Subject: Re: Electric Cars

From: Peter Graham Thomas <[email-masked]>
Date: 26 May 1995 22:35:27 +0100

In article <[email-masked]>
           [email-masked] "joseph oberlander" writes:

> There is a very easy way to do all of this, but it isn't cheap.
> 
> Use a giant flywheel.
> 
> Saves on space, no 800lb of batteries to store or hulk around, has the
> ability to dump 30Kwh in the required time(actually in a few ms, in
> theory), can be slowly recharged overnight by a generator, power lines, or
> even a simple diesel engine in emergencies.
> 
> Building huge flywheels for energy storage is easy to do, and is time and
> space-efficient.  No employees to pay, and you just have to get it checked
> about once a month to make sure it is in good shape.(Not to mention the
> jobs created for all the inspectors)
> 
> The only problem would be in the case of an earthquake or something that
> caused it to fail, but it would be built below ground to minimize
> damage.(probably less than a gas line rupturing, which happened hundreds
> of times when we had the last huge earthquake here, with no loss of life.)
> 
> Joe

Joe. Just how much energy can be stored in a flywheel for energy storage - 
and how much do they cost to install in $/kW and $/kWh? Does anyone know?

Regards 

-----------------------------------------------------------------------------
Pete Thomas           |  "First you forget their names, and then their faces
Yr Wyddgrug           |   Next you forget to pull your zipper up
Welsh Wales           |   Then you forget to pull your zipper down"....
-----------------------------------------------------------------------------

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From: [email-masked] (Emil Naepflein)
Date: 26 May 1995 08:21:12 +0200

In article <[email-masked]>,
Peter Graham Thomas  <[email-masked]> wrote:
>Me again. Emil has a point. We already have such a system in an area
>where our commercial guy's did a too good a job at selling 'storage 
>heaters' (for those who don't know - these store off-peak electricity
>as heat in high capacity thermal blocks for release at on-peak times).
>
>In this case the peak demand reversed and we had a problem at 1:00am
>in the morning as all these heaters switched on!
>
>What was done was to control the switch on by a message sent over the
>local radio transmitters. The customers still get their no of hours
>for charging the heaters, but the switch on time is varied to suit the
>system and the electricity price.

We have a similar system here in germany.

>
>I'ts not a big step to do this with EV's but would 7 hours (the typical
>'off-peak' time) be sufficient? And if the EV density became too great
>then this time slot would have to become totaly variable - and a daytime
>charge is no use to someone who needs the EV during the day!

Unless we know the current demand and maximum available capacity 
during such off-peak periods we can only speculate how many EV's
can be charged. And why shouldn't EV's beeing charged everytime
when they aren't in use. When you drive 100 km per day with an
average speed of 50 km/h it is only in use for 2 hours. The other
22 hours it is available to the utility for load leveling. The
utility can use a special tarif at a extra low price for providing
your EV's battery as load leveling device. When your vehicle has
a range of 300 km, but you drive only 100 km a day, you specify 
a minimum charge of 50 % (some reserve). The other 50 % of the
battery capacity is available to the utility for load leveling.
This way you are sure that the range of the vehicle is great enough
and you may have got a extra charge very cheap. So it is a 
big advantage for you to connect your EV to a charging station
whenever possible. This concept can be also used to store excess
electricity from intermittent power sources like PV and wind.
When they produce more than 20 % of the total electricity some
kind of storage is necessary. Why shouldn't this storage beeing
implemented in a distributed fashion with the EV's batteries.
You can even go a step further and feed electricity back
to the network when demand arises. It all depends on how much
capacity is available to the utilities and how intelligently
it is managed.

Emil Naepflein

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From: [email-masked] (Emil Naepflein)
Date: 26 May 1995 08:28:35 +0200

In article <[email-masked]>,
DaveHatunen <[email-masked]> wrote:
>In article <[email-masked]>,
>Emil Naepflein <[email-masked]> wrote:
>
>[...]
>
>>But is no extra load, when charging is done at night or other
>>low load times. By using special rates for night load, the utilities 
>>can shift the load to times where their base load power plants are not 
>>fully used.
>
>If a significant number of EVs are being charged at night, night will
>no longer be a low-demand period.

Tell me what is a significant number? Unless we have the difference
between the current demand and the available capacity, we can only
speculate. May be someone can provide an example. It would be
very interesting to have these numbers. And with low load
times I mean not only time during night. The power demand also
varies during day time considerably.

BTW Dave, wouldn't the charging of EV's increase the power from
nuclear power plants even more? :-)

Emil Naepflein

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From: [email-masked] (DaveHatunen)
Date: Thu, 25 May 1995 17:34:50 GMT

[...]

[...]

-- 

    ********** DAVE HATUNEN ([email-masked]) **********
    *     Daly City California: almost San Francisco      *
    *   but with parking and lower car insurance rates    *
    *******************************************************

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From: [email-masked] (Donna Davis)
Date: 28 May 1995 15:55:07 GMT

In <[email-masked]>, [email-masked] (Emil Naepflein) writes:
>>>Thanks to all you folks who've been engaging in the EV discussion!
 It's been much better reading than my alternative-the Sunday paper!
     Maybe another possibility is to dream BIG!  How about the possibility
of advances in battery technology, as well as development of residential
co-generation of power (or even self sufficiency) concurrent with the
proliferation of EVs?  Maybe the unplugging of spent battery modules,
and their replacement with pre-charged ones at "service stations"
wouldn't be so improbable if some breakthroughs were made in battery
technology?  Maybe gains in efficiency would make that a moot point?
     I know it borders on science fiction, right now, but how do you suppose 
our existing transportation scenario would have looked to someone in the
horse-and-buggy days? That wasn't so long ago....
     You folks are all on the right track it seems:  identifying the problems
is surely the first step in finding solutions! 

                                                 Another EV Dreamer,
                                                 Donna

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From: [email-masked] (joseph oberlander)
Date: 26 May 1995 00:34:37 GMT

Use a giant flywheel.

Joe

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From: [email-masked] (Donna Davis)
Date: 28 May 1995 15:55:07 GMT

Another EV Dreamer,
                                                 Donna

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From: [email-masked] (Donna Davis)
Date: 28 May 1995 15:55:07 GMT

Another EV Dreamer,
                                                 Donna

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From: [email-masked] (joseph oberlander)
Date: 26 May 1995 00:34:37 GMT

Use a giant flywheel.

Joe