internal combustion engine (ICE) power. Many companies, including UQM Technologies, Inc., are working on vehicle electrification alternatives that provide a variety of benefits to their customers.
Vehicle electrification may involve simply replacing inefficient belt and gear driven under-the-hood auxiliaries (pumps, heating/air conditioning, cooling fans, etc.) with efficient electric powered ones. It can also combine electric propulsion with ICEs in various parallel, series, and plug-in hybrid configurations to increase efficiencies, or eliminate the ICE entirely by replacing it with full electric propulsion, such as in a battery or fuel cell powered vehicle. Generally, as vehicle power becomes more electric, fuel efficiency improves and cost and complexity increases. With rising fuel prices, vehicle makers are finding it much more feasible to justify electrification, particularly when other benefits are considered.
Powering under-the-hood auxiliaries with electric motors has a number of advantages. Auxiliaries can be relocated as needed because they do not require proximity to an engine-driven belt or gear, allowing for more flexible vehicle architectures and improved access for service and maintenance. Operation is also independent of engine speed, which allows variable speed and power modulation while improving controllability and reliability. Importantly, powering auxiliaries with electric motors takes a significant load off the engine and reduces both fuel consumption and emissions. In order to power these auxiliaries, the conventional inefficient alternator must be replaced with a higher power, efficient generator, which can also provide export power to run other on or off-board equipment. Under-the-hood electrification is a key strategy of many diesel powered vehicle makers to meet pending diesel emission mandates.
Vehicle electrification offers different value propositions to different vehicle makers and end users. When electric motors are used for vehicle propulsion, their ability to instantly deliver high torque results in exhilarating performance. Consider a 12,100-pound GVW hybrid electric HMMWV with four 100 horsepower electric motors – one driving each wheel – that does 0 to 50 mph in 7.5 seconds, climbs a 60 percent grade, can be skid steered, is capable of operating in stealth mode, and consumes 30 percent less fuel than a conventional ICE powered HMMWV. The vehicle can also serve as a mobile powerplant, eliminating the need to tow a generator and delivering sufficient power to run a field hospital, command post, or 25 homes. This power can also be used to operate electrically based weapon systems.
In agricultural tractors, electrification allows the replacement of the inefficient and imprecise transfer of mechanical power through a power-take-off shaft and hydraulics with electric power. With electric propulsion, the tractor has improved performance, consumes less fuel, and has sufficient electric power to operate implements equipped with electric motors for planting seeds, applying chemicals, and harvesting crops with precise control, resulting in less waste and higher yields. The tractor becomes a mobile powerplant capable of literally powering the entire farm.
Lawn tractors, like the one used to cut your lawn, can have similar capabilities when electrified. Individual electric wheel motors and electrically-driven cutter blades improve performance and consume less fuel. And, like its agricultural big brother, the lawn tractor is a mobile power generator capable of delivering electric power to operate hand tools like saws, drills, weed trimmers, and chain saws, and in fact an entire home’s electrical needs in case of a power outage.
With these examples, you can only imagine the possibilities that an electric grid-connected, mobile power plant that pulls into your garage each night might bring to its owner.
William G. Rankin is president and CEO of UQM Technologies (www.uqm.com), a recognized technology leader in the development and manufacture of high performance, power dense, and energy efficient electric motors, generators, and power electronic controllers.