Blogs, Grid Scale, Solar, Storage

Energy Storage: Progress and Promise

The pending boom of the energy storage industry is right around the corner, and the U.S. is taking a front seat. According to recent IHS research, the U.S. is the largest market for grid-connected energy storage installations through 2017, and global sales of combined solar energy storage systems are expected to reach nearly $30 billion by then.

This mounting interest in energy storage is evident from the expanded deployment of storage-backed solar, extensive battery research efforts across the country and increased investment activity. California continues to be a progressive leader in renewable energy technologies and now has a mandate calling for 1.3 GW of energy storage by 2020. The state has already applied for installation projects totaling double the required amount. Even the Intersolar North America Conference this past July had multiple sessions dedicated to energy storage. The industry has also seen growth in venture capital funding sparked by technological improvements and local policies, and the first quarter of 2014 attracted $107 million in investments for smart grid and energy storage in the U.S.

Energy storage systems can be beneficial on a small or large scale.

  • Commercial consumers combine storage with renewables or demand response.
  • Residential consumers pair storage with PV installations to reap maximum benefits of solar systems.
  • Utilities use storage as reserve capacity to accommodate peak loads and improve grid resilience.

Although the basic technology has been around for years, there have been many improvements in effectiveness, safety and cost. Current grid-scale storage typically uses lithium-ion or sodium-sulfur batteries, which provide multi-hour capacity at relatively high temperatures. The main technologies currently emerging in the market are flow batteries, fly wheels, solid state and thermal. Sodium-beta batteries are also being tested. They operate at significantly lower temperatures, allowing cheaper materials to be used and reducing overall production cost.

Flow batteries are an emerging form of storage due to their longevity and dynamic capacity, which is promising for grid-scale storage. These batteries have the ability to increase energy capacity by adding electrolytes that serve as a storage medium. Flow batteries have taken a leadership position in large-scale projects, such as the NYC Con Edison project. Con Ed and the MTA chose to install a German flow battery technology, CellCube, in downtown Manhattan in the first attempt to bring grid-scale storage to the congested city.

Although many of these new storage technologies seem superior to the lithium-ion battery, the growth of the electric vehicle (EV) market continues to spur innovation into lithium-ion, making it the battery of choice for these cars. This growth has spurred lowered production costs and makes these batteries competitive in the market. EV’s themselves can also be used as storage. Second-hand batteries can be repurposed as storage, and many advanced vehicles can be used during emergencies as a source of power.

Energy storage has the potential to disrupt the power industry by creating renewable energy inventory. However, cost is a huge roadblock in reaching that goal. Many R&D labs across the globe are focused on driving down costs to achieve grid-scale deployment, and innovative business models, such as Green Charge Networks, can go a long way in providing appropriate consumer incentives. The future of energy storage looks promising, but we still need a combination of technological advancements and clever financing for it to reach its full potential. 

Keri Masterson contributed to this article.