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An important measurement of your vehicle’s efficiency is understanding the cost per mile of your daily driving. For a gasoline vehicle, one merely divides the cost of a gallon of gasoline by the miles-per-gallon the vehicle gets to determine cost per mile. As we move into the electric vehicle era, determining a vehicle’s operating cost becomes more complicated. That’s because an electric vehicle’s cost per mile can depend on many factors that influence what you pay for charging its batteries – the price of electricity, the length of time it takes to charge, time of day, how close to ‘full’ the battery is, and even an EV’s onboard charger capabilities. Cost can also vary considerably based on whether you charge at home or at public chargers.

We’ll guide you through the process of understanding electric vehicle charging and how this directly impacts driving costs. Just a note, though, that our calculations focus on battery electric vehicles (EVs) and plugin hybrid electric vehicles (PHEVs) when running solely on battery power. Because things get more complicated when the gasoline engine of a PHEV is operating, this is not covered here.

CRUNCHING THE NUMBERS Electric vehicle energy use is measured in terms of kilowatt hours per 100 miles (kWh/100 miles). This would be like gallons per 100 miles in a gasoline vehicle. The Environmental Protection Agency (EPA) includes this number on the window stickers of plug-in vehicles along with their estimated miles per gallon equivalent (MPGe), since we’re so used to a gas vehicle’s mpg rating as an efficiency reference. EPA determines MPGe by assuming a gallon of gasoline is equivalent to 33.7 kWh of electrical energy (MPGe = 3370/kWh/100).

So how do you determine what each mile of driving costs in your electric vehicle? Let’s do an example. The cost of electricity in a sample California city is about 15 cents per kWh ($0.15/kWh). If a current model Kia Soul Electric with an EPA rating of 31 kWh/100 miles was charged here, it would cost $4.65 to travel 100 miles. This translates to $0.15/ kWh x 31 kWh/100 miles = $4.65/100, or 4.65 cents per mile.

Gasoline prices in the U.S. vary considerably depending on markets and world events. In recent times, that range was between $3 to $4 per gallon, while the average price of electricity ranged from $0.095/kWh in Louisiana to $0.31/ kWh in Hawaii. Even within a state the rate depends on what a specific utility charges, which can differ substantially. Thus, the cost to drive an electric Kia Soul could range from 2.95 to 9.6 cents per mile. In comparison, the cost of driving a gasoline Soul could range from 10.0 to 13.3 cents per mile.

CHARGING AT HOME Unlike gasoline, the price of electricity can vary not only by location, but the time of day it is used. Utilities typically have two types of rate plans – level-of-use and time-of-use. With level-of-use, the price rises with the amount of electricity used. Here, the last kilowatt used in a month could cost more than the first one, which would most likely be the case for electric vehicle owners. With time-of-use, utilities divide a day into peak, off-peak, and sometimes a mid-peak period. Some utilities have as many as six time-of-use periods. In any case, electricity is most expensive during peak usage times, usually in the morning, late afternoon, and early evening. Others offer a lower rate for EV charging than the rest of a home’s electrical service, but the savings may not amortize out considering the fee charged for installing a separate meter. Additionally, many offer the option of a special EV rate plan that can make the cost of charging an electric vehicle more financially favorable.

You can charge an EV or PHEV using Level 1 household 110 volt current using a portable charger often provided with a plug-in model, with the charger powered via a standard wall outlet. Typically, electricity is supplied at a 1.4 kW rate. This is workable for topping off batteries after limited daytime driving where little battery power was used, but the time required for charging a fully depleted battery can be considerable. For example, to charge a Chevy Bolt’s 66 kWh battery to 80 percent state of charge (SOC) with Level 1 charging would take about 38 hours…far too long for most drivers. This time is reduced to about 7 hours with a Level 2 charger at 240 volts and a 7.2 kW charging rate. Level 2 charging is recommended for any vehicle with a battery capacity larger than 10 kWh.

While the latest generation EVs and some PHEVs have the capability to fast-charge to 80 percent SOC in a half-hour or less at a Level 3 and above charging rate, Level 3 charging is not available for homes since this requires 480 volt electrical service. In all cases it’s important to avoid discharging EV batteries to near-zero percent SOC to avoid diminishing battery longevity.

Charging at home at a more convenient Level 2 rate requires special Electric Vehicle Supply Equipment (EVSE). These wall or portable chargers cost between $200 to $1000, with wall chargers also requiring installation that can run from $800 to $1300. Most automakers offering EVs and PHEVs have a recommended EVSE provider, but there are many companies selling EVSEs.

In penciling out the financial benefit of a plug-in vehicle, your number crunching should include the cost of the EVSE. For example, if an EVSE costs $1500 installed and you plan to drive an EV 75,000 miles over a five year period, the EVSE’s amortized cost will be 2 cents per mile. Since most people will likely drive their EV for many more years, amortized EVSE cost could be much lower.

While the overall cost of driving electric can vary widely depending on vehicle purchase or lease cost, electricity rates, EVSE and installation cost, and the length of time an EV is driven, as a general rule owning and operating an EV will be less than that of an equivalent gasoline vehicle.

The driving range of electric vehicles is becoming less of an issue as they surpass 200 miles or greater, approaching the distance between fill-ups of some internal combustion engine vehicles…or maybe the bladder capacity of their drivers. However, the time it takes to recharge an EV is still a negative attribute.

Generally, EVs charge at a fairly slow rate. A 240-volt Level 2 home or public charger will charge a Chevy Bolt from depleted to full in about 4 1/2 hours, providing a range of about 238 miles. That’s a far cry from 5 minutes to fill a gas tank. It’s significantly slower when charging a Bolt with a Level 1 charger using a household’s standard 120-volt power since this adds only about 4 miles an hour!

Of course, charging companies and automakers are working together to expand the small-but-growing network of fast chargers in key areas of the country, allowing EVs to gain up to 90 miles of charge in around 30 minutes. Tesla claims that its Supercharger stations being upgraded to Version 3 can charge a Tesla Model 3 Long Range at the rate of about 15 miles a minute, or 225 miles in just over 15 minutes under best conditions.

If current technology EVs become popular for mid- to long-range travel, gasoline stations, truck stops, and public charging stations equipped with Level 2 and even somewhat faster chargers run the very real risk of becoming parking lots.

Photo: EVgo

When it comes to charging EVs, charging times come down to kilowatts available. The best Tesla V3 charger is rated at 250 kilowatts peak charge rate. Now, much research is being done here and in other countries on what is called Extreme Fast Charging (XFC) involving charge rates of 350-400 kilowatts or more. The U.S. Department of Energy is sponsoring several projects aimed at reducing battery pack costs, increasing range, and reducing charging times.

