Energy storage is a suite of technologies that capture and store energy for use at a later higher value time. Energy can be stored in many ways: chemically (e.g. batteries), gravitationally (e.g. pumped hydro, pictured here), mechanically (e.g. flywheels) and thermally (e.g. molten salt). On the electric grid, where supply must always equal demand, energy storage increases efficiency by avoiding expensive transmission and distribution upgrades and substituting for the most polluting “peaker” power plants. Energy storage is also expected to play a key role in enabling the grid to integrate large quantities of variable renewable energy resources such as solar and wind.
1) The optimization of the grid, including peak reduction, contribution to reliability needs, or deferment of transmission and distribution upgrade investments;
2) The integration of renewable energy; and
3) The reduction of greenhouse gas emissions to 80 percent below 1990 levels by 2050, per California goals.
One point of controversy has been whether large-scale (50 MW or more) pumped storage projects should be included or excluded under the procurement framework. The proposed decision excludes pumped storage because the sheer size of pumped storage projects would dwarf other smaller, emerging technologies and, as such, would inhibit the fulfillment of market transformation goals.
The CPUC’s proposed “Energy Storage Procurement Framework and Design Program,” which will be considered for approval on October 3, 2013, establishes specific targets to be procured by Pacific Gas and Electric Company, Southern California Edison Company and San Diego Gas & Electric Company by 2020 and sets a schedule for solicitation of energy storage. The decision also requires community choice aggregators to procure energy storage equal to 1 percent of their annual peak load by 2020 and electric service providers to procure energy storage equal to 1 percent of their annual peak load by 2016.
The proposed decision implements California Assembly Bill 2514, which became California law in 2010.
In an interview with BERC, Janice Lin, co-founder of the California Energy Storage Alliance, a membership-based advocacy group, hailed the proposed decision as “the market signal that is going to launch energy storage as a mainstream resource used for electric power system planning.”
- On October 3, 2013, the CPUC will meet to consider the proposed decision and order.
- If approved, the order would require the investor-owned utilities to procure energy storage through competitive solicitations.
- The initial competitive solicitation would be scheduled for no later than December 1, 2014, and every two years thereafter.
All energy storage resources as defined by Pub. Util. Code § 2835(a), except for pumped storage resources 50 MW or greater, are eligible to bid into the energy storage solicitations.
CPUC Energy Storage Site (includes cost-effectiveness studies and use cases): http://www.cpuc.ca.gov/PUC/energy/electric/storage.htm