Vantage Data Centers has asked the California Energy Commission to grant a small-power-plant exemption for 44 large diesel generators at a proposed data center in Santa Clara.
Residents near the proposed backup generation are concerned about a potential increase in particulate-matter emissions. The plant would be located near homes, a park and a senior living center on Walsh Avenue.
Josh Montemayor, a member of the public, filed comments to the CEC expressing his concern about the location of the facility.
"The nearest residences are only a couple hundred feet away," Montemayor said. "Due to its close proximity, residents in the area may be subject to emissions generated by the proposed facility at unsafe concentrations."
One concern expressed by Montemayor is that regulators ensure the diesel power plant does not run for other than backup power purposes. However, the California Public Utilities Commission this year approved a new program to pay certain facilities to turn on their backup power-generation resources not during grid outages, but when grid demand is high, such as on hot summer days.
The CPUC's Emergency Load Reduction Program allows for diesel backup generation to participate as a means for creating load reduction, CPUC spokesperson Terrie Prosper said in an Aug. 10 email to California Energy Markets.
Similarly, Gov. Gavin Newsom's July 30 emergency proclamation includes a load-reduction program that might encourage more participation from backup generators than would occur under ELRP, Prosper said.
Newsom's order would require the state to pay large electricity users, such as data centers, to run their diesel backup generators rather than pull grid power during extreme heat events, representatives for the California Justice Alliance said in an Aug. 5 letter.
The Silicon Valley and San Francisco Bay Area region currently houses about 1.2 GW of backup diesel generation capacity at its data centers. Another 1.5 GW of diesel capacity has been proposed.
Vantage Data Centers' power plant would provide about 96 MW of backup generation capacity and would use Caterpillar Model 3516E generators that have Tier 4 diesel particulate filters, Vantage representatives said [21-SPPE-01]. The power plant would not be connected to the transmission grid—it would only connect to the data center, the application says.
The CEC is awaiting a study that will determine the data center's impact on the transmission system and on Silicon Valley Power's electricity supply, an Aug. 6 letter to the commission from Vantage Data Centers representatives says. However, the representatives said the facility can be provided with initial power—i.e., a portion of the data center can be occupied as soon as the data center is built, but the remaining areas would require additional electricity supply, and more than is currently available from the local power supplier, Silicon Valley Power, prior to occupation.
"[Vantage] understands that . . . system transmission upgrades will need to be completed in order for additional electricity to be imported into the SVP system," Scott Galati, counsel for Vantage Data Centers, said in the letter. "The conceptual timeline for completion for outside the system projects is the fourth quarter of 2025."
The CEC certifies thermal power plants with capacities of 50 MW or more in California, but can grant small-power-plant exemptions for facilities sized between 50 and 100 MW if the commission determines that a facility will not significantly affect the environment or energy resources. The CEC is "not the final approval necessary for construction and operation" of the diesel generators, even if it grants the exemption—local agencies will assume jurisdiction over the project if an exemption is granted, the commission said.
Galati asked the commission to accelerate its review: Vantage wants to start construction as soon as possible in 2022, he said.
