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Solar-Powered Ford Aims to Drive Off-Grid

The views expressed are those of the author and are not necessarily those of Scientific American.

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The automaker is set to unveil a concept car that tracks the sun’s movement and rolls back and forth for optimal exposure and faster charging. Image courtesy of Ford Motor Company.

Solar-powered cars have been little more than a novelty to date, experimental vehicles resembling photovoltaic-laden surfboards designed mostly for racing across deserts. Expensive batteries, relatively inefficient PV energy conversion and the lack of intense sunlight in many places have made sun-powered passenger vehicles impractical.

Ford is looking to change that with a version of its plug-in hybrid C-MAX Energi that would allow drivers to charge the hatchback’s lithium-ion battery via PV panels mounted on the roof. Other carmakers already sell models that use solar cells to power cabin ventilation (Toyota) or accessories (Nissan).  The C-MAX Solar Energi Concept—which Ford will showcase at next week’s International Consumer Electronics Show (CES) in Las Vegas—would be the first mass-produced, commercially available automobile to offer drivers the ability to recharge a depleted battery via solar power or by plugging into an outlet.

The recharging process gets a boost when the solar C-MAX is parked under an accompanying 20-square meter acrylic canopy equipped with 20 Fresnel compact lenses—the kind used in lighthouses—that act as a giant magnifying glass, directing intense rays to the car’s solar panels. Used in tandem over the course of six to eight hours, the rooftop solar cells and concentrator canopy would fully recharge the car’s battery, which can power the car for up to 34 kilometers before the hybrid’s gasoline engine needs to kick in.

Further improving solar-charging efficiency, the new C-MAX would use sensors and cameras to track the sun’s position and autonomously reposition the car for optimal sunlight exposure. Ford already offers this technology to help drivers maintain a pre-set distance from the vehicle in front of them (via adaptive cruise control), stay in their lane and avoid vehicles in their blind spots. The C-MAX Solar would use these capabilities when parked under its canopy to automatically roll up to 2.5 meters forward or backward as the sun shifts in the sky. The combined canopy and tracking system will enable the car to charge up to eight times faster than simply parking the solar-powered car in the sun, says Mike Tinskey, Ford global director of vehicle electrification and infrastructure.


Image courtesy of Ford Motor Company

“What we’re trying to do here is essentially replace the plug,” Tinskey says. “We’ve been calling this the world’s first plug-in vehicle that doesn’t need to be plugged in.”

The C-MAX Solar Energi Concept is a collaborative effort, with SunPower Corp. in San Jose, Calif., supplying the roof’s high-efficiency solar cells and Georgia Institute of Technology helping Ford develop ways to speed up the charging process so that it would be practical for commuters.

Ford obviously has some kinks to work out if its C-MAX Solar Energi is to ever see the light of day, much less a sales floor. The cost of the solar cells, tracking system and canopy are an open question. Ford would have to deliver the technology at a reasonable cost to compete with other hybrids.

The vehicle’s proposed system of rolling back and forth could likewise pose logistical and safety problems. Would there be enough space in the average driveway to park and robotically roll a C-MAX Solar? What’s to stop it from inadvertently running over an object in its path—such as a driver’s wallet or foot? Questions also arise as to whether such a vehicle would ever be practical in places without much direct sunlight, such as a shade-covered driveway or parking space.

Despite these challenges, it’s an automotive move in directions we’d all like to explore—wireless, energy independent and off the grid.

Larry Greenemeier About the Author: Larry Greenemeier is the associate editor of technology for Scientific American, covering a variety of tech-related topics, including biotech, computers, military tech, nanotech and robots. Follow on Twitter @lggreenemeier.

The views expressed are those of the author and are not necessarily those of Scientific American.

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  1. 1. oldfarmermac 3:50 pm 01/3/2014

    Given that the roof mounted panels will be capable capable of adding energy equivalent to a gallon of gasoline once a week or so to the battery, and that gasoline is already around eight bucks a gallon in Europe, the self charging car may be a practical possibility.

    In fifteen years the owner of such a car would save around six thousand bucks on gasoline at current prices in Europe, which would probably cost him closer to ten thousand bucks in pretax income.

    It seems very likely Ford can eventually get the cost of the system low enough to sell it on it’s own merits as an economy measure, given that the car is already a hybrid anyway, without the necessity of paying for the special carport with fresnel lenses, etc..

    Ford can buy all the components in bulk without middlemen getting a cut and install them on the assembly line, thereby bypassing the Achille’s heel of small scale solar- the necessity of dealing with a long chain of middlemen , the building inspector, the zoning office, a lender, the fire insurance company, the installation crew, and so forth.

    I doubt the special high tech carport will ever sell in quantity for the simple reason that ordinary pv panels are already cheap enough use them profitably to charge a car, except for the high cost of installation.

