Yes. Enapter will take back old hardware and reuse or recycle it.
There is no simple mechanism to detect dryer end of life. When the adsorbent materials in the cartridges degrade too much, they will not be able to fully dry the hydrogen anymore, and the will water content in the output hydrogen stream will increase. This could be detected with a dew point measurement.
Once the stack end of life criteria is reached, even with fresh electrolyte and at nominal operating temperature the power supply within the electrolyser will not be able to reach the maximum production rate anymore.
The electrolyte is not used up. As the KOH is only circulating within the machine, it remains in the system and does not get diluted after several refillings. However, the electrolyte will accumulate impurities and degrade during operation and therefore needs to be exchanged once per year.
None. The Water Tank does not need any maintenance if the water inside meets the electrolyser’s purity requirements. However, it should be checked for leakages.
Almost none. But it should be checked that the ventilation ports are free of dust and obstacles and that there are no leakages.
Almost none. The main regular maintenance needed is draining and refilling electrolyte once a year or if the electrolyte quality is degraded. The used electrolyte needs to be disposed according to the local regulations. It should be checked that the ventilation ports are free of dust and obstacles and that there are no leakages. Please see the user manual for more information.
No. Changing the production rate does not influence the lifetime.
The expected lifetime of the electrolyser is more than 30.000h. Also, the dryer’s lifetime is at least 30.000h. Enapter expects those numbers to further increase in the future.
Enapter has defined an end of life criteria for the electrochemical stack when an average cell voltage of 2.0V is exceeded (at nominal production rate, nominal operating temperature, and with fresh electrolyte solution). This means, roughly 15% of the stack degradation of a brand-new stack. Even after that point, the electrolyser will still be functional and can continue to produce hydrogen at a lower efficiency or production rate.
The electrolyser produces hydrogen gas pre-compressed at 35 bar, which is sufficient for most stationary storage projects. Only for very large amounts of hydrogen to be stored, or if hydrogen is produced for mobility (hydrogen vehicles), then a compressor is needed to reach higher pressures.
These functions are automatically controlled by the electrolyser. The production rate can be set via the Energy Management System (EMS). Manual regulators are not necessary and cannot be added.
No. The pressure difference between the oxygen and hydrogen sides ensures that no significant oxygen concentration can arise at the hydrogen outlet.
No. A buffer tank is not needed but recommended for setups where the hydrogen outlet is not directly connected to a storage tank. In those cases, a buffer tank of 50 L per electrolyser keeps the pressure at the output stable and prevents the system from ramping up and down too often.
The water storage capacity of the Enapter WT is 35 litres. The pump of the WT offers a supply rate of up to 3.8 L/min. Depending on the length of the pipes to the electrolysers a single typical refilling can be accomplished in between 1-2 minutes. (WT2.1 data sheet)
The Enapter dryer raises the output purity of hydrogen gas from the AEM electrolyser to >99.999% in molar fraction. It is a hybrid temperature/pressure swing adsorption system that comprises two cartridges filled with a highly adsorbent material. The system is fully integrated into the Enapter Energy Management Sytem (EMS) to monitor the state, temperatures, and pressures.
An interruption at the dry contact will immediately trigger a shutdown of the electrolyser system. The electrolyser will then go into error mode, and the hydrogen production will stop. The valve at the purge line will open as well to release the internal pressure.
No. But it is recommended to keep the power supply as stable as possible to preserve the internal components.
The electrolyser can be easily started and stopped via the Energy Management System (EMS) in standby-mode, via Modbus TCP or the front panel button. Please see the software chapter for more information.
A table of the meanings can be found here.
Unfortunately, the electrolyser must be mounted in a horizontal position and as described in the product documentation. Please check the product manual for further information.
Enapter products may contain small amounts of liquids when they leave Enapter. Therefore, Enapter products shall always be stored between +1°C and +45°C. Make sure to follow the operation temperature requirements before switching it on to avoid damages.
The datasheets contain an overview of the different products. The owner’s manuals include more precise information about setting up devices, connecting them and starting the hydrogen production.
No. There are no other substances released beside H₂, O₂, H₂O (steam) and KOH (when drained).During each purge 1-10ml of water (mostly liquid) is released. The O₂ vent line contains 250 NL/h of oxygen saturated with water vapor.
Theoretically yes, but it is neither pressurized (<0,5 bar) nor purified.
