- By Nishadi Davis
- Operations & Management
The clean hydrogen ecosystem needs control systems integration and network planning.
After decades of speculation and false starts, it is likely that hydrogen’s time has finally come. Federal investment and funding opportunities have created unprecedented opportunity for private entities to partner with federal agencies to jumpstart the hydrogen economy. The DOE’s Bipartisan Infrastructure Law includes $9.5 billion in clean hydrogen incentives with the intention of establishing several regional clean hydrogen hubs.
Hydrogen is a versatile energy carrier, and its applications today range across a number of industries. This allows us to leverage existing assets to scale up the hydrogen economy by combining these assets with a range of new technologies to quickly establish the basis for regional hydrogen hubs.
While the most recent focus in establishing these hubs has rightly been in developing solutions for the individual assets within a hub, the backbone of hydrogen hubs will be the control systems that link the individual entities together. This means that system integration will play a key role in the success of these projects.
Hydrogen hub anatomy
The anatomy of the hydrogen hub can be divided into four main segments: hydrogen generation, hydrogen storage, hydrogen transportation, and electrical power generation (Figure 1).
Each of these major segments can then be divided further. Hydrogen generation, for example, will occur through a variety of different processes from many different producers. Production methods will range from existing fossil fuel facilities that will likely be modernized by adding carbon capture units, to new electrolyzer and biomass facilities that have yet to be built. Hydrogen that is produced across these entities will then need to be transported to either storage facilities or electrical power generation units. All these different pieces will need to be monitored effectively and controlled efficiently to ensure a robust hydrogen network.
Because hub establishment will require multiple partners across the energy industry, the controls systems within each hub will have a drastic range of systems from different vendors, as well as a wide range of functionalities and communication protocols. It will therefore be necessary to establish some form of a supervisory control system to integrate all the individual controls into one centralized system to get an accurate view of what is happening across the entire hub at any given time.
Hydrogen hub considerations
When considering the controls systems piece of hydrogen hub establishment, the following should be considered across the entire hub:
- Centralized controls
- Safety systems
- Centralized human-machine interface (HMI)
- Alarm rationalization
- Information technology (IT)/operational technology (OT) infrastructure
To design a seamless operating system, a control systems integration plan should be developed in early hub planning stages and not as an afterthought. The systems integrator must take existing network architecture into consideration as well as plan adequately for future expansion because hub development will roll out in stages and continue to expand.
A control plan must be developed to outline which information is necessary to be relayed to the central control system. The central control room, at a minimum, should supervise electrolyzers and other hydrogen generation units, monitor pipeline activity, control electro-chemical fuel cell interface with the power grid, and interface with the safety instrumented system (SIS). This means data from programmable logic controllers (PLCs), distributed control systems (DCS), and SIS will converge to a central location with the help of remote/supervisory control and data acquisition (SCADA) systems. Advanced applications will need to be evaluated for integration between hydrogen hubs and the electric grid to manage grid balance.
Begin with safety
Safety system implementation is an integral piece of hub integration, as hydrogen is both volatile and explosive. Because hydrogen use is well-established across industries, regulations, guidelines, and codes and standards already exist to facilitate safety guidelines around the industrial use of hydrogen.
In addition to existing regulations, systems have already been put in place to establish codes and standards that facilitate hydrogen and fuel cell commercialization. Layer of protection analysis (ISA84/IEC 61511) will continue to govern safety integrity level (SIL) implementation for SIS. The hydrogen hub centralized control room will be required to interface with safety systems to facilitate remote shutdowns as well as take necessary control action during abnormal events.
HMI development also should be planned carefully for the central control room. The goal of the HMI should be to provide control room operators with as much visibility into the entire hydrogen hub without loading unnecessary data onto graphics. The HMI should be structured so that operators are quickly alerted to abnormal conditions and can take immediate action to rectify any issues.
High-performance graphics, following the ISA101 HMI standard, should be developed so that operators are presented with useful information rather than being overloaded with data points. Display hierarchy is critical to the development of a hydrogen hub HMI because of the vast network of assets that are integrated to a central system. Analysis should be done in advance to determine how to structure this hierarchy, as well as how to best integrate future assets as they become connected to the hub.
A robust alarm system will be an important part of the hydrogen hub’s central control system.
Alarm rationalization should be performed following ANSI/ISA84, Management of Alarm Systems for the Process Industries standard. Alarm rationalization will minimize the number of alarm activations and nuisance alarms. Following rationalization, the alarm system generally results in rapid response from control room operators who learn that the alarm system can be trusted to only report on necessary events. This also reduces complacency. A robust alarm system will be an important part of the hydrogen hub’s central control system because operators will need to be quickly alerted to abnormal conditions across the entirety of the hydrogen hub.
IT/OT network infrastructure
Another piece of the control systems integration effort is the IT/OT network infrastructure planning. Industry practice for industrial control systems (ICS) is based on ISA/IEC 62443 standards. Technology advances in recent years have led to a push for the convergence of IT and OT systems, but it is important to understand the purpose of each system. OT systems prioritize maintaining reliable and safe production operations while IT systems prioritize securing business data. When it comes to hub planning in this regard because many different private entities will form a single hub, networks will have to be carefully planned so businesses can share vital production data with the entire hub, while securing their own business networks. The hydrogen hub in turn will likely require its own independent IT network infrastructure. Early planning of this network architecture allows communication to be streamlined across networks.
Integral to IT/OT infrastructure planning, is cybersecurity. Traditional IT risk assessments do not fully capture process risks at the OT level. This is where new cyber risk assessments as part of CHAZOP (Control Systems HAZOP methodology specified in NIST SP 800-82 and ISA/IEC 62443) is useful. Performing CHAZOP allows us to systematically identify key risks at the OT level that have health, safety, and environmental implications. Performing a CHAZOP will help stakeholders and decision makers identify true risks across the hydrogen hub and take appropriate mitigation measures.
Control systems integration is a key component in establishing hydrogen hubs. Individual pieces of the hydrogen ecosystem can only function together if they are able to communicate effectively with one another other. Control systems and network planning should be started early in the hub development phase to ensure that communication is streamlined across entities.
Defining communication protocols at the hardware purchasing stage is ideal. Identifying all necessary hardware interfaces up front will also be beneficial to the planning process. Alternatively, trying to piece together communication links in the late stages of hub development is more expensive and time consuming. Control systems planning in hub development should be systematically planned to design a robust control network.
We want to hear from you! Please send us your comments and questions about this topic to InTechmagazine@isa.org.