Sunday, January 10, 2010

Some of you may remember the electric car guy who gave me hell

for having trouble believing that just charging the cars at night would deal with the "Where is the electricity going to come from?" question. Well...
The myth that thousands of EVs will seamlessly fold into the power grid by charging at night, using otherwise idle generating plants and power grids, is breaking down. Utilities worry that EV charging could black out the neighborhoods of some early EV adopters and give the emerging technology a black eye. Policy experts worry that the change in the grid's use could unintentionally muck up their green energy plans.
EVs need lots of power, especially when charged quickly. Utilities bet that most buyers will want a 240-volt charger that can "fill the tank" of a modest-size EV in 2 to 3 hours, four times as fast as a standard 120-V charger can. Such "AC Level 2" chargers, as defined by the Society of Automotive Engineers' emerging J1772 standard, draw up to 6.6 kilowatts. Turning one on is like adding up to three homes to a neighborhood, and that's with the air conditioning, lights, and laundry running.

Turning on two or three Level 2 chargers could burn out the street-level transformers that are the distribution grid's weakest link. Most utilities employ undersized transformers, which are designed to cool overnight. Without time to cool, sustained excess current will eventually cook a transformer's copper windings, causing a short and blacking out the local loads it serves
So there is indeed a big problem with "Just use the excess capacity at night" idea. Whoda thunk it?

And since, according to the article, CA is planning on using 'smart meters'(as in "You can have the power we say you can, when we say you can") to 'synchronize demand with the state wind farms'. WHich means when it's not windy enough, or too windy and some farms have to be shut down, or there's ice in winter...

This promises to be not much fun. Especially since Californicated will be demanding the rest of the country help save them from the hole they dug themselves into.


Roger said...

Most folks do not understand much about how electical energy arrives at their home. They might coo about how "efficient" an electic car is. Okay, the car itself may be efficient in the use of the energy it carries and uses.
How about a factual primer?

Energy comes in many forms, chemical, heat, mechanical, etc.
Whenever energy changes form, such as from chemical energy to heat energy, some energy is lost, known as inefficiency. Remember the loss at each change of form.
1, Chemical energy (coal) is burned and converted to heat energy.
2, The heat energy is converted into steam energy,(boiler)
3, The steam energy is converted into mechanical energy (steam turbine)
4, The turbines energy is converted into electrical energy (generator)
5, The electrical energy is transformed into the high voltage for transmission & transmitted over high voltage transmission lines.
5 The high voltage is transformed back into lower voltage for local transmission.
6, The local lower voltage is transformed into housepower (240v)
7, The house power electrical energy is transformed and rectified into Direct current at the needed voltage for the cars batteries.
8, The rectified / transformed housepower electrical energy is converted into chemical energy (battery power in the car.)
9, The chemical energy is converted back into electrical energy.
10, The batteries electrical energy is converted into mechanical energy in the cars electric motor. the motors move the car.

At each stage of transformation / transmission there is energy lost.

compare this to my elderly Jaguar XK 120.
1, Chemical energy (gasoline) is converted into mechanical energy. (burned in the engine)
2, mechanical energy moves my car.

Remember something else. The electric /cars are stone UGLY. My Jaguar is one of the most beautiful motorcars ever made.

Therefore, logically, everyone should buy, restore or otherwise get an elderly Jaguar and cease thinking of uuuuugly 'lectric cars.

GuardDuck said...

I had a row with one of those 'off peak rechargers' as well.

He didn't seem to understand that off peak power tends to be provided by the least carbon producing generators while peak demand was covered by more carbon producing generators.

So 'leveling' out the round the clock demand would only mean that coal, oil and gas fired power plants would remain online more hours a day than is current (haha) practice.

Not very enviro-friendly is it?

martywd said... has a pretty damning post up now regarding the 'benefits' of electric cars to consumers.

Stephen said...


There is energy lost at each stage but each stage is quite efficient especially when compared to your Jaguar, which only turns about 20% of the chemical energy into mechanical energy at the flywheel.

Also electric vehicles can be made to look anyway you like. Even your Jaguar could be converted to electric if that's what you want to look at.

About the article in general, well it just sucks that America's electrical grid was so poorly designed but I don't have to live there so :P hehe

Where I live, the off peak charging will actually help because currently we have to keep our big dirty coal power stations running and not generating power overnight (because it takes too long to turn them on and off - as in days). This wastes fuel but if we increase the power demand overnight then we can actually be using that power instead of wasting it.