Power-to-X processes can buffer the peaks and troughs in the productivity of renewable energy generators. Green hydrogen is therefore a key component of the transition to the “All Electric Society”. Absolute safety has to be united with efficiency and economy when automating all of the technology necessary for this - from electrolyzers, through pipelines and storage systems, all the way to the fuel cells. Digitalisation, modular designs, and scalability are supported through state-of-the-art concepts.
The weather catastrophes of the past few months have once again made the climate crisis the focus of attention. Not least because of this, the energy transition is gaining increasing acceptance. The future vision of the All Electric Society, in which carbon-neutrally generated electricity dominates the power supply, is often discussed as a solution. A fundamental part of the All Electric Society concept is renewably generated electrical energy - from the power of the sun, for example - that is converted into storable energy. This is precisely where power-to-X technologies come into play. The surplus electricity generated by the respective systems - for example, when solar radiation is high, when winds are strong, or when there is an oversupply of water - is used to produce fuels (power-to-fuel), hydrogen (power-to-gas), ammonia, methanol, or other chemicals. Within the framework of the All-Electric-Society concept, some of the agents produced in this way are in turn used to generate electrical energy again; that is to say, they take on the role of an energy store that buffers the fluctuation of the renewable energies listed above, ensuring a continuous supply of energy. Such power-to-X technologies promote sector coupling, in which the electricity, heat, gas, and mobility sectors are coupled together.
Making renewable energies storable
Power-to-X can therefore be seen as the answer to the aspiration of climate neutrality. With this approach, renewable energies will become storable and transportable in large quantities for long periods of time. Power-to-gas in particular is considered a key technology in terms of the mobility sector. The ability to generate hydrogen from water in electrolyzers is not a new development. The respective technologies have been in use in the chemical and gas-producing industries for a long time. Fuel cells that convert hydrogen into electricity by reacting it with oxygen have also been around for many years. As part of the energy transition - in which these new energy sources are not only intended to be a carbon-free, but also an economically competitive alternative to fossil fuels - these processes have to be made significantly more cost-effective. In the case of electrolyzers, for example, a reduction to around a third of the current price is considered necessary. On the flip side, carbon taxes are promoting the decarbonisation of industry, transport, and the private sector. The German Federal Government’s stated goal of reaching greenhouse-gas neutrality by 2045 has to be pursued at full speed right now.
The “green automation” concept can and must play a central role in this. VDMA Robotik + Automation and the Fraunhofer Institute for Production Engineering and Automation have established a joint initiative to this end. Their approach is multifaceted. First, manufacturing processes are to be designed to be sustainable - that is to say, resource-conserving and energy-saving. Second, automation technology is to be used to promote innovative solutions that support and drive forward decarbonisation and make this process affordable. In the context of power-to-gas, various applications can be considered for this purpose: water electrolysis processes and fuel cells benefit from intelligent automation in connection with digitalisation, as does the operation of pipelines and the monitoring of storage facilities.
With power-to-X to the All Electric Society
Phoenix Contact has declared the future vision of the All Electric Society as its own strategic goal. One of the key starting points for a large number of activities is in supporting Power-to-X technologies through all points in the supply chain for converting renewable energies into hydrogen, methanol, and other chemicals and fuels, right through to converting these back into electricity, a field in which automation plays an important role. In this context, it is important to provide safety and security for the critical infrastructures that are used in this, which also includes explosion protection and IT security. The focus is on hydrogen applications within the framework of mobility, for example for buses and trucks, as well as in industry and in buildings. A large number of products and solutions from Phoenix Contact that have proven themselves in traditional processes are also relevant for the generation, transport, storage, and conversion of power-to-X (P2X) products into electrical energy. The initial projects - including the automation of fuel cell systems and electrolysis systems in particular - also highlight that both modularity and scalability are also proving to be important in this field.
Innovative automation concepts based on open, state-of-the-art industry standards
There is currently a flood of P2X projects, creating an atmosphere similar to that of a gold rush. Every day, new projects are being presented for the production of green hydrogen at locations in the steel, oil, and gas industry for the extension of pipelines, for investment plans enabling electrolyzer manufacturers to increase capacity, as well as feasibility studies for hydrogen plants on greenfield sites adjacent to large solar systems and wind farms. In light of this boom, it is self-evident that the resulting new industry sector should also strive to adopt new automation concepts. These should include the openness required in the framework of digitalization as well as the latest industrial standards.
