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EV Basics

Key Terms | Types of Electric Cars | Items of Interest

Electric Car Compendium (updated Aug 2009)

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Key Terms:

Motor. A motor is an electro-mechanical device that is powered by electrical energy.

Back in the early days of the automobile (1890-1905), most cars were electric, and in those heady days of this new personal freedom technology, “motoring”, and a car driven by a “motorist” powered by a “motor” became popular terminology. When the internal combustion engine became dominant in the early teens, the term motor simply held on in common use. Today there are many examples of businesses with “Motors” in their names that have never used one in their vehicles. However, that is changing at companies such as General Motors and Mitsubishi Motors.

AER or All Electric Range. That portion of automobile travel driven solely from battery supplied electricity, recharged by grid power.

Traction Pack.

This is the large set of batteries that provides the high voltage, high amperage electrical energy to power the car. It also provides power to the standard 12V battery in every vehicle used to power all the accessories, lights, and instrumentation. Traction packs are charged from the grid when parked, and also through regenerative braking while driving.

MPGe.

Since electric cars don’t burn any fuel, there are no “gallons” in the battery pack. MPGe is the equivalent efficiency of a electric vehicle when compared to equal amounts of energy. It is debatable whether a refined energy source like electricity can really be compared to an explosive liquid, however, the equivalent energy of a gallon of gasoline is approximately 34KWh of electricity. For electric cars, MPGe can be greater than the amount of electricity charged into the battery pack through the energy recovery gained in regenerative braking. Regenerative braking is most effective in city driving, and least effective for highway driving. This is one of the explanations that the Chevrolet Volt claims 230MPGe in city driving, when they also offer the statistics that 25KWh of energy will power the car about 100 miles. (25KWh for 100 miles, without “re-gen”, is approximately 134MPGe). Exactly how they got to 230MPGe is in the details of EPA measurement techniques.

ICE

An abbreviation commonly used by electric car enthusiasts to refer to internal combustion engine cars.

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Types of Electric Cars:

Full Performance Electric.

Those electric vehicles commercially produced to meet all high speed crash test requirements, or conversions of ICE production cars. These cars typically outperform any ICE car off the line, and have no top speed limitations imposed on them by regulation, other than posted speed limits and technical specifications of the electric drive system used.

Low Speed Vehicles (LSV) or Neighbourhood Electric Vehicles(NEV).

Typically created by small start-up companies, these vehicles became popular in the 1990s as relatively inexpensive vehicles that could enjoy the benefits of electric propulsion in the dearth of electric car offerings by the major auto makers. Without full high speed testing, regulators allowed them to be on the road (45 States and various municipalities in British Columbia) with the provision that they are governed not to exceed 40KMH in Canada, and 35MPH or 45MPH (Medium Speed Vehicle states) in various jurisdictions in the USA. While these cars are not a full substitute for ICE cars, they are perfectly suited to neighbourhood or campus use, or for new drivers learning to drive and the rules of the road. (I’d be happy to allow my teenager to use these instead of my full-performance electric car!)

Hybrids.

In the late 1990’s the hybrid vehicles recommenced production after a ninety year hiatus. In hybrids, an electric motor and a small traction pack strategically support the ICE providing significant energy efficiency and emissions control benefits. The leading hybrid vehicles include the Toyota Prius, Honda Insight, and the Ford Escape. The mating of the electric motor to the ICE provides the opportunity to have a smaller ICE installed than normal, and the ability to turn off the ICE entirely when the car is stopped at an intersection, coasting, or braking. Additional energy is collected from regenerative braking by the motor, and this in turn boosts overall efficiency. It also provides up to three times more brake life than in conventional ICE cars. However, all of the energy of hybrids come from the gas tank. No grid electricity is supplied directly to the vehicle.

Plug-in Hybrids.

Plug-in hybrids are modified gasoline/electric hybrid cars that have larger battery packs that are designed to discharge energy and not be recharged by the ICE. Therefore, they benefit from the first 40-60kms from grid supplied electricity. Commuters who don’t normally go more than 50kms per day may never have to touch the energy stored in their gas tank. (But then, why buy all that extra machinery if you are not going to use it?) Plug-in hybrids are a dramatic improvement for GHG emissions and reduction of fuel use. However, they have the drawback of having two drive systems in a vehicle, when ultimately, you may only need one.

