l Recently, I had the opportunity to spend a few weeks at the 2011 North American International Auto Show in Detroit, one of the premier locations for automotive manufacturers to unveil new models as well as concept vehicles. Although this is a consumer show, it has direct application to the law enforcement community because our future patrol vehicles will most likely be based on these models.
An underlying thread that united all of the major players (and some minor ones) this year: Hybrid and electric propulsion technologies are here in a big way. As these technologies become the norm rather than the exception, the real question becomes whether it makes sense, or even provides an advantage, to incorporate electric and hybrid vehicles into law enforcement fleets. Before talking about the specific advantages and disadvantages of hybrid and electric vehicles in law enforcement use, let’s first discuss the technology itself.
The first thing to understand is that electric and hybrid cars are not the same. Full electric vehicles, such as the 2012 Focus Electric, rely entirely on battery power, usually a lithium-ion or nickel-metal hydride battery-pack, to provide power to a high-voltage electric motor. The high-voltage side provides power primarily to the electric motor while a parallel 12-volt battery system powers the vehicle’s electronics, such as the radio, power windows and HVAC. There are times where the high-voltage system will “downgrade” power to supply the 12-volt system if needed. Electric vehicles have no internal combustion engine and must be plugged into to be recharged.
Hybrid vehicles are different than electric vehicles. The term hybrid implies a blend of two things; all hybrid vehicles blend electric motors and internal combustion engines for propulsion, although they do so in different ways.
The argument for full-electric vehicles in law enforcement is definitely getting stronger, but agencies considering all-electric vehicles should be aware of both the advantages and disadvantages of these vehicles.
Advantages
• Since electric motors spin, there are few parts that ever wear out, drastically reducing long-term maintenance and operation costs. Conventional multi-speed transmissions are no longer needed because the electric motor can achieve max power at any RPM, thereby eliminating rebuild costs.
• An electric motor can make maximum torque and power from rest, providing instant torque and acceleration. This is why modern locomotives use electric motors powered by diesel engines.
• Electric vehicles can function as a power-delivery device and a power-generation device, which means that a single electric motor can also generate energy to recharge itself.
• Electric vehicles are whisper-quiet, providing a tactical advantage for responding to incidents, surveillance operations and other duties.
• Electric vehicles produce no direct emissions, which can go a long way toward a department or government entity’s goal of reducing localized carbon footprints and improving air quality.
• Electricity is cheaper than fossil fuels.
Disadvantages
• Electric vehicles are range-limited. If you run out of juice, it’s like running out of gas, except now you need to find a plug instead of a gas pump. Also, the range of current electric vehicles is short compared to conventional gas vehicles.
• Electric vehicles need time to charge, which is directly related to the voltage level of the charger, the available infrastructure and the size of the battery pack.
• Charging stations for electric vehicles aren’t widespread, so departments and governments that integrate full-electric vehicles will need to install charging stations too—an added cost.
• New technology isn’t cheap, so while fuel savings can be realized by converting to full-electric, it must be weighed against the up-front cost of acquiring the vehicles.
• All the cool law enforcement gear we use sucks power like crazy and this can quickly tax the electric vehicle. Options to increase battery power do exist, such as adding additional 12-volt batteries, but ultimately, power limitations remain a key challenge to using electric vehicles in law enforcement.
As with full-electric vehicles, hybrid-electric vehicles also present advantages and disadvantages for law enforcement use.
• Hybrid vehicles have a longer range. The ability to use battery power for in-town use provides for minimal or no use of gasoline, which can be saved for higher speed situations or battery recharging while also providing great acceleration. Example: The Ford Fusion Hybrid can provide a range of 700 miles on a single tank, with a 0–60 time of about 8.5 seconds.
• Existing infrastructure can be used because, regardless of the specific hybrid configuration, all power generation is possible within the vehicle itself. Hybrid vehicles can be driven to the gas pump as needed; officers will never need to worry about finding a plug or having a short driving range.
• Hybrids reduce or eliminate emissions where it counts the most: in congested urban environments. Since they primarily run on electric mode at low speed, this cuts emissions and improves air quality.
• The fuel economy savings achieved from hybrids, although not as significant as full-electric vehicles, are still substantial when compared to a traditional full-gasoline patrol vehicle. Departments can realistically promote “green” operating strategies in their fleets, which is advantageous to the environment and demonstrates social responsibility in the community.
• As with full-electric vehicles, one of the biggest challenges with hybrids in law enforcement is the power requirements of the various systems on board. This is especially problematic at lower speeds or when the vehicle is parked, when power is being consumed but not replenished. This isn’t an issue when the vehicle is running, because the gasoline engine can replenish the high-voltage pack which, in turn, can recharge the 12-volt system.
• Hybrid vehicles are typically more expensive to purchase than their gasoline counterparts, so realized savings must be projected over the life of the vehicle to determine if a real savings occurs when balancing gasoline savings vs. up-front expense. This also applies to the cost of replacing the technology itself in a collision or failure.
• Service personnel must be properly trained on the unique requirements of servicing hybrid vehicles and the significant potential hazards that high-voltage systems present.
The use of electric and hybrid vehicles in law enforcement is by no means widespread, but there are examples of it succeeding. The Aspen (Colo.) Police Department had been working to integrate hybrid vehicles into its patrol fleet since before 2005, but couldn’t find a suitable vehicle that met their needs. Then, in 2006, Toyota released the Highlander AWD Hybrid, which caught the department’s attention. In 2008, the department purchased the model for testing and integration into the patrol fleet.
“We wanted to do our part to reduce CO2 emissions, to reduce the fuel we use, as well as provide a fully functioning police patrol vehicle,” says Chief Richard Pryor.
In all three of these areas, the department has seen success. In fact, when comparing the operating costs of the Highlander Hybrid and the department’s fleet of Volvo XC70 AWD wagons, there was a realized fuel economy gain of up to 72% with the Highlander. Furthermore, the yearly reduction in CO2 emissions is projected at nearly 20 tons—for one vehicle—while the department expects to save more than $7,000 in fuel costs.
Aspen did face some challenges in getting the battery system to play nicely with law enforcement gear, but the department conjured up some innovative solutions to solve them. They have since published an excellent summary of their experiences with the Highlander Hybrid, which is available at http://bit.ly/aspen_hybrids.
Electric and hybrid vehicles aren’t suited for all law enforcement needs, but as the Aspen Police Department’s experience shows, they can be effectively integrated into a police vehicle fleet. At the very least, the ability to reduce carbon emissions, drastically reduce fuel costs and reduce our dependence on foreign fuel sources makes these technologies worthy of consideration in general. If they can do all of this while providing police-worthy vehicles, there’s a compelling argument for the consideration of full-electric and hybrid vehicles in law enforcement.
1 A series hybrid system is one in which the electric motor always powers the drive wheels of the vehicle, but an on-board gasoline engine is used to recharge the battery pack or to directly drive an electric generator for propulsion. Example: Chevrolet Volt.
2 A parallel hybrid system uses both the battery pack and the gasoline engine to power the vehicle simultaneously. Example: Honda Civic.
3 A series-parallel hybrid system can run on battery power and/or the gasoline engine, depending on the power demand. Often considered the “best of both worlds,” series-parallel hybrids are popular because they can get excellent in-town mpg, but also have great power for freeway use. Example: Ford Fusion, which can run up to 47 mph on battery power alone, then defers to its gasoline engine for higher speeds and power demands.