# Charge electric car from dryer plug?

#### mgb_phys

Homework Helper
Certainly, the Great British Public (and other groups) seem to think that Electricity is, somehow, both cost-free and pollution-free.
That's not true.
Yes they want to shut down the large coal fired stations that supply a lot of the power but produce CO2
And obviously you don't want nuclear, cos nuclear is bad m'kay.
And gas is fine as long as you don't need want to transport LPG in tankers or build pipelines

Of course hydro would be good, as long as it doesn't involve flooding any farmland or wilderness.
Wind would be ideal, as long as the turbines aren't visible anywhere pretty, or anywhere that could affect birds, or offshore. And it's a pity that solar isn't really practical.

So as long as the power doesn't produce CO2 and doesn't affect the view, or farmers or birds or involve buying fuel from foreigners - then they are right behind electricity generation

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#### russ_watters

Mentor
I sure haven't seen any washing machines that run on anything except 120V. The code requires a dedicated 20 amp circuit for it. Most of the time standard outlets in the U.S. are 15 amp. Seldom any 120V circuits in a residence are greater than this excpet the laundry, one (maybe 2) in the kitchen, and I believe one for the bathroom. Electric clothes dryers have a four prong 240/120 volt plug. The heating element runs on 240V and the motor runs on 120V. I would imagine a gas dryer would run on 120V but could require a dedicated circuit.
Dang, you're right - just checked and most of my circuits are 15A. I have one that says "washer" and it is 20A/120V - That may be both the washer and dryer because I don't see one for the dryer. The heat is from propane, though. My kitchen general power circuit is 20A.

Too used to commercial where the minimum is 20A.

#### russ_watters

Mentor
Hang on a bit. Just changing the Law isn't suddenly going to magic a power distribution network that can handle everyone's extra vehicle charging loads. (Looking at the future, when 'everyone' is electric.)
No, but it will force the cost and responsibility onto the power company instead of the consumer. The power company will just end up back-charging us through our electric bills, but the rates are regulated too...

#### russ_watters

Mentor
That's not true.
Yes they want to shut down the large coal fired stations that supply a lot of the power but produce CO2
And obviously you don't want nuclear, cos nuclear is bad m'kay.
And gas is fine as long as you don't need want to transport LPG in tankers or build pipelines
It is true (in the US and I'd wage in the UK too), otherwise electric cars would never be getting all the press and environmentalist attention they are. In that other thread, the linked study showed an average 27% improvement in emissions by going from an average car to a full electric in the US. With the advent of hybrids as an alternative, there would be a net increase in pollution due to driving an electric car!

It is fine that they are in development because it will take decades for them to become ubiquitous, but coal power is a much bigger and not to mention much easier problem. And it is one that is pretty rarely talked about in the media and not real high on the list for environmentalists. And I bet this is true almost everywhere - heck, Germany decided a few years ago that they would get rid of all their nuclear plants and the result is an increase in coal power. They take credit for a reduction in CO2, though, because of the integration of East Germany.

#### mgb_phys

Homework Helper
They take credit for a reduction in CO2, though, because of the integration of East Germany.
Germany have a new technique, they are reducing their CO2 emission to Kyoto levels by shipping their nasty lignite coal to Poland, burning it in Polish power stations and shipping the power back.

Most of their new domestic power generation is coming from a gas pipeline form Russia.

ps. I need to put irony warning in bold.

#### Averagesupernova

Gold Member
Dang, you're right - just checked and most of my circuits are 15A. I have one that says "washer" and it is 20A/120V - That may be both the washer and dryer because I don't see one for the dryer. The heat is from propane, though. My kitchen general power circuit is 20A.

Too used to commercial where the minimum is 20A.
Your post brought up something I had forgotten. A furnace such as gas or propane would require a dedicated 120V 20A circuit also. Your heat is from propane, I assume you mean the heat for the dryer right?

#### mheslep

Gold Member
It would be interesting to know.
Certainly, the Great British Public (and other groups) seem to think that Electricity is, somehow, both cost-free and pollution-free.
Any new form of transport is bound to have environmental costs, one way or another.
The point is that some have much less impact than others.

#### OmCheeto

Gold Member
Wow. How far do some of you have to drive to get to the mall?

Here are some calculations of my daily commute to and from work:

gas powered
Total distance: 26 miles (ref: odometer)
mpg: 26 mpg (ref: my log)
actual motive energy: 4 kwh (ref: chargecar)
energy consumed: 34.7 kwh (ref: http://www.uwgb.edu/dutchs/pseudosc/200mpgcar.htm" [Broken] = 34.7 kwh(conversion widget))
efficiency: 0.116 (ref: 4/34.7)
total cost of trip: $2.60 (ref: sign at gas station) current annual cost:$1000 (ref: pocketbook)

now, switching to electric
Total distance: 26 miles
actual motive energy: 4 kwh
energy consumed: 5 kwh(ref: http://www.evalbum.com/1137")
efficiency: 0.8
cost of a kwh: $0.11/kwh(ref: my electric bill) total cost of trip:$0.55
potential annual cost: $210 annual savings:$790
which should be enough to cover the cost of installing a charging station in your garage.

charge time at each end: 20 minutes.(240v 32a = dryer plug)
or 40 minutes at home each night.

And I really think that those of you that routinely drive more than 200 miles per day might want to avoid electric cars. For the time being anyways.

http://www.batteryuniversity.com/partone-12.htm" [Broken]
The charge time of most chargers is about 3 hours.
Or are there batteries out there that can accept a full charge faster than that, that I am not aware of?

