Angel says that his plan is "no substitute for developing renewable energy: the only permanent solution".

安吉尔认为他的计划“不能取代对可再生能源的开发，那才是唯一永久的解决方案”。

youdao

No one can offer a permanent solution to the problem.

没有人能提出解决这个问题的长久之计。

《新英汉大辞典》

"It's not a permanent solution," she says.

她说：“这不是长远的解决方法。”

youdao

It ordered the company to provide a permanent water solution for families whose wells are polluted.

VOA: standard.2010.01.02

But she still wanted a permanent solution for immigrants living in the U.S. illegally.

WSJ: Laurene Powell Jobs, Widow of Steve Jobs, Goes Public to Promote Dream Act

These efforts worked for a while but were not seen as a permanent solution.

CNN: Flower power threatens Kenya's Lake Victoria

I'd had a permanent scare from the tornado, and I wanted a permanent solution.

WSJ: Anna Quindlen on a Message Delivered by Tornado | House Call