Residential Solar Energy Storage Examined As A Promising Grid Resource

SI Staff
Written by Michael Puttre
on July 08, 2014 No Comments
Categories : New & Noteworthy

14333_batterybutton Residential Solar Energy Storage Examined As A Promising Grid Resource While California is often at the forefront of solar development in the U.S., its ambitious targets for grid-tied energy storage makes it a world leader in evaluating technologies and creating policies that will shape energy storage's global deployment.

Chris Edgette, senior advisor to the California Energy Storage Alliance, says solar deployment in California is demonstrably affecting the overall operation of the electrical grid. Chairing a panel at Intersolar North America in San Francisco this week, Edgette said so many technologies and policies are involved that working out the technologies, business models, regulations and incentives that will define how storage will function requires significant input from a wide spectrum of stakeholders.

Carla Peterman, commissioner of the California Public Utilities Commission (CPUC), said during the panel discussion that as the first state in the U.S. to set formal storage targets, California is also on point in working out how such targets are to be met.

‘Think of the 1.325 GW target for energy storage in California as a floor, not a ceiling,’ Peterman said.

While energy storage is commonly viewed from the transmission and grid distribution angles, Peterman said in many ways customer-side ‘behind the meter’ storage represents the most significant challenge. Certainly, the 200 MW carve-out for customer-side storage represents a considerable portion of the current target. However, the nature of the storage systems and interconnection issues involved at this level are exceedingly complex.

‘This is a new asset class that is not comparable with other generation resources,’ Peterman said. ‘It has its own properties.’

An important driver of this segment of the storage market is the extension of funding for the Self-Generation Incentive Program (SGIP) that will enable it to run through 2020. While SGIP provides financial subsidies against the up-front costs of customer-side storage, Peterman said deployment incentives are only part of the equation.

‘We are providing for utility and third-party ownership of customer-side storage,’ she said, adding that flexibility with regard to business models is important at this stage for helping grow a supporting industry.

On the industry side, Phil Undercuffler, director of strategic platforms for Outback Power, said that the solar sector has licked the problem from a production standpoint. The problem now is how to balance the grid. He suggests the same economic forces that enabled photovoltaic generation to penetrate must be put in place for storage.

‘When people began to loan money for PV development based on the promised revenue stream, the industry started to take off,’ Undercuffler said, adding that when storage shows such potential, it will also take off.

Andrew Schwartz, deputy director of government affairs for SolarCity, said the regulatory and policy issues were more important to the future of solar energy storage than technological ones. There is a lot of confusion in the rules, he said, particularly with regard to residential customers.

‘Residential customers want backup [power] and energy arbitrage,’ Schwartz said, referring to the ability for customer-side storage owners to produce and sell energy to their best advantage. ‘The incentives are not in place for residential customers to fully leverage their systems.’

Heather Sanders, director of regulatory affairs for distributed generation at the California Independent System Operator (CAISO), said in order for energy storage to take its place as a full-fledged generation resource, it has to have the appropriate characteristics, including ISO dispatch control. Enabling such control and other issues at the level of customer-side systems is the focus of an energy storage roadmap effort CAISO is pursuing in partnership with the CPUC and the California Energy Commission.

"Now that we have solar energy, the real question is how to manage variability,’ Sanders said. ‘You wouldn't care about the shape of the load if you have storage in the right place in the right amounts.’

Thus, in order for storage to assume its full potential on the grid, the ISO has to be able to treat it as a generating resource. Sanders said that for this to happen, the deliverability of storage – its ability to generate required loads at the ISO's beckon call – has to be established. Much work still needs to be done on this count.

Leave a Comment