WASHINGTON — Sen. Lamar Alexander says he’s just exercising his congressional oversight powers. But a clean energy advocacy group says he’s trying to micromanage the Tennessee Valley Authority.

Around 4:30 pm last Wednesday, Alexander headed to the Senate floor to launch yet another attack against one of his favorite targets: wind power.

For nearly 12 minutes, the Maryville Republican spoke out against a Texas company’s plans to build a $2 billion, 700-mile transmission line that would bring Oklahoma wind power across Arkansas to Memphis.

As he has done before, Alexander argued TVA should not buy power from the Clean Line Energy Partners’ wind transmission project, known as the Plains and Eastern line.

Buying electricity from Clean Line Energy could cost TVA ratepayers more than $1 billion over the next 20 to 30 years — the typical length of such an agreement — and would mean that TVA would have to raise Tennesseans’ electricity bills, Alexander warned.

“TVA is on a good path,” the senator said. “Its leadership has made sound decisions that will benefit ratepayers and our region.”

TVA has concluded it doesn’t need more power for the foreseeable future, Alexander said, but even if it did, “TVA should not agree to buy more wind power, which is comparatively unreliable and expensive.”

The head of an organization that tracks energy issues in the southeast called the senator’s comments inaccurate, misleading and an obvious attempt to pressure the TVA.

“This is one senator micromanaging the Tennessee Valley Authority, and I think it’s inappropriate for him to do that,” said Stephen Smith, executive director of the Southern Alliance for Clean Energy. “He can’t even get his facts right.”