Bringing Storage Beyond the Closet and into the Socket

rp_ca_innov_series_icon_283x204.jpgEDF’s Innovators Series profiles companies and people across California with bold solutions to reduce carbon pollution and help the state meet the goals of AB 32. Each addition to the series will profile a different solution, focused on the development of new technologies and ideas.

When someone says the word “storage,” the first thing that usually comes to mind are boxes stuffed into the back of the closet, or that deserted facility with orange doors near the freeway off-ramp.

These days, energy innovators across California are giving storage a whole new meaning – and helping to revolutionize the system that brings electricity to homeowners and businesses alike. One of the entities leading this revolution is Pacific Gas & Electric Company (PG&E), a utility in the midst of piloting new battery energy storage technology to determine how effectively it can provide a variety of grid services, including the integration of intermittent renewable generation from solar and wind.

Increasing amounts of distributed energy generation in both urban and rural areas – coupled with increasing customer demand associated with things like population growth and consumer electronics – makes energy storage an important tool to keep generation and energy use in balance. This balancing function is an important asset for integrating renewables into the grid, as storage can soak up solar and wind energy when they are abundant and discharge that energy when it is otherwise unavailable. Through this charge / discharge cycle, energy storage could lower the need for traditional fossil fuel sources and reduce resultant air pollution.

In collaboration with the California Energy Commission, PG&E is developing and deploying two promising grid-scale battery projects: a two megawatt (MW) facility at a substation in Vacaville, and a four MW facility in San Jose, the latter being the largest of its kind in the state.

Who: Pacific Gas & Electric Company, an investor-owned utility in California that provides natural gas and electric service to approximately 16 million people across the northern and central parts of the state.

What: PG&E is helping to revolutionize the electric grid in California through innovative research projects, such as large-scale sodium sulfur battery centers in San Jose, the largest of its kind in the state, as well as Vacaville.

Where: PG&E is based in San Francisco, and serves customers all over northern and central California.

Why: By enabling capture of renewable energy, PG&E is providing important grid benefits and helping to meet the state’s greenhouse gas emission goals.

“What’s exciting – and challenging – about these projects,” says Dave Fribush, Project Manager of Battery Storage Systems at PG&E, “is that we’re doing something very innovative. We’re bringing a new technology online and demonstrating that it can indeed provide a number of different benefits to the grid, including helping integrate renewables.”

Fribush cautioned that “it’s important to remember, though, that energy storage is not ‘green’ by nature, because you get less energy out than you put in. So when you talk about the big picture, how we use storage is key to getting these benefits, and a lot of work remains to be done by all industry stakeholders to ensure that we practically realize the benefits that storage can provide.”

Mark Higgins, Senior Director at the California Energy Storage Alliance, concurs in this assessment: “PG&E is doing critical work with their sulfur sodium battery project. By developing a model that has tested every step from project conception to interaction with the California Independent System Operator (CAISO) market, they have positioned themselves as a true leader in this space. The fact that they have identified and addressed any issues that might impede progress is a huge service to the storage market and paves the way for similar projects down the line.”

PG&E’s pursuit of energy storage doesn’t begin and end with batteries. The utility is working under a Department of Energy (DOE) grant to explore the viability of large compressed air energy storage (CAES) using depleted natural gas wells.

PG&E’s innovation on storage has been spurred in part by policies like AB 32 (California’s global warming law) and AB 2514 (a California energy storage law) that place a premium on solutions that cut climate pollution and modernize the energy grid. AB 2514 (Skinner) kick-started a California Public Utilities Commission (CPUC) proceeding and subsequent decision requiring utilities to procure 1,325 megawatts (MW) of energy storage by 2020 – with specific targets for each of the investor-owned utilities. In response to AB 2514 and the Commission’s decision, PG&E is developing innovative ways, such as the projects described above, to help meet the nearly 600 MW of transmission and distribution storage the CPUC has mandated the utility to install by 2024.

PG&E employees work at the Vaca-Dixon Substation

PG&E employees work at the Vaca-Dixon Substation

Southern California Edison (SCE), operating under a similar mandate, recently signed contracts with 69 vendors to procure 2,221 MW of energy storage. This amount of storage, which comes from a diverse set of technologies, is enough to power 950,000 homes in SCE’s service territory and is well above the individual mandate the CPUC set for the utility. Their biggest project, the Tehachapi Energy Storage Project – the largest storage project in North America – is comprised of lithium ion batteries and offers 32 megawatt-hours of storage. In addition, the project is strategically located in a high wind area, so that SCE can take advantage of the 4,500 MW of renewable energy that the area is expected to provide by 2016.

The energy storage solutions that PG&E and other utilities install under AB 2514 will allow for a number of important results:

  1. Offset peak demand for fossil fuels. Certain forms of renewable energy generation are available only at certain times– for example, solar energy is only available during the day. Since renewable generation doesn’t always match consumer demand, other energy sources have to fill the gap when these renewables aren’t available or are powering down. By capturing renewable energy when it is available and discharging it to the grid during peak demand times, energy storage can dramatically reduce the need for dirtier sources of energy generation, helping to meet AB 32’s greenhouse gas reduction goals.
  2. Integrate renewables into the grid. Relatedly, one of the primary concerns with use of renewable energy is its inherent intermittency – the wind can suddenly stop blowing and the sun can hide behind clouds. By capturing renewable energy and using it to smooth any of these “bumps” in electricity generation, storage can help ensure a strong, clean, reliable grid.
  3. Defer potentially expensive technology upgrades. By using storage devices, utilities can defer transmission and distribution line upgrades that would otherwise be required for increased energy demand in the coming years – improvements that would potentially cost a significant amount of money; by some estimates, deferring upgrades for one year can save as much as a few hundred dollars per kilowatt hour.
  4. Act as an energy “island.” The four MW San Jose system PG&E has deployed can disconnect from the utility grid and supply downstream loads in the event of an outage. Thus, even if there is a utility-wide power outage, energy storage facilities like this one can keep the lights on and continue to enable vital functions.

PG&E is one of multiple companies that are helping California bring storage more robustly into the energy realm, in addition to its longstanding association with personal belongings. As energy storage becomes increasingly varied and commercialized, it is poised to become a ubiquitously known concept and one that is weaved throughout the state’s grid – perhaps one day even in your home. This kind of storage is good for the grid, the environment, and public health.

Photo source: Pacific Gas & Electric Company

Please note that EDF has a standing corporate donation policy and we accept no funding from companies or organizations featured in this series. Furthermore, the EDF California Innovators Series is in no way an official endorsement of the people or organizations featured, or their business models and practices. 

This post originally appeared on our California Dream 2.0 blog.

This entry was posted in California, Clean Energy, Energy Storage. Bookmark the permalink. Both comments and trackbacks are currently closed.