The Use of a Hydrogen Fuel Cell as Emergency Power for Critical ITS Elements

A pilot project installed an emergency power system using a hydrogen fuel cell assembly to provide continuous power to critical ITS assets at a signalized intersection affected by the Public Safety Power Shutoff (PSPS) events while meeting California's Climate Change Initiative (SB 100). The emissions are only heat and water.

The installation of the hydrogen fuel cell for emergency power is an effort to mitigate the Public Safety Power Shutoff (PSPS) by the local power utility company and to future-proof the emergency power type due to California's goal of zero carbon emission by 2045.

The hydrogen fuel cell assembly is scalable based on the power demand and duration. In the pilot project, the hydrogen fuel cell was designed to supply seven days of continuous power. It supports a traffic signal system, two camera system, three flashing beacon system and a communication system.

The operation is autonomous. When utility power is lost, the fuel cell module begins to generate electricity until either utility power is restored or the hydrogen fuel is depleted. When the utility power is restored, the hydrogen fuel cell assembly resets itself ready for the next power outage. The periodic maintenance is an annual cleaning of a reusable intake filter. Troubleshooting and alerts are monitored remotely in the Transportation Management Center (TMC).

At the completion of the pilot, a white paper will be written evaluating the performance, levels of operability, maintainability, integration to both existing and new power systems. Typical details and specification will also be developed. A 20-year lifecycle cost analysis and breakeven point will be calculated. The possibility of integrating the hydrogen power system at the service equipment enclosure to provide emergency power to critical ITS elements will be explored.

There were 2 risks in implementing this innovative technology. First, district maintenance personnel would be reluctant to add an unknown equipment in their inventory, to learn a new process of maintaining the equipment, cost of replacing both the equipment and various key components. Second, The availability of hydrogen fuel in the future. There are a small number of companies selling hydrogen in the San Diego County. If when the availability does not proliferate but instead dwindles in the future, the hydrogen fuel cell assembly will need a hydrogen reformation component.

Since commissioning day, the system ran for 21 hours due to unscheduled power outage without maintenance personnel involvement. The Signal Engineer and Field Technician has since accepted the installation as beneficial. The installation was a success. The hydrogen fuel cell assembly performed as expected and its performance met the State's Climate Change Initiative and much more.

Funding and the acceptance of the innovative solution were the two factors that needed to be overcome. From the time the solution was developed, it took 4 years to be funded. Guarantees and reassurance to various stakeholders had to be negotiated.

Submitted by:
Louie La Compte, Design Engineer/Project Engineer/Construction Engineer

For more information, contact Louie La Compte at [email protected].

A 2021 PowerPoint Presentation

Inside the NEMA 3R enclosure housing the Fuel Cell Stack and control module

Loading the K cylinders of compressed Hydrogen gas.  Each K cylinder constitute 9kWhr

Prototype installation layout

Commissioning Day: Div. of Maintenance buyoff, Div. of Construction check off list, Div. of Safety inspection, TMC acceptance and proof of operation

Finally done!

The installation is in a remote signalized intersection where yearly power shut off occurs due to the risk of wildfire

In summary: the baselines (1) provide the highest degree of operability for all critical ITS elements and (2) operate for 7 or more days