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BMW Unveils the Solar Charging Carport of the Future
cartechboy (2660665) writes "The carport hasn't changed much over the years. Made out of wood, aluminum or steel, they are simple structures meant to cover your vehicle from the elements. BMW has just revealed a concept carport that takes these structures into the future. Made out of bamboo and carbon fiber, this concept carport features solar panels that harvest the sun's energy and use it to charge your BMW i-vehicle. "With the solar carport concept we opted for a holistic approach: not only is the vehicle itself sustainable, but so is its energy supply," explained Tom Allemann of BMW Designworks USA. "This is therefore an entirely new generation of carports that allows energy to be produced in a simple and transparent way. It renders the overarching theme of lightweight design both visible and palpable." The entire thing is quite beautiful, and could be the way to make not only charging your electric car sustainable, but also building your carport."
How long would it take to charge your car with a 15ft x 20ft panel? Hours? Days? Weeks?
(Is it just me or does BMW make an incredible effort at failing to design pretty cars?)
I hadn't the slightest objection to his spending his time planning massacres for the bourgeoisie... (P.G. Wodehouse)
..., a qualification which usually applies to "concepts". It's a nice idea to charge your car using solar panels, but if you're commuting, your car will not be sitting in that car port during the most sunny hours of the day. Besides, you can put those solar panels anywhere; choose the most efficient spot, which isn't necessarily the carport roof. Also: simply laying down solar panels on a flat roof is inefficient; you'll want to mount them at a 30 or so degree angle facing south.
If construction was anything like programming, an incorrectly fitted lock would bring down the entire building...
If you read the fine print, it's a grid-tie system, it feeds the electricity to the house/grid for net metering if a car isn't sucking down all it can provide and more.
Anyway, is "functional art" mean to be a euphemism for "ugly as sin"?
It's also not to my taste, but I can see somebody liking it. It has more 'soul' than conventional painted beams would.
I don't read AC A human right
Double checked my math. More like 22 kwh, or 66 miles worth of electricity a day.
I don't read AC A human right
I suppose beauty is in the eye of the beholder, but to this beholder it looks like something that would drive property values down, not up.
As I am currently looking into buying an electrical car, I was considering doing (almost) exactly this : Installing solar cells on the roof of the house to charge the car. It wouldn't even take that much solar cells; 20 square meters would charge the car in a reasonable amount of time. Free energy, right?
While considering the idea, a fundamental problem stuck me: Most of the time when the Sun shines, the car isn't parked at home. It is either parked in front of my office or, when I'm not working, I'm driving somewhere else, enjoying the Sun that could have charged my car. The solution to this issue was to add batteries to the concept, in order to store the Suns energy as I am away and transfer this energy back to the car at night when I am home.
Considering the car has a capacity exceeding 20 kWh, the battery solutions becomes extremely expensive - as expensive as the car itself actually (if not more). Without the battery, it's a nice expensive systems that will produce a lot of power when I don't need it. It's always possible to sell back the excess power to the utilities, but you get a loss let out of it this way and it makes your life quite complicated.
Forgetting this fundamental limitation, after doing a lot of calculation, it turned out that it would take over 20 years to amortize; and I doubt the battery system would last 20 years under the kind of stress it would be put too (nearly daily full deep cycles). And this is assuming the normal electricity prices. In fact, the charge stations are highly subsidized and your are basically paying the price large industry would pay for electricity. Suddenly your amortization period goes up over 40 years.
It's not (yet) worth it, although the technology is actually there and ready.
Conclusion : Power accumulation solution in the 20 - 40 kWh range are too expensive and power is too cheap.
A typical sedan gets about 30 mpg. Figure the average car travels 15000 miles in a year, or 41 miles per day on average. That means it burns 1.37 gallons of gas each day.
A gallon of gas has about 120 MJ. Gasoline engines are about 25% efficient, so the 1.37 gallons of gas consumed represents 123.3 MJ lost as heat, and about 41 MJ of energy used to push the car each day.
Charging a battery is about 75%-85% efficient; call it 80%. Realistically you'd need another battery to sit at the carport charging (leaving the car parked there all day to charge means you can't drive it). This battery would also help even out the cloudy days with the sunny days. So since you're charging from battery-to-battery, you're hitting this 80% efficiency loss twice. Electric motors are about 90% efficient (that's peak, but then so is the 25% efficiency for an ICE). So for an EV to put 41 MJ into pushing the car, it needs 41/(.8*.8*.9) = 71.2 MJ sent to the carport's battery.
PV panels generate about 150 W/m^2 peak. Multiply by the average capacity factor for the U.S. of 0.145 to get 22 W/m^2 on average. Multiply by 24 hours and you get 1.9 MJ/m^2 per day.
So to charge your typical sedan EV entirely with solar power to drive it 41 miles per day, your carport would need 71.2/1.9 = 37.5 square meters of solar panels. Or 404 square feet for those in the U.S. That's a mighty big carport.
As if a BMW owner will live in a place with a "car port" and not a garage.
No the 20 something working at walmart that is driving the beat up 325i does not count.
Do not look at laser with remaining good eye.
I spent a few months living in Arizona some years back. I lived in an apartment complex where most of the space between the buildings was the carpark. The most coveted spaces were the ones that had a sort of awning or overhang, so that the car was out of direct sunlight. It made a huge difference in how hot the car got.
As an engineer, seeing this vast swath of paved-over space (more than an acre all told), some of which was itself covered with structures specifically intended to block the sun, I thought to myself: why in the hell don't they just cover the entire carpark, and cover it with solar panels, to boot? The complex could advertise itself as having all-shaded parking (and commensurate higher rent) and reduce its net electricity consumption. In sunny Arizona, such a project could have paid for itself in less than a decade; today, the economics are even more favorable.
My question is: why isn't this (grid-tied, solar panel-shaded parking lots) done by every piece of commercial real estate in sunny climes? You make greater use of a resource (land area), the tenants' cars end up cooler (you can charge higher rent for that), it has a more or less guaranteed return in a reasonable time span, and reduces operating expenses (lowered electric bills). See, for instance, the western parking lot at the Googleplex headquarters. Why isn't this done everywhere?
Google's bus system works better because it runs on a monster budget compared to public transit. Not because it's more clever or efficient. They're just willing to dump healthy sums of money into giving their employees a ride to work, because they have so much money they don't really know what to do with it (which is why they came up with Google X labs way back when - to find new things to do with the money).
"When information is power, privacy is freedom" - Jah-Wren Ryel
I'm pretty dumb. Can you come help me do the oil and coolant change in my Leaf?