If we weren't constrained by how few reactors we've built, we'd probably store electrical energy as fuel using http://en.wikipedia.org/wiki/Haber_process http:/

If we weren't constrained by how few reactors we've built, we'd probably store electrical energy as fuel using http://en.wikipedia.org/wiki/Haber_process http://en.wikipedia.org/wiki/Haber_process to create liquid ammonia from hydrogen (electrolyzed water) and nitrogen (distilled air). Batteries may eventually become competitive in recharge rate and useful lifetime, though.