Napa Valley town that once rode out emergencies with diesel gets a clean-power backup

CALISTOGA, Calif. (AP) — For residents of this quaint tourist town on the northern edge of Napa Valley, the threat of wildfire is seldom out of mind. The hillside bears burn scars from a 2020 fire that forced all of Calistoga to evacuate, and the 2017 Tubbs fire that killed 22 people in wine country started just a few miles from downtown.

When fire danger required shutting off transmission lines that might spark a blaze, the town relied on a bank of generators in a popular recreation area that belched choking diesel exhaust and rumbled so loudly it drove people away.

But now Calistoga is shifting to a first-of-its-kind system that combines two clean-energy technologies — hydrogen fuel cells and batteries — for enough juice to power the city for about two days. Experts say the technology has potential beyond simply delivering clean backup power in emergencies; they say it's a steppingstone to supporting the electric grid any day of the year.

As the system was undergoing its final tests in late May in an area that includes a dog park, ball fields, community garden and bike trail, residents said they were grateful to be guaranteed clean energy year-round. Lisa Gift, a resident who also serves on the city council, noted Calistoga is already grappling with climate change that is fueling more intense and frequent wildfires.

“Continuing to depend on fossil fuels was simply not sustainable,” Gift said. "That's what excited me about this. It’s a clean and reliable energy solution that ensures the safety and resilience of our community.”

Energy Vault, an energy storage company based in California, built the new facility that was to come online in early June. Next year, it could be exporting power to the electric grid whenever needed once its application to fully connect is approved.

The installation sits next to where Pacific Gas & Electric used to set up nine mobile generators every year from late spring through fall. Behind a chain-link fence stand six hydrogen fuel cells standing two stories tall made by Plug Power in New York. Water vapor wafted from one of the fuel cells being tested as The Associated Press got an exclusive tour of the site as it was in final testing.

Shipping containers hold two pairs of Energy Vault's lithium-ion batteries. Nearby, a cinder block wall surrounds a massive, double-walled steel tank that holds 80,000 gallons (302,833 liters) of extremely cold liquid hydrogen that gets converted to gas to run the fuel cells.

California utilities, especially PG&E, have had to pay large settlements over igniting wildfires. PG&E began cutting power at times to reduce fire risk in 2018, one of California's deadliest and most destructive wildfire years. It ships diesel generators to about a dozen towns to provide backup power during those periods.

Calistoga, the largest with about 5,000 people, has had its power shut off 10 times. When generators ran, they spewed exhaust with harmful nitrogen oxides, carbon dioxide and soot. PG&E considered replacing Calistoga's diesel generators with a natural gas version that would pollute less, but opted instead for Energy Vault's fully clean solution, said Dave Canny, the utility’s vice president for the North Coast Region.

Energy Vault CEO Robert Piconi said other communities, military bases and data centers could all use something similar, but potential customers wanted to see it function first.

“There’s a massive proof point with this project,” he said. “I think it’ll have a lot of implications for how people think about alternative, sustainable solutions."

The fuel cell maker, Plug Power, is planning for these types of products to be its main business in a decade. Energy Vault said it’s buying clean hydrogen, produced with low or no greenhouse gas emissions, to run the fuel cells in Calistoga.

“This solution is just beautiful," said Janice Lin, founder and president of the Green Hydrogen Coalition, a nonprofit that advocates for green hydrogen projects to combat climate change. "No noise, no emissions. And it’s renewable. It’s dumping diesel.”

Calistoga caters to tourists with a main thoroughfare that emphasizes local shops, restaurants, tasting rooms and art galleries over franchise stories. Residents pride themselves on a smalltown vibe, and say Calistoga isn't posh like much of the rest of Napa Valley.

Some of those residents were concerned at first about the hydrogen, which is flammable and can be explosive. Fire Chief Jed Matcham said the “very, very large tank” got his attention, too.

He collaborated with Energy Vault on emergency planning and training, and said he's comfortable with the safety measures in place. Energy Vault's batteries also come with alarms, detectors and piping to extinguish a fire.

The next time PG&E turns off the power to the area to prevent wildfires, it will tell Energy Vault when it’s safe to electrify Calistoga. The batteries will get things back up and running, discharging the energy stored inside them to the local microgrid.

Then the hydrogen fuel cells will take over to generate a steady level of power for a longer period. By working in tandem — the company likened it to the way a hybrid vehicle works — the batteries and fuel cells are expected to keep the lights on for about 48 hours or longer.

Clive Richardson, who owns downtown's Calistoga Roastery and can typically be found behind the counter, drinking coffee and chatting with customers, said people in Calistoga get on edge when the winds kick up. And he knows what it's like to have to empty out his store when power goes out — a big hit for a small-business owner.

A year-round clean solution for emergency power gives him a measure of comfort.