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#### mheslep

Gold Member
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#### Borek

Mentor
the point of this thread has been that fast charge batteries won't do you much good as the charging infrastructure required is impractical.
Which just made me thinking - what if the charging station has its own battery of batteries, which are charged all the time with more or less constant current? Sure, that means lower efficiency, at the same time it means almost constant load.

#### OmCheeto

Gold Member
http://web.mit.edu/newsoffice/2009/battery-material-0311.html", though the point of this thread has been that fast charge batteries won't do you much good as the charging infrastructure required is impractical.
Using their new processing technique, the two went on to make a small battery that could be fully charged or discharged in 10 to 20 seconds...
Holy Mary mother of Merry Chistmas everyone that's fast!

hmmmm.... being that I used to personally lug around http://www.brighthub.com/engineering/marine/articles/23761.aspx", I don't see that an 8 minute charge time every 200 miles is much of a problem anymore.

With a second charging plug in the vehicle for low power needs or course. I mean really, who goes home or to work and stays less than 8 minutes?

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#### mheslep

Gold Member
Which just made me thinking - what if the charging station has its own battery of batteries, which are charged all the time with more or less constant current? Sure, that means lower efficiency, at the same time it means almost constant load.
Possible, but there's some still some serious drawbacks. A battery backed charging point becomes expensive and thus it can't be distributed every few meters as can be simple 4kW charging points using only the grid. Second, handling 200-500KW electric cables is problematic - probably can't be left to the vehicle operator. Third the charging circuitry and mechanical interface on the vehicle side also has to become capable of handling that charge rate and thus it becomes more expensive.

Edit: One solution to this problem was worked out a hundred years ago, at least on small scales for a commercial fleet: NY taxis used a battery exchange system, originated by the electric trolley operators - on your way in two minutes.

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#### OmCheeto

Gold Member
Second, handling 200-500KW electric cables is problematic - probably can't be left to the vehicle operator.
That's why they still won't let us http://www.capitalistchicks.com/?q=node/223", like everyone else.

But I guess that means we're a bit further ahead in infrastructure than the rest of the nation.

Trainer: Do not touch those shiny metal bits there. Got it?
Tron pumper trainee: Yes boss.
Trainer: And don't pull this trigger till its latched. Got it?
Tron pumper trainee: Yes boss.
Trainer: Ok. You're ready. Go pump some trons.
Trained tron pumper: Yes boss.

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#### mheslep

Gold Member
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#### OmCheeto

Gold Member
That's about 0.2 kWh/mile, a bit optimistic.

Here's some EV efficiencies by vehicle type:
Vehicle Class [kWh/mile]
Compact sedan 0.26
Mid-size sedan 0.30
Mid-size SUV 0.38
Full-size SUV 0.46
from Table 1, Page 9 here
http://energytech.pnl.gov/publications/pdf/PHEV_Feasibility_Analysis_Part1.pdf
For most people maybe.

OmCheeto said:
my daily commute to and from work
I average 23.4 mph.

I'm afraid the dryer plug will be perfect for my needs. The rest of you will have to fend for yourselves.

And although they used the word "regeneration" once, the authors of your sited paper didn't really expand on it.

I probably should have not been so coy in hiding the fact that chargecar.org thinks I'll be able to recoup 32% of my energy with their dumb system. Hence my optimistic number.

Vehicle Class_____kWh/mile_______kWh/m with 32% regen
Compact sedan______0.26__________0.18
Mid-size sedan_____0.30__________0.20
Mid-size SUV_______0.38__________0.26
Full-size SUV______0.46__________0.31

The unfortunate economic and technologically limited facts of the past are fortunately slipping away faster than I can keep up. Which of course, makes me very happy.

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#### russ_watters

Mentor
Your post brought up something I had forgotten. A furnace such as gas or propane would require a dedicated 120V 20A circuit also. Your heat is from propane, I assume you mean the heat for the dryer right?
Well everything that makes heat is except the dishwasher - dryer, water heater, range/oven and furnace. My furnace is actually 120/15, which is all it needs for a >1hp fan for the air circulation and a much smaller one for the combustion air. My only 240V circuit is my condensing unit, which is 40A.

#### LURCH

Which just made me thinking - what if the charging station has its own battery of batteries, which are charged all the time with more or less constant current? Sure, that means lower efficiency, at the same time it means almost constant load.
This is exactly the infrastructure I envisioned ever since reading about the work being done at MIT on a so-called "synthetic battery," which is actually a capacitor capable of storing as much electricity as a lithium ion battery of the same size. Fueling stations would have a large capacitor underground, analogous to the storage tanks they currently use to hold petroleum fuel. These storage capacitors would continually "sip" from the utility lines, and discharge rapidly into vehicles. Of course, this rapid discharge would require some fairly substantial cables, but I don't think they would need to be any larger than the hoses currently used to pump gasoline.

Of course, these capacitors are not yet available, and storing a large battery underground does bring up some environmental concerns. However, I don't think these concerns are any greater than those associated with storing petroleum fuels the ground.

#### mgb_phys

Homework Helper
Of course, these capacitors are not yet available, and storing a large battery underground does bring up some environmental concerns.
Today for multi-MW short term storage, especially if you can bury them underground you would probably look at flywheels.
You can buy 5MW flywheel backup systems off the shelf, they are used for data centers because they have higher power density than batteries and can supply very high peak power levels.

#### LURCH

Today for multi-MW short term storage, especially if you can bury them underground you would probably look at flywheels.
You can buy 5MW flywheel backup systems off the shelf, they are used for data centers because they have higher power density than batteries and can supply very high peak power levels.
Now there is an option I had never considered.

#### rbj

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