Experimental Aerodynamics & Concepts Group Micro Renewable Energy Systems Laboratory Georgia Institute of Technology Monday Thrissur (every day, Week of Jan.9) Mostly dry, Warm (max 31°C, min 23°C), Wind will be generally light Deciding What to Wear in Winter Nashville Monday Jan. 9: High 6 deg. C, low -3 deg. C. Partly cloudy, Chance of rain showers and snow. Northwest winds 10 to 20 mph. Wind chill readings 10 to 20.

Experimental Aerodynamics & Concepts Group Micro Renewable Energy Systems Laboratory Georgia Institute of Technology Barefoot Sidewalk What? Portfolio of projects and laws to require clean, safe pedestrian environment. Transform Kerala into the cleanest and most comfortable land in the world Safe and Preferential pedestrian Crossings and foot/bicycle paths Why? Stamp of integrity, quality, culture, comfort and appeal of Kerala Brand. Rise to the true potential of Mahabali’s land. Fundamental change in environment, appearance and pride of population in their surroundings How? Disney-standards of urban cleanliness Enforcement against littering and digging-up pavement All local projects to ensure barefoot pedestrian wheelchair access. Greenery requirement with all construction Bicycle Lane access connecting all communities and in City Centers No Powered Vehicle/No Pollution Market Zones content/uploads/2010/12/lifestyle-in- kerala.jpg a/dynamic/00830/08TVRAIL_ f.jpg 9/16/2015

Experimental Aerodynamics & Concepts Group Micro Renewable Energy Systems Laboratory Georgia Institute of Technology Power Through The Sky: A Comprehensive Architecture for Beamed Electric Power Delivery Narayanan Komerath Professor Daniel Guggenheim School of Aerospace Engineering Georgia Institute of Technology Atlanta, Georgia USA Relevance to this conference: Smart Grid control problem, with billions of mobile, transient transmitters and receivers and dynamic grid storage, with time scales from hours to microseconds. INTERNATIONAL CONFERENCE ON POWER, SIGNALS, CONTROL AND COMPUTATIONS January 3-06, 2012

Experimental Aerodynamics & Concepts Group Micro Renewable Energy Systems Laboratory Georgia Institute of Technology Conversion, transmission, reception and use of electric power as narrow, focused wireless beams. 1m to 10 9 m, 100W to 1 GW; 2.4E9Hz to 2.0E15Hz Why Emergency response systems Rural electrification & connectivity Highway speed EV charging Retail beaming to microgenerators Space-based power exchange between renewable plants Space Solar Power Energy Independence! IssuesHow What Antenna Size Reduction Frequency & Distance Conversion EfficiencyInCA, NarrowBand PV MMwave generationSolid state, optronic?? Atmospheric PropagationTether waveguides, BurnThru Policy/Investment BarriersSynergy, retail architecture Ultimate Controls Problem?Smart, Massively Distributed

Experimental Aerodynamics & Concepts Group Micro Renewable Energy Systems Laboratory Georgia Institute of Technology Already In Use: Inductive Charging content/uploads/2010/03/south-korea-electric- system.jpg ges/2011/05/03/wireless-induction- charging4_GTTz6_40056.jpg amazon.com Short range Stationary /Tracked Strong field Well-developed No further interest here.

Experimental Aerodynamics & Concepts Group Micro Renewable Energy Systems Laboratory Georgia Institute of Technology Range of Solution Types Regional global Surface range to visible horizon, km Local Altitude, km

Experimental Aerodynamics & Concepts Group Micro Renewable Energy Systems Laboratory Georgia Institute of Technology bretagne.eu/data/mo/Gallery/ Parab8GhzH2.gif High-Gain Antenna Near-field Radiation 1 st sidelobe dia >> primary Diffraction-Limited Antenna Size D r D t = 2.44 L for 84% capture D r D t = L for 96% capture Design difference between communications and Power beaming!

