Lý do nào người dân Montana vật lộn trong giá buốt?

-----

...It was a perplexing (phức tạp, rắc rối, khó hiểu) and costly (hao tiền tốn của, tai hại) dilemma (thế tiến thoái lưỡng nan, tình trạng khó xử), and it took a stroke of luck to solve the mystery of what was causing the outages on NorthWestern’s transmission lines (truyền điện, dây điện).

Late one winter afternoon, NorthWestern Energy employee James Lueck was out with a crew who were working on the 500kV lines. Just as the sun was starting to set, huge flocks of ravens (đàn quạ khổng lồ) began landing on the 500kV towers to roost (đậu, ngủ) for the night.

“It was like something out of a Hitchcock movie,” Lueck said.

Ravens are a challenge for energy companies because their numbers — flocks can number in the thousands.

They roost on power lines and leave droppings (phân chim) on insulators (cái cách điện). When the dried droppings combine with fog (sương mù) or light rain, the mixture conducts electricity and creates a bridge along the insulator “skirts,” which causes a fault (rò điện) on the line. It creates the perfect opportunity for outages (mất điện).

Bài trước: Im lặng không là vàng