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A US-India Power Exchange Towards a Space Power Grid. Brendan Dessanti, Nicholas Picon, Carlos Rios, Shaan Shah, Narayanan Komerath Daniel Guggenheim School of Aerospace Engineering, Georgia Institute of Technology komerath@gatech.edu. ISDC 2011, Huntsville, AL May 2011. Summary of the Paper.
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A US-India Power Exchange Towards a Space Power Grid Brendan Dessanti, Nicholas Picon, Carlos Rios, Shaan Shah, Narayanan Komerath Daniel Guggenheim School of Aerospace Engineering, Georgia Institute of Technology komerath@gatech.edu ISDC 2011, Huntsville, AL May 2011
Summary of the Paper • Most of humanity does not get the $0.10/KWhe, uninterrupted electric power that we take for granted. • Residents pay exorbitant costs for the first few watts or watt-hours and lack basic opportunities. • A real-time power exchange through a Space Power Grid (SPG) will help terrestrial power plants become viable at ideal but remote sites, smooth supply fluctuations, and reach high-valued markets. • With infrastructure and market established, 2nd-gen SPG will add and expand SSP beyond 4TW. • SPG architecture is viable at a healthy ROI, modest development funding, and realistic launch costs. • The launch cost risk in GEO-based SSP architectures is exchanged for the R&D risk of efficient millimeter wave technology in the next decade. • A US-India space-based power exchange demonstration is a first step towards SPG and SSP. • 2 options for near-24-hour power exchange: • 4 near-equatorial satellites at 5500km, with ground stations in USA, India, Australia and Egypt. • 6 satellites in 5500 km orbits, with ground stations only in the US and India. • Risk Reduction Roadmap
A US-India Power Exchange Towards a Space Power Grid SSP is an old dream SSP is hard See Space as the way to synergy with terrestrial SPG Phase 1 SPG to full SSP US-India collaboration for SSP is a new opportunity Startup: India-US India-US with Japan, Australia, North Africa Challenges
We all Love SSP: Update on Space Solar Power from New Scientist, ~2008 Magazine: Dec.22. 2008 http://www.newscientist.com/data/images/archive/2631/26311601.jpg
Beyond Apollo? Case for Space Shuttle: 1000s of launches at $100/lb to LEO SSP is an old dream Arthur C. Clarke: ET Relays, GEO opportunities: 1945 1st artificial satellite, 1950s Peter Glaser (Arthur D. Little Co) GEO SSP architecture: 1968 NASA/ASEE Space Settlement study, 1977 NASA/DOE. NASA TM81142, 1979 Beyond SkyLab? STS? ISS? SLI? Heavy Lift? Commercial Launch Moon-Mars 6. SAIC Fresh Look: NAS3-26565, 1996 7. SPS2000 JAXA/NASA, 1992-present 8. “Gold Rush to LEO” 9. JAXA LEO demo wide-area beaming proposal Global Warming, Peak Oil, Etc. 10. India-US Strategic Partnership (Garretson, 2010) http://3.bp.blogspot.com
2. SSP is Hard LAUNCH COST Specific Power PV Efficiency Millimeter Wave NASA JAXA RKA ESA http://www.africa-ata.org/images/ETGIFS/ngorongoro-crater-elephants.jpg
Receiving antenna size for 84% capture vs. beam distance Come Down From GEO, Use Millimeter Wave Beaming 2000km GEO • Must bring down the Specific Mass in Orbit, and ground infrastructure size • Beyond 10 GHz, beaming is affected severely by moisture • Lasers offer small receiver size, but are banned in space Transmitter Diameters: Laser: 10m. Mmwave: 150m Log10 (Receiver Dia, m) • No government will invest $$T in SSP before 1st revenue, when terrestrial energy options exist (solar, nuclear fission, fusion, distributed renewables). • $1T will not get to 1st power by GEO-based SSP – and will not lead to scale up to TW levels. Beam distance, 1000s of kilometers
Prospect of Breakeven: k ~1 P: price of space-generated power in (e.g. $0.2/KWHe) h: efficiency of converted power transmission to the ground. (e.g. 50%) s: (KWe/Kg): Technology of conversion, giving mass needed per kilowatt of electric power generated in space. (e.g., 1 KWe/kg) c: Launch cost in $ per kg to Low Earth Orbit. (e.g., $2500/kg) Technical barriers: h, s
Space Power Grid Approach to SSP • Phase 1 Revenue by beaming terrestrial power to terrestrial and space-based customers. • Trades launch cost risk of GEO-based SSP against technology risk of mmwave. • Constellation of 100 relay sats at 2000km trading with 250 ground stations. 220 GHz mmwave. • System breaks even inside 17 years with fairly realistic parameters. (17-yr R&D window for SSP conversion technology) • Phase 2-3: High-orbit (MEO) collectors beaming sunlight to Converters at 2000 km orbits. • Economically viable ramp-up to 4TW or beyond.
