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Tuesday, July 24, 2007 Plug-in Hybrids Get Green GradesOverall, plug-in cars are a plus for the environment, despite the fact that they would increase the demand for electricity. By Kevin Bullis
Plug-in hybrids, which use electricity from the grid to replace gasoline for daily driving, would cut gas consumption and save commuters from high fuel prices. But some experts have been concerned that switching from gas to electricity, much of which is generated from fossil fuels, would actually significantly increase pollution in some parts of the country, as opposed to decreasing it. A study released last week by the environmental group National Resources Defense Council (NRDC) and the largely utility-funded Electric Power Research Institute shows that plug-ins, once they're on the market, will significantly cut greenhouse gases. Across the country, the vehicles will on average also decrease other pollutants, but the impact in local areas will depend on the source of electricity. In plug-in hybrids, a large battery pack that is recharged by plugging it in stores enough energy to power a car entirely, or almost entirely, with electricity for the first 40 miles or so of driving. For longer trips, the car reverts to conventional hybrid operation, relying largely on gasoline for power but improving efficiency: by storing energy from braking in the battery and using it for acceleration, for example. The study shows that if plug-in hybrids are adopted widely in the United States, and if measures are taken to clean up power plants, by 2050, plug-in hybrids could reduce carbon-dioxide emissions by 612 million metric tons, or roughly 5 percent of the total U.S. emissions expected in that time frame, according to Marcus Sarofim, a researcher at MIT's Joint Program for the Science and Policy of Global Change. That's a significant amount, he says, considering that transportation accounts for only about a third of the total greenhouse-gas emissions. But if plug-in hybrids account for only a small part of the total vehicle sales in 2050 (about 20 percent, compared with 80 percent in the first scenario), and if little is done to improve pollution from power plants, the vehicles will still reduce greenhouse emissions by about 163 metric tons, according to the study. |
Does Car-Mounted Solar Make Sense?
07/14/2008



Comments
deejay on 07/24/2007 at 3:55 AM
22
These could possibly provide some amount of on-going electric power to a vehicle that has to travel more than the 40 miles stated in the article. Another advantage is that during the day, at any given time, the roof plus one side at least would get direct sunlight.
Further, with the vehicle moving at typical speeds of 40 mph plus, vents that collect on-rushing air to drive miniature wind turbines possible?
This would decrease the load on large, centralised power plants like those stated.
Anyway, talk of timelines like 2050 etc scare me in to thinking of the type of world that we will be leaving for the next generation!
bj on 07/24/2007 at 7:32 AM
24
http://www.unisa.edu.au/solarcar/
http://www.wsc.org.au/
Hardheadjarhead on 07/26/2007 at 9:41 AM
15
Envision parking garages with solar panels for a top roof...each of which went to plugs for people to charge their cars. One solar panel roof likely wouldn't charge all the cars. But still....
Gypsy_EV on 07/30/2007 at 4:35 PM
15
jesup on 07/24/2007 at 7:36 AM
6
TANSTAAFL == There Ain't No Such Thing As A Free Lunch
pmcha5e on 07/24/2007 at 11:34 AM
1
PHEV batteries have an installed cost about $1K per kWh with perhaps an 8-year warranty and store off-peak electricity which costs 6 – 10 ¢ per kWh. Thin film solar cells have an installed cost of $6K per peak kilowatt (kWp) with a 20-year warranty and, for cities in the lower tier of states, provide a daily average of 5 kWh per kWp at 0 ¢ per kWh. (ref. http://www.solarpanelsplus.com/solar-insolation-levels/ )
The kicker is variability of solar radiation, daily and seasonally. Other issue is that the horizontal area on a medium sized car is limited - about 3 sq. meters and thin film solar cells have an efficiency of about 10% (less for a-Si; more for CIGS and CdTe). So, this means that only 300 watts of peak power, or an average of 1.5 kWh daily, is available using thin film cells. Crystalline silicon solar panels have an efficiency of about 20% but their integration into the car's skin would be more difficult than with flexible thin film panels.
