CALISTOGA — 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.
Interesting project. It seems that PG&E is putting up the $50 million to replace diesel generators that would need to be temporarily set up in case of fire. That puts a pretty hefty price tag on diesel generators.
It’s likely that PG&E’s money would be better spent on wildfire mitigation projects.
This is a great use of this technology for emergency backup power. But I’m not convinced that it would make sense for everyday use. Perhaps the battery could be used everyday. But where would the hydrogen come from and how much would it cost?
I read the whole article and this wasn’t addressed.
From the Department of Energy, 95% of the hydrogen produced in the US comes from natural gas. Some people might fool themselves into thinking that hydrogen fuel cells are “green”, but producing hydrogen from natural gas releases a lot of CO2. You might as well burn the natural gas in a simple cycle gas turbine to produce the power. As for cost, hydrogen is more expensive than natural gas.
For now Air Products is a leading supplier of hydrogen. They also do liquid hydrogen for space travel. Linde is also a possible supplier.
Air Products just went through a proxy fight and got a new CEO who wants to shut down green hydrogen projects.
Yes, most hydrogen in the US is made from natural gas and CO2 is a co-product. For synthesis of ammonia it is routinely collected and sold. Its a clean source of CO2 often used in carbonated beverages. Yes, once collected it can easily be sequestered.
We hear progress is being made on green hydrogen by electrolysis of water but cost continues to be high. Most hydrogen probably moves as compressed hydrogen in trucks but maybe one day we will have pipelines.
The article says the town gets clean power backup which is correct. A simple cycle gas turbine is dirty and would pollute the town. The microgrid system will use green hydrogen as stated in their approval documents:
This Resolution approves Pacific Gas and Electric (PG&E) Advice Letter (AL) 6808-E. In D.21-01-018, as amended in Resolution E-5164, the Commission ordered PG&E to start the transition to clean backup generation by pursuing at least one clean substation microgrid project for Public Safety Power Shutoff (PSPS) mitigation. This resolution approves PG&E’s plan to develop that project at the Calistoga substation, and the associated procurement contract with Energy Vault. PG&E proposes an 8.5-megawatt microgrid capable of powering the Calistoga substation for 48 hours, and thus keeping the substation energized during a PSPS event effecting the transmission system that normally powers the substation. The microgrid would be developed by Energy Vault in coordination with PG&E and would operate for 10.5 years starting in 2024. The microgrid would combine a battery energy storage system with a fuel cell fueled by green hydrogen. This project would be the first long-term, clean energy, substation microgrid in the PG&E service territory. Forecasted costs for the project fall below the benchmarks set in D.21-08-018, and the costs would be covered by a one-way balancing account capped at $46.3 million dollars. This Resolution also requires PG&E to submit reports on the pilot project, detailing the actual costs incurred, its technical performance, and any lessons learned, and to encourage the use of project resources during normal grid conditions.
The town needs some source of electricity if it wants to remain powered up during a wildfire. In the fire five years ago they used diesel generators. In this project they are going to use batteries and hydrogen at a cost of $50 million.
It seems this is a sort of beta-test for a microgrid with hydrogen backup. PG&E is footing the bill (of $50 million for a couple thousand households) as part of its penance for the 2020 wildfire. Its seems pretty expensive for common application.
A gas generator would be much cleaner (NOx, etc) than diesel, much quieter and lower CO2. You could shade it with solar panels and use this power all the time.
So I asked Chat GPT to compare costs for 3 days use per year and it picked 100 KW system to compare as follows
Cost Breakdown