With its existing product portfolio and the open, safe PLCnext Technology automation system, Phoenix Contact is providing the basis for realising concepts such as Open Process Automation and for establishing the simple connectivity of modular system parts through the Module Type Package (MTP) standard. This enables accelerated system and plant design, engineering, construction, and commissioning. Moreover, PLCnext Technology also supports the NOA (Namur Open Architecture) concept, which makes using production data easy and secure and forms an essential basis for continuous process optimisation, predictive maintenance, and the numerous other advantages that digitalisation promises. With special features such as a cloud modem, safety controllers, and access to an app store, the open source PLCnext Technology ecosystem is a future-proof basis for the automation of those systems that are currently being created.
Functional and data security as essential framework conditions
The requirements being placed by power-to-X industries on IT security (cybersecurity) are just as high as those of conventional power providers. In this case, it is not just a case of installing firewalls at one point or another in critical infrastructure. To minimise all cyber security risks in these P2X systems, the protection goals should be defined and based on the well-established IEC 62443 standard, “IT Security for Industrial Automation Solutions”. As a certified ICS security service provider, Phoenix Contact is able to provide sustainable support in this field. Its holistic approach also includes security-oriented product development. For applications in the hydrogen industry, the products used must be explosion-proof as well as resistant to vibration and temperature.
Functional safety is also of considerable importance. Experience gained in the process industry clearly demonstrates that controlling risks is not only essential with regard to protecting the environment and people, but also to maintaining the systems and thus protecting the investment. In addition to the safety integrity level (SIL), the performance level (PL) plays an important role in the use of automated safety systems. Decentral, flexibly configurable solutions such as SafetyBridge Technology are already being used in SIL 3 applications in a wide range of fields today. These solutions can be easily integrated into the control system.
Reliable warning of potentially explosive atmospheres
Powerful safety controllers for complex applications within the field of P2X can also be integrated into PROFIsafe and PROFINET networks. This enables safe shutdown, safe gas detection, and other functional safety functions to be realized regardless of who the manufacturer is. In addition, components for surge protection and, for example, cameras for monitoring decentral infrastructure can also play a role in safety and security.
A further key safety issue has to be taken into consideration due to the often-combustible gases that are generated, transported, and stored within the P2X framework. If they escape unnoticed, an explosive or toxic atmosphere can develop. Appropriate sensor technology and gas warning devices are necessary to warn personnel in these cases. Works traffic must also be kept away from such areas. Traffic lights that regulate this traffic are coupled with the gas warning devices via suitable transmission technology.
Equipping tank farms and underground chambers
An ever-increasing number of tank farms will be built as part of the P2X supply chain in the future, and not just as interim storage sites for hydrogen for fuel cells, for example. Large tank farms situated on industrial steel and cement production sites will provide hydrogen as a raw material for power-to-gas and power-to-liquid processes. This provides the opportunity to take the carbon dioxide that has been produced until now as an exhaust gas and react it with hydrogen to form synthetic hydrocarbons such as methanol or kerosene.
In the context of the energy transition, renewable fuels (e-fuels) produced from climate-damaging CO2 through carbon capture and utilisation are considered to be an interim solution at the very least and an important part of the circular economy. An even more climate-friendly solution is to convert the CO2 contained in the exhaust gas into chemical raw materials so that is bonded for a much longer timescale. Phoenix Contact has been equipping such tank farms with SIL-certified and intrinsically safe products - including, for example, overfill protection - and modular controllers for some time now. In addition, storing hydrogen in underground chambers, for example in former natural gas caverns, is also being discussed, meaning that these will also have to be equipped with automation technology or adapted.
It is self-evident that what applies to the handling of conventional fuels also applies to the handling of e-fuels - they are explosive. The principles of explosion protection must therefore be observed during transport and storage. To automate the required systems, a supplier should be chosen that has experience in equipping such processes in hazardous areas and, of course, one that has the necessary products. Among other systems, Phoenix Contact has already automated hydrogen and natural gas filling stations, integrating safety applications at the same time.
Redundancy in the compressor station
Phoenix Contact also has many years of experience in automating pipelines that include compressor stations. Along with pipelines for transporting the various gases, the power-to-X industry will also need pipeline systems for supplying buildings. Apart from the safety solutions, redundancy concepts that safeguard supply in the event of a compressor failure will also be required here. In addition to the automation of different compressor drive systems, such as electric motors, turbine drives, and piston drives, proven asset monitoring solutions tailored to the respective application will also help to ensure trouble-free operation.
