As of today, there are fewer than 100 hydrogen refueling stations in North America, with the vast majority of those situated in California. The operational performance of these first-generation stations is generally poor. According to the head of one of the major fueling network operators in California, “Fueling systems universally underperform. Nothing is any good.” NREL national lab studied the issue and found that most stations were down for unplanned maintenance at least every two weeks. Hydrogen car owners are pulling their hair out. Many installed stations have never even successfully started up. Equipment vendors are getting sued and others have pulled their products from the market.
What went wrong and how do we do better with future refueling systems for mission-critical heavy duty commercial vehicles?
Engineering Integration
Many existing fueling stations are a collection of different subsystems, cobbled together in the field and expected to work as a reliable integrated system. A compressor package or cryopump from one supplier might be connected to a dispenser from another supplier. Each subsystem might come with its own industrial controls, but then a new master controller will need to be developed by a separate team to glue the siloed controllers together. Even when a single vendor sells these subsystems together, the subsystems are typically not designed and tested together as a unified system by a unified engineering team.
At Hyfluence, we’ve made the core commitment to deliver fully engineered and integrated fueling systems, so that we can stand behind the performance of the entire fueling system. Our systems operate under a single harmonized control system, and each subsystem is specifically designed and optimized within our overall system architecture.
Fault-Tolerant Architectures
First-generation systems were generally engineered as a single linear process chain - if any one component in the system failed or required maintenance, the system could not operate. Components will occasionally malfunction and maintenance is periodically required, so future system designs must allow for that.
Fault-tolerant architectures are designed to respond gracefully to component faults through failover to redundant modes or subsystems.
At Hyfluence, we use a fault-tolerant approach, with multiple smaller subsystems rather than a single large one, along with controls that allow flexible automatic reconfiguration of subsystem functions. For example, three compressors in a Hyfluence fueling system can together achieve 150 kg/hour peak dispensing capacity across multiple dispensers, or any one compressor can be reallocated when needed to unload a hydrogen tube trailer delivery, or to boost ground storage pressures, or to be taken offline for compressor maintenance. Under such an architecture, operational impacts of a failure or a lack of component availability are minor -- generally just a reduction in maximum system capacity that would only be noticed during periods of peak demand.
The use of real-time analytics can also help prevent station downtime by anticipating when system inspections or maintenance should take place. Early detection of potential faults and predictive tracking of component wear can anticipate and mitigate operational issues before they happen.
Testing with Hydrogen
Surprisingly, many refueling systems operating today were never tested with hydrogen until they were installed in the field. For smooth start-up and ongoing reliability, refueling equipment must be thoroughly tested, using hydrogen, before leaving the factory. Components will sometimes fail out of the box, calibrations will drift and assembly errors happen. These issues should be detected and rectified at the factory. Hydrogen is a unique gas and testing with a substitute gas is… no substitute. During field installation is not the time or place to be debugging these issues.
At Hyfluence, we test each system individually and extensively with hydrogen at the factory, before shipping, even if we have shipped the same design many times before.
Achieving Reliability and Uptime
To ultimately reach hydrogen’s potential in helping decarbonize commercial road and off-road transportation, everyone involved needs full confidence that the fueling infrastructure can reliably support the fleet investment through maximum operational uptime. Reliability and uptime are affected by many factors, including individual component reliability, component and subsystem redundancy, proper maintenance procedures and practises and robust design considerations.
At Hyfluence, we collaborate with our component suppliers to determine the operating and lifetime limits of each component, so that we can make sure our control system maintains all components within their appropriate operational limits. We also integrate component monitoring into our control system’s built-in analytics, so that our hydrogen station can proactively anticipate component failures long before a failure occurs, and automatically prompt the station’s maintenance personnel to inspect and service the station. With these strategies, along with our fault-tolerant design approach, Hyfluence can provide the reliability and uptime our customers need.
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