There are several challenges for XFCs. First, when lithium-ion (Li-ion) batteries are fast charged, they can deteriorate and overheat. Tesla already limits the number of fast charges by its standard Superchargers because of battery degradation, and that’s only at 120-150 kilowatts. Also, when kilowatt charging rates increase voltage and/or amperage increases, which can have a detrimental effect on cables and electronics.

This begs the question: Is the current electrical infrastructure capable of supporting widespread use of EVs? Then, the larger question is whether the infrastructure is capable of handling XFC with charging rates of 350 kilowatts or more. This is most critical in urban areas with large numbers of EVs and in rural areas with limited electric infrastructure.

The answer is no. Modern grid infrastructures are not designed to supply electricity at a 350+ kilowatt rate, so costly grid upgrades would be required. Additionally, communities would be disrupted when new cables and substations have to be installed. There would be a need for costly and time-consuming environmental studies.

One approach being is XFC technology being developed by Zap&Go in the UK and Charlotte, North Carolina. The heart of Zap&Go's XFC is carbon-ion (C-Ion) energy storage cells using nanostructured carbons and ionic liquid-based electrolytes. C-Ion cells provide higher energy densities than conventional supercapacitors with charging rates 10 times faster than current superchargers. Supercapacitors and superchargers are several technologies being considered for XFCs.

According to Zap&Go, the C-Ion cells do not overheat and since they do not use lithium, cobalt, or any materials that can catch fire, there is no fire danger. Plus, they can be recycled at the end of their life, which is about 30 years. Zap&Go's business model would use its chargers to store electric energy at night and at off-peak times, so the current grid could still be used. Electrical energy would be stored in underground reservoirs similar to how gasoline and diesel fuels are now stored at filling stations. EVs would then be charged from the stored energy, not directly from the grid, in about the same time it takes to refuel with gasoline.

The fastest charging would work best if C-Ion cell batteries are installed in an EV, replacing Li-ion batteries. EVs with Li-ion batteries could also be charged, but not as quickly. Alternatively, on-board XFC cells could be charged in about five minutes, then they would charge an EV’s Li-ion batteries at a slower rate while the vehicle is driven, thereby preserving the life of the Li-ion battery. The downside is that this would add weight, consume more room, and add complexity. Zap&Go plans to set up a network of 500 ultrafast-charge charging points at filling stations across the UK.

General Motors is partnering with Delta Electronics, DOE, and others to develop XFSs using solid-state transformer technology. Providing up to 400 kilowatts of power, the system would let properly equipped electric vehicles add 180 miles of range in about 10 minutes. Since the average American drives less than 30 miles a day, a single charge could provide a week’s worth of driving.

The extreme charging time issue might be partly solved by something already available: Plug-in hybrid electric vehicles (PHEVs). As governments around the world consider banning or restricting new gasoline vehicles in favor of electric vehicles, they should not exclude PHEVs. Perhaps PHEVs could be designed so their internal combustion engines could not operate until their batteries were depleted, or their navigation system determines where they could legally operate on electric or combustion power.

ron-cogan-capitol-hillCharging your electric vehicle used to be an easy thing, at least in many areas where electrification has long been promoted. Public chargers were installed in high-profile areas like shopping centers, parking garages, and at the workplace. For the longest time, it wasn’t unusual to see these chargers go unused for long periods of time. Green Car Journal editors experienced this first-hand for many years during our daily travels with plug-in test cars.

Often enough, ours was the only electric vehicle plugged in at a bank of four chargers at a local commercial center in our city. It was the same story in the parking garage downtown. But that’s changed, signifying both the positives and the challenges of a plug-in vehicle market that’s gathering momentum, and numbers. These days those chargers are often occupied when we pull up. Like most places, there simply don’t seem to be enough chargers to go around.

Many have heard about incidents at Tesla Supercharger sites, places where you can top off 80 percent of your battery charge in 30 minutes and then be on your way. The problem is, not everyone plugs in and then moves on. Superchargers, and chargers in general, are often located in areas where businesses are nearby so the experience is convenient and there’s something to do while charging. Tesla, in fact, has hinted that it’s taking this further and exploring Supercharger sites with food and amenities for those charging up their cars.

To be sure, not everyone stops for a 30 minute cup of coffee while charging. Shopping experiences in nearby stores can take much longer than that, and if all chargers are being used with others waiting to top off before continuing their journey, long waits are a problem. At times that leaves EV drivers frustrated with those who leave their car plugged in long after their needed charge is complete. The result? An interesting phenomenon in recent years called ‘charge rage.’

charging-at-two-chargersThis isn’t unique to Superchargers or to public charging sites. Workplaces can have similar experiences as employees in increasing numbers step up to battery electric and plug-in hybrids. They’re encouraged to do so not only to drive ‘greener,’ but also to benefit from shorter commutes in states that allow solo EV drivers in high occupancy vehicle (carpool) lanes. That privilege alone has spurred many commuters to go electric. Time isn’t just money. It’s also…time. Spending a half-hour less each way during the daily commute is worth more than money in many respects. And once the commute is done, it’s time to charge.

Most companies offering chargers have limited numbers and often site these in favorable parking areas close to the workplace, further encouraging employees to go electric. It’s good for a company’s image and it’s the right thing to do. That said, expecting employees to free up a charger after a few hours and move their car farther out in an expansive parking lot is asking a lot, human nature being what it is.

charging-bankConsider, too, charging sites at public parking garages adjacent to convention centers and other venues. Those who plug in while attending a conference of expo aren’t likely to return after an hour or two to unplug and move to another less convenient parking spot. With a limited number of charging spots available, other EV drivers counting on a range-extending charge aren’t likely to be pleased if all charging spots are taken.

Yes, there’s change afoot. Charging companies, automakers, utilities, and both state and local governments are striving to install an exponentially larger number of public chargers to alleviate the problem and keep pace with the growing number of plug-in vehicles on the road. But it hasn’t been fast enough…certainly not at a pace that’s keeping up with the larger number of electric vehicles on the road today.

charging

Drivers have long been promised perks like free public charging, access to carpool lanes with a single occupant in an electric vehicle, and favorable parking with charging available, all to encourage them to go step up to a battery electric or plug-in hybrid vehicle. While not disappearing, these perks are getting harder to realize. And that’s not a good thing for the electric vehicles and the industry as a whole.

ron-cogan-capitol-hillWill electrified vehicles dominate our highways in the future? It’s a question on the minds of many these days as an increasing number of battery electric and plug-in hybrid models come to new car showrooms. The answer is not an easy one, especially since there’s the potential that future CAFE (Corporate Average Fuel Economy) requirements could be modified. CAFE has been a driving force in the accelerated research and development in plug-in vehicles and new model introductions.

