Session: 11-01: Alternative Energy Converstion Technology (including Wind, Geothermal, Hydro, and Ocean)

Paper Number: 169819

169819 - Preliminary Design, Modeling & Analysis of a Gigawatt-Scale Cycloturbine Innovation for Offshore Wind Energy 

Abstract: 

The USA had ambitious targets for 100% carbon-pollution free electricity by 2035 and net zero carbon-dioxide emissions by 2050. To achieve these ambitious targets while minimizing additional allocations of large land areas with other competing potential land uses, it is strategically vital to dramatically increase implementation of offshore renewable energy systems in an overall renewable systems portfolio, especially considering that the USA has the World’s largest offshore Exclusive Economic Zone (EEZ) of around 12 million square kilometers. Offshore wind is the only offshore renewable energy technology that is currently implemented on a large scale, but current floating Horizontal Axis Wind Turbine (HAWT) designs suffer from high center of gravity, long load paths from blade aerodynamic centers to floating foundations below, and high weight & correspondingly high capital and lifecycle costs. This paper presents preliminary data, modeling & analysis of an entirely new architecture intended to more cost-effectively harvest offshore wind, using a very-large-diameter cyclorotor supported by a floating truss. The new architecture is called a “Revolving Overhead Windmill System” or “ROW System.” The new architecture significantly lowers center of gravity and reduces load paths from aerodynamic centers to floating support below, while using a circular vertical-axis wind turbine (VAWT) geometry that inherently optimizes power harvest regardless of wind direction. A further advantage is that the ROW System architecture can enable offshore wind turbines at much larger power ratings than the current largest HAWT design at 26 MW rated power. In this paper a nominal ultra-large ROW System design sized to 1.2 GW or 1200 MW rated power will be proposed – a scale that is unprecedented and deemed unachievable by designers of offshore floating HAWTs.  A preliminary ROW System design will be modelled using Computer Aided Design (CAD) with SolidWorks, and preliminary analyses will include aerodynamic analysis, finite element analysis (FEA), loads and weights analyses, power harvest at rated windspeed, and preliminary estimates for system capital cost (CAPEX) & lifecycle cost (LCOE). The opportunities to simultaneously achieve lower weight per unit power, lower CAPEX per unit power, lower offshore lease area per unit power and lower LCOE will be quantified using preliminary analysis tools and methods - to provide strong motivation for further research, development, and demonstration (RD&D) of ROW Systems. RD&D topics and other preliminary qualitative considerations will also be summarized for ROW Systems, including concepts for production and installation, reliability & maintainability considerations, storm-survival and safety considerations, potential synergies with other offshore renewable energy systems, and green hydrogen. A preliminary technology and development roadmap will conclude this preliminary engineering exploration of a new offshore wind energy system architecture using a large diameter cycloturbine - that could plausibly evolve into the next horizon of cost-effective offshore wind energy harvesting systems.

Presenting Author: Mithra Sankrithi RIC Enterprises

Presenting Author Biography: Mithra Sankrithi has a Ph.D. in Mechanical & Aerospace Engineering from Princeton University & an MBA from Seattle University. Mithra is deeply passionate about disruptive innovations in renewable energy & climate change mitigation. To advance these he co-founded RIC Enterprises in 1997. RIC Enterprises is a US nonprofit company and Mithra serves as CEO, driving progress on pioneering innovations with strong potential to benefit humanity and our global environment- including progress in the areas of wind energy, solar cogeneration, offshore solar, hydrokinetic renewable energy and pumped storage. RIC Enterprises is also proposing a unique, nature-based-solution to reducing or reversing sea level rise driven by climate change. In addition to leading RIC Enterprises, Mithra had a 37-year productive aerospace career as a visionary leader working on “green aviation” efforts at Boeing, culminating in a role as Senior Manager for Airplane Architecture, Innovation and Product Evaluation. Mithra’s innovation experience includes an invention portfolio with 86 issued US patents in addition to international patents. Mithra’s external engagements have also been extensive, including engagements with Innovation Research Interchange, World Future Society, supplier companies, NASA, FAA, EASA, AIAA, airport authorities, US and international airlines, engine companies and Universities including Georgia Tech, Columbia, Cornell, MIT, Florida Atlantic, Univ. of Washington, Washington State University, Purdue, Case Western, USC, Cal Poly SLO, Oregon State University, Oregon Institute of Technology, U of Texas, Texas A&M, University of Tulsa, University of Alaska, Ilisagvik College, Technical University of Munich, & Cranfield University.