The oxygen outlet primarily contains oxygen (O₂) and a little amount of water steam. As it is not meant for further usage, there might be small amounts of H₂ and traces of KOH/K₂CO₂. For safety reasons, the H₂ concentration at the oxygen vent is always kept below a safe limit of 4% at around 2%. A water trap is recommended to separate the water from the oxygen at the vent outlet. Ensure that the oxygen vent and hydrogen purge line outlets are led to safe areas and not close to each other.
The purge line is used during ramp ups and ramp downs as well as every 12h during operation to remove water inside the electrolyser and increase the quality of the hydrogen at the hydrogen outlet. The purge line of the dryer can be connected with the one of the electrolyser and contains the water which has been extracted during the drying process.
The electrolyser purges about 20NL/h for each ramp down and once a day if it is running continuously.The dryer purges about 15NL/h of hydrogen to drag away the humidity. These amounts are not part of the produced amount at the hydrogen outlet, so they do not lower the production rate.
Hydrogen and oxygen should always be kept separately to avoid explosions and fire! To avoid a dangerous situation, you should never mix the oxygen and hydrogen outputs from the electrolyser. Please always follow the instructions in the manual and apply safe engineering practices.
Yes. The internal working pressure of the electrolyser is always at least 29 bar when it is operating and can increase to a maximum allowable pressure of 35 bar. The internal pressure is controlled by a pressure regulating valve, and it is usually independent of the hydrogen output pressure. The pressure on the electrolyser hydrogen output depends on the storage volume and the amount of hydrogen produced. The maximum electrolyser outlet pressure, which determines the pressure where the electrolyser stops working and enters a “standby – max pressure” state, is 35 bar by default. This value can be freely set by the operator between 0-35 bar, so if the attached tank can only safely hold up to 7 bar, it is possible to set a reduced electrolyser stop pressure of 7 bar. Important note: To ensure the safety of your system, you must install appropriate overpressure protection devices on your hydrogen storage system connected to the electrolyser outlet.
Yes. The hydrogen is produced at adjustable constant pressure and will flow into an external tank or pipeline until the pressure at the outlet reaches the threshold. Please see the datasheet for details.
The hydrogen outlet contains more than 99,9% pure hydrogen (H₂). There are small amounts of water (~1000ppm H₂O) and even smaller amounts of oxygen (O₂). Those amounts can be further decreased with a hydrogen dryer to reach up to 99,999% pure hydrogen. Please see the datasheet for more information. The electrolyser itself does not have any sensors to measure the amounts of oxygen or water contamination.
The electrolyser has a standard ¼” Swagelok bite-type Stainless Steel connector for the hydrogen outlet piping. Internally it is protected by relief and check valves to prevent backflow of external tank/H₂ distribution lines. In some few cases, local rules or regulations require welding.
Yes. Enapter designs all hydrogen piping in accordance with ASME B31.12. All European guidelines refer to the ASME, which are very high standards for hydrogen piping and pipelines.
Our products are not designed to be installed in an ATEX area, and do not create explosive atmospheres when installed correctly. The output gases are only released from the designated interfaces (H₂ outlet, O₂ vent, and H₂ purge). These have to be correctly managed during the on-site installation. It is the operators responsibility to ensure that the area where the electrolysers are installed must never contain any explosive atmospheres. An appropriate safety concept must be implemented to mitigate the risks of any failures and consequences of leakages of flammable gases. Such a safety concept could involve, for example, hydrogen sensors, forced ventilation, or natural ventilation.
The EL2.1 is CE certified.
Modbus TCP/IP is a protocol which can be used to access registers of the electrolyser via the Ethernet port. This can be used to read statuses and sensor data as well as to write commands like start, stop, reboot. A description of all available registers can be found here.
Yes. They can be downloaded and installed via the mobile phone app or the cloud.
Yes. However, the most convenient and simple way to manage and monitor the electrolyser is via the Enapter Cloud or mobile phone app.
Yes, of course, in case of an emergency, the power to the electrolyser can just be cut off. When the emergency is resolved, the electrolyser can be powered on and restarted again within a few minutes.
Enapter’s mobile phone application is an interface for system integrators and end-users who want to connect their devices such as electrolysers, dryers, communication modules and extensions. The Enapter mobile phone app allows an easy and secure system setup using QR codes to manage and monitor devices all over the world. It is available for Android and iOS.
Yes. Due to the rule based control, the system can be programmed to be as versatile as needed. In that way, weather and time depending control and other sensor driven actions can be realized by a simple CLI if-then-else logic. For an extended functionality and more complex situations, the scripting language Lua can be used. Generally, for rule based control, the Enapter Gateway is needed.
