On Novemver 7, 2016, ESA sent a  follow-up comment to IRS on Notice 2015-70.

The ITC remains an important incentive for emerging energy technologies, including solar, wind, and other renewable energy technologies that incorporate integrated energy storage to more effectively make use of renewable energy when it is needed.

ESA commends the IRS for issuing Notice 2015-70 in recognition of both the increasing popularity of pairing energy storage equipment with other qualifying energy property and the lack of clear guidance on that equipment’s eligibility. In light of continuing innovation in energy storage, ESA asks that the IRS issue guidance on the ITC that ensures the eligibility of a broad diversity of storage technologies, configurations, and use cases, all of which meet the same goal of better utilizing qualifying energy property. Additionally, ESA asks that the IRS issue guidance that enhances flexibility and certainty for owners of eligible energy storage equipment, such as through a primary use eligibility standard and modified recapture rules for Dual Use Equipment, the eligibility of storage added to existing projects, and eligibility of separately-owned equipment.