美国能源部长赖特：天然气、核能和煤炭是美国电网未来的关键。

Core Viewpoint - The U.S. Secretary of Energy, Jennifer Granholm, emphasizes that natural gas, nuclear energy, and coal will be critical for the future of the U.S. power grid [1] Group 1: Energy Sources - Natural gas is highlighted as a key component for maintaining energy reliability and supporting the transition to renewable energy [1] - Nuclear energy is recognized for its role in providing a stable and low-carbon energy source [1] - Coal, despite its declining use, is still considered important for energy security in certain regions [1]