Micro Renewable Energy Laboratory, Georgia Institute of Technology, Daniel Guggenheim School of Aerospace Engineering

A US-India Power Exchange Towards a Space Power GridBrendan Dessanti, Nicholas Picon, Carlos Rios, Shaan Shah, Narayanan Komerath

Daniel Guggenheim School of Aerospace Engineering, Georgia Institute of Technologykomerath@gatech.edu

ISDC 2011, Huntsville, AL May 2011

Micro Renewable Energy Laboratory, Georgia Institute of Technology, Daniel Guggenheim School of Aerospace Engineering

•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

Summary of the Paper

Micro Renewable Energy Laboratory, Georgia Institute of Technology, Daniel Guggenheim School of Aerospace Engineering

1. SSP is an old dream2. SSP is hard3. See Space as the way to synergy with terrestrial4. SPG Phase 15. SPG to full SSP 6. US-India collaboration for SSP is a new opportunity7. Startup: India-US8. India-US with Japan, Australia, North Africa9. Challenges

A US-India Power Exchange Towards a Space Power Grid

Micro Renewable Energy Laboratory, Georgia Institute of Technology, Daniel Guggenheim School of Aerospace Engineering

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

Micro Renewable Energy Laboratory, Georgia Institute of Technology, Daniel Guggenheim School of Aerospace Engineering

1. SSP is an old dream1. Arthur C. Clarke: ET Relays, GEO opportunities: 19452. 1st artificial satellite, 1950s3. Peter Glaser (Arthur D. Little Co) GEO SSP architecture: 19684. NASA/ASEE Space Settlement study, 19775. NASA/DOE. NASA TM81142, 1979

6. SAIC Fresh Look: NAS3-26565, 19967. SPS2000 JAXA/NASA, 1992-present8. “Gold Rush to LEO”9. JAXA LEO demo wide-area beaming proposal

10. India-US Strategic Partnership (Garretson, 2010)

SLI? Heavy Lift?Commercial LaunchMoon-Mars

SLI? Heavy Lift?Commercial LaunchMoon-Mars

Beyond Apollo? Case for Space

Shuttle: 1000s of launches at $100/lb

to LEO

Beyond Apollo? Case for Space

Shuttle: 1000s of launches at $100/lb

to LEOBeyond SkyLab? STS? ISS?

Beyond SkyLab? STS? ISS?

Global Warming, Peak Oil, Etc.

Global Warming, Peak Oil, Etc.

http://3.bp.blogspot.com

Micro Renewable Energy Laboratory, Georgia Institute of Technology, Daniel Guggenheim School of Aerospace Engineering

http://www.africa-ata.org/images/ETGIFS/ngorongoro-crater-elephants.jpg

NASAESA

JAXARKA

Millimeter Wave

Specific PowerLAUNCH COST PV

Efficiency

2. SSP is Hard

Micro Renewable Energy Laboratory, Georgia Institute of Technology, Daniel Guggenheim School of Aerospace Engineering

Receiving antenna size for 84% capture vs. beam distance

Transmitter Diameters: Laser: 10m. Mmwave: 150m

• 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

Come Down From GEO, Use Millimeter Wave Beaming

Log 10

(Rec

eive

r Dia

, m)

Beam distance, 1000s of kilometers

2000km GEO

•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.

Micro Renewable Energy Laboratory, Georgia Institute of Technology, Daniel Guggenheim School of Aerospace Engineering

k

25000*P *s *c

P: price of space-generated power in (e.g. $0.2/KWHe): 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)

Prospect of Breakeven: k ~1

Parameter Present Needed

P, US$/ KWHe 0.1-0.2 0.2

?? (0.1?) 0.5

c, $/kg to LEO $2K - $15K <$2.5K

s, Kwe/Kg in space <0.1 >1

Ground receiver dia ~ 100km <1km

Technical barriers: , s

Micro Renewable Energy Laboratory, Georgia Institute of Technology, Daniel Guggenheim School of Aerospace Engineering

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.

Micro Renewable Energy Laboratory, Georgia Institute of Technology, Daniel Guggenheim School of Aerospace Engineering

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

Micro Renewable Energy Laboratory, Georgia Institute of Technology, Daniel Guggenheim School of Aerospace Engineering

Space Power Grid Architecture

Parameter Phase 1 Relay sat

1GWe Converter/Relay “Girasol”

Reflector, per Gwe“Mirasol”

Dry Mass, kg 2680

Total Mass, kg 3526 856,000 53,000

Array dia, m 50 150

Orbit height, km 2000 (5500)

2000 >10,000

Packed length,dia, m

4.6, 2.2 m ??

