Assessment of Space Solar Power for Defense Applications
E2S2May 12, 2011
Authors
The Tauri Group David Kerner Jason Hay Carie Mullins Suzette Johnson Mandy Sweeney Carissa Christensen, Managing Partner
Topics
Purpose of this Analysis Energy Concerns Defense Energy Applications Space Solar Power (SSP) Systems Overview Analysis: Does This Fit? Defense Application Characteristics Findings Conclusion Analysis Methodology Details
Purpose
Provide technology-agnostic tool for evaluating energy technologies to support DoD missions
Support development of capabilities appropriate to defense mission needs
Provide background on defense energy vulnerability
Provide analysis of SSP applicability to DoD needs and application areas
National Security Energy Vulnerabilities
Systemic, nation-wide reliance on limited, non-renewable resources
Fluctuations, shortfalls, and restrictions from human causes
Political, economic, environmental, military, and infrastructure risks
Insufficient plans for future, long lead times to develop adequate substitutes
DoD depends on the same resources as the nation’s economy
Nation-wide push to find energy alternatives that reduce vulnerabilities
DoD’s Energy Resilience
Lacks resilience to energy resource fluctuations
Leading U.S. energy user
About 1% of its energy from renewable sources
Fully burdened cost of fuel: DoD can pay > $400 per gallon
Defense Energy Applications
Fixed facilities Long-term installations Short-term installations Forward engagement bases Sensor systems
Mobile platforms Ground Air Sea (surface) Submarine
Sources: U.S. Air Force, U.S. Army, and U.S. Navy
Space Solar Power Systems
Potential renewable alternative energy source for defense applications?
Source: NASA
Space Solar Power Systems: Microwave vs. Laser
Microwave transmission systems• Efficient energy conversion on the ground• Minimal atmospheric attenuation• Low power density• Large apertures in space and rectennas on the ground
Laser transmission systems• Higher beam power density and smaller footprint for beam
collection• Multiple conversion methods• Atmospheric losses• Lower conversion efficiencies
Space Solar Power Systems: Non-GEO vs. GEO
Geostationary systems• Constant coverage• Limited eclipse periods• Power to multiple locations within the satellite’s field of view
Non-Geostationary systems• Power to multiple locations around globe• Reduced free space loss and launch cost• Easier to target• Requires a pulse power system with on-ground storage or
supplemental power• Some orbits cannot provide power during the night
Analysis: Does This Fit?
Three dimensional matrix: applications, characteristics, SSP evaluation
Allows consistent assessment of other energy technologies Does not consider economic, political, environmental, or
social factors
•Types of SSP Systems•Laser GEO•Laser Non-GEO•Microwave GEO•Microwave Non-GEO
Evaluation Ratings
Green = Current technology in an optimized system meets the characteristic needs for a application area.
Yellow = There are some technical challenges that need to be overcome, and a development pathway to overcome these challenges exists.
Red = Technical challenges are significant, potentially insurmountable, and development pathways are not identified.
Defense Application Characteristics
Character: load, duration, periodicity Position: operational footprint, range, speed, distributed
vs. centralized Time: deployment, engagement, removal Logistics: materiel deliveries, infrastructure, personnel,
skill sets, maintenance, deployment environment Stealth Security
Findings
• SSP may increase energy security at military facilities• Harder to disrupt transmission between the satellite
and ground station• Could reduce the need for fuel convoys• Steady power supply may enhance facility safety and
security in a hostile environment• Technology and application-specific analysis is required
to assess if an SSP concept has a net positive or negative impact on security
SSP is a possible, though technically challenging, alternative to conventional, non-renewable energy resources for defense
Findings: Advantages, Challenges, and Unknowns
• Can be deployed anywhere on the globe• Provides high levels of centralized power• May reduce field maintenance and logistical burden
SSP advantages
• Deployment and removal time• Deployment environment safety and security• Infrastructure, real estate, and personnel
SSP challenges
• Does it reduce energy vulnerability?
SSP unknowns
Findings: Details
Fixed Facilities Best Application for SSP
Large facilities have the real estate and infrastructure for Laser or Microwave systems
Best fit is facilities with long deployment timelines and multi-year missions
Geostationary systems are ideal for constant power
Mobile Platforms Pose Greater Technical Challenges
Laser systems are necessary due to smaller footprint Still requires large surface area (e.g. large ship)
Advanced beam tracking necessary; easier with slower vehicles
Alternative approach could include centralized facility with synthetic fuel plant
Challenges: Rapid Deployment and Removal
U.S. military applications require rapid deployment and removal
Long lead times for system construction
Retasking reduces deployment time, but current capabilities do not meet some requirements
Challenges: Deployment Environment, Stealth, and Security
Military applications may involve austere or hostile environments Satellites and ground systems are
attractive targets Rectennas and solar arrays tend
to be fragile and require hardening or shielding
Current power beaming technologies would reveal system locations and may provide information on capabilities
Challenges: Infrastructure and Personnel
SSP is best suited for high-power, centralized systems Requires large power distribution systems Several military applications do not have access to this
infrastructure or the real estate to build it
Distributed SSP systems for mobile applications Requires advanced beam tracking systems Requires applications that use low-power, diffuse beams
Skilled workforce to maintain ground systems may not be available on small bases or mobile platforms
Conclusion
Most promising application: Powering fixed facilities with GEO satellites
Mobile applications are also possible, but technically challenging
SSP may reduce the U.S. military’s energy vulnerability, but there are significant challenges, costs, and risks
Further analysis is needed to compare economic considerations versus other alternative technologies
Analysis tool can provide comparative analysis of energy systems with respect to national security needs Critical to remember that the mission drives the technology
Analysis Methodology Details:Defense Energy Application Categories
Fixed facilities Long-term installations Short-term installations Forward engagement bases Sensors
Mobile platforms Ground Air Sea (surface) Submarine
Analysis Methodology Details:Defense Energy Application Characteristics
Character: Load – the level of energy demand Duration – how long demand lasts Periodicity – the character of the demand, e.g., continuous, at regular
intervals, as-needed, or for surge requirements
Position Operational footprint – area occupied by a fixed application Range – distance mobile application may travel from point of origin Speed – how fast a mobile application will travel Distributed vs. centralized – the manner with which energy may be
provided throughout a facility or mobile platform
Analysis Methodology Details:Defense Energy Application Characteristics
Time Deployment – the time in which a facility or platform is made
ready for operation Engagement – how long the facility or platform may be
operationally engaged Removal – the time in which a facility or platform is removed
from operation
Analysis Methodology Details:Defense Energy Application Characteristics Logistics
Materiel deliveries – the nature of materiel supply requirements, including delivery frequency, dependability, and quantity
Infrastructure – the type of infrastructure and degree to which a facility or platform is reliant upon it
Personnel – typical number of personnel Skill sets – typical range of skills available Maintenance – degree to which maintenance capabilities are
available and performed Deployment environment – characteristics of the environment in
which a facility or mobility platform operates
Stealth – degree to which a facility or mobility platform may need to operate covertly
Analysis Methodology Details:Defense Energy Application Characteristics Security – multi-faceted
How well a physical installation or mobility platform is protected from hostile and/or dangerous conditions
How well the operational capabilities of an installation or mobility platform are protected from hostile and/or dangerous conditions
Security capabilities enabled by energy systems/resources The vulnerabilities of an installation’s or mobility platform’s
energy system/resources to hostile and/or dangerous conditions Vulnerabilities posed to the installation or mobility platform by the
physical presence of energy systems/resources Vulnerabilities created by the use of energy systems/resources Operational and strategic vulnerabilities associated with reliance
on an energy system/resource