    If there’s a large enough roof handy, or enough space available for a ground mounted array, the ordinary panels required to charge the car on a daily basis will be the better deal for the owner, most likely.

    Plugging and unplugging a car takes only a few seconds and eliminating this very minor chore is not likely to entice many people to spend a whole lot more money to avoid it.

    And given the historical rising cost trend oil oil, gasoline may be expensive enough here in the states for such a system to be a practical investment in a few more years

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  2. 2. Mikek 9:13 pm 01/3/2014

    The author obviously did not understand how it works. The lens system is the top of a car port. The cars rolls back and forth under the car port as the Sun travels across the sky.

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  3. 3. Uncle.Al 1:18 pm 01/4/2014

    “up to 34 kilometers” is up to a ten-mile reach given a brand new battery pack, flat road, no opposing wind, flowing traffic… The bottom line is less optimistic in autumn, winter, spring – and pretty much anywhere in the UK (clouds).
    Said car need do some fancy moving.

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  4. 4. jerryd 2:58 pm 01/4/2014

    As both an EV and RE designer, builder this has little value as it’ll produce way too little to be much better that keeping an already charged pack, aux battery charged.

    For less money just put the PV array of a decent size on the carport and make, sell much more valuable peak power and charge at night on otherwise wasted power utility.

    Home/building PV panels have become 10 percent of it’s cost 10 yrs ago so well shopped, done in most places cost half of utility power and it never goes up in price, saving even more. And that is before any RE subsidies and with the massive FF susidies.

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  5. 5. oldfarmermac 9:26 am 01/6/2014

    I believe owners of the Chevy Volt are mostly getting the battery mileage they expect.I’ve been following a bunch of Volt forums and the owners who aren’t happy are very few compared to the ones who are.

    The people who constantly ridicule the performance of electric and hybrid cars appear to me to be the same ones who are still saying cfl’s only last a few weeks and take five minutes to turn on.

    The Ford hybrid in question will get pretty the mileage on it’s battery that is advertised, on the average, across the board, under all conditions for all drivers.

    Of course a driver in Minnesota in the winter isn’t going very far on battery power alone, but he will never the less still get considerably better mileage than the owner of a conventional comparable non hybrid car .

    The nay sayers fail to account for the fact that most vehicles aren’t driven very far on any given day, and that a typical plug in hybrid owner who has a relatively short commute and/ or a few daily local errands to run can save anywhere from fifty to seventy five percent on gasoline on a net cost basis. Recharging isn’t free unless you’re lucky enough to be a Tesla owner living near a Tesla station!

    Toyota has proven that the technology can be durable and reliable by putting Priuses on the road in large numbers for years now.Very few of them have needed new batteries.

    People who think batteries are always going to cost more than conventional engines and transmissions are deluding themselves.

    The tech is relatively new but there are tons of older patents on it that will be expiring soon, and the engineers who design the machinery and factories needed to build the batteries are just now hitting their stride.

    There’s every reason to believe that plain old elbow grease of the engineering sort combined with the economies of scale that will come with increasing sales of these batteries will result in their selling for half the current price in five or six more years.

    They aren’t going to go into automobiles alone; they’re also going to be sold in vast numbers- in different packaging and sizes- as backup power supplies and as peak load management devices to businesses that are large users of grid source electricity – electricity costs an arm and a leg when there’s a spike in demand in many places which have rate schedules that can double or triple the cost of juice on a really hot or cold day.

    They will also find a large market among homeowners who have pv systems of their own.Not all utilities will pay for the excess power generated by such systems ; some will only give a credit against the cost of purchased power and some won’t cooperate at all.

    Then there are all the people who once home generation gets a little more popular- and a little cheaper- will want to just go off grid altogether- granted there aren’t many such people for now, but there will be more every year as the cost of purchased electricity goes up and self generated electricity goes down.

    I currently use a couple of large heavy lead acid batteries to power my small fishing boat. Theres at least a million such small boats in this country and the owners of all of them will be glad to switch to more powerful, lighter, longer lasting batteries such as the ones used in hybrid cars once the price comes down some more.

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  6. 6. karlchwe 12:13 pm 01/6/2014

    Putting solar cells on the car sounds like a great idea, because it could possibly free you from have to stay within range of a charging station. Except with this system, you have to stay within range of the solar canopy/concentrator. So what is the point? Maybe the canopy is cheaper than a home charging station. Except it doesn’t charge very well, and not on cloudy days. Also, what effect will sun intensified by 8 times have on the paint, upholstery, etc? Also, the car rolls back and forth to follow the sun, which means the car has to be parked in an east/west direction (and also not be shaded by buildings, trees, etc.) Also, your existing carport won’t do, so you will have to find a new (east/west) parking spot for your car. Etc., etc.

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