Optimal innovating with hydrogen power systems
Optimal is working with a customer to harness the potential of renewably generated hydrogen to support the transition to Net Zero emission energy. Solar power is used to split water into its primary elements, oxygen and hydrogen. This hydrogen can be used as fuel for transport, mixed with natural gas for storage in the existing natural gas network, or stored for power generation when the sun is not shining, or the wind is not blowing. The is using this hydrogen to decarbonise the gas network and provide a pathway for 100% renewable gas network. Stored hydrogen will also be used to generate electricity on site to demonstrate the technology available to generate power from hydrogen.
Optimal Group was selected to provide a flexible power solution for the project. Our scope of works was to provide a microturbine power generation system as well as a hydrogen fuel cell. These two technologies both convert hydrogen to electricity, but each have different strengths which complete the other. Optimal engineered and packaged the fuel cell at our facility in Mulgrave, Victoria, including the PCS (power conversion system) and controller.
Capstone C65 Microturbine
Capstone have been developing a new fuel system for their microturbine capable of operating on 100% of hydrogen in collaboration with the U.S. Department of Energy’s Argonne National Laboratory. Work has been focused on first commercialising the 65kW Capstone C65 turbine, before developing the 200-kW turbine and larger modular package.
Optimal have provided a C65, 65 kW microturbine for the project which combusts the hydrogen to drive a power turbine to generate electricity. While being lower in electrical efficiency (29%) than a fuel cell, the turbine can also provide high quality heat from the exhaust. This heat can be easily captured as hot water (90°C), providing up to 120 kW for domestic hot water, building heating or process heat using an integrated heat recovery module (HRM). Alternatively, the heat can be used to drive an absorption chiller to provide chilled water for cooling applications. This enables fuel efficiencies up to 85% in a combined heat and power application.
In addition, microturbines are suited to ramping up and down based on changes in electrical demand, making it ideal for sites with variable loads.
Optimal FC30 Fuel Cell
A fuel cell uses a chemical process to convert hydrogen into power without combustion, with water as the only by-product. Fuel cells are used in transport applications in hybrid electric vehicles including cars, trucks, buses and marine to extend mileage. They can also be used to generate power.
Optimal developed a packaged 30 kW hydrogen fuel cell, designed from the ground up specially for this project. A 30-kW fuel cell stack was selected from Ballard, a global leader in fuel cell stack design for the mobility and transport markets.
To adapt the stack for use as a stationary power generator, Optimal had to design the ancillary systems to provide a complete package. This included the design of the enclosure, power conversion systems (converting the DC output from the fuel cell to 3 phase AC output), safety systems, cooling system, fuel system, controller and programming.
Optimals team adapted an enclosure of a Capstone C65 to house the system, which provides a highly serviceable outdoor rated package.
Fuel cells are highly electrically efficient (~55%), providing more power for the same amount of hydrogen compared to a microturbine. While they also produce waste heat from the generation of power, the heat is low grade and has limited opportunity for use in other applications.
In addition, fuel cells generally prefer to operate at a steady output, unlike the microturbine. Together, the FC30 and C65 technologies provide an ideal mix of electrical efficiency, useable high quality heat and flexibility in site demand following.