Automakers as a whole have said the current CAFE requirement of 54.5 mpg by 2025 cannot be achieved without a serious emphasis on electrification and the efficiencies these models bring. Thus, there has been an undeniable momentum for plug-ins underway as witnessed by the 39 battery electric and plug-in hybrid models from 20 automotive brands available in the U.S. market during calendar year 2017.

It has been a long path to get to this point since modern electrics emerged in the early 1990s. Along the way, early battery electric vehicles have been constrained by the limitations imposed by the very nature of battery electric propulsion. Simply, batteries are very heavy and costly, which result in two distinct penalties – greater weight that saps overall efficiency and high production costs that either make these vehicles expensive to buy, or require automakers to absorb much of these costs.

Those were the issues in the 1990s and, not coincidentally, these remain the issues today. Battery electric cars in 2017 are an order of magnitude better than those of a few decades back. But driving range and cost remain significant challenges. Plug-in hybrids are another matter.

Since these offer both all-electric driving and hybrid operation after batteries are depleted, there is no ‘range anxiety’ – the concern that a battery electric vehicle’s battery power could be insufficient for daily driving needs. Automakers are into plug-in hybrids in a big way and this has become a very competitive part of the automotive landscape.

So what does our driving future hold? There are nearly 40 plug-in vehicles for sale this year and that’s a big statement. Most major automakers have thriving electric research and development programs underway with electric model launches of one type or another in the pipeline. We will see an expanding offering of plug-in hybrids with battery electric models featuring greater driving range, as witnessed by the benchmarks being set by Chevrolet and Tesla and the new commitment to electrics by Volvo.

One wild card is that internal combustion continues to achieve surprising efficiency gains, at reasonable cost compared to electrics. That means the combustion vehicles we’ve had on our roads for more than a century will continue to ply our highways for some time to come, at approachable cost and without the need for the federal and state incentives that now help motivate buyers to go electric.

Still, there’s a growing desire for the emissions and inherent efficiencies of electric drive so there’s every reason to expect this interest to increase. We don’t yet know if plug-in vehicles of one stripe or another will dominate the market in the years ahead. But what is clear is that electrification is poised to play a major role moving forward.

bmw-13-chargingA movement to reduce air pollution and encourage alternative fuel transportation to National Parks has been launched by the National Park Foundation, National Park Service, Department of Energy, and BMW of North America. The first of up to 100 electric vehicle charging stations in national parks and nearby communities has just been launched at Thomas Edison National Historical Park in West Orange, New Jersey.

An integrated team from the public-private partnership is identifying park locations for more charging stations, taking into consideration distance from nearby charging locations, natural and cultural landscape considerations, and proximity and strength of EV markets. Already, dozens of parks are exploring site options. This partnership supports the National Park Foundation’s Centennial Campaign for America’s National Parks.

2017 Chevrolet Bolt EVChevrolet’s milestone Bolt EV will be coming to showrooms in late 2016 as a 2017 model, representing the first truly affordable battery electric vehicle with a sought-after 200 mile driving range. This is a big win for Chevrolet since the Bolt beats the 200 mile Tesla Model 3 to market, likely by a long shot. Unlike the Chevy Spark EV, an adaptation of a gasoline-powered model that’s been available in select markets since 2013, the Bolt EV was designed from the ground-up as an electric vehicle. Thus, there are no compromises along the way.

The heart of the Bolt EV is a nickel-rich lithium-ion battery pack developed with LG Electronics. The 200 mile range provided by this pack is about twice that of competitive EVs now on the market. New battery chemistry delivers desired levels of power, in this case 160 kW, and energy of 60 kWh. The chemistry also provides improved thermal performance that requires a smaller active thermal conditioning system to keep the battery operating at its optimum temperature, delivering longer battery life and maintaining peak performance under varying climates and driver demands.

2017 Chevrolet Bolt EVThe battery pack consists of 288 lithium-ion cells in a configuration that spans the entire floor to maximize interior space. The five-door Bolt EV seats five passengers and has 16.9 cubic feet of cargo space behind the rear seat. Thin-frame seats enhance rear-seat roominess.

A standard 7.2 kilowatt onboard charger allows overnight charging from a 240 volt wall charger. A typical commute of 50 miles requires a charge of less than two hours. The Bolt also features an optional SAE Combo DC fast charging connector so the battery can be charged to deliver up to 90 miles of range in just 30 minutes at a public fast charger, if one is available.

2017 Chevrolet Bolt EVElectricity is supplied to a 200 horsepower drive motor featuring 266 lb-ft torque that delivers 0-60 mph acceleration under 7 seconds and a top speed of 91 mph. Power delivery is controlled by Chevrolet’s first Electronic Precision Shift system. This shift and park-by-wire system sends electronic signals to the Bolt EV’s drive unit to manage precise feel and delivery of power and torque based on drive mode selection and accelerator inputs. A by-wire shifter requires less packaging space than a traditional mechanical shifter resulting in more interior space and improved interior layout.

Regenerative braking has become more than a means to boost range by recapturing energy. Now it can also can provide an improved EV driving experience. The Bolt EV has a new regenerative braking system that can provide one pedal driving through a combination of increased regenerative deceleration and software controls. When operating in Low mode or by holding the Regen-on-Demand paddle located on the back of the steering wheel, a driver can bring the vehicle to a complete stop under most circumstances by simply lifting their foot off the accelerator. However, the system does not eliminate the need to use the brake pedal altogether. Operating in Drive mode without pulling the paddle while decelerating requires using the brake pedal to stop.

2017 Chevrolet Bolt EVhe Bolt EV will offer connectivity and infotainment technologies that seamlessly integrate smartphones and other electronic devices. Low energy Bluetooth, designed specifically for the Bolt EV to minimize energy usage, seamlessly connects a smartphone to the car as an owner approaches the vehicle. Many of the Bolt’s technologies are supported by OnStar 4G LTE, which turns the Bolt EV into a Wi-Fi hotspot that provides easier access to apps and services via a high-speed wireless connection.

Additional connectivity and infotainment features include a 10.2-inch MyLink color touchscreen display, rear camera mirror, and Surround Vision that provides a bird’s-eye view around the Bolt for improved safety during low-speed driving and while parking. An all-new MyChevrolet Mobile App combines important owner and vehicle information and functions including battery charge status, OnStar Map service, remote start, cabin pre-conditioning, owner’s manual information, and dealer service scheduling. EV-specific navigation capability provides routes that maximize range and while identifying nearby charging locations. In the future an accurate driving range projection will be based on the time of day, topography, weather, and an owner’s driving habits.