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Electric Car - Items of Interest:

Efficiency of Motors.

Battery powered motors are about 80% efficient in transforming energy into wheel torque. Grid tied motors (electric trains, trolley buses, streetcars) are 90% efficient, the difference being the losses in storage batteries. Even when you plug your electric car into the dirtiest grid in North America (Alberta at 978g CO2 per KWh - 2005) the overall emissions are still slightly less than those of a conventional ICE car. The conventional ICE is at best 25% efficient, with the diesel, slightly more. Fuel cell vehicles (electric vehicles with a fuel cell, instead of a battery) are approximately 50% efficient. You too can be an expert on drive train efficiency – all you need to know is this: If there is an abundance of heat coming off the process, or from the friction brakes, you know that the process is creating excess waste heat, instead of wheel torque.

Electricity in North America.

In North America, there are very few places that do not have electricity. In the most remote off-grid areas, cost effective photo-voltaics and wind turbines are popping up everywhere to fill the void. To be sure, electricity is the energy source of the future. As renewable energy continues to form a greater proportion of grid sourced electricity, our grid is becoming greener. Therefore it makes sense to shift from fossil fuels to electric for powering many of our transportation vehicles.

How much do we need to run all cars on electricity?

Because motors use approximately ¼ the equivalent energy of ICE cars, a lot less than most people think. Here in British Columbia, we have approximately 3.2 million automobiles. It has been estimated that if all of these were converted to electric today, the additional electric energy required would be an 18% increase. Where is the best place to get this from? In a word – conservation. While BC can be proud of the large and CO2 free hydro electric plants we have here, all that cheap electricity for the last 50 years have allowed building codes to be the most lax in the developed world. We have endless number of buildings that have electric lights that burn 24x7 whether or not the light is being used. We have such a huge install base of wasteful electric baseboard heaters that we have the unique distinction that our peak power periods are not during the day or late afternoon, but in the evenings and mornings of the winter months, when the Province warms their homes and businesses. Since it will take decades to convert all our cars to electric, the incremental load increase in future years should not be hard for utilities to handle, since most electric charging will occur during the night.

Charging in Public Spots – Regular Electric Outlets.

Most people charge their electric cars at home, like they do their cell phones. They know when they leave in the morning how far they typically travel and plan their next charge accordingly. Away from home base, public charging outlets are harder to come by, however many business parkades or parking lots have the odd receptacle available for charging. There is yet to be an established protocol for electric car users for compensating the owners of electric outlet energy use. A key problem is the value of the electricity consumed is relatively trivial. For instance the maximum a regular 120V outlet can deliver is approximately 1 KWh per hour. In British Columbia that means 6-8¢ per hour. Where paid parking is in effect a marginal premium to the hourly rate for E-Car spots with outlets will solve this problem. In most parts of Canada and the northern states away from the west coast many parking lots have block-heater outlets which can also be utilized to charge vehicles.

Charging in Public Spots – Dedicated EV Charging.

Commercial charging stations (Better Place, ShorePoint, Coulomb) are becoming more prolific. These include smart billing and account management features for both the operator/franchisee, and the electric car user. As more and more of these stations appear along our highways and popular driving destinations, more and more recharging options will become available for the modern “motorist”. Many retail businesses have installed charge points (a regular outlet, or commercial charge station) as a way to attract those progressive individuals that make up their target markets. In California, solar electric PV arrays are commonly used as carports providing both shade, and charging outlets for those cars utilizing plug-in technology.

Charging Times with Standard Electrical Outlets.

