With all this talk of electric cars, I have one simple question: how long does it take to recharge them, and how much electricity is used?
Let's, for the sake of this discussion, assume you have just made a 13 mile round trip to the grocery store, never exceeding 45mph or climbing any extraordinary hills. Let's also assume that you're plugging into an ordinary 15-amp convenience circuit to recharge.
Will you pop the breaker? If not, how long will it take to replace the power you've used? How many kilowatt-hours will you need?
Reno Great question but how can it be answered? What size motor? what voltage? How many VA is consumed? hard or soft push on the pedal?
Charger can be slow or fast. Big and small.
Use a 1 amp charger and it will take longer than a 12 amp charger which could be used on the 15 amp outlet. Upcoming code changes suggest the slow chargers will need a 20 amp T-slot so maybe a 15 amp breaker would trip after an hour or two. There will also be some high rate chargers and those plugs will be much bigger than 20 amps but still less than generic. I expect there will be cars that cannot be fully recharged overnight if they get close to flat in the day and I assume most battery technology won't allow a complete discharge either. But an 8 hour charge at 120 volts and 16 amps should push 15,360 VA back at the battery. I can't actually know how much will get saved in the battery due to the efficiencies involved. So for sake of this discussion a code compliant 20 amp Tslot from a 120 volt outlet can give you a charge rate of about 1900 VA with no loss due to efficiencies.
Just some gee whiz info is my golf cart takes about 6-7 KWH to bring it back from being pretty dead (6 batteries). A small electric will be 2.3 times that using old time lead technology (the typical Honda kit I was looking at used 14 golf cart batteries). That is worth about 40 miles. The new charger for a Ford Focus is 6.6 KW and they say it will bring it back from the dead in less than 4 hours. That works out to about 26 KWH for an advertised 100 mile range. I am guessing that is going pretty slow on flat land.
Still ... I don't want any theory or what if's. I'd like someone to actually say something along the lines of "I drive my Edison Vunderkar to work daily (25 miles round trip) and it takes 2 hours to recharge and bumps my electric bill $7."
It's not a matter of engineering; it's a question of statistics. Given enough cars and enough miles, some sort of expectations can be had.
It's impossible to make any manner of intellegent decisions without this information.
Let's 'go back to the future,' to a world where we take our car to the grocery store and plug it into a light pole. The first question is: can the existing light pole circuit support the charging of the car? The next question is: will the car completely recharge during the 30 minutes I'm in the store? Finally, how much will that partial charge cost?
I've seen all manner of pie-in-the-sky assertions about the wonderful future of electric cars, but no one has put the promises in these practical terms.
Charge times are temperature limited by what the battery type will survive. The BMW li ion 'Mini' [ the retro-styled travesty of a much loved quintisentially British car, but it goes like a bat out of h. and it's beautifully built like a Roller] has a run time of 3 hours and a similar charge time. Since in England the weather tomorrow is anyone's guess, [which is exactly what our forcasters do!], take those figures with a bucket of salt- if it's cold out, the range will drop 30%. Commercial Charge locations away from home are more pertinant. If you want to go from London to Futtock's Magna, you'll be walking the last few miles!
..and for anyone whos never driven a 'mini'...Wonderful! We had a Cooper 'S' back in the days before the ankle biters. Bored out from a litre to 1.375 by Denise's brother, it was frighteningly fast [120mph] and drove like it was mounted on rails. With little rubber blocks as 'springs' and you had to 'tyre lever' 4 smallish people into it. Unbelievable fun!
I think the real future of electrics as commuter and shopping cars will be the "parking meter" that charges your car as long as you feed it money. These days that may actually be paid for on your phone. (dial the number of the parking meter and it shows up on your phone bill) I have to admit, this is really a pretty cheap way to get around once you buy the car and pay for the maintenance but the battery is really the biggest maintenance cost, ending up costing more than the electricity from my calculations when I was trying to get the numbers to come out. The other side of that is the tax, which would end up being more than what the power costs if we want to replace the gasoline taxes we would be losing.
Reno: I would like to give you info, but I know of not a single electric (100%) car owner as of yet.
On the radio a few weeks back, the first Chev Volt was sold to a guy in north Jersey. The dealer made a big photo/publicity OP out of it. Actually flew the guy back from Florida to take delivery & park it in the service area & a return flight back to Fla.
To give you any input, the 'Leaf' is expected real soon...
Best I could offer is my Twp Prius has 39.3MPG on the computer, all city. My personal Honda Civic (Plain gas) gets 35+ on my commute. To that I have to say...advantage..Civic
We are expecting the first Electric Cars to hit the dealers 3rd Quarter in Canada. Not to many rules yet for the product.
Frankly I am concerned this is more green washing and they just move the pollution to generating stations from the car's tailpipe. Given a choice I would tend to stay with Hybrids over electric except maybe a city only car where it was an in town commuter. No matter how you dice it electric cars are not as green as pundits claim. Batteries will always be an issue and a car's range will slowly reduce until you get stuck 10 minutes out of the driveway after an overnight charge. Batteries change the pollutant, maybe from something toxic to something more toxic. What about the effect of the cold on the battery? Does the car get 1/4 the range at 0 and no range at -40 ? The car itself carries the same environmental footprint in the factory and I just don't believe the net environmental cost is that much better than other energy types now in use? I live in a Province that has a lot of Hydro electric generation so we are one place where electric might have a huge displacement of overall environmental impact but we still generate some power with coal or natural gas fired turbines.