The Grayson Power Plant has been steadfastly serving our City since the early 1940s, and after its successful and prolonged run, much of its existing infrastructure and equipment is due for replacement. The Grayson Repowering Project will replace aged, unreliable, inefficient, and high maintenance equipment at the Grayson Power Plant with a combination of energy storage and new, efficient, faster-starting, and more environmentally-responsible generation technologies. The project means providing efficient and reliable power to Glendale homes and businesses, especially in times of emergency and high demand. 

GWP is proposing a new, cleaner portfolio to replace the retiring Grayson generation (a “repowering project”).  GWP proposes to replace Grayson Units 1,2, 3, 4, 5, 8A and 8BC with new, efficient, and flexible generation to meet multiple objectives, including facilitating compliance with California Renewables Portfolio Standard (RPS) obligations, reduction of Greenhouse Gas (GHG) emissions consistent with state mandates, and local reliability under a variety of conditions, with minimal impacts on retail rates. The existing Grayson will be retained.

The Project site is located in an industrial area of the City of Glendale at 800 Air Way, Glendale, CA 91201, just northeast of the Interstate 5 and Highway 134 interchange.  The site is bounded to the south by the Verdugo Wash and Highway 134, to the west by the Los Angeles River and Interstate 5, to the north by commercial properties and to the east by commercial and residential properties. The site is currently used as the Grayson Power Plant. The Grayson Repowering Project would be located entirely within the existing Grayson Power Plant, an operating power plant. 

Why is a Repowering Necessary? 

Glendale is heavily dependent upon imported power to serve its customers, and the transmission import capacity is less than the peak summer, so GWP needs to have a local source of power to back up the transmission imports and ensure reliable service. Originally commissioned in the 1940s, the Grayson Power Plant is well past its useful life and needs to be repowered in order to meet the current and future energy needs of the City of Glendale. A repowering project would replace the aged, unreliable, inefficient, and high maintenance equipment at the Grayson Power Plant with new, efficient, faster-starting, and more environmentally-responsible generation technologies. The need to repower is also environmental. The modern units will have the flexibility to turn on and off quickly and provide reserve energy to support increasing amounts of intermittent solar and renewable energy.

A repowering of the Grayson Power Plant will achieve the following benefits:

• Reliable service - by helping GWP provide energy to customers when imported energy and local renewable energy sources are not enough.
• Local generation source - a locally-controlled source of generation is important to ensure reliable service when we lose an external energy source, such as when a transmission line goes down.
• Integration of renewable energy – by providing a source of power that helps “fill the gaps” of solar and wind resources due to their varying nature.
• Affordable rates for Glendale Customers - by reducing the high maintenance costs, extra fuel costs, and emergency spot market power purchases costs that we spend now due to frequent break downs of the aged, unreliable, inefficient, and high maintenance equipment.
• Improved air quality – the new technology will be more efficient and will comply with new regulations requiring lower air emissions.
• Supports water conservation - by eliminating the use of potable water for power generation.

An added urgency for repowering Grayson comes from the South Coast Air Quality Management District's (SCAQMD) Rule 1135 which was implemented after the original repower. Rule 1135 requires GWP to commit, by June 30, 2022, to plan to bring the power plant units into compliance with current day emission limit requirements. No later than June 30, 2022, we must inform the SCAQMD whether we will replace or modify older units to meet current day emission limits, or if we intend to shut them down by the deadline: December 31, 2023. By returning the Grayson Unit 9 emissions control system, it can comply with the new requirements. Unit 8A and 8BC would need to meet the rule, however we cannot economically or feasibly modify Units 1-5 to meet Rule 1135's requirements. 

On December 13, 2022 the Glendale City Council authorized the following:

• For the City to enter into a contract with Wartsila North America, Inc. for the engineering, procurement, construction, and commissioning services for 3 Wartsila engines and associated equipment and infrastructure within the Wartsila power island as described in the 2022 Final EIR, in the amount of $170,000,000, subject to City Council’s authorization for financing.  The City Council also directed staff to proceed with the following for the Grayson Repowering Project:

a. Continue with Unit 9 separation;

b. Complete the bidding process for the Demolition and Site Improvement of Grayson Power Plant Units 1-8 and environmental remediation of the Grayson site, and following award enter into a contract for the same;

c. Prepare and release an RFP for the BOS EPC contract, inclusive of for the work and costs to engineer, procure and construct a BESS up to 75 MW/300 MWh and integrate the said BESS and the Wartsila power island into the Grayson Power Plant site;

d. Proceed with necessary engineering, procurement, and construction to prepare for the addition of three Wartsila engines at Grayson;  

e. Proceed with South Coast Air Quality Management District permitting for three Wartsila engines; finalize the negotiation of contracts for purchase of the necessary emissions reduction credits, and present the same to the City Council for approval; and

f. Issue bids for all required bonding, prepare bond document and seek City Council adoption of a bond ordinance, to finance the above.

• For the City to enter into a Collective Work Authorization with the Southern California Gas Company for services related to the improvement and upgrade of the Southern California Gas Company facilities relating to the Grayson Repowering Project. 

GWP has prepared the 2022 Final Environmental Impact Report (FEIR). Click here to view the 2022 FEIR.