Launcher class Delta II On-orbit assembly

Heavy lift

Micro Renewable Energy Laboratory, Georgia Institute of Technology, Daniel Guggenheim School of Aerospace Engineering

SPG model results

Phase 1: SPG:Helping TerrestrialPlants

Phase 2&3: Towards full SSP

Phase 2&3tradeoff betweeninstallation rateand investment

Micro Renewable Energy Laboratory, Georgia Institute of Technology, Daniel Guggenheim School of Aerospace Engineering

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

Micro Renewable Energy Laboratory, Georgia Institute of Technology, Daniel Guggenheim School of Aerospace Engineering

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)

Micro Renewable Energy Laboratory, Georgia Institute of Technology, Daniel Guggenheim School of Aerospace Engineering

6 Satellites, 4 Ground Stations 4 Satellites, 4 Ground Stations

Micro Renewable Energy Laboratory, Georgia Institute of Technology, Daniel Guggenheim School of Aerospace Engineering

6 satellite, US-India

Micro Renewable Energy Laboratory, Georgia Institute of Technology, Daniel Guggenheim School of Aerospace Engineering

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 improvements4. “Burn-through” techniques to improve transmission efficiency4. 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.

POSSIBLE SEQUENCE OF ADVANCEMENTS / DEMONSTRATIONS

Micro Renewable Energy Laboratory, Georgia Institute of Technology, Daniel Guggenheim School of Aerospace Engineering

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.

CONCLUSIONS

Micro Renewable Energy Laboratory, Georgia Institute of Technology, Daniel Guggenheim School of Aerospace Engineering

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.

ACKNOWLEDGEMENT

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.

“When Did You Know?”

Lesson: Mad professors and enthusiastic studentsmust scrounge from International Grand Agendas and solve problems, so that governments eventually get serious.

http://www.fantasticfiction.co.uk/w/leonard-wibberley/mouse-on-moon.htm

Micro Renewable Energy Laboratory, Georgia Institute of Technology, Daniel Guggenheim School of Aerospace Engineering

Impact of rain and fog: Millimeter wave regime is bad. Need “burn-through”.

220GHz

94GHz

Micro Renewable Energy Laboratory, Georgia Institute of Technology, Daniel Guggenheim School of Aerospace Engineering

Micro Renewable Energy Laboratory, Georgia Institute of Technology, Daniel Guggenheim School of Aerospace Engineering

Micro Renewable Energy Laboratory, Georgia Institute of Technology, Daniel Guggenheim School of Aerospace Engineering

Dry Atmospheric Absorption for Vertical Transit

Micro Renewable Energy Laboratory, Georgia Institute of Technology, Daniel Guggenheim School of Aerospace Engineering

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)

Atmospheric Absorption for Horizontal Propagation

Micro Renewable Energy Laboratory, Georgia Institute of Technology, Daniel Guggenheim School of Aerospace Engineering

Atmospheric Transmission in the 200-250 GHz regime

Micro Renewable Energy Laboratory, Georgia Institute of Technology, Daniel Guggenheim School of Aerospace Engineering

Micro Renewable Energy Laboratory, Georgia Institute of Technology, Daniel Guggenheim School of Aerospace Engineering

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

Micro Renewable Energy Laboratory, Georgia Institute of Technology, Daniel Guggenheim School of Aerospace Engineering

Girasol: 1 GWe Intensified Collector/Converter/Relay In 2000km / Other Orbits

http://www.websters-online-dictionary.org

Micro Renewable Energy Laboratory, Georgia Institute of Technology, Daniel Guggenheim School of Aerospace Engineering

SSP is hard Why SSP? Why has it Remained a Dream?

Feature SSP Ground-based solar power

Steady generation 24 hour, year-round. ~12,000KWh/m^2 per yr

Daily /seasonal/ weather fluctuations. Average ~900 to 2,300 KWh/yr

Waste heat Dissipated in Space Released on Earth

Transmission efficiency Low, weather-dependent High, independent of weather (see above)

Receiver/distributor Infrastructure size

Massive for GEO sats due to beam width, for any power level

Scalable from rooftop to Sahara size

Generator size Massive for GEO sats. Scalable

Installation cost per watt Very high due to GEO launch cost

Moderate

Micro Renewable Energy Laboratory, Georgia Institute of Technology, Daniel Guggenheim School of Aerospace Engineering

SPG BASELINE ASSUMPTIONS COMPARED TO JPL “HALO” GEO ARCHITECTURE