Yes. Individual electrolyser can be interfaced to a PLC using Modbus TCP/IP and the electrolyser’s Ethernet port. A group of devices set up on a site with an Enapter Gateway can be interfaced to a PLC via an MQTT connection to the Enapter Gateway.
Yes. The Energy Management System allows full monitoring and control via a website or mobile phone app. It also allows for efficient support and service.
The water quality is not analysed. Depending on the supplied water, suitable maintenance intervals can prevent a decreasing water quality and damage of the electrolyser.
Yes. The EMS can be adapted to read and write data from all common communication standards of micro-grid systems and analogue inputs. If you would like to integrate a new system (inverters/power meters/fuel cells) into the EMS ecosystem, feel free to contact us!
The Enapter Management System (EMS) allows tracking of warning and error messages, inlet and outlet pressures, production volume and more. It can be accessed by any standard internet browser, such as Google Chrome and Firefox. Specific data sets can be downloaded in CSV format with a few clicks on the exports page.
Yes. The electrolyser, dryer, water tank and water purification system also work without WiFi. However, for the initial setup it is mandatory to connect them to a network and add them to a virtual customer site. Please note that not all functionalities may be available without WiFi.
A table of error codes and their meaning can be found here. Please look up the firmware version of your device before searching for the error or warning as those might change depending on the firmware version.
Enapter is constantly expanding its Energy Management System Toolkit, which it provides to all customers. The EMS Toolkit allows integrators to create a comprehensive Energy Management System (EMS), connecting any hydrogen or energy device into a unified energy network via simple hardware and software integrations. It thus enables monitoring and control of energy systems of any size and shape. Its tools include Universal Communication Modules (UCM), the Enapter Telemetry Platform, the Enapter Cloud and our Mobile App. The EMS Toolkit also offers developer tools like Web IDE and Enapter Blueprints, as well as documentation to help system integrators and component manufacturers add our solutions to their products.
Enapter’s electrolyser is designed to be intrinsically safe. It self-pressurises the hydrogen side and performs leak test routines at regular intervals. Electrolysers from generation EL2.1 on are CE certified, which allows straightforward integrations into existing safety concepts. In some cases, it might be necessary to install additional safety devices (e.g. hydrogen detectors on the top of the cabinet) to satisfy local regulations and safety concepts. These hydrogen detectors can be connected with the dry contact on the front panel. It is recommended to define two safety levels (e.g. at 10% and 25% of the lower explosive limit):
Enapter’s electrolysers have various sensors to ensure a safe operation at all times. If a leak is detected or the pressure unexpectedly falls, the electrolyser will shut itself down and send an error message via the Enapter Management System (EMS). The maximum amount of hydrogen gas inside one electrolyser is around 18 NL. An internal ventilation system dilutes any possible leakages below the hydrogen lower explosive limits (LEL).
No, it should only be used to shut down the electrolyser as a preliminary measure, before a real safety risk occurs. To realize a true safety shutdown, please use a certified safety circuit and simply cut off the power to the electrolyser.
Enapter believes that all hydrogen production must be green, therefore Enapter electrolysers are intended to be run from renewable energies, which by nature are decentralized and intermittent. If electricity is available at the right cost for 24 hours, it will result in a faster return of invest of the electrolyser. However, that is a rare occurrence and so Enapter’s devices are designed to be started, stopped, and production rates adjusted as needed.
Please get in touch with us.
The electrolyser requires a yearly change of electrolyte, which can be performed by the customer in an easy 20 minutes process.
AEM is the most promising technology for bringing down the cost of electrolysis, because it combines low stack material cost and low BOP (Balance Of Plant) complexity and cost. The AEM technology allows compact, scalable devices which produce pre-compressed, highly purity hydrogen to be stacked to any flowrate needed.
With the AEM electrolyser we need 4.8 kWh to produce 1 Nm³ of hydrogen. That means it takes 53.3 kWh to produce 1kg of hydrogen (compressed at 35 bar and with a purity of ~99.9%). 1 kg of hydrogen contains 33.33 kWh/kg (lower heating value), i.e. our electrolyser already has an efficiency of 62.5%. It is important to compare apples with apples: power input, hydrogen production, pressure and purity. These are very different for different manufacturers. System efficiencies (not stack efficiencies) need to be compared.
Enapter specializes on the AEM electrolyser and auxiliary equipment related to the hydrogen production. Enapter does not offer turnkey solutions with tanks, fuel cells, and other equipment preassembled on site. The good news is, our partners do and you can find them here.