2017 Chevrolet Bolt EVThe Bolt will be built at GM’s Orion, Michigan assembly facility while its battery pack, motor, and drive components will come from Korea. Its price is expected to be $37,500, a figure that dips below $30,000 after full federal tax credits.

 

There’s something almost magical about plugging your car into an outlet at night and waking up to a full ‘tank’ in the morning. There’s no need for a stop at the gas station, ever. Plus, there’s no nagging guilt that the miles metered out by the odometer are counting off one’s contribution toward any societal and environmental ills attendant with fossil fuel use.

This is a feeling experienced during the year Green Car Journal editors drove GM’s remarkable EV1 electric car in the late 1990s. Daily drives in the EV1 were a joy. The car was sleek, high-tech, distinctive, and with the electric motor’s torque coming on from zero rpm, decidedly fast. That’s a potent combination.

ev1-rolling-chassis-1The EV1 is long gone, not because people or companies ‘killed’ it as the so-called documentary Who Killed the Electric Car suggested, but rather because extraordinarily high costs and a challenging business case were its demise. GM lost many tens of thousands of dollars on every EV1 it built, as did other automakers complying with California’s Zero EmissionsVehicle (ZEV) mandate in the 1990s.

Even today, Fiat Chrysler CEO Sergio Marchionne says his company loses $14,000 for every Fiat 500e electric car sold. Combine that with today’s need for an additional $7,500 federal tax credit and up to $6,000 in subsidies from some states to encourage EV purchases, and it’s easy to see why the electric car remains such a challenge.

Fiat 500 BEV

This isn’t to say that electric cars are the wrong idea. On the contrary, they are perceived as important to our driving future, so much so that government, automakers, and their suppliers see electrification as key to meeting mandated 2025 fleet-wide fuel economy requirements and CO2 reduction goals. The problem is that there’s no singular, defined roadmap for getting there because costs, market penetration, and all-important political support are future unknowns.

The advantages of battery electric vehicles are well known – extremely low per-mile operating costs on electricity, less maintenance, at-home fueling, and of course no petroleum use. Add in the many societal incentives available such as solo driving in carpool lanes, preferential parking, and free public charging, and the case for electrics gets even more compelling. If a homeowner’s solar array is offsetting the electricity used to energize a car’s batteries for daily drives, then all the better. This is the ideal scenario for a battery electric car. Of course, things are never this simple, otherwise we would all be driving electric.

Ford Focus ElectricThere remain some very real challenges. Government regulation, not market forces, has largely been driving the development of the modern electric car. This is a good thing or bad, depending upon one’s perspective. The goal is admirable and to some, crucial – to enable driving with zero localized emissions, eliminate CO2 emissions, reduce oil dependence, and drive on an energy source created from diverse resources that can be sustainable. Where’s the downside in that?

Still, new car buyers have not stepped up to buy battery electric cars in expected, or perhaps hoped-for, numbers, especially the million electric vehicles that Washington had set out as its goal by 2015. This is surprising to many since electric vehicle choices have expanded in recent years. However, there are reasons for this.

RAV4 EV Action Right

Electric cars are often quite expensive in comparison to their gasoline-powered counterparts, although government and manufacturer subsidies can bring these costs down. Importantly, EVs offer less functionality than conventional cars because of limited driving range that averages about 70 to 100 miles before requiring a charge. While this zero-emission range can fit the commuting needs of many two-vehicle households and bring substantial fuel savings, there’s a catch. Factoring future fuel savings into a vehicle purchase decision is simply not intuitive to new car buyers today.

Many drivers who would potentially step up to electric vehicle ownership can’t do so because most electric models are sold only in California or a select number of ‘green’ states where required zero emission vehicle credits are earned. These states also tend to have at least a modest charging infrastructure in place. Manufacturers selling exclusively in these limited markets typically commit to only small build numbers, making these EVs fairly insignificant in influencing electric vehicle market penetration.

bmw-i3

Battery electric vehicles available today include the BMW i3, BMW i8, Chevrolet Spark EV, Fiat 500e, Ford Focus Electric, Honda Fit EV, Kia Soul EV, Mercedes-Benz B-Class Electric Drive, Mitsubishi i-MiEV, Nissan LEAF, Smart ForTwo Electric Drive, Tesla Model S, Toyota RAV4 EV, and VW e-Golf. While most aim at limited sales, some like BMW, Nissan, and Tesla market their EVs nationwide. The Honda Fit EV and Toyota RAV4 EV are being phased out. Fleet-focused EVs are also being offered by a small number of independent companies. Other battery electrics are coming.

BMW’s i3 offers buyers an optional two-cylinder gasoline range extender that generates on-board electricity to double this electric car’s battery electric driving range. A growing number of electrified models like the current generation Prius Plug-In and Chevy Volt can also run exclusively on battery power for a more limited number of miles (10-15 for the Prius and up to 40 miles in the Volt), and then drive farther with the aid of a combustion engine or engine-generator. Both will offer greater all-electric driving range when they emerge as all-new 2016 models. Many extended range electric vehicles and plug-in hybrids like these are coming soon from a surprising number of auto manufacturers.

coda-evIt has been an especially tough road for independent or would-be automakers intent on introducing electric vehicles to the market. Well-funded efforts like Coda Automotive failed, as have many lesser ones over the years. Often enough, inventors of electric cars have been innovative and visionary, only to discover that becoming an auto manufacturer is hugely expensive and more challenging than imagined. In many cases their timeline from concept and investment to production and sales becomes so long that before their first cars are produced, mainstream automakers have introduced models far beyond what they were offering, and at lesser cost with an established sales and service network to support them.

A high profile exception is Tesla Motors, the well-funded Silicon Valley automaker that successfully built and sold its $112,000 electric Tesla Roadster, continued its success with the acclaimed $70,000-$100,000+ Model S electric sedan, and will soon deliver its first Tesla Model X electric crossovers. While Tesla has said it would offer the Model X at a price similar to that of the Model S, initial deliveries of the limited Model X Signature Series will cost a reported $132,000-$144,000. It has not yet been announced when lower cost 'standard' Model X examples will begin deliveries to Tesla's sizable customer pre-order list.

tesla-model-sTesla’s challenge is not to prove it can produce compelling battery electric cars, provide remarkable all-electric driving range, or build a wildly enthusiastic – some would say fanatical – customer base. It has done all this. Its challenge is to continue this momentum by developing a full model lineup that includes a promised affordable model for the masses, its Model 3, at a targeted $35,000 price tag. It will be interesting to see if the Model 3 ultimately comes to market at that price point.

