#EnergyStorage : Arizona Public Service issues RFP for approximately 106 MW of energy storage (~$100 million) to connect to existing APS solar systems to store peak solar production & feed it to customers during peak demand. Here is the link to the rfp: bit.ly/APS_Storage_RFP
Velerity Insight: The importance of this rfp is the application, time shifting stored energy from peak solar production to peak customer demand. This is one of the more challenging business cases for energy storage from an economics perspective, as historically, the combination of the pricing spread combined with annual hours of operation are typically insufficient to support the capital carrying cost of the the energy storage system.
What makes this case different? APS is regulated and vertically integrated. The cost of the energy storage system will likely be borne by ratepayers, with the justification being system resilience, reaching renewable energy goals, and evaluating the use of storage to reduce peaking plant operation, including reducing environmental impacts. It may also be that in the case of APS, they are facing stranded electrons from peak solar production, with curtailment hours increasing in step with increases in solar penetration. They also may be facing significant peaking requirements and high peaking power costs.