上周末,寻找新探索的地方, my wife and I drove down to Northfield, Massachusetts, to check out the cross-country ski center. The skiing was great, and it occurred to me that readers of this column might be interested in learning about the pumped-hydro power plant on the mountain—the ski center was created as a recreational amenity for this power project.

When the Northfield Mountain pumped-hydro power station was built in 1972, it was the largest facility of its type in the world. To understand why the plant is so significant, it helps to understand one of the problems with an electrical power grid: storage.

电力由发电厂产生，电流（电子元件）流过大量电流环 - 我们的电网。我们挖掘这个网格，以操作我们的灯和电器，加热我们的房屋，并（总有一天）甚至为我们的插件混合动力汽车充电。

问题是电力很难储存。启动和关闭电厂需要很长时间，因此公用事业公司即使在生产更多的电力时，公用事业公司必须保持这些植物运行，从而浪费大量电力。这是泵送存储的地方。

在世界各地的泵浦水电设施，在非高峰期间利用过多的电力（当公用事业公司生产更多的电力而不是客户需要的电量）来抽水。在Northfield Mountain，水通过1,100英尺长的地下轴从康涅狄格河泵送到河上方800英尺的人工储层。然后，在公用事业公司需要额外的电力时达到峰值需求（或在紧急情况下，当其他发电厂关闭时）时，允许水流通过相同的轴，并且水旋转涡轮机以产生电力。

The Northfield Mountain upper reservoir covers 300 acres and holds 5.6 billion gallons of water. Deep underground there are four reversible turbines. Each of these can pump 20,000 gallons of water per second to the upper reservoir and then generate 270,000 kilowatts of electricity from the return flow, so the total output for the four turbines is 1,080 MW—enough to serve peak-power requirements of 1.7 million customers.

随着泵送 - 水力储存，泵送（以及从上层储存器蒸发）的损失，但是当水流退回时，通常会恢复出色的70-85％的电气能量上坡。。

Pumped-hydro is by far the most economical method of storing large amounts of electrical energy—far less expensive than batteries.

另一个能量存储选项仍然是实验性，将以类似的方式在地下洞穴中使用压缩空气。采用这种方法，耗时的电力将用于电动大鼓风机，迫使空气牢固地封闭地下洞穴或废弃的矿山。然后，当需要峰值功率时，将允许该空气通过风力涡轮机吹出。迄今为止，没有实用规模的压缩空气蓄电系统，尽管在这项技术上进行了研究。

由于泵浦水电为公用事业公司提供了如此多的意义，因此在过去几十年中建造了相当多的系统。Northfield Mountain只将其荣誉视为世界上大约一年的最大的设施。今天最大的今天，弗吉尼亚州的两倍大，容量为2,100兆瓦。尽管如此，我们的附近系统占全国总泵送水力发电容量的5％。如果有更多的地方来构建这种类型的植物，如果它们很容易构建，那么可能会有更多的东西。

So if you feel like some cross-country skiing or a nice hike sometime, head down to Northfield Mountain (on Route 63 a few miles north of Route 2), and enjoy a workout. Various trails climb the 800-foot rise to the upper reservoir, offering a nice view of this body of water—and plenty of exercise. It took us about an hour to ski to the top via the Reservoir Road trail, and I was told that the record for skiing back down is eight minutes! Unfortunately, you won’t be able to see the turbines or much else with the system, because most of it is deep underground. But I find it fascinating to think about the massive infrastructure that’s pumping millions of gallons of water up and down the mountain on a daily basis—a process that helps keep our electricity affordable and provides emergency back-up in the event of power plant failures.