(1.5 kWh would translate to about 4 or 5 miles of travel.)
lambdafunds on 07/25/2007 at 11:40 AM
9
JRT on 07/14/2008 at 12:08 PM
4
I believe that you have just suggested a perpetual motion machine. :-D
hansy on 07/24/2007 at 7:08 AM
2
Sjobeck on 07/30/2007 at 2:55 AM
15
kdigiovi on 07/30/2007 at 10:45 AM
1
It's too bad the U.S. didn't pour more resources into battery technology (companies like A123)and wind and solar earlier. We could have taken the $500 Billion spent on Iraq to secure oil and built some renewable energy plants instead, which would make alot more sense. Hopefully our Congress will do what's right here rather than what the special interests want, and we'll be charging in our cars from cleaner, more sustainable energy sources in the future.
jesup on 07/24/2007 at 7:43 AM
6
You'd want the power stations near the use, but most of those areas are both a) expensive, and b) unlikely to be easy to site in due to NIMBY (Not In My Back Yard - see the Cape wind power fiasco). And then there's the environmental damage of mining all that additional coal (see West Virgina), and acid rain issues (especially if the new plants aren't cleaner, though perhaps using the existing pollution-trading methods may help).
cwl on 07/24/2007 at 9:08 AM
2
has to me but one would hope that - especially with batteries improving - plug-in are mostly plugged in during the night when the demand for electric power is lower anyway.
Christoph
tsaidak on 07/24/2007 at 9:26 AM
5
burnside on 07/24/2007 at 1:27 PM
6
One entry into that market already on the road is the Tesla. The design is poised to take ready advantage of any progress in electrical storage media, but in the meantime it's a sharp, fast, uncompromising design and free of emissions.
cullen on 07/25/2007 at 2:00 PM
3
Thus you force people into a two-vehicle strategy - one for short trips, another for long.
Sjobeck on 07/30/2007 at 3:01 AM
15
It is no surprise that the short-term mentality of US auto makers (who ought to be ashamed of themselves on so many levels, not just this issue) are no where on this one. (We need all the fat white 58 year old men holding out for retirement in Detroit to just get out of the way & let this generation who is raring & ready to do this thing get on with it)
I drive around Oregon & am stunned how many hybrids there are ... let us take this to the next level.
Thanks.
Jason Sjobeck
cullen on 07/30/2007 at 11:08 PM
3
Gypsy_EV on 07/31/2007 at 1:09 PM
15
Either way it would be a huge improvement to current choices.
RichardL on 07/24/2007 at 12:35 PM
3
cripdyke on 07/24/2007 at 1:01 PM
14
JRT on 07/14/2008 at 12:27 PM
4
If you have a small Otto or Diesel engine, a large electric motor, and a battery that can run it for a short time, there is a rather large problem: how do you charge the battery?
The answer is that you are going to need some sort of an auxiliary power unit to supply either mechanical or electrical power to charge the battery and to help run the vehicle when the battery has been depleted.
Gaetano Marano on 07/24/2007 at 1:45 PM
55
in my latest article ("Cellphone Battery Electric Cars") you can find a SIMPLE solution to the main problem of all Electric Cars: the (still) low autonomy
http://www.gaetanomarano.it/articles/033cellphoneCAR.html
.
sroszko on 07/24/2007 at 11:28 PM
1
While I do think the electric car technology is cool and important, you can make an impact today without waiting for the next generation of plug ins.
How about a solar array on the garage roof to charge the car while parked? That would be my dream.
But I would still ride a bike.....
burnside on 07/25/2007 at 11:37 AM
6
That Calif. car builder I mentioned above (no, I'm not an investor) makes essentially a duplicate of a production Lotus Exige. The gas-fired variety gets 23 city/29 hwy while its electric twin will travel considerably more than 200mi on a four-dollar charge. At current prices that's easily in excess of 100mpg, so you see the implications.
Incidentally, one of my old college chums installed a 24kw solar array at his home in FL. He likes the power bills much better now - I think it's only a connection charge. He's feeding excess power INTO the grid during the day, draws what he needs at night, the net is just about zero.