🚀 go-pugleaf

Howard Berkowitz wrote:
> In article <cq95c6$5lf$1@reader2.panix.com>, 
> EskWIRED@spamblock.panix.com wrote:
> 
> 
>>In ne.general Howard Berkowitz <hcb@gettcomm.com> wrote:
>>
>>
>>>It's an interesting question whether distributed small generators 
>>>should 
>>>also be considered a source of cogeneration,
>>
>>Generally, cogeneration refers to generation of electricity by using a 
>>by-product of another process, usually heat.
> 
> 
> Indeed, that's the most common usage, relevant to exothermic industrial 
> processes. The term has been used for such things as residential solar 
> collectors that create excess poser.
> 
>> or the overhead of 
>>
>>>financial data collection, safety and assurance of the grid, etc., make 
>>>it more of a per-building or even small-tract (office park, etc.) 
>>>solution.  Industrial cogeneration seems to have taken off in some 
>>>areas 
>>>but not others.
>>
>>>Another major concern is the technology level of the North American 
>>>electrical grid, coupled with regulatory changes.  In many cases, it 
>>>has 
>>>become more economic for utilities to buy power than generate it. 
>>
>>I'm not sure what you mean by "utilies".  These days, generation, 
>>transmission and distribution are handled by different companies.  The 
>>distribution companies are, in general, prohibited from owning generation 
>>facilities.  And again, generally, the distribution companies are 
>>required to accept interconnections from generators.
> 
> 
> Shorthand for both.  One of the problems of this regulatory split into 
> generation and distribution is that it did not take engineering safety 
> into account. The reality is that a number of distribution companies 
> were spinoffs of existing plant, and were not optimized for 
> interconnection, being the older AC high-voltage treansmission systems. 
> 
>>>There's nothing inherently wrong with that -- if, hypothetically, there 
>>>were a breakthrough in solar, then major power might come from the 
>>>Southwest.
>>
>>>The technical problem is more subtle, in that much of the North 
>>>American 
>>>grid is not designed for interconnection of utilitiee, as we have seen 
>>>in the technical analysis of regional blackouts. Factors include that 
>>>older regional grids use high-voltage alternating current (AC),
>>
>>High voltage would be the transmission portion of the grid.
>>
>> with 
>>
>>>often electromechanical switchgear,
>>
>>What else could high voltage switchgear be other than air breaks?
> 
> 
> Thyristors and other new solid-state components. The Texas grid, for 
> example, has primarily solid-state DC connections to ther grids.
> 
>>
>> and the additional requirement to 
>>
>>>match the frequency and phase of AC before interconnecting -- lest 
>>>there 
>>>be dangerous surges.
>>
>>It is crucial that the interconnecting generator be matched to the system 
>>it is connecing to.  How could it be otherwise?
> 
> 
> If you connect with DC, there's no issue of phase and frequency match.

Howard, you really got my curiosity up now.  Maybe I miss the point you 
are making, but are we not talking about moving power (electricity) from 
the source to the market?  I believe you could run DC power and 
accomplish everything you do now with AC but everyone is geared up for 
AC and it would cost billions to convert everything to DC only.


> 
>>
>> Newer, extremely high voltage systems are direct 
>>
>>>current (DC) with solid-state switching and no frequency or phase to 
>>>match. DC also lends itself better to computer control.  
>>
>>DC?  Where?  For what?
> 
> 
> A number of new, extremely high voltage (e.g., 750 KV and above) 
> transmission facilities are DC, not AC. Since my experience is more with 
> computer electronics, I was surprised, but heard from multiple trusted 
> sources, that there have been reliable breakthroughs in semiconductors 
> that operate in these voltage and power ranges.

It sounds like you are suggesting that AC and DC be transmitted on the 
same transmission lines. I think that is doable as the AC will just ride 
  along on the DC level.  But somewhere you will have to separate the 
two for use at the subscriber level.  In that event, you will still have 
AC entering the grid which must be phase aligned with what is on the grid.

In Palm Springs, I saw all those wind generators and wondered how the 
heck they could be generating all that AC and then pour it onto the grid 
to be sent down the line for use.  How do they synchronize that AC?  It 
turns out to be simple.  They first excite or inject the AC from the 
grid to the components of the Wind Gen and the resuling output is 
already in sync.  But how does your system work?

Ed
USA Ret
> 
>>>Unfortunately, to upgrade the North American grid interconnection 
>>>system 
>>>will have a cost in the tens of billions, at a time where competitive 
>>>utilities are extremely sensitive to cost.  Incidentally, some upgrades 
>>>will also harden the grid against high-tech terrorism.  So far, we 
>>>haven't seen major deliberate attempts, but there was a warning in one 
>>>of the more recent Northeast blackouts. While the Supervisory Control 
>>>And Data Acquisition (SCADA) networks for the power grid should be 
>>>totally isolated from the Internet, we had at least one incident of a 
>>>bored contractor attaching a SCADA computer to the Internet with 
>>>personal equipment, which allowed a virus to get into the electrical 
>>>SCADA system. 
>>
>>Do you have a cite?  I searched Google News for SCADA Virus and found no 
>>articles.
> 
> 
> Probably in the RISKS Digest, but also on a number of professional 
> mailing lists. Some of these dealing with infrastructure security may 
> not be open and indexed by Google.
> 
>> SCADA networks, incidentally, are critical to other 
>>
>>>national resources such as oil & gas pipelines, water, etc., and 
>>>urgently need protection, probably on the order of moderately high 
>>>security military networks.
>>>
>>>>In the short run, conservation makes more sense than anything.