Fuel cells and electrolyzers in the spotlight
Along with the transfer of knowledge from similar applications over to the P2X industry, Phoenix Contact has dedicated itself to specific new applications. For example, fuel cells were equipped with automation technology as part of a series of pilot projects. Also, the provider of automation and connectivity solutions has already made detailed optimizations: Fuel cell stacks from a well-known manufacturer can now be connected easily with VARIOCON-type connectors. With 40 I/O points, the efficiency of the assembly line has been increased significantly.
Electrolysis processes are also among the systems that Phoenix Contact intends to equip in the future. Initial pilot projects are underway to formalize the special requirements of such applications. To this end, a pilot plant was fully automated, resulting in its performance being increased significantly. In light of the fact that the manufacturer has already equipped a large number of chemical processing plants with automation technology, the technology that is necessary to ensure high availability for electrolyzers and thus to ensure competitiveness is already available. To further reduce system costs, principles such as Design to Cost are also to be supported, and capacities ramped up. Here, the possibilities of digitalization also have to be exploited. The digital twin, for example, could be used as part of process optimization and modernization in the future. The digital transformation will continue to open up new ways to make electrolyzers and a range of other systems within the P2X industry significantly more efficient in the future and, consequently, their products more cost-effective.
From terminal blocks through to safety controllers
Ultimately, Phoenix Contact has gained experience in almost every sector of P2X production, storage, and transport. In addition to the applications described above, the projects already completed also include pumps and compressor skids that are used in hydrogen systems. Practically the entire Phoenix Contact portfolio is used in these various applications: From terminal blocks and connectors, through power supplies and I/Os, all the way to surge protection components, firewalls, switches, and safety controllers.
Blue hydrogen as a bridging technology
Even though the path to a completely climate-neutral economy with the support of green hydrogen remains long, the first step has to be taken right now. Against the backdrop of the current energy mix in Germany, which is characterized by a high fluctuation in the productivity of wind, solar, and hydropower, storage solutions have to be created. The energy transition will not be realized by increasing the amount of wind power and solar systems alone. Massively increasing the facilities for storing electrical, renewable energy is the only way that it will be possible to buffer drops in productivity and to one day dispense entirely with natural gas.
Hydrogen and other power-to-X products play a key role here. When ramping up the necessary infrastructure and supply chains, what is referred to as blue hydrogen will almost certainly be necessary as an intermediate technology. Some of the first cluster regions, such as those identified by the German Energy Agency (dena), already have hydrogen pipelines. Activities in the field of mobility are being driven forward through the development of hydrogen filling stations. Not least, the chemical industry locations and refineries are becoming the centers of such clusters because, for example, hydrogen from fossil fuels and natural gas can be replaced by green hydrogen or synthetic methane.
Hydrogen pipelines – cheaper than high-voltage lines
Green hydrogen as a future energy source will make some discussions about high-voltage lines superfluous in a few years. Hydrogen pipelines already stretch across Europe. Extending this pipeline grid will not only be significantly cheaper than extending that of the electricity grid: a high-voltage line costs about ten times as much as a pipeline. It does not spoil the landscape in the way a power distribution system that is around ten times taller does. Hydrogen is also unbeatable when it comes to competing with batteries as an energy storage system. A quantity of 6,000 metric tons of hydrogen, which can easily be stored in conventional salt caverns(1), corresponds to the storage capacity of battery technology worth €23.6 billion.
Extending the green hydrogen infrastructure
The extreme weather conditions experienced in the summer of 2021 should have convinced the last doubters and delayers. The time is ripe to vehemently accelerate the energy transition and, along with that, to create the infrastructure for green hydrogen as a means of sector coupling. It is, after all, clear that the demand for energy will by no means decrease, even if all energy-saving possibilities are exploited. On the contrary, digitalisation and the ever-growing number of data centres being built as a result will further increase the demand for energy. In all likelihood, mobility and the transport of goods will not decrease either. Phoenix Contact can - based on its experience gained in the process industry, including in the fields of cybersecurity, explosion protection, and functional safety with scalable, modular solutions - provide effective support for plant manufacturers and the installers of hydrogen infrastructure within the P2X industry. In this way, the energy transition will become an opportunity for a large number of companies that demonstrate expertise, drive, and innovation.