I think Matt Roberts makes a key point here. Many people, myself included, have made the association between Solar PV in the mid 2000's and energy storage now. It's an obvious one to make, especially as it's in recent memory, and many of us experienced that journey, or Solarcoaster. It doesn't take much thinking though to realise the similarity is skin deep. Solar has grown enormously over the last ten years, but in reality the technology change has been slow. Slight improvements in efficiency, and big reductions in cost and therefore deployment. Energy storage is an entirely different ball game, the growth and advance in technolgies, as well as rapid cost reductions play one part, but so does the whole set of different grid and service opportunities. Decentralised energy is coming at pace. Solar and wind have done a great deal to path the way, but storage is about to change the world as we know it.
The oft made analogy is that energy storage resembles the solar industry circa 2005. Though from my seat the road ahead looks very different than that of the past decade for renewables. According to the ‘U.S. Energy Storage Monitor’, 2015 saw over 250% growth in system deployments – doubling the entire US installed capacity. In the last quarter there was more energy storage deployed than all of 2013 & 2014 combined. By the beginning of next decade, more than 6.5GW of energy storage have been deployed. In the past 18 months, ESS costs have declined more than 70% and the balance-of-system costs are projected to decline another 41% before 2020. Ramped up manufacturing and production and expanded market access will depress prices for storage technologies further, and the ES Monitor projects more than 25% in additional cost declines before 2018.