Europe's first multi-energy filling station in Berlin runs smoothly for more than two years. The higher-level process control system from Siemens monitors the networked plant and communicates with the different modules of the cooperation partners that provide the hydrogen generated from wind power and solar energy.

A host of technological components of different manufacturers – process plants today are often the result of system environments that have grown heterogeneously over the years. This presents a challenge to plant operators at the latest when it comes to intelligently coupling individual systems and their automation programs and integrating them into the overall plant. The "view from above" solution is the obvious choice here: In the control room as the highest operations control level, plant sections from different manufacturers can be integrated into one system, regardless of whether this involves machine level or process-level automation.

The advantages are clear: One user interface level, standardized alarms, and the plant operator is concerned with only one process and not with monitoring and handling different systems. How can this harmonization be implemented without significantly affecting the automation technologies of the cooperation partners? This was precisely one of the requirements in the H2BER project.

Europe’s first hydrogen-based multi-energy filling station

"One of the great challenges of the Berlin project was integrating the technological components of all partners into the higher-level Simatic PCS 7 process control system," explained Tristan Kretschmer of McPhy Energy Germany. The project team of the EU-backed "H2BER" project have had a lot to do in recent months. Under the auspices of the Clean Energy Partnership (CEP) and jointly with the cooperation partners Total Germany, Linde and 2G Energy, the task was to configure and implement – within sight of the new Berlin Airport – Europe's first hydrogen-based multi-energy filling station. In the future at this filling station, hydrogen will be used as an energy source throughout its entire cycle from production, through power and heat generation, right up to its use as a fuel. This required harmonizing and integrating the technological components of the individual partners and their control systems. This included the cogeneration plant, individual storage technologies as well as the tank technology for the two H2 pump stacks, where, in the future, it will be possible to fill up cars and buses equipped with 350 bar and 700 bar tanks. As well as filling vehicles with fuel, the hydrogen will also be used on-site in a bivalent block heat and power plant for generating power and heat for the adjacent filling station. The Reiner-Lemoine Institute provided valuable scientific support for the project. The plant employs a modular approach, which already today is generally encountered in the process industry, and which will continue to be the trend in the future: The individual partners and manufacturers supply their components and plant sections, taking into consideration the respective processes, equipment, electrical engineering, automation engineering, and associated hardware and software.

One open system for control and visualization of all components

Right from its inception, the engineering solution was to integrate all of the plant sections into a higher-level process control system. The choice here fell on the Siemens Open OS solution, an integral part of Simatic PCS 7. It harmonizes heterogeneous system landscapes and with its open architecture, allows third-party components to be integrated and operated from a central control room. These components include Simatic S7-1500 controller and different third-party components. The project partners involved had very little work to do regarding the overall synchronization. The Open OS data for signal processing is acquired from plant sections at the same level and lower levels and combined in a control room, taking into account know-how protection. Individual components such as PLCs and controllers from other manufacturers can be integrated into the PCS 7 process control system via WinCC communication channels or OPC, in just the same way as ready-to-install package units. In this way, Open OS creates a PCS 7-compatible image of the system to be integrated, with the result that the plant operator has a uniform and standard control and visualization system.

Customer praised well cooperation of all project members

Tight scheduling, know-how protection for the individual plant sections and 24/7 availability: For those responsible at McPhy, the H2BER pilot project represented several challenges with regard to realizing the higher-level control system. "All of the partners collaborated closely right from the start of the project to determine which data is relevant, how it can be captured and which signals are transferred," explained Wolfgang Kraus, Project Engineer at McPhy. "For this pilot project, we developed a solution where we coupled the Simatic PCS 7 process control system to the third-party controllers and the Simatic S7-1500 controllers via OPEN OS – and then transferred the relevant data via standard communication channels. The Siemens online and 1st level support organization, with its numerous experts and application examples, provided valuable technical support. We were able to benefit greatly from this free service, especially in the initial project phase."

Benefits of the process control system

Another advantage of Simatic PCS 7 Open OS is the data archiving option, an important feature when looking at the specifications for the Berlin project. "Data must be archived for approximately one and a half years, and the procedure must be fully automated. The solution from Siemens is a perfect fit to address these requirements as visualization can be standardized – in a single system – and data is simultaneously archived. We run this on the Process Historian server from Siemens. This is another component of Simatic PCS 7 that captures the process data and makes it available for further processing." Open OS also offers the option of saving data in the form of an XML file, with the result that, once set up, solutions can be reproduced. This will significantly reduce the engineering costs for a second H2 filling station. All of the project partners benefit from this integrated solution that has been engineered, and which can be reused on a one-to-one basis. "We can now claim that our on-site electrolysis and storage solutions are fully reproducible," is how Tristan Kretschmer sums up the knowledge gained by McPhy from the hydrogen filling station.

Structurally, the Berlin Simatic PCS 7 process control system consists of a user interface level with a client-server architecture. The Process Historian system is also integrated here and ensures long-term data archiving for the networked plant. Some aspects of the architecture have even been designed redundantly – to increase availability and to minimize downtimes. At the system level below this, McPhy's software engineers have installed an Ethernet ring that is connected to all of the lower-level systems. Open OS captures the data from the various third-party systems here, and makes it available to the user interface level in a standard form.

Huge response from business leaders and politicians

While still a pilot project today, in the future it will be possible to use the process control system of the Berlin project as a full version as soon as plant operators have agreed on the underlying legal framework within an integrated and networked plant.

This H2BER project has already prompted a huge response from business leaders and politicians with the inauguration of the filling station for more than two years. In the meantime, the first fuel cell automobiles are on the market. A total of fifty filling stations for hydrogen-fueled vehicles were planned across Germany initially by the end of 2015 but later with a subsequently correction to end of 2016. Redundant technologies for the control centers will play an important role here as in other sectors with networked plants. Similar scenarios to those realized for renewable energies can then be conveniently applied to heterogeneous process environments such as the pharmaceutical, chemical and oil & gas industries using systems such as Simatic PCS 7 Open OS. The step-by-step migration of third-party systems and merging entire control rooms can also be engineered and realized in a similar fashion.