Ford C-Max Solar Energi Concept (w/video)


“Let the Sun In: Ford C-MAX Solar Energi Concept Goes Off the Grid, Gives Glimpse of Clean Vehicle Future.”

Says Ford.

The C-Max Solar Energi Concept will make its grand debut at the upcoming 2014 International Consumer Electronics Show (CES) in Las Vegas, Nevada on January 7.

Though officially a concept, Ford could quickly implement the Solar Energi’s solar system if indeed the panels and special lens work as expected.

Sketch of Special Concentrator Lens Ford Solar Energi Must Park Under

Sketch of Special Concentrator Lens Ford Solar Energi Must Park Under

“C-MAX Solar Energi Concept with a solar panel roof draws power from a special solar concentrator lens similar to a magnifying glass.

“By using renewable power, Ford C-MAX Solar Energi Concept is estimated to reduce the annual greenhouse gas emissions a typical owner would produce by four metric tons.”

That’s per Ford, who continues by saying:

“Instead of powering its battery from an electrical outlet, Ford C-MAX Solar Energi Concept harnesses the power of the sun by using a special concentrator that acts like a magnifying glass, directing intense rays to solar panels on the vehicle roof.”

“The result is a concept vehicle that takes a day’s worth of sunlight to deliver the same performance as the conventional C-MAX Energi plug-in hybrid, which draws its power from the electric grid.”

Solar Energi

Solar Energi

We’re not so sure this is the breakthrough product Ford pitches it as, but we do like the idea of combining solar with a plug.  However, previous attempts at this have shown solar panels affixed to vehicle to be very weak in terms of energy output.  Ford does say that “After C-MAX Solar Energi Concept is shown at CES, Ford and Georgia Tech will begin testing the vehicle in numerous real-world scenarios. The outcome of those tests will help to determine if the concept is feasible as a production car.”  So, even Ford seems uncertain of the usefulness of solar on the vehicle.

Solar Energi Concentrator Diagram

Solar Energi Concentrator Diagram

Solar Energi

Solar Energi

If this turns out to be a breakthrough, then a credit goes mostly to California-based SunPower and Georgia Institute of Technology, the organizations behind the unique solar panels.

“SunPower, which has been Ford’s solar technology partner since 2011, is providing high-efficiency solar cells for the roof of Ford C-MAX Solar Energi Concept. Because of the extended time it takes to absorb enough energy to fully charge the vehicle, Ford turned to Georgia Institute of Technology for a way to amplify the sunlight in order to make a solar-powered hybrid feasible for daily use.”

“Researchers developed an off-vehicle solar concentrator that uses a special Fresnel lens to direct sunlight to the solar cells while boosting the impact of the sunlight by a factor of eight. Fresnel is a compact lens originally developed for use in lighthouses. Similar in concept to a magnifying glass, the patent-pending system tracks the sun as it moves from east to west, drawing enough power from the sun through the concentrator each day to equal a four-hour battery charge (8 kilowatts).”

“With a full charge, Ford C-MAX Solar Energi Concept is estimated to have the same total range as a conventional C-MAX Energi of up to 620 miles, including up to 21 electric-only miles. Additionally, the vehicle still has a charge port, and can be charged by connecting to a charging station via cord and plug so that drivers retain the option to power up via the grid, if desired.”

“Off-the-grid car”

“By tapping renewable solar energy with a rooftop solar panel system, C-MAX Solar Energi Concept is not dependent on the traditional electric grid for its battery power. Internal Ford data suggest the sun could power up to 75 percent of all trips made by an average driver in a solar hybrid vehicle. This could be especially important in places where the electric grid is underdeveloped, unreliable or expensive to use.”

Categories: Ford


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24 Comments on "Ford C-Max Solar Energi Concept (w/video)"

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Harnessing the unlimited power of the sun is the way to go. Even without the concentrator, a days worth of sun offers the C-MAX Energi at least 3 miles of EV power. Which means the vehicle will be charging while driving and parked in the sun.

But at the same time, a SunPower Solar Concentrator mounted on a garage, attached to a storage battery pack, would capture enough power daily to fully charge the 21 mile, 8kWh battery pack at night via the plug. Off the grid.

This is neat. I’d be interested to hear how much range it can actually get from a day’s worth of sun. My guess is 5 miles or less. Still, this would be nice as that is 5 free miles of driving per day. That could add up to almost 10,000 free miles over a 5 year period.

I would, however, say that I would not buy the car unless it ALSO had the ability to plug-in. The way the text reads makes it sound like this takes the place of the plug completely. What about days when the sun isn’t shining, or you are parked in the shade? I’d want to be able to plug-in.

The concentrator magnifies the sun’s power by 8 times, so with just driving or parked in the sun, the solar panels can offer about 3 miles daily.

The vehicle also has a plug. There is more on on the Ford website site:

I don’t buy the “concentration” thing. There is only so much surface area to absorb the sun. You can’t create more surface area by using a lens. The same amount of sunlight is absorbed regardless.

Agreed David, the Fresnel lens is only of limited usefulness. Maybe in southern california or Arizona.

