[2006 ]

On April 17, shortly after 4 p.m., hundreds of thousands of Texans started losing power. The operator of the Texas power grid, the Electric Reliability Council of Texas, suddenly found itself without enough available generating capacity and ordered rolling blackouts across the state. Although ERCOT acted quickly to avert a more serious system-wide outage, its response nonetheless raised serious management questions. “You can’t be out there cowboying, operating on your own,” state Sen. Troy Fraser told organization officials shortly afterwards. Sen. Fraser and others complained that ERCOT had failed to alert key policymakers and law enforcement officials. He said regulators were caught flat-footed, and police officers were sent scrambling to direct cars after traffic signals unexpectedly stopped working.

2006年4月17日の午後4時を過ぎた頃、数十万人のテキサス人たちは電力を失いはじめた。テキサス電力グリッドの運用者であるERCOTは、突然、発電容量が十分でないことに気づき、州全域に輪番停電を発令した。ERCOTは迅速に対処し、州全域停電という深刻な事態を回避したが、しかし、その対処は管理能力に対する重大な疑問を生じさせた。これからほどなく、Troy Fraser州上院議員はERCOT当局者に対して「自分自身のも乗りこなせないのか」と言った。Fraser州上院議員たちはERCOTに対して、主要な政策担当者や司法当局へ事前警告しなかったことに不満を述べた。規制当局は不意討ちにあって、警察は予期せずして信号が消えてから、交通整理に緊急出動した。

PUC Chairman Paul Hudson also blasted ERCOT’s response, complaining that grid managers did not call him directly about the emergency. “My immediate one-word reply is a bit too colorful to restate,” Hudson said. But the PUC chairman also said that when it came to dealing with ERCOT, such communications breakdowns were nothing new.

PUCのPaul Hudson委員長は、非常事態について電力グリッド運用者たちが自分に直接連絡してこなかったことに不満を述べ、ERCOTを強く批判した。「私が即座に放った一言は強烈で、ちょっと口にできない。しかし、ERCOTを相手にしていると、このような通信途絶は珍しいことではない。」

The organization, charged with scheduling power across 38,000 miles of transmission lines, had done little to earn the confidence of lawmakers and regulators. Since the passage of SB 7 in 1999, ERCOT had mismanaged the deregulation pilot project, appeared incapable of efficiently processing switch requests for many months and drew fire for multi-million dollar billing errors. There were also problems with the organization’s financial controls, as evidenced by the guilty pleas of several former executives on bribery and corruption charges.

[2011 ]

The resource adequacy issue received even more scrutiny in 2011 after a series of reliability emergencies. The first occurred in early February, when dozens of generating plants seized-up during a cold snap. At the same time usage peaked. ERCOT responded by ordering rolling blackouts and as a result, millions of Texans lost power. All told, approximately one-third of the state’s generation fleet was unavailable during the most difficult point of the crisis, according to federal officials.


ERCOT also faced repeated grid emergencies in July and August, when the state broke demand records during a historic heat wave. Although ERCOT did not resort to rolling blackouts, it took other emergency action - such as disconnecting some big industrial consumers, and calling for the public to shut off appliances during peak hours. New statewide electricity usage records were set on Aug. 1st, 2nd and 3rd.


Although Luminant in North Texas claimed that it lost money during the February blackouts, the crises represented a potential profit bonanza for other generators. That’s because in both the summer and winter grid emergencies, prices in the wholesale electricity market shot up to a $3,000 per megawatt/hour cap - or about 50-60 times higher than typical prices. Prices remained at those inflated levels for hours. That some companies were rewarded during the emergencies raised additional questions about the state’s electricity market, especially given that ERCOT had been obligated to order statewide rolling blackouts twice in just five years under the system, but only once ordered similar rolling outages in its 30-plus years before deregulation.


Robert McCullough, an Oregon-based economist, was among those raising the questions. He noted, for instance, that the cold snap that led to the rolling outages in 2011 was not an unprecedented event. There were similar cold weather events in 1983, 1989, 2003, 2006, 2008 and 2010, but in only one of those instances - during the cold weather event of 1989 - had ERCOT resorted to rolling blackouts. McCullough also questioned whether a lack of efficiency under the new nodal system played a role, noting that prices spiked to the nearly unprecedented levels shortly after the new nodal system went into effect, and only within a day of the lifting of price caps.

オレゴン州を本拠地とするエコノミストRobert McCulloughは、疑問を提起した者のひとりである。彼は、たとえば、2011年の一時的寒波による輪番停電は前例のない出来事ではなかったと言う。同様の気象条件は1983年、1989年、2003年、2006年、2008年、2010年にあったが、1989年のみERCOTは輪番停電をせざるをえなかった。Robert McCulloughは、新しいノードシステムの稼働後に、前例のない価格高騰が起きて、価格上限に到達した唯一の日となったことから、新しいノードシステムにも疑問を呈している。

However, a separate investigation by the state’s Independent Market Monitor failed to find any problems with the nodal system nor any evidence of market manipulation. A government organization known as the Texas Reliability Entity blamed the outages for the most part on inclement weather, although it said plant operators could have done a better job. The North American Electric Reliability Corporation noted that “given the high demand and the huge loss of generation” it was not so surprising that prices hit the $3,000 per megawatt/hour cap.