There is yet to be a definitive standard adopted for the electric car. It’s still a little early, however it is likely that SAE J1772 will likely be a contender. What is that? It’s a 220V electrical service with data communications link. Think of it as the same energy you can get from your dryer plug and your ethernet/internet connection at the same time. The future will be very interesting. For the moment, conversions and commercially produced vehicles coming shortly can all be charged from these standard electrical outlet configurations within the existing electrical code in Canada [20KWh charge time]: 120V-15A duplex (Standard outlet) [20hrs]; 120V-20A (Canadian Electric Code s86 for electric car charging)[11hrs]; 220V-30A (Dryer)[4hrs]; 220V-50A (Stove)[2.5hrs]. Proprietary chargers offered by vehicle manufacturers and other commercial charging stations provide up to 220V-70A (such as the Tesla roadster). Europe has adopted a 400V standard which will be even faster. In North America the top charging rates are expected to occur at 450V, however the cars with chargers to handle this power are not in use outside development labs at this point.

Typical Range of Electric Cars.

Typical traction packs for full performance electric cars have usable storage capacities ranging from 10 to 50KWh of energy. The typical electric car will use 200Wh per km in average driving; therefore, electric car range can vary from 50-400km. See the next section for an explanation of the other variables.

What Determines Range?

Range is a function of many things. For the car itself, lighter, smaller, and more aerodynamic cars, require less energy to drive. Drive train efficiency (components, batteries), and driving conditions (city or highway, hills or flat) will also impact range. Given these variables, the final range determinant is the quantity of energy storage available in the traction pack. Traction pack batteries can use various technologies: Lead Acid, Nickel Metal Hydride and Lithium Ion are the most common. Lithium Ion is currently is the leading technology for energy density and range. There is a rainbow of Li-ion technologies being commercialized and developed currently. In addition new technologies utilizing molten Nickel Sodium and solid state ultra-capacitors offer potentially viable options for electric cars.

Performance.

The first contemporary production electric car of note, the Tesla, goes 0-60MPG in 3.7 seconds. This is faster than any other factory ICE vehicle, no matter what its pedigree. Need we say more? You can have less if you like.

A discussion on the cost of Electric Cars.

The price of any new technology has always been high. Do any of you remember the first PC’s in 1983? They were $10K, but they came down in price and performance increased dramatically in the first 10 years. The electric car will be no different. However unlike PC’s electric cars will offer much more value to consumers in that they will be much more durable. Because they will likely outlast ICE cars many times over, and will require virtually no maintenance over their lifetime they will hold value, and even increase in value over time, with inflation. Batteries in the first few years will be the unknown. Most are expected to last in the order of 10 years, however with new technology, you can never be sure. One thing that is certain is that in five years from now, battery technology will be greatly enhanced and costs will come down. Battery manufacturers are typically promising 3,000 cycles of charging before any serious degradation. If they are correct, 3,000 cycles should be 10 years of use. Some battery developers, such as Altair Nanotech are promising up to 15,000 cycles. Can you imaging a battery that lasts 50 years? Actually you don’t have to. Thomas Edison produced Nickel-Iron batteries back 100 years ago that can easily last that length of time and more. They packed 30% more energy than lead acid, but not a cost or energy density competitive option today. We may very well have this performance again in Lithium ion.

Current sampling of Production Car prices.

Tesla Roadster US$108K; Tesla S sedan (2010) US$57K; Mitsubishi MIEV (2010) CAD$40K; Dynasty IT (LSV-2008) $18K; BYD, China (2010) $22K est.; Aptera (2010) US$28K; Other offerings to look out for: Bright Automotive; Smith Trucks; Detroit Electric; Fiskar; Nissan; Renault; Subaru. (GM, Ford and Chrysler are all offering plug-in hybrids)

Cost of Converting and ICE to Electric.

There are two ways to go. Expensive or less expensive. On the expensive option there are no limits. Single orders of high-end components have high list prices, or simply unavailable from suppliers, who are typically interested in supplying the emerging commercial electric car industry. In this category you will find AC and Brushless DC motors with regenerative braking, fast chargers, and large capacity lithium ion battery packs with sophisticated battery management systems to protect your investment in energy storage. In the less expensive category, DC motors and lead acid batteries thrive – conversion kits and components are all readily available, and relatively easy to install for the DIY mechanically inclined. (But always consult a certified electrician for electrical components and connections!) The trade-off of the less expensive option will be performance, range, and driving experience, however, these vehicles make a very acceptable, economical and pleasing vehicle, knowing that you are driving with a light touch on the environment and passing by all those gas stations.