January 2016

 By Roger Lin

The use of energy storage as an alternative to traditional wires and substation upgrades can be an attractive option for utilities. Energy storage can support distribution system operation in lieu of upgrading the entire distribution circuit, which could be difficult due to restrictions or constraints in certain environments. Depending on the conditions, storage could be a more effective and less expensive option; use of energy storage will also help the utility more effectively use the existing transmission or distribution capacity. This can be a valuable option compared to upgrading the capacity for peak hours, especially if they occur infrequently over the course of an entire year. However, beyond the upfront comparative cost-to-benefit analysis, there can be other challenges that arise after the decision to install storage is made, especially when deploying it in dense urban environments.

 By Kiran Kumaraswamy

Primary Frequency Response, or PFR, is a critical system service required to ensure the reliability and security of the electric grid. Though necessary, a recent study performed by the North American Electric Reliability Corporation (NERC) showed frequency response in the entire Eastern Interconnection is declining as increased levels of renewable generation and decreased levels of traditional generation plants no longer have enough inertia to supply the necessary system response. Little to no financial incentive exists to provide this critical service, so utilities, policy makers and regulators are now looking to resources that can cost-effectively provide this service and meet other market needs.

 By Matt Kromer, Sidharth Choudhary, Christof Wittwer, Felix Braam and Robert Kohrs

A combination of the rapid growth of distributed solar photovoltaic (PV) generation in Germany, a changing regulatory regime that has limited price supports for PV generation while subsidizing battery/PV systems and falling costs of battery-based energy storage has spurred intense interest in behind-the-meter battery/PV systems as a means to cost-effectively integrate solar PV into the German power distribution system. While these systems are not yet economical, multiple converging technology trends – in particular, continued storage system cost reduction, improved systems integration, and development of an integrated, interoperable control framework – offer the potential for broad-based adoption over a five-year time horizon. These emerging trends within the German PV market offer insight as to how the less mature U.S. market might evolve.

 By Jerry Melcher

The market for behind-the-meter energy storage has recently been reported growing by 15 times year-over-year. This is a significant development in direction and magnitude with over 13 megawatts installed in the third quarter of 2015. There are a number of factors contributing to this uptick, but along with the opportunities a host of challenges exist. This update will review various factors for each.