In a revolutionary leap that could transform solar power from a marginal, boutique alternative into a mainstream energy source, MIT researchers have overcome a major barrier to large-scale solar power: storing energy for use when the sun doesn't shine.

 

Until now, solar power has been a daytime-only energy source, because storing extra solar energy for later use is prohibitively expensive and grossly inefficient. With today's announcement, MIT researchers have hit upon a simple, inexpensive, highly efficient process for storing solar energy. 

 

(Video after the jump!)

There's power in them thar waves! That's why Portugal built Agucadoura, the world's first wave farm off its coast, consisting of three Wave Energy Converters generating a total of 2.25MW.

The elongated metal contraptions bob up and down with the waves, while internal pistons, attached to the sea floor, remain stationary and pump hydraulic fluid. This drives electric generators, whose power is brought ashore by underwater electrical cables. The wave farm is now tapping into enough constant, renewable energy to power 1500 homes.