DIYbanter - 90 amps for electric car charge!

On Feb 15, 5:20*pm, George wrote:
On 2/15/2010 4:08 PM, Bill wrote:

Well I'm getting out my popcorn to sit back and watch the show in California
with this. They [California] had a fit with everyone buying those new TV's
which use a bit more energy. (Overloading the electric grid.) In California
no one wants any new major electric transmission lines built in their
backyard.

If quite a few people buy these cars in California, it will be interesting
to see what they do when it places a strain on their electric grid.
Neighborhood nukes?

Or for that matter if there was a concentration of these new cars in one
neighborhood anywhere. Say 3 homes all on the same electric company
transformer. Then all 3 homes get electric vehicles, and they all recharge
them at 6:00 pm when they get home on a hot summer day, and also have their
AC and everything else going full blast???

Neighborhood Nuclear Power...
http://www.hyperionpowergeneration.com/about.html

Aren't you assuming worst case? I think a lot of diversity will be
involved. Many would likely just use a longer term lower current draw
charge.- Hide quoted text -

- Show quoted text -

You have a choice. In his hypothetical case of several homes sharing
a transformer, you can either design for worst case or ignore it. The
latter could very well result in the transformer overloading and the
homes being without power. And his point is a very valid one. The
existing transformer loads were calculated based on some assumptions
of what loads would be in the future and a worst case scenario had to
be calculated. I would not be surprised that suddenly having homes
where new 70A loads for 4 hours appear could exceed the system design,
with his transformer loading being a good example.

As for using a longer term lower current, there are two big problems
with that:

1 - The longer it takes to recharge the car, the less attractive these
cars become and they become totally excluded from many applications.
That's especially true when you compare their operating costs with
similar size ICE cars available today, eg hybrids, that have no
charging issues.

2 - In today's instant gratification world, I doubt many people are
going to want to charge it at less than the maximum. You need to run
a new circuit to charge them anyway, so why would you not make it
capable of charging at the max? And once you have that 90A circuit,
you know people are going to use it. You could discourage this by
offpeak pricing. But that gets back to what I said a long time ago,
which is that you need to talk about a COMPLETE solution, from energy
generation to the point of usage, not just an electric car. Yet, the
miracle, clean, green electric car is all the media cares to talk
about.