Sempra Energy subsidiary San Diego Gas & Electric Co. on Thursday said it had finalized deals for a 20-megawatt energy storage facility as well as a series of energy efficiency projects estimated to save 18.5 megawatts.

The storage facility, to be provided by Hecate Energy Bancroft, will involve the largest lithium ion battery project in the San Diego area, according to SDG&E. The battery will store energy from solar, wind and other sources when that power is relatively inexpensive to produce and release it during peak hours.

Hecate will own the facility and supply energy under a 20-year purchase agreement. It is expected to be completed in 2019.

SDG&E also said it had contracted with Willdan Energy Solutions for a series of projects through 2024 that will help users reduce their energy consumption.

Both contracts must be approved by the California Public Utilities Commission.