しかし、州のIndependent Market Monitorによる独立した調査では、ノードシステムの問題点も、相場操縦の証拠も見いだせなかった。Texas Reliability Entityとして知られる州政府機関は、停電の原因を主として天候だとしたが、発電所のオペレータがもう少し、うまくやれた可能性があると述べている。North American Electric Reliability Corporationは「大きな需要と発電機の大量脱落があれば、3000ドル/MHWの価格上限に到達するのは驚くことではない」と述べている。

The head of the Texas Public Utility Commission expressed concern Friday that a new federal air quality rule, set to take effect Jan. 1, will cause disruptions in electric service.

If implementation of the Cross-State Air Pollution Rule is not delayed, "I have no doubt in my mind that this rule will result in reliability issues and rolling outages in Texas," Donna Nelson said at the start of the commission's meeting.

The rule, issued in early July by the Environmental Protection Agency, would require substantial reductions in emissions of nitrogen oxides and sulfur dioxide at power plants in 27 states.

The EPA says the rule will save and prolong lives by reducing harmful smog and soot pollution. Gina McCarthy, an EPA assistant administrator, said in a previous statement that power plants in the state "will be able to cut their pollution without jeopardizing reliable electricity service for Texans."

テキサス州公益事業委員会(PUC)委員長は、2012年1月1日に発効する連邦の排出規制が電力供給を崩壊させるだろうとの懸念を、金曜日に表明した。州間大気汚染規制の適用が延期されないと、「この規制はテキサス州の電力の信頼性問題と輪番停電をもたらすと確信している」と委員会の開会時に、Donna Nelson委員長は発言した。

7月初めに環境庁が公告した規制は、27州の発電所で窒素酸化物と硫黄酸化物の排出量を大幅に削減を義務付けている。環境庁は、この法規制は、有害なスモッグと煤塵汚染を浴抑制することで、生命を守り、長らえさせることができると述べている。環境庁補佐官のひとりGina McCarthyは以前の声明で、テキサス州の発電所は「テキサス州の電力供給の信頼性を損なうことなく、汚染を削減できるだろう」と述べていた。

But Dallas-based power generator Luminant says it doesn't have enough time to comply and has asked that the EPA delay implementation.

The company says the industry's standard time frame for installing emission controls is several years, but the rule requires compliance in six months. So Luminant, a subsidiary of Energy Future Holdings, has said it may have to shut down some coal-fired power plants in East Texas.

"Curtailing plant and/or mine operations will be the only option" if the 1,323-page rule goes into effect as planned, Luminant said.

しかし、Energy Future Holdingsの部門であり、ダラスを本拠地とする発電会社Luminantは、「法規制遵守には十分な時間がなく、環境庁に適用延期を求めている。排出対策の実装には業界標準では、数年のタイムスケールが必要であるが、この規制では半年間しかない。Luminantは東部テキサスの石炭火力を幾つか停止せざるを得ない」と述べた。

[ Jack Z. Smith- "New EPA rule could lead to rolling blackouts in Texas, PUC chairwoman says" (2011/08/19) on Star Telegram ]
これに対して、2011年9月にはERCOTは影響推定を公表。テキサス州検事局はあらゆる手段で、法規制阻止に動き出し、2011年12月にThe U.S. Court of Appeals for the D.C. Circuitは法規制一時停止を命じた。

The Electric Reliability Council of Texas expects to continue calling for conservation this summer even though it has added roughly 2,000 megawatts of generation.

The increase in power comes from 2,000 MW of capacity that had been mothballed, or taken offline for an indefinite period of time. Owners have decided to put those units back into production.

The total also includes about 430 MW of capacity that was not available during last summer's brutal heat wave.

“Even with this additional generation, we expect that there may be some calls for conservation when energy use is particularly high or if generation supplies are impacted by unplanned outages,” said ERCOT CEO Trip Doggett. “Having nearly 2,000 MW of additional generation available this summer will help reduce the likelihood of rotating outages.”

ERCOT expects to have nearly 74,000 MW of generation resources available to serve summer needs.



「この夏に向けて発電容量を積み増したが、エネルギー使用が非常に高くなった場合や、発電機が計画外停止した場合は、節電を要請することになるだろう。200万kW近い発電容量の積み増しにより、輪番停電の可能性は減少した。」とERCOTのCEOであるTrip Doggetは述べた。

[ Frank Heinz- "More Power Generators Coming Online This Summer" (2012/05/01) on NBC DFW ]


  • 最終更新:2012-09-09 02:30:48