This is no easy thing. Battery costs remain very high and, in fact, Tesla previously shared that the Tesla Roadster’s battery pack cost in the vicinity of $30,000. While you can bury the cost of an expensive battery pack in a high-end electric car that costs $70,000 to over $100,000, you can’t do that today in a $35,000 model, at least not one that isn’t manufacturer subsidized and provides the 200+ mile range expected of a Tesla.

tesla-model-xThe company’s answer is a $5 billion ‘Gigafactory’ being built in Nevada that it claims will produce more lithium-ion batteries by 2020 than were produced worldwide in 2013. The company’s publicized goal is to trim battery costs by at least 30 percent to make its $35,000 electric car a reality and support its growing electric car manufacturing. Tesla has said it’s essential that the Gigafactory is in production as the Model 3 begins manufacturing. The billion dollar question is…can they really achieve the ambitious battery and production cost targets to do this over the next few years, or will this path lead to the delays that Tesla previously experienced with the Tesla Roadster, Model S, and Model X?

Tesla is well-underway with its goal of building out a national infrastructure of SuperCharger fast-charge stations along major transportation corridors to enable extended all-electric driving. These allow Tesla vehicles the ability to gain a 50 percent charge in about 20 minutes, although they are not compatible with other EVs. For all others, Bosch is undertaking a limited deployment of its sub-$10,000 DC fast charger that provides an 80 percent charge in 30 minutes. A joint effort by ChargePoint, BMW, and VW also aims to create express charging corridors with fast-charge capability on major routes along both coasts in the U.S.

chargepoint-chargerThe past 25 years have not secured a future for the battery electric car, but things are looking up. The next 10 years are crucial as cost, infrastructure, and consumer acceptance challenges are tackled and hopefully overcome to make affordable, unsubsidized electric cars a mass-market reality. It is a considerable challenge. Clearly, a lot of people are counting on it.

Der neue Volkswagen e-GolfVolkswagen has called for greater state and federal government support to bolster the next level of adoption of electric vehicles. At the 2015 Electric Drive Congress in Washington D.C., VW product marketing and strategy VP Jörg Sommer pointed out that automakers have largely delivered the electric vehicles that can satisfy the needs of most drivers, but also said more is needed. VW is investing $10 million in electric vehicle charging infrastructure by 2016 with other companies and industries also making significant EV infrastructure investments. Still, Sommer says that continuing legislative support is needed to accomplish strategic electric vehicle goals.

Specifically, VW would like to see federal financing support for creating fast charge networks along interstate corridors and in urban areas. It is also calling for a greater commitment on the part of state and federal organizations to buy battery electric vehicles and plug-in hybrids, with federal purchasing guidelines that support this by giving fleet purchasers greater flexibility. Also on VW’s radar is additional congressional support with the mid-term review of EPA’s greenhouse gas regulation, with the aim of extending plug-in vehicle multiplier credits beyond the 2021 model year.

DC Fast ChargeExpanding the driving range capabilities of electric cars through fast charging is of growing interest. Tesla has keyed in on this with its high-profile Supercharger network of fast chargers along major transportation corridors. While this is great for Tesla owners, it’s not a comfort to drivers of other EVs since the SuperCharger network is not compatible with their cars.

Enter ChargePoint, VW, and BMW, which have joined together to offer similar capabilities for other electric vehicle models. The three are developing express electric vehicle charging corridors with fast charging stations that allow EV drivers to recapture up to an 80 percent charge in just 20 minutes. Fast charging sites will be strategically spaced no more than 50 miles apart to make longer trips possible for EVs that incorporate a DC fast charging capability.

Initial efforts will focus on heavily-traveled routes on the East and West Coasts, providing 100 DC fast chargers at existing ChargePoint sites. The aim is to expand fast charging capabilities to other sites within the ChargePoint network, which already offers more than 20,000 charging spots in North America. EV drivers can access the network with a ChargePoint or ChargeNow card or with the ChargePoint mobile app.

prius-plug-inPlug-in hybrid electric vehicles (PHEVs) combine the functionality of a gasoline-electric hybrid with the zero-emission capabilities of an all-electric vehicle. Unlike conventional hybrids that rely solely on an internal combustion engine and regenerative braking to charge their batteries, PHEVs also allow batteries to be charged through an electrical outlet or EV charging station.

A PHEV’s battery pack is significantly larger and more powerful than a conventional hybrid, but still quite smaller than that of a dedicated battery electric vehicle. Thus, a PHEV’s electric driving range is shorter than an electric vehicle. Still, the added functionality of 20 to 40 miles of zero-emission electric driving is a real plus to many hybrid owners.

2011 Chevrolet Volt Battery Animation

Examples of PHEVs already available to U.S. consumers include the BMW 13 and i8, Chevrolet Volt, Cadillac ELR, Ford C-MAX Energi, Ford Fusion Energi, Honda Accord Plug-in Hybrid, Porsche Panamera S E-Hybrid, and Toyota Prius Plug-In. Other PHEVs from various automakers are in the works.

The larger battery pack in a PHEV can add several thousand dollars to a hybrid’s purchase price. For example, Ford's Fusion and C-MAX Energi models use a 7.6 kilowatt-hour lithium-ion battery that provides about 21 miles of electric-only driving. This compares to the smaller and less expensive 1.4 kilowatt-hour battery in Ford hybrids without plug-in capability. The kilowatt-hour capacity of a battery is an indicator of the miles a PHEV can travel in electric-only mode, much like the gasoline in a conventional car's tank indicates its range.

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A PHEV’s greatest advantage is that driving range is not limited by the finite battery capacity carried on board, thus there is no ‘range anxiety.’ Once battery power is depleted, a PHEV reverts to conventional gasoline-hybrid operation or, depending on its configuration, powers its motors with electricity created by an on-board internal combustion engine-generator. For this reason, PHEVs are often called extended range electric vehicles (EREVs).

Calculating PHEV fuel economy is complicated due to differing operating modes – all-electric with no gasoline used, combined electric and gasoline use, and gasoline-only operation. Plus, series and parallel plug-in hybrids operate differently. For this reason, federal PHEV fuel economy labels have been established to illustrate a plug-in hybrid’s expected efficiency measured in miles-per-gallon (MPG) when running on gasoline-electric hybrid power and MPGe (miles-per-gallon equivalent) when running on electricity.

2015-green-car-of-the-year-logoOver the 10 year history of Green Car Journal’s Green Car of the Year award program, there has never been a battery electric car that has been compelling enough to be recognized as the best-of-the-best in an ever-expanding field of ‘green’ cars. That has changed with the groundbreaking BMW i3, Green Car Journal’s 2015 Green Car of the Year®.