Afternoon Sun Scenario for SPG Phase 1 startup. • 80 minutes of access per 24 hours per location. • This orbit performs 23 revolutions around the earth every 48 hours. Ground Tracks of 6 sun-synchronous satellites at 1900 km
SPG model results Phase 1: SPG: Helping Terrestrial Plants Phase 2&3: Towards full SSP Phase 2&3 tradeoff between installation rate and investment
SPG BASELINE RESULTS COMPARED TO JPL “HALO” GEO REFLECTOR/CONVERTER ARCHITECTURE • SPG ~ 0.9 kg/KWe in orbit, most of it in 2000Km orbits • HALO ~ 10.9 kg/KWe in orbit, all of it in GEO • HALO Orbital mass driven by Converter mass of ~ 3Kg/KWe and GEO-based 2.45GHz transmission • PV arrays ~ 1kg/KWe shown possible at small scale. • Brayton Cycle converter ~ 0.4 kg/KWe possible at large scales: Technology risk
US-India Demonstration Model Demonstrate feasibility of beaming power using few satellites and ground locations. Model development using STK Orbit-modeling software Model characteristics: 5500 km altitude, 3 to 6 satellites (near-equatorial orbits) 4 ground facilities: India (near Mumbai), US (NM), Middle East (near Cairo), Western Australia 2 facilities (India & US)
6 Satellites, 4 Ground Stations 4 Satellites, 4 Ground Stations
POSSIBLE SEQUENCE OF ADVANCEMENTS / DEMONSTRATIONS 1. Dynamic power beaming between a ground station and a satellite in a sun-synchronous orbit. 2. Terrestrial and earth-space-earth millimeter wave beaming at progressively higher frequencies, culminating in a 220GHz system. 3. Millimeter wave conversion efficiency improvements 4. “Burn-through” techniques to improve transmission efficiency 4. Millimeter wave power beaming between satellites. 5. Waveguide type relay of millimeter wave power through a satellite to another satellite in space. 6. A 2-satellite, 2-ground station relay of millimeter wave power. These will then lead naturally to the 6-satellite and 4-satellite systems describe above, growing from there to the full SPG.
CONCLUSIONS 1. Renewed interest in SSP must be viewed with healthy skepticism, but careful analysis of opportunities. 2. The scale of the SSP system needed to reach 4TWe of space-based power generation poses immense difficulties requiring new approaches. 3. To make SSP viable, improvements are needed in specific power, beaming efficiency, and launch cost. 4. Millimeter wave beaming and orbits at 2000 km in a Space Power Grid architecture, can provide order-of-magnitude improvement in viability. 5. Primary gas turbine power generation may close the specific power viability gap, when used with SPG. 6. A US-India power exchange provides a unique opportunity to start the Space Power Grid towards full SSP. 7. With 4 or more nations participating, it is possible to set up nearly continuous power exchange with 4 to 6 satellites in 5500 km orbits. 8. With only the US and India participating, a constellation of 6 satellites suffices to demonstrate a continuous power exchange.
ACKNOWLEDGEMENT The senior author (NK) is supported by the NASA “EXTROVERT” initiative to develop cross-disciplinary innovation resources and concept explorations. Mr. Tony Springer is the technical monitor.
“When Did You Know?” The Mouse on the Moon (1963) The Grand Duchy of Grand Fenwick is picked by the U.S. and USSR as a showpiece for the Internationalization of Space Research. While the Grand Duke is dreaming of gold toilets and hot baths, their (mad) Professor, the Prince and his smart Fiancee are slapping together a rocket. The U.S. and Soviets get into a desperate race to beat Fenwick to the Moon. http://www.fantasticfiction.co.uk/w/leonard-wibberley/mouse-on-moon.htm Lesson: Mad professors and enthusiastic students must scrounge from International Grand Agendas and solve problems, so that governments eventually get serious.
Impact of rain and fog: Millimeter wave regime is bad. Need “burn-through”. 220GHz 94GHz
Atmospheric Absorption for Horizontal Propagation http://ops.fhwa.dot.gov/publications/viirpt/sec5.htm Line A: Average absorption at sea level, 20C, 1atm, H2O vapor 7.5 g/m3) Line B: Altitude 4 kilometers pressure altitude, (0C, Water Vapor Density= 1 g/m3)
Mirasol: High Orbit Ultralight Collector/Reflector In Constant View Of The Sun, Focusing On to Collector/Converter/Relay Sats in Low Orbits http://www.sancarloscity.org/sunflower-detail-excellent.jpg
Girasol: 1 GWe Intensified Collector/Converter/Relay In 2000km / Other Orbits http://www.websters-online-dictionary.org
SPG BASELINE ASSUMPTIONS COMPARED TO JPL “HALO” GEO ARCHITECTURE