GWP had planned for many years to retire and replace the aging Grayson Power Plant. The proposed repower plan, a 262 MW combined cycle natural gas power plant, was rejected by the Glendale City Council under pressure from local environmental groups.
The Council asked GWP to look for viable alternatives to a new power plant. This was made more challenging by the fact that Glendale has very limited access to transmission for resources outside the LA basin, which meant that the replacement resources needed to be local.
Ascend was asked to administer and evaluate a Clean Energy Request for Proposals (RFP) for zero/low-carbon energy and capacity resources options to enter service by 2021. This was a true all-source RFP, which received 35 proposals from vendors offering renewable energy, energy efficiency, demand response, energy storage, utility-scale storage and thermal generation. Ascend and GWP screened and evaluated several portfolio combinations to meet the specific needs of GWP and its customer base.
Ascend's final recommended portfolio included:
The analysis showed that while a full ICE repower (portfolio C below) would be least cost, Portfolio E, a balanced portfolio of DERs, large utility battery, and ICEs for backup reliability, would be the best balance between reliability, cost, and emissions reduction.
Ascend used its planning software PowerSIMM™ to calculate the economic costs and revenues for each portfolio above, including the value of resources to capture sub-hourly Energy Imbalance Market (EIM) revenues. The preferred portfolio was found to save Glendale customers more than $130 million compared with the natural gas combined cycle repowering proposal.
Ascend also found that Portfolio E represented the most economic approach to meeting future zero emissions goals when incorporating other sectors such as transportation electrification. The chart below shows GWP's emissions under the preferred portfolio. When crediting conversion of gasoline vehicles with electric vehicles (EVs), GWP clean energy fueled cars would save enough GHG emissions to offset electricity emissions by 2030.
Ascend compared the costs of emissions reduction between two cleaner but less reliable portfolios with fewer engines (portfolio F) and no natural gas (portfolio G) versus the costs and emissions benefits of programs in other sectors. Ascend found dramatically lower costs for instituting programs in energy efficiency, forestry offsets, and transportation electrification. Focusing efforts on these programs will achieve the same emissions benefit at much lower cost to Glendale electricity customers.
Over 300 people came to the City Council session to discuss the proposed plan, including citizens, representatives of organized labor, and environmental activists. The City Council voted unanimously 5-0 to approve the new resource plan, including one of the nation's largest battery projects and the 93 MW of ICEs. A prominent local environmental leader supported moving forward with the plan. The story made headlines across energy media including this article from Greentech media.
Steve Zurn, General Manager of GWP said, "we could not have accomplished these ambitious goals to decarbonize our power supply portfolio without Ascend. From start to finish, Ascend navigated a very challenging environment with great skill supported by outstanding analytic insight".
Ascend Analytics, an innovative leader at the forefront of the energy transition, offers advanced software and consulting services that capture the evolving and real-time dynamics of energy markets. The company provides its customers with optimized and comprehensive decision analysis that covers everything from long-term planning to real-time operations in the electric power supply industry.