Lower-cost Hydrogen (H2) Fuel Production from Distributed Wind via Paralleled Self-Excited Induction Generators (SEIG's) & Close-coupled Electrolysis at Multi-turbine Off-grid Windplants

W.C. Leighty
Alaska Applied Sciences, Inc.,
United States

Keywords: wind, hydrogen, low-cost, transportation, fuel


We may significantly reduce the cost of wind-source hydrogen fuel generation by simplifying the design, capex, and O&M costs of wind turbines, windplants, and electrolysis plants, by: 1. Designing the turbines with simple, robust, low-cost, squirrel cage induction motors as generators, operating in Self Excited Induction Generator (SEIG) mode; 2. Connecting the "wild DC" outputs of the wind turbines to a common DC bus; 3. Close-coupling the electrolysis stacks to the windplant DC bus, with minimum power electronics; 4. Integrating all wind-to-hydrogen system controls in a single SCADA. In California in year 2050 the demand for CO2-emission-free (CEF) transportation fuel will probably exceed the demand for CEF grid electricity by > 30 %, a major new market for wind and other CEF energy sources. Fuel cell transportation will succeed only to the extent that abundant H2 fuel is ubiquitously available at competitive prices. We need to consider Gaseous Hydrogen (GH2) and Anhydrous Ammonia (NH3) energy systems as alternatives to electricity systems, including for offshore wind. This could launch a very large impact, emulating Japan's interest in importing tanker loads of H2-rich liquids from CEF sources worldwide -- perhaps especially from Alaska. Japan's NEDO assignments: Kawasaki, LH2. Sumitomo, NH3. Chiyoda, Methylcyclohexane (C7H14) < > Toluene. In CA in 2050, transport H2 fuel alone will require ~20 times today's installed wind capacity or ~ 25 times today's installed solar capacity, or equivalent combinations with other CEF sources. AASI has demonstrated SEIG mode operation on one of its stranded Palm Springs turbines, delivering rectified "wild AC", at variable speed, to a DC resistive load bank: Fig 1-2. https://vimeo.com/160472532 No other company has proposed demonstrating this technology of SEIG-equipped turbines, closely coupled to electrolysis stacks or Anhydrous Ammonia synthesis reactors, on an operating multi-turbine windplant. This project's success could be scaled to multi-MW turbines and windplants, to produce, for example, ~7 million tons per year of H2 fuel required for the CA transportation sector in year 2050 -- a larger market for CEF energy than electricity for the CA grid: AASI's vision. The R&D project's H2 fuel will be delivered to Sunline Transit, 15 miles east on I-10, for their fuel cell buses, and / or to other local markets. Thus, we build a global energy "hydrogen sector". The H2 fueling stations now being installed with CA funding must acquire one-third of their dispensed H2 from CEF sources. As fuel cell light duty vehicles (LDV's), buses, and trucks proliferate, demand for CEF H2 will rapidly increase. This H2 will bestow large benefits on CA's energy economy, and beyond, as US and the world emulate the CA "lighthouse" transportation fuel and electricity systems. R&D&D success will enable proliferation of off-grid windplants equipped with the simpler SEIG-driven H2 generation systems, producing high-purity H2 fuel, over a large geographic area not served by electricity transmission.