The objective of the PEI Wind-Hydrogen Village Project has been to develop an integrated wind-hydrogen energy system that is self supporting and can be operated in isolation of the provincial power grid.
The major process components of the wind-hydrogen system include: wind power production; water purification; hydrogen production, collection, drying, compression and storage; and genset power production.
Several wind turbines are available to supply power to the micro-grid which transmits and distributes the electricity to connected loads including the hydrogen production system. The cumulative production capacity of the available wind turbines is approximately 250 kW.
Water is supplied to the wind-hydrogen facility from an existing on-site well. Prior to electrolysis, the raw groundwater is softened and then purified by passing it through a reverse osmosis/deionization water treatment system.
The electrolyser is the heart of the wind-hydrogen facility. As such, selection of the type of electrolyser best suited to operate under the dynamic conditions of fluctuating and intermittent wind power was given careful consideration. Following a review of the available options, a 300 kW (6 kg/hr) unipolar liquid alkaline electrolyser was selected for the project.
Unipolar electrolyser technology produces hydrogen and oxygen at essentially atmospheric pressure. From the electrolyser, the oxygen is vented to atmosphere and the hydrogen flows into a low pressure gasholder which serves as a buffer/holding tank for the compression system.
The compression system has the operating capacity to pressurize approximately 7 kg/hr of nominally atmospheric pressure hydrogen to approximately 300 psi. From the compressors, the hydrogen gas flows through a dryer system to achieve a hydrogen moisture content of less than 10 ppmv prior to storage.
The hydrogen storage system consists of three tanks which provide a total cumulative storage capacity of approximately 500 kg. The tanks are of steel construction and rated for 250 psig.
Stored hydrogen is fed to a 130 kW bi-fuel hydrogen/diesel genset when there is insufficient wind power available to support the micro-grid. The genset effectively serves as the back-up power system that allows the PEI Wind-Hydrogen Village to remain disconnected from the provincial grid for extended periods.
If the electrolyser is the heart of the wind-hydrogen facility, then the controls are the brains. A wind-hydrogen production controller (WHPC) fully integrates the controls between the wind-turbines, the process equipment, the bi-fuel genset, and the safety management system. The WHPC is built on a programmable automatic controller (PAC) platform and includes a supervisory control and data acquisition (SCADA) system with dedicated hardware and high-speed internet connection.
The schematic below taken from a SCADA screenshot provides a graphical representation of the system.