The BMW i3 came out on top of a field of finalists that included the Audi A3 TDI, Chevrolet Impala Bi-Fuel, Honda Fit, and VW Golf. The array of technologies and fuels represented included high efficiency gasoline, electric drive, clean diesel, and natural gas.

bmw-13-action-rightBMW’s i3 stands out as one of the most innovative vehicles ever to be introduced by any major automaker. It breaks the mold – literally – with a strong and lightweight body using materials and technology at home on the race track, and now used for the first time to construct a mainstream production car. It is a milestone, forward-thinking approach.

Meeting both near-term and far-reaching goals is no easy thing. The challenge is to design and build cars that offer meaningful environmental achievement while delivering the traditional touchstones desired by new car buyers, among them comfort, safety, convenience, connectivity, performance, and value. Also important in the world of advanced vehicles like battery electric cars is a significant commitment to the manufacturing and sale of these vehicles that goes beyond a few thousand units sold in select geographical areas. BMW’s commitment with the i3 is focused not only nationally in the U.S., but globally as well.

bmw-i3-cutawayOffering a lightweight carbon fiber reinforced plastic (CFRP) body on an aluminum space frame, BMW’s innovative i3 brings environment-conscious drivers all-electric drive with an optional internal combustion range extender. The most unique aspect of the i3 is the car’s body structure, which incorporates the first-ever use of carbon fiber reinforced plastic (CFRP) to form the body and passenger cabin of a mass-production vehicle. CFRP is as strong as steel and 50 percent lighter. It is also 30 percent lighter than aluminum.

This BMW’s drive module includes an electric drivetrain, 5-link rear suspension, and an aluminum structure. Its lithium-ion battery pack is mounted mid-ship beneath the floor. Strategic placement of the 450 pound battery pack and drive components provides a very balanced 50-50 weight distribution to enhance handling and performance.

bmw-i3-dashAcceleration is crisp, with a 0-60 elapsed time of 7.2 seconds provided by an electric motor producing 170 horsepower and 184 lb-ft torque. With a curb weight of just 2,700 pounds, the i3 has is sprightly even at highway speeds. Strong regenerative braking characteristics often allow the i3 to be driven with just the accelerator pedal in city driving. When a driver lets off the accelerator, regen slows the car quickly and allows it to come to a complete stop without touching the brake pedal.

Charging at home with an available 220 volt charger delivers a full charge in about three hours. Where available, public DC fast charging can bring an i3 to 80 percent state-of-charge in 20 minutes and a full charge in 30 minutes. The i3 BEV features an 81 mile EPA estimated range on batteries. The i3 REx, equipped with an internal combustion range extender that creates on-board electricity as needed to help keep batteries charged, features a 72 mile battery driving range and 150 miles total with the range extender.

bmw-i3-chargingEfficiency is a given. EPA rates the i3’s city fuel economy at 137 MPGe (miles per gallon equivalent) and 111 MPGe on the highway, with a combined 124 MPGe. For the REx-equipped model, EPA rates mileage at 117 MPGe combined.

The 2015 Green Car of the Year® is selected by a majority vote of an award jury comprised of Green Car Journal staff and invited jurors, including TV personality and car aficionado Jay Leno plus leaders of the nation’s most high-profile environmental and efficiency organizations. These jurors include Jean-Michel Cousteau, president of Ocean Futures Society; Matt Petersen, board member of Global Green USA; Mindy Lubber, President of CERES; Kateri Callahan, President of the Alliance to Save Energy; and Dr. Alan Lloyd, President emeritus of the International Council on Clean Transportation.

bmw-i3-side-doorsThe diversity of new car models at showrooms today reflects an evolving and sophisticated market in which a growing number of new car buyers have decided that environmental performance must meet their needs and expectations, on their terms. As it happens, 2015 Green Car of the Year jurors have clearly decided that this year, the electric BMW i3 does it best.

 

It is an exciting time to be involved with the auto industry, or to be in the market for a new car. The auto industry has responded splendidly to the challenge of new emission, fuel economy, and safety standards. The public is offered a greater than ever selection of vehicles with different powertrains, lightweight materials, hybrids, and electric drive vehicles across many platforms. We see increasing numbers of clean diesel vehicles and natural gas is making a resurgence, especially in the heavy-duty sector.

alan-lloydThe positive response by the auto industry to the ever-tightening pollutant emission and fuel economy standards includes tactics such as the use of aluminum in the Ford F-150 and the increased use of carbon fiber by BMW, among many innovations introduced across many models and drivetrains. These evolutionary changes are a major tribute to the automobile engineers who are wringing out the most they can in efficiency and reduced emissions from gasoline and diesel engines. I view this evolutionary change as necessary, but not sufficient to meet our greenhouse gas goals by 2050.

New car ownership is currently down in Europe and is leveling off in the U.S. For global automotive manufacturers, however, this trend is offset by the dramatic growth in places like China and India. The potential for dramatic growth in the developing world is clearly evident: In the U.S., there are about 500 cars per thousand people, compared to about 60 and 20 in China and India, respectively.

How can these trends be reconciled with the environmental and health concerns due to climate change and adverse air quality in the developing world? The evidence for climate change accumulates by the day. Hazardous air quality in many major cities in China has drawn global attention, providing a visual reminder of how far the developed world has come and how much environmental protection needs to be accelerated in the developing world. Damaging air pollution is increasingly seen as a regional and even worldwide challenge. Dramatic economic growth in many developing countries is generating pollution that knows no boundaries. Air pollution from China, for example, fumigates Korea and Japan and is even transported across the Pacific to impact air quality in California and other Western states.

It will take a revolutionary change to provide personal mobility without unacceptable energy and environmental consequences. As a recent National Academy of Sciences (NAS) document states, it is likely that a major shift to electric drive vehicles would be required in the next 20 to 30 years. Electric drive vehicles, coupled with renewable energy, can achieve essentially zero carbon and conventional pollutant emissions. The NAS report also predicted that the costs of both battery and fuel-cell electric vehicles would be less than advanced conventional vehicles in the 2035-2040 timeframe.

This transition will not occur overnight and we will be driving advanced conventional vehicles for many years to come. In a study for the International Council on Clean Transportation, Dr. David Greene calculated that the transition could take 10 to 15 years, requiring sustained investment in infrastructure and incentives in order to achieve sustained penetration. While this investment is not inexpensive, it is projected that the benefits of this investment will be 10 times greater than the costs.