The first Red Flag was the press release can’t even get the terms correct. Instead of 8kw of power, they should say 8kwh of energy.

You would hope the people working on the project would least know the difference. If they really don’t, it doesn’t surprise me that they end up with minimal results. So what’s the price for this added 5 miles of ‘free’ driving?

Forget the lens, put it on the hood as well and generate enough to always be trickle charging the car…


All EV’s and EREV’s should come with this type of solar panel roof if only to maintain battery and cabin temperatures without depleting the battery charge while parked during a sunny day.


This is a great idea for people who felt that L1 charging was too fast, and they were looking for something that runs at a slower pace!

Jokes aside if these cells and lenses are as good as they claim, why not put them om buildings?

These solar panels are on buildings. And the concentrator technology is already being used in giant solar farms.

None of this is ‘new’ technology, but just new to being used on a plug-in vehicle to fully charge the battery pack….off the grid.

Are you talking about the curved glass concentrators used in the west? Those are being commercially abandoned for traditional PV, and all they did was reflect sunlight to a steam tower.

For the same money; I would rather have more batteries placed under the floor and a smaller gasoline tank and maybe even a smaller ICE. Besides Truckers, who needs to go over 600 miles on 1 tank of fuel? Fresnel lenses are nothing new. IMHO you would be better off putting solar panels on your home or on .25$ per hour L1 covered parking solar charging spaces. It is a novel concept but not practical enough for the moneyJMO.

If it was me I would cover the hood of the car along with the roof and maybe even the sides of the car with thin film solar panels I would do it in that if you drive ten miles and work for eight hours you could safe on costs. I think if you did this idea the sun on a solar panel it might burn out over time vs. covering more of the car with solar panels. I would really like them to do this with the Nissan Leaf and i-Mev in that for the C max it’s not as important considering it’s a plug i hybrid.

Hmm, you park the car in the sun and then waste energy on your A/C to cool the interior. Interesting… 😉

Absolutely impractical.

I have 5 years of experience managing a SunPower installed 3MW PV array and I can say that none of this PV-on-cars stuff will ever work. Even concentrated, there isn’t enough energy in the sun to provide enough energy to result in a meaningful charge of the traction battery.

Never underestimate the power or perception. This story was on every green site today. What an advertising boost for Ford.

As for the practical, every manufacturing facility could have a stylish solar canopy out front. While the EV market grows, the power would simply go back to the facility. As the need arises, add chargers. I would probably pay a little extra for electricity to have a shaded canopy to park under and a premium front parking space. And once again, never underestimate the power of perception.

So, how much does the lens cost? Is it less then the equivalent cost of 8 times the solar panels mounted on the car? I like the idea of solar panels on a car, but normaly they are more useful on a roof faced to the sun. Solar panels aren’t that expansive any more, that substracting their numbers with other tec would make much economic sense.

Another thing that comes to mind with focused sunlight – what if people parked their car wrong? Could parts of it (like rubber or the console) catch fire? Isn’t there a curvy building somwhere that focuses the sunlight so strong that it had damaged parking cars?

Good points. There is a building at 20 Fenchurch Street, London, England that, was designed with the south facing facade having a concave shape. It focused the sunlight on the street below it and was damaging stuff. Apparently, replacing highly reflective glass with less reflective glass solved the problem.

I don’t like the idea of concentrating the solar power hitting a car by a factor of 8. In the tropics where I live there would have to be some serious insulation between the panels and the interior or the interior of the car would get too hot. In addition the targeting of the lens would have to be incredibly precise.

On the other hand, covering the skyward facing surfaces of the car with thin film, making it fashionable lie carbon fiber and using it to add 10% to the range of the car or reduce the energy needed for AC, like some models of the Prius, might make sense.

If Tesla’s panoramic roof is designed to reflect 90 % of solar radiation away in order to keep cabin cool. And if solar panel is designed to absorb 90 % of solar radiation.

Then how large negative effect solar panels has on energy consumption due to increased need for airconditioning?


Stories like this put the spotlight on which manufacturers are willing to lie about technology. Ford already said its C-Max hybrid was good for 47 cty/hwy, and is now making money sending $500 checks to owners whose real fuel costs will exceed a greater margin than their EPA “estimate” (~39.3 Bravo, the bottom line. This, and solar roofs, is the example Ford sets.

This was merely a publicity stunt to remind the world that Ford has EV’s. This story has spread to numerous blogs and “news” sites, most of which are so poorly written that the reader is left with the impression that the car runs entirely on solar.

Why not layer these lenses over every solar panel nationwide, so we start collecting 8x the energy and feed that into the grid?

Also, why not build the lense over the solar panel and affix it to the roof of the car, so the car is self sustaining

How do you know the size of the solar roof?
Anyway I calculate that, at least in Central italy, you’d need 2 kWp in summer or 4 kWp in winter to charge 8 kWh, and at a maximum of 20% efficiency and 1 kW/m2 sun radiation, this would meen 10 and 20 square meters respectively.

Apart from this, “secret” project from Italian FIAT for “Phylla” car already envisaged a sun-powered car lasting 20 km. But it was a small car, so we can assume around 100 Wh/km, which for 20 km means just 2 kWh.