Science & Space
When solar panel cleaning pays off for your energy bill
Dirty panels do lose power, but a wash often earns back less than it costs. Here is how to tell if yours need one and how to clean them safely.
Energy Efficiency
Tech Business
Petra Power fuel cells promise lower fuel bills for data centers
The 15-person startup makes ceramic cells that turn natural gas into electricity without burning it, and is aiming at AI data centers and military vehicles.