Complementary batteries are needed

In Short

Complementary batteries are needed for an all-electric solution based on solar and wind energy.

A Few Details

Cheap and fast-charging batteries still need to be developed to compete seriously with fossil fuels:
-For electricity storage to compensate intermittent solar and wind;
-For energy vector for mobile devices (car, chainsaw…) not permanently connected to grid;
-For swapping a discharged battery with a full battery powering a mobile device.

More Info