ITM Power’s PEM electrolyzers are pure-water proton-exchange-membrane (PEM) electrolysis systems developed by the UK-based company ITM Power specifically for green hydrogen. The entire product line consists of standardized skids, and the flagship model, NEPTUNE 2MW, is currently in continuous operation at numerous hydrogen refueling stations and industrial by-product hydrogen replacement projects across North America and Europe. Many operations and maintenance personnel new to ITM Power systems tend to apply their experience with alkaline electrolysers, assuming that these systems also use nickel cathodes and titanium anodes. However, ITM Power specializes in pure PEM water electrolysis, which employs a completely different electrode design: the anode consists of a titanium substrate coated with iridium oxide, while the cathode consists of platinum nanoparticles loaded onto carbon paper. ITM Power officially never sells anode plates separately; it only accepts entire stacks returned to its Manchester factory for recoating and reinstallation. The quoted price for refurbishing a single stack (1 MW) in 2025 is $115,000, which includes iridium metal replenishment and new seals. This full-stack recycling and refurbishment model means that none of the core components in contact with the membrane electrode assembly can be replaced at the customer site; spare parts management must focus solely on the BOP. The selection and maintenance of components in each subsystem directly determine whether an ITM Power electrolyzer can achieve its design lifespan.
ITM Power integrates AEG Power Solutions’ IGBT rectifier modules into each NEPTUNE 2MW skid, with two 1MW units operating in parallel. For an ITM Power electrolyzer project in Texas, the front-end isolation transformer and main switchgear were integrated by Eaton in accordance with local grid requirements. Genuine AEG power modules may occasionally trigger over-temperature alarms after accumulating more than 18,000 operating hours. The replacement price for a single module (excluding tax) from the North American spare parts inventory is $11,500; keeping one module on-site can save at least 72 hours of downtime.
The ITM Power system requires the resistivity of the feedwater to be consistently greater than 18 MΩ•cm and is equipped as standard with a two-stage RO plus EDI water purification system from Veolia or Evoqua. At a site in northern Germany directly maintained by ITM Power, due to high raw water hardness, the 10-inch PP cotton filter cartridges from Evoqua must be replaced every three months; the unit price is $12.80 when purchased in bulk from Grainger in the U.S. According to ITM Power’s after-sales maintenance guidelines, the mixed-bed resin inside the EDI module must be completely replaced and refilled annually; a service package including labor is quoted at $4,200 per visit, which is a fixed expense.
Every ITM Power electrolyzer thermal management circuit is equipped with an Alfa Laval all-welded plate heat exchanger and a Grundfos CR Series stainless steel vertical multistage centrifugal pump. The mechanical seals on Grundfos pumps are highly prone to micro-leaks after approximately 15,000 hours of operation; a set of original replacement seals costs $680 when purchased in Germany. ITM Power imposes strict requirements on cooling water outlet temperature control, with fluctuations not exceeding ±1.5°C. Consequently, Siemens electric control valves are extensively used in the circuit, and since the valve actuators operate frequently, it is recommended to keep them on hand as spare parts; each is quoted at $2,100.
The anode plates in ITM Power’s PEM electrolyzers are made of titanium with an iridium oxide coating, while the cathode plates and bipolar plates also extensively use titanium with a hydrogen embrittlement-resistant coating. DONGSHENG Precious Metals Recycling is willing to purchase these scrap materials at a high price. The iridium loading on the anodes is estimated at approximately 1.5 to 2 kilograms per megawatt. Based on the latest quote from DONGSHENG’s precious metals price page as of July 6, 2026—which lists iridium powder at $7,688 per ounce—the raw material value of iridium alone exceeds $442,091. The platinum loading on the cathode side is approximately 0.2–0.4 milligrams per square centimeter; although losses are extremely low, it is still subject to fluctuations in the precious metals market. ITM Power’s PEM-specific porous titanium fiber felt transport layer becomes embedded in the membrane surface after long-term operation; once adhesion occurs, both the membrane electrode assembly and the titanium felt must be replaced simultaneously, incurring additional costs exceeding $35,000 per instance. therefore, the on-site team consistently maintains the anode inlet water resistivity at 18.2 MΩ•cm or higher and ensures the pressure differential never exceeds 0.5 bar to protect these non-replaceable titanium-precious metal components.
Hydrogen exiting the ITM Power electrolyzer, after water separation, enters the drying and purification unit. The custom-designed combined filtration and drying module from Parker Hannifin contains molecular sieves and a deoxygenation catalyst. Its 0.01-micron precision filter cartridges trigger an alarm when the pressure differential reaches a certain threshold after approximately 6,000 start-stop cycles; a single cartridge costs $345 when shipped directly from ITM Power’s North American after-sales warehouse. If a Siemens laser oxygen analyzer is selected in the system contract, its light source module has an expected lifespan of only 5 years, with a replacement costing $3,800.
Each ITM Power electrolyzer must be equipped with at least 8 Michell dew point transmitters, 6 Mettler Toledo resistivity probes, and dozens of Honeywell hydrogen leak detection points. Dew point transmitters are the most prone to drift; according to ITM Power’s maintenance guidelines, they must be returned to the factory for calibration every two years, with a single calibration service from the Michell factory in the UK priced at $650. Following a winter condensation incident at the Hamburg hydrogen refueling station, the cost of urgently air-freighting a Michell probe—which had failed on-site—to the station reached as high as $2,400; therefore, experienced station managers always keep at least two calibrated probes in stock.
The outlet pressure of ITM Power systems is typically around 30 bar. If filling long-tube trailers is required, a PDC Machines diaphragm compressor must be used as an external unit. This compressor requires preventive maintenance every 4,000 cumulative operating hours to replace the diaphragm, hydraulic oil seals, and guide rings. The publicly listed price in North America for a standard PDC factory maintenance package is $14,200. The Parker pulsation-absorbing accumulator, which is connected in series between the compressor outlet and the ITM Power skid, requires mandatory replacement of its bladder every three years at a unit cost of $1,800; this expense is often overlooked in project financial models.
Language