Experimental Aerodynamics & Concepts Group Micro Renewable Energy Systems Laboratory Georgia Institute of Technology Need Millimeter waves or Lasers for Practical Antennae!

Experimental Aerodynamics & Concepts Group Micro Renewable Energy Systems Laboratory Georgia Institute of Technology Boost Phase Intercept (Lasers) 140GHz Propellant Heating Beam Considered by NASA/USAF Beamed Propulsion (MMWaves) Dynamic Beam Pointing Is Feasible 100 MW-class continuous MMwave beams possible

Experimental Aerodynamics & Concepts Group Micro Renewable Energy Systems Laboratory Georgia Institute of Technology Phased Arrays Use 1000s of Antenna Elements to Control BeamPointing Using Relative Phases of Elements 95 GHz Power Beam 20 GHz Radar ciples_phased_array.png

Experimental Aerodynamics & Concepts Group Micro Renewable Energy Systems Laboratory Georgia Institute of Technology Many Demonstrations of Power Beaming Exist Microwave Optics PV

Experimental Aerodynamics & Concepts Group Micro Renewable Energy Systems Laboratory Georgia Institute of Technology Relative humidity, percent 1 atm, 310 K Attenuation, dB per km Spectrum Considerations Millimeter Wave Transparency is poor through a wet- dense atmosphere

Experimental Aerodynamics & Concepts Group Micro Renewable Energy Systems Laboratory Georgia Institute of Technology Dry Atmospheric Absorption for Vertical Transit to 2800m (Mauna Kea) Millimeter Wave Transparency is excellent above 3 km!

Experimental Aerodynamics & Concepts Group Micro Renewable Energy Systems Laboratory Georgia Institute of Technology Proposed Solution for Rural Electrification: 4km Aerostats and Tether Waveguides Komerath, Pant, Kar: ISED 2011

Experimental Aerodynamics & Concepts Group Micro Renewable Energy Systems Laboratory Georgia Institute of Technology Emergency Response System Using Aerostats From: Komerath, ACWR2011, Dec Internal Antenna Carriage feasible

Experimental Aerodynamics & Concepts Group Micro Renewable Energy Systems Laboratory Georgia Institute of Technology Retail beaming to augment micro renewable generators PV-antenna integration Nano-antenna Micro-antenna

Experimental Aerodynamics & Concepts Group Micro Renewable Energy Systems Laboratory Georgia Institute of Technology Highway Charging of Electric Vehicles: Smart Grid and Aerostats EVs as distributed storage!

Experimental Aerodynamics & Concepts Group Micro Renewable Energy Systems Laboratory Georgia Institute of Technology Which Brings Us to the Ultimate Dream: Clean, unlimited Space Solar Power How am I doing on time, please?

Experimental Aerodynamics & Concepts Group Micro Renewable Energy Systems Laboratory Georgia Institute of Technology SPACE SOLAR POWER: Specific Power and Minimum Installed Cost Specific Power : Target of most PV systems ~ 1kW per kg in space. Present reality ~ 0.1 to 0.3 kW per kg in space PV system mass scales linearly with power Intensified PV: Beyond 2 Suns, Active Thermal Control System mass Launch cost alone is over $6000 / kg to GEO. Hence launch cost alone is > $6 / Watt if 1 kW/kg is achieved, and around $20 - $60 per Watt today Add system costs. Hard to see how we can do better than $10/Watt installed cost even in the long term. Compare to $1 - $2 /Watt installed cost of nuclear or wind power, or $3 / Watt of terrestrial solar, doable now with no technical uncertainty (see prices at $0.7 /Watt claimed for PV panels alone.

