Engineer around the stack
The balance of plant establishes the conditions in which an electrolyser operates. Water or electrolyte handling, electrical supply, gas separation, thermal management and pressure control all influence the system’s behaviour. Hy-7 approaches these as connected parts of the test system, with process, electrical and controls requirements considered together.
The consultancy’s technology scope includes PEM, AEM and alkaline electrolysis. Founder Dr Marek Malinowski’s experience includes 5 kW and 50 kW alkaline electrolyser prototypes at PAN INTiBS during 2024–2025 and earlier work involving PEM electrolysis at HySA / UWC. The design starting point remains the requirements of the particular stack and experiment.
Define requirements before selecting equipment
A useful scope sets out the current, voltage, flow, temperature and pressure envelope, together with gas quality requirements and expected changes in demand. Start-up, standby and shutdown matter alongside steady operation. Available electrical capacity, cooling, water and discharge arrangements also shape the design.
PEM, AEM and alkaline systems have different fluid handling and material requirements. The stack supplier’s limits should guide water quality, electrolyte handling, circulation and permissible pressure differential. Rated power alone is not a sufficient basis for transferring a balance-of-plant design from one technology to another.
Connect flow, power and heat
Process flow diagrams, P&IDs and mass and energy balances provide the basis for integrating the subsystems. Water treatment and feed, gas-liquid separation, drying, cooling and venting each need a defined role within the operating envelope. Electrical diagrams connect the supply and auxiliary equipment to the process requirements.
Performance measurements also need an agreed boundary. Stack consumption and complete system consumption differ when pumps, cooling and gas treatment are included. The instruments and data acquisition should make that boundary visible in the results, with reference conditions and measurement uncertainty considered when interpreting performance.
Bring operating intent into the controls
TwinCAT PLC, HMI and DAQ form part of Hy-7’s controls scope. Operating sequences, permissives, alarms and responses to faults should be developed from the process requirements. Safety assessment and documentation accompany the engineering through HAZOP, risk assessment, COSHH and SOPs where relevant.
Hy-7 follows Scope → Design → Build → Test & hand over. A project discussion can begin with the stack specification, test objectives and site utilities, establishing how the balance of plant must support the intended programme.