I wanted to follow up on The Orchid's post from yesterday about the power outage in San Diego and southwestern Arizona.
I'll start with a bit of background on how such an event happened, why we are where we are with power distribution, and finally, how this national security concern has been known about for years- but ignored or downplayed.
There are two major interconnects that tie San Diego Gas & Electric's distribution system into the greater Western Interconnect:
SCE-SDG&E interconnect: A northern 500kV interconnect that links SDG&E's transmission/distribution system with Southern California Edison- with the likely connection occurring near the San Onofre Nuclear Generating Station switchyard.
Path 46: The "North Gila - Imperial Valley" route, which runs from the Yuma substation that triggered the cascading failures causing yesterday's outage- composed of a 500kV AC line, delivering power from the various Arizona plants (Palo Verde Nuclear Generating Station and other combined-cycle natural gas plants in south-central Arizona).
The loss of the Path 46 line through cascading failures at the Yuma switchyard caused a load unbalance that ultimately forced the shutdown of SONGS. In a normal situation, a load unbalance will be picked up with the transmission of electricity into the area with a need for more electricity- like water flowing from a high area, to a low area. The removal of Path 46 didn't create a pothole like a single generator going off line would- it created a canyon.
The SONGS (or close by) interconnect was like trying to fill this canyon with a fire hose. It just wasn't going to happen. This massive draw caused monitoring systems to "trip" the generators to prevent any more catastrophic damages. A similar situation occurred in Arizona earlier this decade, when a 230kV transmission line was grounded- and multiple generating stations tried to deal with the load imbalance by pouring all of the power into the ground. Multiple generators tripped (including all three PVNGS units) leading to a large, extended power outage for the Phoenix Area.
See the SDG&E press release for their explanation.
Why we're here
How could the loss of a single transmission line cause so many cascading failures? Well, apart from environmental concerns regarding the addition of new 500kV lines (a second SDG&E backed line from Arizona was rejected, and is in limbo), the US electrical grid has suffered from a chronic and dangerous lack of investment.
From IEEE Spectrum:
What happened? Starting in 1995, the amortization and depreciation rate has exceeded utility construction expenditures. In other words, for the past 15 years, utilities have harvested more than they have planted. The result is an increasingly stressed grid. Indeed, grid operators should be praised for keeping the lights on, while managing a system with diminished shock absorbers.
R&D spending for the electric power sector dropped 74 percent, from a high in 1993 of US $741 million to $193 million in 2000. R&D represented a meager 0.3 percent of revenue in the six-year period from 1995 to 2000, before declining even further to 0.17 percent from 2001 to 2006. Even the hotel industry put more into R&D.
Our first strategy for greater reliability should be to expand and strengthen the transmission backbone (at a total cost of about $82 billion), augmented with highly efficient local microgrids that combine heat, power, and storage systems. In the long run, we need a smart grid with self-healing capabilities (total cost, $165 to $170 billion).
Now, we can't expect the private industry to fully shoulder the blame on this one. The Western Area Power Administration (WAPA) and other Department of Energy entities (like FERC) have a public responsibility to ensure critical infrastructure is built and maintained. Additionally, state entities such as the California Public Utilities Commission and the Arizona Corporation Commission must approve new infrastructure in their jurisdictions. If just one party (out of sometimes as many as 6- including BLM, USDA, etc) drags their feet or doesn't approve... game over, the project dies or is 20 years behind where it needed to be.
The laissez-faire attitude of these bodies in not truly regulating and engaging in furthering the public good needs to be addressed yesterday. Our energy infrastructure got a D+ grade from the American Society of Civil Engineers. Hardly anything to cheer about.
Finally, what about this National Security Concern?
Since the September 11th attacks, power stations such as SONGS and PVNGS have had nearly complete overhauls in security. Other infrastructure such as water treatment plants, airports, and harbors have been secured as well.
But perhaps the most vulnerable pieces of infrastructure, the 500kV regional interconnects and 230kV distribution connects, have been overlooked. Perhaps because most people don't think about their vulnerability, they are secured by that ignorance.
Indeed, as we have seen in this incident, our transmission system is precarious in some places. A single failure in Yuma, Arizona, managed to leave San Diego County without power for hours. A single failure in northwest Phoenix several years ago (of a single transformer) left many facing mandatory blackouts during the middle of summer.
A planned attack on these critical sites, which can be found with very little effort looking online, can cripple economies and cause severe loss of life. Imagine if Phoenix, America's sixth largest city, were to be completely blacked out in the middle of a string of 110+ degree days.
This isn't anything new. Talk to some knowledgeable engineers in the utility industry and they will tell you how critical these transmission lines are. Some will even tell you anecdotes about how hunters who fired at insulators on these lines were able to cause blackouts in major cities hundreds of miles away. Not even to mention the effect this would have on the generating stations (nuclear and fossil)- where every unplanned shutdown could spiral to catastrophe.
I think if we learn anything from the San Diego power outage, it should be just how precarious our lives sit. Just 100 years ago, electricity was a luxury. Today, we cannot live without it (literally, in some climates). Private and public entities both have a responsibility to residents in this country to provide a safe, reliable electric grid. To do that, they need to quit harvesting the fruits of investment planted more than 70 years ago, and start sowing new seeds today. If this is unheeded, at best we will end up with a decrepit third world electric grid marked by outages and use-restrictions; at worst, the complete economic devastation and loss of many lives due to failures or intentional sabotage.
12:28 PM PT: Per the suggestion in the comments from several users:
Take Action and let your Representatives know this kind of thing is only more likely to happen. See barath's post here: http://www.dailykos.com/...
Talking point: The American Jobs act will create a National Infrastructure Bank that can give utilities the capital they need to finance improvements to prevent blackouts like this from occurring in the future. The billions of productivity lost from this blackout and future ones will be more than enough to justify keeping America productive and safe!