“This will give us far more security than we had before,” he said. “It’s fantastic that it’s come. Here we are, little ol’ Calistoga, and we’ve got the first-of-a-kind system that hopefully will be endorsed and go all over the world.”

The Associated Press’ climate and environmental coverage receives financial support from multiple private foundations. AP is solely responsible for all content. Find AP’s standards for working with philanthropies, a list of supporters and funded coverage areas at AP.org.

A sign for a hot spring is displayed on Tuesday, May 27, 2025, in Calistoga, Calif. (AP Photo/Annika Hammerschlag)

Calistoga Roastery owner Clive Richardson sips coffee behind the counter Tuesday, May 27, 2025, in Calistoga, Calif. (AP Photo/Annika Hammerschlag)

Calistoga Fire Chief Jed Matcham poses for a portrait Tuesday, May 27, 2025, in Calistoga, Calif. (AP Photo/Annika Hammerschlag)

Carlos Rubio waters his plants at the community garden adjacent to the dog park that used to house diesel generators Tuesday, May 27, 2025, in Calistoga, Calif. (AP Photo/Annika Hammerschlag)

A power line connected to the grid stands in Calistoga, Calif., Tuesday, May 27, 2025. It will carry electricity from a backup system powered by hydrogen and batteries. (AP Photo/Annika Hammerschlag)

Energy Vault CEO Robert Piconi poses for a portrait Tuesday, May 27, 2025, in Calistoga, Calif. Energy Vault is creating an emergency power system that relies on hydrogen and battery storage. (AP Photo/Annika Hammerschlag)

An employee drives a forklift at Energy Vault, a company that is creating an emergency power system that relies on hydrogen and battery storage, on Tuesday, May 27, 2025, in Calistoga, Calif. (AP Photo/Annika Hammerschlag)

Craig Horne, senior vice president of advanced energy solutions for Energy Vault, a company that is creating an emergency power system that relies on hydrogen and battery storage, shows a battery system Tuesday, May 27, 2025, in Calistoga, Calif. (AP Photo/Annika Hammerschlag)

A worker walks through Energy Vault's facility, a company that is creating an emergency power system that relies on hydrogen and battery storage, on Tuesday, May 27, 2025, in Calistoga, Calif. (AP Photo/Terry Chea)

A worker lays cables at Energy Vault, a company that is creating an emergency power system that relies on hydrogen and battery storage, on Tuesday, May 27, 2025, in Calistoga, Calif. (AP Photo/Annika Hammerschlag)

An employee works at Energy Vault on Tuesday, May 27, 2025, in Calistoga, Calif., where the company is building an emergency power system using hydrogen and battery storage. (AP Photo/Annika Hammerschlag)

Kendell Weis pedals on a popular bike path past a dog park that used to house noisy diesel generators on Tuesday, May 27, 2025, in Calistoga, Calif. (AP Photo/Annika Hammerschlag)

Brush grows in Calistoga, Calif., Tuesday, May 27, 2025. (AP Photo/Annika Hammerschlag)

Calistoga resident and City Council member Lisa Gift poses for a portrait Tuesday, May 27, 2025, at the community garden in Calistoga, Calif. (AP Photo/Annika Hammerschlag)

Burn scars from the 2017 Tubbs Fire, visible on the trees without leaves, stand along a ridge Tuesday, May 27, 2025, in Calistoga, Calif. (AP Photo/Annika Hammerschlag)

FILE - A firefighter passes flames while battling the Glass Fire in a Calistoga, Calif., vineyard Oct. 1, 2020. (AP Photo/Noah Berger, File)

A tank that holds liquid hydrogen, left, which is converted to gas to run the fuel cells, sits at at Energy Vault, a company that is creating an emergency power system that relies on hydrogen and battery storage, on Tuesday, May 27, 2025, in Calistoga, Calif. (AP Photo/Annika Hammerschlag)

A worker lays cables at Energy Vault, a company that is creating an emergency power system that relies on hydrogen and battery storage, on Tuesday, May 27, 2025, in Calistoga, Calif. (AP Photo/Annika Hammerschlag)

RHO, Italy (AP) — No ice is colder and harder than speedskating ice. The precision it takes has meant that Olympic speedskaters have never competed for gold on a temporary indoor rink – until the 2026 Milan Cortina Winter Games.

In the pursuit of maximum glide and minimum friction, Olympic officials brought on ice master Mark Messer, a veteran of six previous Olympic speedskating tracks and the ice technician in charge of the Olympic Oval in Calgary, Canada — one of the fastest tracks in the world with over 300 records.

Messer has been putting that experience to work one thin layer of ice at a time since the end of October at the new Speed Skating Stadium, built inside adjacent trade fair halls in the city of Rho just north of Milan.

“It’s one of the biggest challenges I’ve had in icemaking,’’ Messer said during an interview less than two weeks into the process.