So where do we stand today on electric vehicles? We are seeing an unprecedented number of hybrid, plug-in hybrid, and battery electric vehicles across many drivetrains and models. There were about 96,000 plug-in electric vehicles sold or leased in the U.S. last year and more than 10 new PEV models are expected this year. While the sales fall short of some optimistic projections, it is an encouraging start after many years of more hope than delivery. The FC EV is expected to see significant growth after the initial limited introduction of fuel cells in the 2015-2017 timeframe by five major automobile companies.

It will take many years of sustained increasing penetration into new car sales to make this revolution a success. It is indeed a marathon and not a sprint. The challenge is how to ensure sustained sales of electric drive vehicles in the face of the many attributes of advanced technology conventional vehicles.  Electric drive vehicle drivetrains have an affinity with the increasing amount of electronics on board the vehicle, which might ultimately yield very interesting, capable, and competitive vehicles.

I have little doubt that if we are serious about our energy, environmental, and greenhouse gas goals the revolution in technology will occur. All the major automobile companies seem to recognize this in their technology roadmap, which includes advanced conventional vehicles, plug-in hybrid vehicles, battery and fuel cell electric vehicles.

In conclusion, the next 20 years promise to be equally as challenging and exciting as the last 20 years. I have little doubt that the automobile engineers are up to the task ahead, but whether we have the political fortitude to stay the course to achieve the necessary air pollution and GHG reductions is far less certain.

Dr. Alan Lloyd is President Emeritus of the nonprofit International Council on Clean Transportation (ICCT). He formerly served as Secretary of CalEPA and Chairman of the California Air Resources Board.

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ford-c-max-energi-solar-roofThe thought of vehicle-integrated solar cells taking an active role in powering an electric car remains a tantalizing prospect. In fact, the use of solar panels on the roof of a vehicle is not a new idea. It’s been shown that ultra-lightweight solar race cars with solar-packed body shells can actually drive exclusively on the power of the sun. In real life, though, this doesn’t work with production cars weighing thousands of pounds that need to carry varying numbers of passengers and weight, provide the acceleration needed for safe motoring, and in general perform all the functions required of a modern car.

Disappointing to some, car-mounted solar panels typically generate just enough electricity to operate a fan to keep the interior of a parked car cool on a hot day, falling fall far short of providing the kind of energy needed for drive motors. Lowering cabin temperatures in a parked EV does serve a purpose since less energy is needed to cool the passenger space during the early part of a drive. That means less of a drain on batteries needed to power an electric vehicle. In this case, every little bit helps.

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There are other answers and solar charging does take different forms. Plenty of EV owners offset their car’s use of electricity through large solar panels on their homes. Many public charging stations also make use of solar arrays to provide at least part of the power needed for charging electric vehicles. These have been the most logical examples of solar charging to date. Still, efforts toward creating the true solar car continue.

The latest example comes from Ford. Working in a collaborative project with long-time solar technology partner SunPower and Georgia Institute of Technology, Ford’s C-MAX Solar Energi Concept embraces an innovative approach that could potentially deliver the same amount of electrical power as plugging a C-MAX Energi PHEV into the electrical grid. The goal is no less than creating a logical stepping stone toward making a solar-powered hybrid feasible for daily use.

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Ford’s C-MAX Solar Energi Concept benefits from amplifying the sunlight that enables the car’s already-efficient SunPower solar cells to create electricity. A huge jump in solar energy conversion is accomplished with a special solar concentrator lens that directs intense solar rays to the solar panels on the vehicle's roof. The off-vehicle solar concentrator uses a special Fresnel lens of the type originally invented for use in lighthouses, boosting the impact of sunlight by a factor of eight. Similar in concept to a magnifying glass, the patent-pending system tracks the sun as it moves from east to west.

With the aid of the concentrator, the system can collect enough energy from the sun each day to equal a four-hour battery charge for the C-MAX Energi, about 8 kilowatt-hours. Ford says this is sufficient to deliver the same performance as a conventional C-MAX Energi plugged into the electrical grid.  The Ford C-MAX Solar Energi Concept would also have the same total range as a conventional C-MAX Energi of up to 620 miles, including up to 21 electric-only miles. Since the sun isn't always shining, there is still a charge port so this solar Energi variant t can be charged conventionally from the grid.

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The special solar concentrator carport used with the C-MAX Solar Energi is conceptualized in a way that maximizes capturing solar energy as the sun moves throughout the day. This requires an east-west carport orientation and also the ability for the car to autonomously move forward and backward beneath the canopy during daylight hours, thus enabling its solar cells to make the most of sunlight directed by the concentrator. As Consumer Reports posits, not only does this require buying into the concept of an unattended car moving all by itself during the day, but also the potential liability issues that could come with it.

Ford studies suggest that the sun could power up to 75 percent of all trips made by an average driver in a solar hybrid vehicle. Solar charging could be especially valuable in places where the electric grid is underdeveloped, unreliable, or expensive to use. In addition, use of a C-MAX Solar Energi could reduce yearly CO2 and other greenhouse gas emissions from the average U.S. car owner by as much as four metric tons – the equivalent of what a U.S. home produces in four months. If all light-duty vehicles in the United States were to adopt Ford C-MAX Solar Energi Concept technology, annual greenhouse gas emissions could be reduced by approximately 1 billion metric tons.

Next up: Ford and Georgia Tech will be testing the concept under real-world conditions. The outcome of those tests will help determine if the concept is feasible as a production vehicle.

 

 

four-chargersOpportunity charging can be a pretty big deal to electric car owners. Topping off at public charging stations, or for that matter at chargers available at the workplace, can considerably extend electric driving range. This can help relieve range anxiety or simply deliver the additional battery power needed for longer drives. But this strategy depends on a charger being available.

For years, EV owners have expressed frustration whenever drivers of internal combustion engine (ICE) vehicles park in an EV charging spot, thus blocking access to a charge. There’s even a term for it – being ‘ICEed.’ Now there’s a new twist. With the number of electrics on the road far surpassing the number of public or workplace chargers, EV owners are now squabbling among themselves as they jockey for their position at an available charger. Enter a new term – ‘charge rage.’

That’s what’s happening when an EV owner sees another EV at a charger and believes it has already topped off and is now simply hogging the charging opportunity. Or charge rage could also occur when an EV driver really needs a charge to get to where they need to go, and other EVs are simply plugged in and an obstacle to their mobility. What’s happening is frustration, unkind words, and often enough one EV owner unplugging another’s car so they have access to a charge.

There’s no easy to answer to this other than a huge infusion of new chargers. There’s movement by some charging manufacturers to institute a charge reservation program. Some companies are also taking reservations for workplace charging, encouraging EV owners to unplug and move out of a charging space once they’re adequately topped off. There is no instant answer. What there is, simply, is a challenge that has not been adequately considered. It will be interesting to watch this unfold.

