Large power consumers can sign an interrupt able contract with a (deregulation) power company. Interruptible agreements give a discount in exchange for the promise the customer will voluntarily curtail their usage when asked. If they don't, they get socked with penalties. These agreements have existed for decades. On Thursday, PG&E asked its interruptible customers once again to curtail their usage. Involuntary curtailment is different. The prediction is involuntary curtailments and interruptions will become more commonplace as the market adjusts to deregulation. Hopefully, once deregulation is sorted out the proper incentives will exist to construct additional transmission and generation facilities. Some electrical customers disconnect from the grid anytime a potential exists for an unscheduled interruption. For example, some sensitive facilities switch to internal power anytime lightning strikes within five miles. They believe their internal power systems are better (albeit more expensive to operate) than the utility power. There is a different school of thought which believes transferring to an alternate power source is risky in and of itself, so its better to stay with the utility until it fails, because the utility may not fail but the transfer could. Finally, if you speak with the right people at the Edison Institute, they are very frank, there is always the potential for an unscheduled power interruption. Anyone who absolutely, positively can not risk any chance of an interruption should have an independent, standby power source. On Thu, 15 June 2000, gwright@thebiz.net wrote:

lucifer@lightbearer.com writes:

...

At least one major data center disconnected from the grid and went to generator power, prior to the rolling blackouts. The motivation was not stated, but it seems likely that they were requested to do so as part of the voluntary interruption efforts. No interruption of service was seen.

In a conversation with an MFS engineer today I mentioned the problems in the Bay area. He previously worked for SNET (Southern New England Telephone, now part of SBC) for many years and said it was standard practice for them to disconnect COs from the grid and run off generator power for hours or even a day or two during the summer season.

I was under the impression that these power shortages were the result of less over-engineering on the part of power companies due to deregulation but maybe this isn't such a new situation after all?