If Goldilocks were a speedskater, hockey ice would be medium hard, for fast puck movement and sharp turns. Figure skating ice would be softer, allowing push off for jumps and so the ice doesn’t shatter on landing. Curling ice is the softest and warmest of all, for controlled sliding.

For speedskating ice to be just right, it must be hard, cold and clean. And very, very smooth.

“The blades are so sharp, that if there is some dirt, the blade will lose the edge,’’ Messer said, and the skater will lose speed.

Speedskater Enrico Fabris, who won two Olympic golds in Turin in 2006, has traded in his skates to be deputy sports manager at the speedskating venue in Rho. For him, perfect ice means the conditions are the same for all skaters — and then if it's fast ice, so much the better.

"It's more of a pleasure to skate on this ice,'' he said.

Messer’s first Olympics were in Calgary in 1988 — the first time speedskating was held indoors. “That gave us some advantages because we didn’t have to worry about the weather, wind blowing or rain,’’ he said. Now he is upping the challenge by becoming the first ice master to build a temporary rink for the Olympics.

Before Messer arrived in Italy, workers spent weeks setting up insulation to level the floor and then a network of pipes and rubber tubes that carry glycol — an antifreeze — that is brought down to minus 7 or minus 8 degrees Celsius (17.6 to 19.4 degrees Fahrenheit) to make the ice.

Water is run through a purification system — but it can’t be too pure, or the ice that forms will be too brittle. Just the right amount of impurities “holds the ice together,’’ Messer said.

The first layers of water are applied slowly, with a spray nozzle; after the ice reaches a few centimeters it is painted white — a full day’s work — and the stripes are added to make lanes.

“The first one takes about 45 minutes. And then as soon as it freezes, we go back and do it again, and again and again. So we do it hundreds of times,’’ Messer said.

As the ice gets thicker, and is more stable, workers apply subsequent layers of water with hoses. Messer attaches his hose to hockey sticks for easier spreading.

What must absolutely be avoided is dirt, dust or frost — all of which can cause friction for the skaters, slowing them down. The goal is that when the skaters push “they can go as far as possible with the least amount of effort,’’ Messer said.

The Zamboni ice resurfacing machine plays a key role in keeping the track clean, cutting off a layer and spraying water to make a new surface.

One challenge is gauging how quickly the water from the resurfacing machine freezes in the temporary rink.

Another is getting the ice to the right thickness so that the Zamboni, weighing in at six tons, doesn’t shift the insulation, rubber tubing or ice itself.

“When you drive that out, if there’s anything moving it will move. We don’t want that,’’ Messer said.

The rink got its first big test on Nov. 29-30 during a Junior World Cup event. In a permanent rink, test events are usually held a year before the Olympics, leaving more time for adjustments. “We have a very small window to learn,’’ Messer acknowledged.

Dutch speedskater Kayo Vos, who won the men’s neo-senior 1,000 meters, said the ice was a little soft — but Messer didn’t seem too concerned.

“We went very modest to start, now we can start to change the temperatures and try to make it faster and still maintain it as a safe ice,’’ he said.

Fine-tuning the air temperature and humidity and ice temperature must be done methodically — taking into account that there will be 6,000 spectators in the venue for each event. The next real test will be on Jan. 31, when the Olympians take to the ice for their first training session.

“Eighty percent of the work is done but the hardest part is the last 20 percent, where we have to try to find the values and the way of running the equipment so all the skaters get the same conditions and all the skaters get the best conditions,’’ Messer said.

AP Winter Olympics: https://apnews.com/hub/milan-cortina-2026-winter-olympics

Serpentines are set on the ice of the stadium where speed skating discipline of the Milan Cortina 2026 Winter Olympics will take place, in Rho, outskirt of Milan, Tuesday, Nov. 11, 2025. (AP Photo/Luca Bruno)

Ice Master Mark Messer poses in the stadium where speed skating discipline of the Milan Cortina 2026 Winter Olympics will take place, in Rho, outskirt of Milan, Tuesday, Nov. 11, 2025. (AP Photo/Luca Bruno)

Workers clean the ice surface during a peed skating Junior World Cup and Olympic test event, in Rho, near Milan, Italy, Saturday, Nov. 29, 2025. (AP Photo/Luca Bruno)

Ice Master Mark Messer poses in the stadium where speed skating discipline of the Milan Cortina 2026 Winter Olympics will take place, in Rho, outskirt of Milan, Tuesday, Nov. 11, 2025. (AP Photo/Luca Bruno)

Ice Master Mark Messer poses in the stadium where speed skating discipline of the Milan Cortina 2026 Winter Olympics will take place, in Rho, outskirt of Milan, Tuesday, Nov. 11, 2025. (AP Photo/Luca Bruno)