Experimental Aerodynamics & Concepts Group Micro Renewable Energy Systems Laboratory Georgia Institute of Technology GEO 5500 km 2000 km Diffraction Limited Minimum Receiver Diameter to Capture 84% of Received Beam Power Implications of Orbit Choice GEO: Natural choice for large, permanent infrastructure. D r ~ 18 times D r for 2000km sun-sync orbit “Pilot plant” has to be huge. No evolutionary path. “Molniya” (lightning): Long dwell over one plant. Large, varying distance. Sun-Sync: Comes around at the same time every day Molniya Non-GEO/Molniya: Must learn to deal with dynamic beaming (cellphones? beam weapons?) + constellation (GPS?). Enables global distribution from small plants and receivers: Evolutionary path possible. If D t ~100m, R ~36,000,000m, ~ 0.1m, D r ~ 88 km

Experimental Aerodynamics & Concepts Group Micro Renewable Energy Systems Laboratory Georgia Institute of Technology Dream of SSP vs. Reality Ngorongoro Viability Parameter

Experimental Aerodynamics & Concepts Group Micro Renewable Energy Systems Laboratory Georgia Institute of Technology 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 per unit mass that has to be placed in orbit (e.g., 0.8 KWe/kg) c: Launch cost in $ per kg to Low Earth Orbit. (e.g., $2500/kg) Prospect of Breakeven: Need k ~1 ParameterPresentNeeded P, US$/ KWHe  ?? (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 Ngorongoro Viability Parameter

Experimental Aerodynamics & Concepts Group Micro Renewable Energy Systems Laboratory Georgia Institute of Technology Space-based power exchange: The Space Power Grid Approach Use space-based infrastructure to boost terrestrial “green” energy production from land and sea: argument for public support. Full SSP(very large collectors in high orbit) will add revenue- generating infrastructure. 220 GHz beaming and orbits at 2000 km in a Space Power Grid architecture, provide factor of 26 improvement over GEO-based 5.8 GHz SSP concepts

Experimental Aerodynamics & Concepts Group Micro Renewable Energy Systems Laboratory Georgia Institute of Technology PV or InCA? Girasols and Mirasols Gas turbine specific power rises with power level, while PV specific power is constant. Primary gas turbine power generation can close the specific power viability gap, when used with SPG.

Experimental Aerodynamics & Concepts Group Micro Renewable Energy Systems Laboratory Georgia Institute of Technology 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 (Maharashtra), US (NM), Middle East (Egypt), Western Australia –2 facilities (India & US)

Experimental Aerodynamics & Concepts Group Micro Renewable Energy Systems Laboratory Georgia Institute of Technology You don’t need 24-hour power delivery if it is between solar power stations. 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

Experimental Aerodynamics & Concepts Group Micro Renewable Energy Systems Laboratory Georgia Institute of Technology Discussion: Knowledge Needs Millimeter Wave & Dynamic Pointing 1.Generation options 2.Generation efficiency 3.Generation Specific power 4.Antenna geometry 5.Antenna mass 6.Waveguide specific mass 7.Waveguide attenuation / ACTS solutions 8.Phase array antenna DSP solutions 9.Beam profile & pointing accuracy 10.Health effects 11.Atmospheric propagation at high cw levels. Other Issues 1.Sunlight collection and intensification: specific power 2.Wavelength separation: specific power 3.Narrowband PV specific power & efficiency 4.ACTS specific mass at high power levels 5.Airbreathing RLV design for large payloads (50,000 kg to LEO): LACE, hypersonic L/D, takeoff and landing propulsion 6. Policy implications of large SSP stations 7. Retail power beaming & distribution

Experimental Aerodynamics & Concepts Group Micro Renewable Energy Systems Laboratory Georgia Institute of Technology Smart Grid Issues Wireless power beaming can grow to several TW. Drivers: renewable generation, DG, storage, e-mobility and electric vehicles. Power-electronic interface and storage options already being developed for utility scale or microscale VLSI. Square waves, waveform dropouts, storage methods, reactive power. Millions of transient new mobile links, suppliers and sites. On-demand transmission power control is necessary. Time scales of fluctuations: day/night, to millisecond-scale cut-off of beaming to a 60 MW highway charging station or satellite by a safety breaker. Wind plants demand gust load accommodation with 1-second time scale. Reactive load due to these temporal fluctuations must be accommodated and the power redistributed spatially based on demand/capacity computations done at sub-millisecond response times. Many issues similar to VLSI- Smart Grid research underway.

