Batteries are the key to our renewable energy future. For intermittent renewables like solar power and wind turbines to be useful, we need energy storage to make them work over long periods of time. Lithium ion batteries come to mind, but they’re still too expensive for long-term energy storage. Pumped hydro energy storage makes up the largest battery systems in the world, but they’re limited to geography. Over 96% of the earth’s water is contained in the oceans, so what if we could turn oceans or lakes themselves into a battery? There’s some compelling technologies here, but let’s see if we can come to a decision on this.
