Tesla's solar roof was an experiment that never really caught on for the company. But does that mean the concept of roof-integrated solar is dead?

Fusion power startup Inertia Enterprises reduced the fuel filling process from a week to just a few hours. It's one of 10 hurdles the company must overcome to make a profitable power plant.

Y Combinator alumnus Apollo Atomics is shrinking a key nuclear reactor part, which promises to slash the cost of electricity below natural gas.