The cost of green hydrogen is a function of the volume of power needed, the cost of power supplied, the cost of the electrolyser and its system, and the operative system to run the system. We are suggesting to use these factors in a formula to transparently compare pricing.
In addition to the general warranty for our products as set forth in our general terms and conditions, we also provide for an additional voluntary commercial warranty under which Enapter warrants that any product purchased from Enapter will be free from defects in materials and/or workmanship for a period of at least 1-year from shipment. Enapter extends this warranty for all Enapter electrolysers operating with an active Enapter Monitoring Subscription Agreement (EMSA), the two years commencing from the date of shipment.
As soon as information about new devices and products are available, they can be found on the Enapter website. Stay in the loop and sign up for our newsletter.
The rated operating temperature is 55 °C / 131 °F.
Unfortunately, we cannot provide this information as it is part of Enapter’s intellectual property.
Enapter utilizes a proportional relief valve to pressurize the system and several pressure transmitters to control and monitor stack and outlet pressures. A solenoid valve opens and closes to return the system to a safe state if an error occurs.
Unfortunately, we cannot provide this information as it is part of Enapter’s intellectual property.
Unfortunately, we cannot provide this information as it is part of Enapter’s intellectual property.
We expect a lifetime of the stacks of >30,000 hours. For more information, please see the datasheet.
Enapter’s electrolysers do not use Nitrogen.
CO₂ contamination in the air is not a problem for the electrolyser, as the system design avoids potential interaction with the surrounding air. However, CO₂ in the electrolyte (e.g. by refilling with carbonized water reduces the pH value and requires a more frequent electrolyte exchange. When maintained regularly (exchanging the electrolyte), this is reversible and does not contribute to explicit degradation of the electrochemical system.
The air-cooled and liquid-cooled electrolyser are nearly identical devices. The only difference is in the heat exchanger subassembly, which has the primary function to maintain a stable electrolyte temperature for the electrolyser operation.
The electrolyser is highly resilient to water input and can be fed with purified rainwater or tap water. Simple and cheap reverse osmosis processes with resin filters can provide the required water quality. The water input to the electrolyser needs to be desalinated and have a low conductivity. For details, please see the datasheet. It is not possible to use saltwater in the electrolyser.
The AEM electrolyser has an internal tank of approximately 3.5 litres. To produce hydrogen, clean water must be provided to the electrolyser via a refilling pipe at a pressure between 1 bar and 4 bar. The electrolyser refills about 1.5 litres of water every 3 hours.
Shutting down the system is rather easy: either manually by pressing/clicking the stop-button or automatically when the maximum pressure set point is reached at the outlet. One thing to note is that after every shutdown, the system will release the internal working pressure and purge a small amount of hydrogen gas from the purge line.
As with all electrochemical devices, our AEM electrolyser stack’s lifetime is shortened with frequent start/stops. With increasing experience in the field and operational data, we can now recommend our customers to limit the electrolyser’s operative cycles to a maximum of five on/off cycles per day, and one on/off cycle per hour. This helps to ensure the longevity of the electrolyser.
The ramp up time of the electrolyser depends on the electrolyte temperature (the ramp-up is slower at cooler temperatures and quicker at warm temperatures). In most cases, the system will start with a hydration period of 60 seconds, and then ramp up to the nominal production rate with the following values:
The lowest production rate of the AEM stack is 60% of the 500 NL/h, meaning 300 NL/h. The lowest production limit was set to 60% to ensure the devices’ safety. The amount of hydrogen in the vent line is then still well below the flammable limits. The energy consumption decreases roughly linearly with the production rate set point. The power consumption at a given production rate can be seen in the graph below.
Currently, all production takes place in Crespina, Italy, close to Pisa. Enapter is currently preparing a mass production site in Saerbeck, Germany.
Traditional liquid alkaline electrolysers have been on the market for quite a while and are relatively cheap. However, they are comparatively slow at responding to a fluctuating power supply, so it is difficult and costly to pair them with renewable energy sources efficiently. Traditional liquid alkaline electrolysers operate with highly concentrated electrolyte solutions and at low pressure. They require additional purification and compression steps to produce high-quality gas at a higher output pressure. This is only cost-effective for centralized and monolithic multi-MW projects.
Proton exchange membrane electrolysers (PEM) use a semipermeable membrane made from a solid polymer and designed to conduct protons. While PEM electrolysers provide flexibility, fast response time, and high current density, the widespread commercialization remains a challenge primarily due to the cost of the materials required to achieve long lifetimes and performance. Specifically, the highly acidic and corrosive operating environment of the PEM electrolyser cells calls for expensive noble metal catalyst materials (iridium, platinum) and large amounts of costly titanium. This poses a challenge to the scalability of PEM electrolysers.