Experimental Aerodynamics & Concepts Group Micro Renewable Energy Systems Laboratory Georgia Institute of Technology 1.Beamed power requires millimeter waves for practical antennae GHz window offers efficient propagation above 3 km. 3. Emergency Response systems in India can benefit from aerostat antenna / waveguide tether power delivery and communications. 4. Aerostat antennae with waveguide tethers offers scaleable solution for rural electrification in India. 5.Highway charging of EVs offers breakthrough in EV adoption. 6.Space Solar Power can be made viable using Space Power Grid synergy with terrestrial energy suppliers, primary Brayton cycle conversion and millimeter wave beaming. 7.A US-India power exchange provides a unique opportunity to start the Space Power Grid towards full SSP. 8.Roadmap to energy independence. CONCLUSIONS

Experimental Aerodynamics & Concepts Group Micro Renewable Energy Systems Laboratory Georgia Institute of Technology 1.Lab experiments on MMwave beaming, rising with a balloon/aerostat up to 4 km. 2.Rural power beaming demo 3.Emergency Response/ Forward Base systems 4.Highway EV charging demo 5.Power beaming through / between aerostats 6.Dynamic power beaming between a ground station and a satellite in a sun-synchronous orbit. 7.Earth-space-earth millimeter wave beaming. 8.Millimeter wave conversion efficiency improvements 9.“Burn-through” vs. aerostat techniques to improve transmission efficiency 10.Millimeter wave power beaming between satellites. 11.Waveguide type relay of millimeter wave power through a satellite to another satellite in space satellite, 2-ground station relay of millimeter wave power. 13.High-orbit collector / low orbit receiver demo 14.10MW photovoltaic SSP + waveguide power exchange satellite demo satellite and 4-satellite systems described above, growing from there to global SPG. 16.Brayton cycle primary intensified conversion demo MW SSP sat demo MW waveguide satellites of Phase 1 SPG. 19.1GWe Mirasol and Girasol Risk-Mitigation Demonstration Sequence

Experimental Aerodynamics & Concepts Group Micro Renewable Energy Systems Laboratory Georgia Institute of Technology 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

Experimental Aerodynamics & Concepts Group Micro Renewable Energy Systems Laboratory Georgia Institute of Technology Update on Space Solar Power from New Scientist, ~2008 Magazine: Dec Ballpark estimates for a 1 GWe SSP plant from nk: 1 GWe at 20% conversion needs 5 sq. km in orbit The rest (4 GW) must be radiated into Space. 1 GWe has to be beamed down to Earth. And received efficiently on someone’s land. And distributed and sold at a profit. The enterprise must not go broke.

Experimental Aerodynamics & Concepts Group Micro Renewable Energy Systems Laboratory Georgia Institute of Technology What does a power exchange buy us for SSP? a)Rationale for global public investment – help the business case for terrestrial renewable power. b)Global endorsement to overcome the obvious international concerns over SSP c)Public investment in SSP R&D to solve millimeter wave and dynamic phase array pointing. d)Revenue with breakeven at 6% ROI to launch the Phase 1 constellation. e)Prove the market for beamed power, and win development support for the first 1GW station f)Win public support for the massive investment needed in Airbreathing Reusable Launch Vehicles to bring down the launch cost to launch the large SSP stations. f) Global support and investment at the level needed to expand to TW-level SSP. Why don’t we just go ahead to build the 1GW satellites? With what resources, how much, and why/where would you get those resources? What is the business case? How will you achieve low launch costs? Pay for the R&D? Why would profit-seeking enterprise invest in something without a business case? How many votes in the US Congress would you get to win taxpayer funding? Why would the renewable energy community support you?