Green Energy

What is clean coal?

15 things Obama has done for the environment

​What’s the best way to heat your house?

The clean energy breakthroughs that Silicon Valley billionaires are betting on

Michael Bloomberg gifts Sierra Club $30M to fund anti-coal efforts

Super-efficient solar power system sets record

Transparent solar windows generate energy without obstructing the view

SolarCity launches MySolar loan program for lease-shy homeowners

Super-futuristic Hong Kong skyscraper is topped with rice paddy

Wash your whites in this human-sized hamster wheel

A British supermarket that's powered by its own garbage

Spring rewind 2014: 15 singular stories worth revisiting