Millimeter Wave Space Power Grid Architecture 2011

Transcription

1 Millimeter Wave Space Power Grid Architecture 2011 Nicholas Picon Brendan Dessan? Shaan Shah Richard Zappulla Narayanan Komerath Experimental Aerodynamics and Concepts Group School of Aerospace Engineering

2 Conference Papers from Our Team B. Dessan?, R. Zappulla, N. Picon, N. Komerath, Design of a Millimeter Waveguide Satellite for Space Power Grid N. Komerath, B. Dessan?, S. Shah, A GigawaK Level Solar Power Satellite Using Intensified Efficient Conversion Architecture N. Komerath, B. Dessan?, S. Shah, R. Zappulla, N. Picon, Millimeter Wave Space Power Grid Architecture

3 Outline Introduc?on Space Solar Power Background The Space Power Grid Architecture Aerostats Proposed US India Demonstra?on as a First Step System Assump?ons and Parameter Choices Technical and Economic Results Analysis Conclusions 3

4 Introduc?on The Dream of Space Based Solar Power (SSP): Deliver cheap, limitless, clean, quiet electric power to the world Factors Driving Cost and Difficulty of SSP 1. Magnitude of the Problem Cost to First Power 2. Specific Power The power that must be generated per unit mass placed in orbit 3. RelaLonship between orbit height, beam frequency, and receiver size 4. Launch Costs Cost to place mass in orbit 4

5 Space Solar Power Background Space Based Solar Power is an old dream Arthur C. Clarke 1945 benefits of GEO Peter Glaser 1968 Patent for GEO based SSP arch. NASA/DOE Study Late 1970s NASA Fresh Look Study 1997 NASA SERT 1999 Proposed JAXA LEO Demo Etc. Recurring Conclusion: No Technical Show Stoppers Significant Improvements Needed for Economic Viability New Scientist Magazine SSP Illustration 5

6 Space Solar Power Background: Tradi?onal Approaches Geosynchronous Earth Orbit (36000km al?tude) Pros: No dynamic beam poinlng necessary Cons: Distance drives spacecra^ size, immense launch costs, no evolulonary approach possible, requires large inilal investment Microwave Beaming Pros: Atmospheric transmission efficiency, low technology risk Cons: Transmi`er/Receiver Size Photovoltaic Panels for Collec?on Pros: low technology risk Cons: Specific Power, Linear Scaling 6

7 SSP Architecture Analysis: Viability Parameter How much improvement do we need? Prospect of Breakeven: k ~1 k = *P * s *! c 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 kilowak of electric power generated in space. (e.g., 1 KWe/kg) c: Launch cost in $ per kg to Low Earth Orbit. (e.g., $2500/kg) Technical barriers: η, s Parameter Present Needed P, US$/ KWHe η?? (0.1?) c, $/kg to LEO $2K $15K <$2.5K s, Kwe/Kg in space <0.1 >1 Ground receiver diameter ~ 100km <1km

8 Space Power Grid Architecture The BoKom Line: According to our analysis, a roughly 100x improvement in viability is needed for SSP to become a reality Is this possible? Flash Drive Argument (mass produclon collapses cost) Our approach: Trade the launch cost risk of GEO based systems for technology risks associated with SPG 8

9 9 Space Power Grid Architecture Devia?ons from Tradi?onal Approaches Use Primary Brayton Cycle Turbomachine Conversion of highly concentrated sunlight (InCA: Intensified Conversion) Specific Power, s Separate the collec?on of sunlight in high orbit from conversion in low orbit Antenna Diameter Millimeter Wave Beaming at 220GHz Antenna Diameter Use Tethered Aerostats Efficiency Through Atmosphere Power Exchange with terrestrial renewable energy Cost to First Power Barrier

10 Space Power Grid Architecture Relationship between beam distance, frequency, and receiver diameter: 10

11 Beam Distance and Frequency Comparison Assume equal receiver size (100m), equal antenna specific mass (0.05 kg/m^2), assume equal beam capture (84%): Parameter GEO, 5.8 GHz 2000km alt., 220 GHz Reduction Beam Distance, R 35,786 km 2,000 km 17.9x Wavelength, λ 51.7 mm 1.36 mm 37.9x Transmitter Diameter 45.2 km 66.5 m 679x Antenna Area 1.60e9 m^ m^ x Antenna Mass 8.01e7 kg 174 kg x 11

12 Space Power Grid Architecture Phase I ConstellaLon of LEO/MEO Waveguide Relay Sats Establish Space as a Dynamic Power Grid Phase II 1 GW Converter Satellites Girasols Gas Turbine Conversion at LEO/MEO Phase III High AlLtude Ultra light Solar Reflector Satellites Mirasols Direct unconverted sunlight to LEO/MEO for conversion 12

13 Aerostat System Millimeter Wave Beaming Poor Through Rain and Fog 13

14 Aerostat System 14 Possible Solu?on: Use Tethered Aerostats

15 Proposed US India Demonstra?on A demonstralon model for terrestrial power exchange between the US and India was designed to illustrate the benefit and feasibility of the Space Power Grid concept The two countries were chosen based on the US and India s high energy produclon and usage and because of the new Indian US collaboralon as prompted by President Obama and Prime Minister Singh Model highlights the possibility of selling energy to the partner country at non peak usage Lmes 15

16 16 US India Demonstra?on

17 US India Demonstra?on 6 Satellite 2 Facility System Designed to provide 24 hr. access beaming capability between Mumbai, India and Las Cruces, NM Satellites at fixed angles in relalon to one another, simplifying the problem of satellite to satellite beaming 17

18 System Assump?ons and Parameter Choices 18 Key Assumption: Launch Cost Current Launch Cost Rate: >$10,000/kg Other Architectures argue for $ /kg Our calculations assume reasonable reductions

19 Systems Architecture Economic Analysis Breakeven Point: when NPV=0 at specified ROI (6%) from Phase I startup Baseline SPG System (March 2011) vs. Current Architecture Using system assumptions in previous slide 5 year dev. period before 1 st Satellite Launch Attempt to reach 4TW of power capacity Attempt to demonstrate Phase 1 breakeven within 17 years Constraint to demonstrate total architecture breakeven within 50 years relaxed In March 2011, Phase 2 assumed to start after Phase 1, in this paper we investigate beginning Year 12 Ramp rate constrained by infrastructure building limitations 19

20 Technical and Economic Results Analysis: Breakeven vs. Selling Price Baseline: SPG Architecture presented at March 2011 IEEE Aero Conf IηCA: Current architecture including Iηca Concept For Given Price of Power, Significant Improvement in Viability 20

21 Technical and Economic Results Analysis: NPV Trough Phase 1 Full Architecture Amount of Investment Required Reduced Significantly from Baseline 21

22 Architecture Analysis Summary and Conclusions 1. Technical Risk and UncertainLes in Mass and Efficiency in developing mmwave conversion and beaming are main risks to SSP development. Phase 1 SPG addresses these before large 1 GW converters launched. 2. Phase I Waveguide Satellite and Phase II Girasol Mass EsLmates Come in Under Previous EsLmates used in SPG architecture reduced uncertainty. 3. Overlapping Development of Phase I and Phase 2 is considered to reduce deployment Lme of large scale SSP 4. Updated architecture can achieve breakeven by Year 31, with NPV trough <$3T, at $0.11/kWh 5. At given ramp rate, SSP can reach > 5.6 TW by Year Assumes value of unity for k viability parameter 22

23 23 Ques?ons?

24 24 Backup

25 25 Backup