随着中西部和中大西洋地区出现短暂的热浪，与计划中的非季节性维护停机相叠加，服务于约三分之一美国人口的电网电力供应正趋于紧张。
Power supplies are tightening on grids that serve roughly one-third of the US population, as a short-lived blast of heat in the Midwest and Mid-Atlantic collides with planned off-season maintenance outages.
根据美国天气预测中心的预报，未来几天气温预计将比正常水平高出超过25华氏度（17摄氏度），到周三时华盛顿特区的最高气温将接近90华氏度。尽管该地区预计将很快降温，但服务于从中大西洋地区到芝加哥、覆盖6700万人口的PJM Interconnection LLC周二宣布进入低级别紧急状态，并敦促发电厂推迟维护。
Temperatures are expected to rise more than 25F (17C) above normal in the coming days, with highs near 90F in Washington, DC, by Wednesday, according to the US Weather Prediction Center. Though the region is expected to cool quickly, PJM Interconnection LLC, which serves 67 million people from the Mid-Atlantic to Chicago, declared a low-level emergency Tuesday and urged power plants to delay maintenance.
PJM预计本周将能够获得足够的资源来满足需求，但安排关键维护的时间变得越来越困难。
PJM expects to secure enough resources to meet demand this week, but finding time for critical maintenance is becoming more difficult.
PJM发言人杰弗里·希尔兹在一份声明中表示：“不可预测的天气模式正在减少可用于对服务于我们供电范围内的发电和输电设备进行重要维护或施工的天数。”
“Unpredictable weather patterns are providing fewer days to perform important maintenance or construction on the generation and transmission equipment serving our footprint,” PJM spokesman Jeffrey Shields said in an Those appeals have had little apparent impact on generation outages, according to Gary Cunningham, a director at energy advisory firm Tradition Energy. About 60 gigawatts of capacity remained offline Tuesday morning, while demand was expected to reach roughly 112 gigawatts.
然而，根据能源咨询公司Tradition Energy的主管加里·坎宁安的说法，这些呼吁对减少发电停机似乎影响甚微。周二上午，仍有约60吉瓦的容量处于离线状态，而需求预计将达到约112吉瓦。
“We haven’t seen a very strong reaction for generators in PJM rushing back into service since the declaration came out,” Cunningham wrote in an email Tuesday.
坎宁安周二在一封电子邮件中写道：“自该声明发布以来，我们尚未看到PJM地区发电机组因赶紧恢复运行而表现出非常强烈的反应。”
The effort to shore up power reserves this week is a testament to the dual challenges straining US grids. Severe weather and an explosion of demand for always-on power have put transmission and generation resources under pressure.
本周为提升电力储备所做的努力凸显了美国电网所面临的双重挑战。恶劣天气和对持续供电需求的激增正在给输电和发电资源带来压力。
In the central US, the Midcontinent Independent System Operator declared a maximum generation warning to flag the potential for low power reserves as temperatures rise and demand climbs. Projections are above normal for October, but “by no means unheard of,” Cunningham said.
在美国中部地区，中部独立系统运营商（MISO）宣布了最大发电警告，以提醒人们注意随着气温上升和需求攀升，电力储备可能偏低的风险。预测显示10月的气温将高于正常水平，但坎宁安表示：“这绝非前所未有。”MISO尚未就置评请求作出即时回应。
MISO didn’t immediately respond to a request for comment.
随着秋季和春季突如其来的寒潮和暖流日益增多，传统上用电量较低的季节也出现了用电激增。由于用电低谷减少，运营商修复超负荷运行的发电厂和输电线路的时间也越来越少。
Increasingly, sudden cold snaps and warm spells in the fall and spring are boosting electricity usage at what’s traditionally been a quieter time of year. With fewer lulls, operators have less time to repair overburdened power plants and transmission lines.
全年用电需求现在始终保持在较高水平，这主要得益于始终运行的数据中心快速扩张。新建发电厂和输电线路的速度跟不上需求增长，这意味着现有且老化的基础设施被迫加大负荷运行以维持供需平衡。
Demand is now sustained at higher levels throughout the year, with the rapid expansion of always-on data centers. New power plants and lines can’t be built fast enough, which means existing — and aging — infrastructure is forced to work harder to keep up.
人们还担心夏季高温持续时间延长、秋季变短，尤其是在德克萨斯州和PJM电网需求快速增长的地区。那些跳过维修停机的发电厂在最需要的时候更容易发生故障。
Concerns have also been mounting that summer heat is lasting longer and the fall season is growing shorter, particularly in areas with fast demand growth in Texas and on PJM’s grid. Plants that skip outages for repairs are more prone to breaking down when they’re needed most.
尽管美国电网通过增加可再生能源来补充老旧资源，但储能电池的采用进展不均。得益于风能、太阳能和储能的组合，德克萨斯州最大的电网今年夏天成功抵御了持续数周的极端高温（气温超过38摄氏度）。
Though US grids have added more renewables to supplement older resources, the adoption of battery storage has been uneven. The largest Texas grid withstood weeks of extreme, triple-digit heat this summer thanks to a combination of wind, solar and batteries.
但据Cunningham称，尽管PJM在扩大风能和太阳能装机容量，却未见类似的储能推进力度。
But PJM has not seen a similar push to add storage, despite building out wind and solar capacity, according to Cunningham.
他说：“如果不可调度的资源在需要时无法发电，这种变化就会带来风险期。”他补充道，PJM电网周二预计将实现的强劲风能和太阳能发电“将无法满足晚间用电需求”。
“That change creates periods of risk if the non-dispatchable resources are not producing when needed,” he said, adding that the robust wind and solar generation expected on PJM’s grid Tuesday “will not be up to the task of meeting evening demands.”