Available next month in California and Oregon, the new 2014 Spark EV 1LT can now be leased for as low as $199 per month for 36 months. Requiring a nominal $999 due at lease signing, which includes a security deposit but is exclusive of tax, title, and registration, now makes this small Chevy EV an affordable option for new car buyers interested in electric transportation.

The Chevy Spark EV's MSRP starts at $27,495 but is as low as $19,995 when factoring in an available $7,500 federal tax credit. Other state and local tax credits may be available to bring the price down further. Chevy says that compared to the average new gasoline-powered vehicle, the Spark EV can save drivers an average of $150 per month in fuel costs.

Driving range is an EPA estimated 82 miles, similar to that of other small EV models. Its combined fuel economy equivalent is rated by EPA at 119 MPGe. Charging with a Level 2 240-volt charger takes about seven hours and a 120-volt convenience charge cord comes standard, although charge time is considerably longer. Chevy points out that the Spark EV is the first electric vehicle on the market to offer an option to be charged via the recently approved SAE combo charger for DC Fast Charging, which will enable the Spark EV to recharge up to 80 percent of its capacity in 20 minutes. Of course, that’s when DC Fast Charging stations become available.

In-vehicle connectivity is well looked-after with Chevy’s MyLink infotainment system, which includes a seven-inch touch screen and integration with third-party apps and features such as Siri Eyes Free, Pandora, and BringGo navigation. These features require the user to purchase third party apps separately on a compatible smart phone. The Spark EV RemoteLink application, which requires a smart phone and OnStar subscription, provides an array of desired functions including charge status, scheduled charge timing, interior temperature pre-conditioning, and the ability to send a text or email for charge reminders.

Honda’s efforts in creating a showcase Honda Smart Home US goes beyond the expected attributes of zero-carbon home life. It includes, as one might expect, a mobility component that adds electric vehicle ownership as part of the mix. Honda is building its zero-carbon home on the campus of U.C Davis, located near California’s capital of Sacramento where so much clean and green legislation comes to life. So, no surprise here. Construction and project overviews are included at a dedicated Honda Smart Home US website.

The driving force of this project is the state of California's goal of requiring all new residential construction to be ‘zero net energy’ by the end of this decade. Honda says its concept home will use high-efficiency HVAC (heating, ventilation, air conditioning) and lighting systems designed by UC Davis, enabling the home to use less than half the heating, cooling, and lighting energy of a similarly sized new home in the Davis area. The result is a home that will generate on average more electricity from on-site renewable power sources than it will receive from its electric utility provider.

An array of other energy-saving technologies are being integrated in the home including a solar power system that will provide enough energy for the home and for daily commuting in an electric vehicle like the Fit EV. A Honda Energy Management System also incorporates smart-grid technology that actively manages energy use and communicates with the homeowner and utility provider. This allows the home to maximize energy efficiency while responding to the needs of the electrical grid in real time. Many passive energy-saving and sustainability features are being incorporated into the showcase home.

In addition to the HVAC system, UC Davis energy research centers are focused on designing high-efficiency, cost effective solutions to major home energy loads. A particularly interesting project focuses on direct solar photovoltaic-to-vehicle charging, which would reduce losses associated with DC-to-AC and AC-to-DC conversion and substantially improve charging efficiency. PV-to-EV charging would also decrease EV-related CO2 emissions by avoiding the carbon associated with grid electricity production.

Integrating photovoltaic cells on vehicles is nothing new. In fact, solar-powered race cars have been around for more than 25 years, proving that the power of the sun can indeed provide enough energy to propel a car down the road.

Of course, these cars are ultra-lightweight and plastered with solar cells on every conceivable surface, tasked with carrying just a driver at a constant speed.

While not practical for driving as we know it, they are valuable engineering exercises that helped move the bar in developing electric vehicle efficiencies. Just one example is GM’s Sunraycer solar race car, built under the guidance of the renowned master of efficiencies, the late Paul MacCready of AeroVironment, which won the World Solar Challenge in Australia in 1987.

Lessons learned were applied to the GM Impact electric car prototype – precursor to the GM EV1 – that AeroVironment built under contract for GM and was unveiled by the automaker at the 1990 L.A. Auto Show.

Solar panels were notably integrated on the hood and rear deck of Solar Electric Engineering’s Destiny 2000, an electric car upfitted from a gasoline powered Pontiac Fiero we test drove back in 1994. Today, Audi uses a solar panel on its top-of-the-line A8. Toyota offers an optional Solar Roof package for the Prius.

While some might think these can help power an electric car, their relatively low energy output can realistically do little more than trickle-charge batteries or, more appropriately, power low-demand ventilation systems while an electric car is parked to help keep interior temperatures cooler on hot days without draining the battery.

Today there’s a new champion of solar ingenuity on the road. The Fisker Karma plug-in electric hybrid luxury sedan features probably the most sophisticated solar roof ever offered on a production model, using the world’s largest continuous-formed glass solar panel on an automobile. Not only does it keep the Karma’s interior cool on a hot day, but also supplies electricity to the car’s 12 volt system used for starting and accessories, relieving the high voltage lithium-ion battery system from tapping energy needed for driving. This can increase range, though admittedly a small amount.

To create the large solar panel, 80 small monocrystalline cells are individually hand-laid under automotive safety glass to follow the contours of the roof.  The solar panel has four electrically separate zones, each consisting of 20 cells in series. Each of the four zones incorporates MPP (maximum power point) tracking to optimize power output under various solar radiation angles and partial shading conditions. The splayed solar cell array design maximizes solar ray absorption under various lighting conditions, while the graphic accent running between the cells lends a unique and futuristic appearance.

A Karma driver can choose three solar power modes. In the Charging mode, as much solar energy as possible is stored in the battery. When Climate is chosen, solar power is used to ventilate the passenger compartment to reduce the effects of radiant heating. In the default Auto mode, the Karma will use solar power to maximize energy recovery and usage.

On a typical day, the solar panel supplies 0.5 kilowatt-hours of electricity. When used for battery charging, Fisker says over the course of a year that translates to maybe 200 emissions-free miles. That’s free energy, for sure. But how meaningful is that in the scheme of things? Like others before it, the Karma’s solar roof – with its imposing look and obvious green credentials – is a step in the right direction, showcasing innovation and yet another way to embrace renewable energy. It is an environmental friend, with benefits…but it’s hardly a statement that solar powered, highway capable cars are upon us. Still, free energy is, well…free energy…and we like it.