Rows of solar panels are seen at the Mangilao Solar Farm on Aug. 28, 2024 in Pågat, Mangilao.
Photo by David Castro/The Guam Daily Post
HAGÅTÑA (The Guam Daily Post) — The Guam Power Authority is looking to procure significant energy storage system services to make use of stored solar energy during peak demands times at night, and to facilitate greater renewable energy integration and grid reliability.
But wherever the batteries for this system are sourced, they won’t come from any nation adversarial to the U.S. because of cybersecurity reasons, according to GPA General Manager John Benavente.
“I’d like to also note that, in this thing, we’re saying that there will be no China, North Korea or non-friendly-nation batteries provided,” Benavente told members of the Consolidated Commission on Utilities Thursday, during a work session.
“It’s very important because this is very key when we’re talking about cybersecurity and all of that. So this must not come from any adversarial countries,” Benavente added.
But that prompted Commissioner Michael Limtiaco to ask if the same had been true for GPA’s ongoing Phase 4 renewable energy procurement. Although Phase 4 is about renewable power and not specifically energy storage, GPA had also required bidders to have certain energy storage and shifting capabilities for the procurement.
The utility has already contracted with one bidder under Phase 4 — a consortium involving the Korea Electric Power Corp. — and is working to contract with others.
GPA Assistant General Manager John Cruz said the power authority had ensured that inverters to be used in Phase 4 projects were not sourced from the People’s Republic of China, but added that bids did include Chinese batteries. However, the power utility has cybersecurity measures to address that, according to Cruz.
“I don’t understand, if you’re allowing it for Phase 4 … and not for this, what’s the difference?” Limtiaco asked.
Benavente said GPA just didn’t want to take the risk.
“We’re actually looking to, more and more, trying to get the whole policy done. Even transformers, wires and other things. Again, this is something we could do right now,” Benavente said.
For the proposed energy storage procurement, GPA would be seeking services from firms to provide 90 megawatts/360 megawatt-hours of storage capacity for energy shifting, and 180 megawatts/90 MWh of capacity for grid services, including a grid controller for automated monitoring, coordination and control of storage system energy in existing, new and future storage system sites.
“This project is necessary to integrate more renewables, shift energy in (the) system from a rechargeable source and provide (a) grid controller for a stable system composed of diverse generating facilities,” GPA’s presentation for the energy storage procurement stated.
“The energy-shifting ESS (energy storage system) will store the excess energy from solar PV (photovoltaic) during the day and discharge it during the evening hours when the demand load is higher. The grid-services ESS will allow the integration of high amounts of inverter-based resources (IBRs) into the GPA grid, improving grid stability, resiliency, reliability, and affordability,” the presentation added.
The project would be funded through the Levelized Energy Adjustment Clause, or LEAC, a major surcharge in monthly power bills. Although it’s largely associated with paying for the cost of fuel oil, the LEAC is also used to pay for GPA’s solar-power purchases and other energy-related costs.
The estimated cost for the proposed energy storage system is $180 million, with annual costs at about $18.4 million. That amounts to possibly around a one-cent impact to the LEAC, according to Benavente.
“A one-cent impact on the LEAC for such a huge reliability, potential for growth and everything is really insignificant, no?” Benavente said Thursday.
The bid announcement for the project is tentatively scheduled for September, and requires the review and approval of the CCU, Public Utilities Commission and Office of the Attorney General.