Enapter’s core product is the standardized and stackable anion exchange membrane (AEM) electrolyser. Electrolysers use electricity to split water (H₂O) into hydrogen (H₂) and oxygen (O₂) through an electrochemical reaction. The stack is the electrolyser’s heart and comprises multiple cells connected in series in a bipolar design. Enapter’s unique technology is the design and operation of these cells, consisting of a membrane electrode assemble (MEA), made from a polymeric AEM and specially designed low-cost electrodes. The anodic half-cell is filled with dilute KOH (alkaline) electrolyte solution; the cathodic half-cell has no liquid and produces hydrogen from water permeating the membrane from the anodic half-cell. Oxygen is evolved from the anodic side and transported out from the stack through the circulating electrolyte. The hydrogen is produced under pressure (typically 35 bar) and already extremely dry and pure (about 99.9%). Using Enapter’s ancillary dryer module, hydrogen is delivered at 99.999% purity.
Enapter’s electrolyser produce 0.5 Nm³/h (500 NL/h) or 0.04494 kg/h. One electrolyser module produces 12 Nm³ of hydrogen gas in 24 hours, weighting >1kg (1.0785kg). At the normal output pressure of the electrolyser with 35 bar, 1 kg of hydrogen occupies a volume of 0.343m3 (343 L).
The weight of hydrogen is 0.08988 g/L.
The energy content of hydrogen is described by its (lower and higher) heating value. The lower heating value of hydrogen can be expressed as 33.33 kWh/kg or 2.78 kWh/Nm³. The higher heating value is 39.41 kWh/kg or 3.28 kWh/Nm³. A practical medium value to keep in mind is roughly 3 kWh/Nm³. The energy content of 1 Nm³ hydrogen gas is equivalent to 0,34 L gasoline, 1 L liquid hydrogen is equivalent to 0,27 L gasoline and 1 kg hydrogen is equivalent to 2.75 kg gasoline (based on the lower heating value).
Hydrogen is a flammable gas and like with any other gas, appropriate safety measures when handling it must be ensured at all time. Hydrogen’s properties make it safer to handle than commonly used fuels. It is non-toxic, and it is an element lighter than air, so, it will quickly disperse in case of a leak. When planning a hydrogen system installation, it is important to implement appropriate safety measures, such as ventilation and leak detection.
When properly stored, there are no losses. Unlike diesel for example, hydrogen does not have an expiry date and can be stored for years.
The world has reached a turning point in our understanding of energy. Solar and wind are the two fastest growing energy sources. While governments and industry increasingly understand that fossil fuels are a thing of the past, the challenge remains to make solar and wind usable when we need them. Variable renewable are competitive, and customers are increasingly demanding reliable, secure and independent energy supply from sustainable sources. On site green hydrogen production allows for complete green energy independence and security. A burgeoning global industry is taking shape around hydrogen’s potential as a storable fuel or energy carrier and many advantages over battery-electric technology result in hydrogen gaining traction with industry, environmentalists and leading governments.
The vast majority, around 99%, of hydrogen used globally is still produced from fossil fuels. Most of that is done by steam methane reforming of natural gas, a process which emits large amounts of greenhouse gases. We speak about green hydrogen when renewable energy sources are used in an electrolyser to make hydrogen from water. Hydrogen is the bridge between renewable power generation and other types of energy vectors and allows us to clean up more than just the electricity sector with fossil-free fuels.
Hydrogen is an energy carrier and as such, a true multi talent. Today, hydrogen is directly used mainly in industrial processes of many kinds, such as ammonia fertilizer production, food processing purposes, the float glass industry, cooling for power plants, semiconductor and electronics industry, and many more.
We believe that hydrogen will play a central role for the design of modern energy systems to allow for complete green energy independence and security. A burgeoning global industry is taking shape around hydrogen’s potential as a storable fuel or energy carrier. The many advantages it has over battery-electric technology result in hydrogen gaining traction with industry, environmentalists and leading governments. With an abundance of variable renewable energy resources coming on-line, green hydrogen is the solution to power the green energy system of the future.
Hydrogen is the first chemical element of the periodic system. Hydrogen is the most abundant element in the universe. It is the lightest and simplest element we know, one proton and one electron, yet it is high in energy. Hydrogen is an energy carrier and a great multi-talent: it can be transformed into electricity, used as a fuel for transport, used for heating and cooling purposes, as well as various other industrial applications.