The Poway City Council on Sept. 17 gave final approval for construction of a 300-megawatt battery energy storage system in the Poway Business Park despite opposition by residents concerned about the possibility of fires.

The Nighthawk Energy Storage Project will be built on 10 acres of an 83-acre site at Kirkham Way near Paine Street.

When completed, sometime around the second quarter of 2025, the project would help the local power grid capture solar and wind energy, then store the power in batteries and discharge it when needed most, said Josh Coon, vice president of development for the owner of the facility, Arevon Energy.

The power will be sent via an underground transmission line to the Sycamore Canyon Substation, which is owned by San Diego Gas & Electric and located about two miles from Poway at Marine Corps Air Station Miramar, Coon said at the Aug. 20 council meeting when the project received preliminary approval.

“Once the power is on the grid, it goes to the closest source wherever it’s needed,” he said, noting the project will store enough energy to power up to 300,000 homes.

But speakers at the Sept. 17 meeting – when the item was listed on the consent calendar for a second reading and adoption – expressed concerns about the project’s potential health and safety impacts. They cited the recent fires at the Gateway Energy Storage Facility in Otay Mesa on May 15 and at an SDG&E battery storage facility in Escondido on Sept. 5.

The Escondido fire prompted the evacuation of about 500 businesses and led to classes being canceled for one day at nearby schools, according to an article in The San Diego Union-Tribune.

News reports indicated the Otay Mesa and Escondido facilities store lithium-ion batteries. Firefighters’ recommended response was to let the fires burn themselves out.

Melissa Morris, a Poway resident of 12 years, said she was told by proponents that this facility would be safer because it uses lithium iron phosphate batteries, which some say have more advanced technology.

But Morris said she did some research and read that lithium iron phosphate batteries are not safer. They are a greater flammability hazard and create a greater toxicity, she said.

“We saw the cloud from Escondido, gases expand as they heat they have to release somewhere,” said Morris, who added the risk is not worth the payoff promised by Arevon Energy.

Sally Lusk, a Poway resident of 15 years, said wildfires are an ongoing concern and asked council members how they could mitigate battery fire risks related to earthquakes and high weather temperatures. She said it wasn’t clear how the company would address safety during these types of conditions.

Lusk said businesses such as Amazon, Costco and General Atomics in the Business Park could also be at risk of closing down in the event of a fire.

“How long will it take for a fire to burn itself out?” Lusk asked the council members. “How do you tell a loved one to shelter in place?”

Arevon stated the company’s top priority is the safety of those who live and work in the project community.

“Arevon has an exceptional safety record and has operated energy storage facilities in California communities since 2021 without a single incident,” Arevon officials said in a written statement emailed after the meeting. 

Christina Hennigan, a Scripps Ranch resident, said if a battery facility is installed, she prefers that it not be placed near homes. She said these batteries may be less flammable, but there is still potential for fires.

Hennigan identified numerous concerns, including one-way in and one-way out access to her Stonebridge neighborhood and safe evacuations for students.

“Nighthawk is right in the middle of our development,” said Hennigan. “I live in the back of the development so we’re not going to be able to get out in the event of a fire.”

Poway council member Peter De Hoff said the battery energy storage facility has created a “perception of risk,” particularly with unknown factors, but he does not see the facility as causing more risks than what already exists in the Business Park.

De Hoff said storage containers would essentially contain a fire and any concentration of toxicity resulting from a fire would be diluted at distances farther away.

The owner of the facility is proposing to add sensors to detect gases, he said before making the motion to approve the project.

Keith Latham, vice president of project development for Nighthawk’s consulting firm Tenaska, said the evolution of batteries started with lithium-ion batteries in the 1980s and advanced to lithium iron phosphate batteries in the early 2020s. Latham said the lithium iron phosphate batteries were an “improved product.”

“The lithium iron phosphate batteries are more stable and are less likely to catch fire,” said Latham, adding that the project is designed to sustain earthquakes and high weather temperatures. “There are also a lot of controls to mitigate against the possibility of the facilities catching fire. If there’s an abnormality in the systems it will shut down.”

During the meeting, council member Caylin Frank confirmed with Poway Fire Chief Jeff Chumbley that the Otay and Escondido fires did not extend beyond the battery energy storage facilities.

“These facilities cannot be put in the middle of nowhere because there would be no other facility to benefit from them,” Frank said, referring to the transfer of power to SDG&E’s substation. “We need to take a step back from the fear of the unknown.”

Mayor Steve Vaus said even if the council rejected the Nighthawk project, the decision could be appealed to the state Legislature and they would likely approve it based on a push toward clean energy projects in the state.

In a separate item, council members agreed to send a letter to San Diego County District Attorney Summer Stephan on behalf of the city in support of Proposition 36.

The Homelessness, Drug Addiction and Theft Reduction Act on the Nov. 5 ballot seeks to change aspects of Proposition 47, which was approved by California voters in 2014 with the intent of alleviating the state’s prison overcrowding by reducing many theft and drug felonies to misdemeanors.

Proposition 36 would increase penalties for theft-related and drug-related crimes, the report said. Additionally, it would promote drug and mental health treatment among offenders.

“The unintended consequences of Proposition 47 can no longer be ignored,” states the letter signed by Vaus and Frank. “It’s imperative there be real consequences to those who commit property theft against businesses and those who sell and distribute illicit drugs in our communities.”