20-04-2012, 04:57 PM
Wireless Power Transmission Options for Space Solar Power
solar power wpt_options_for_ssp_potter.pdf (Size: 925.2 KB / Downloads: 53)
Far Term Space Systems to beam power to Earth
– Radio-Wave WPT System
– Light-Wave Systems
– Photovoltaic power generation
– Solar dynamic power generation
– Power levels of 1 to 10 GW, beamed from
geostationary orbit
• Near term Technology Flight Demonstrations
– Model System Concept 1A: 100 kWe satellite
– Model System Concept 1B: 10 kWe lunar system
Near-Term Market: Military Bases
Much of the cost in lives and dollars of operating a military base
in a war environment is due to the delivery of fuel
• Cost of delivery of gasoline under such circumstances is about
100/gallon, which contains 130 megajoules of energy = 36 kWh
• At this rate, 40 remote military bases (each using 5 MW) will
require 40 bases x 5 MW/base x 24 hours/day x 30 days/month =
144,000 MWh/month
• This is equivalent to 4,000,000 gallons of fuel per month or $400
million per month for fuel.
– Conversion from thermal to electrical energy not accounted for.
Actual fuel usage will be higher.
• These bases, using a total of 200 MW could instead be supplied
by just 20% of the power beamed from a single 1 GW power
satellite
• may be 6
Graceful growth toward this market achievable by
considering a constellation of smaller (5 to 10 MW) satellites.
Orbit Trade Study: Altitude (2 of 2)
High Earth Orbit, particularly GEO
– Pros:
• Satellite has long dwell time over rectenna (continuous in GEO), so little or no beam
steering is necessary
• Minimal beam steering losses
• In almost continuous sunlight
• Exclusion zone around beam is large, but fixed
– Cons:
• High delta-V, so high launch costs
• High beam divergence, therefore:
– Large antenna size
– Large overall system size, leading to higher cost to first power, complex assembly, and
challenging integration into existing markets
• Must transmit beam through lower orbits
• Middle Earth Orbit (MEO)
– Most pro and con characteristics are intermediate between LEO and GEO,
however …
– Taking full advantage of MEO altitude may involve placing it in higher inclination
orbits. This would have the advantage of placing the satellite over areas where it
is needed much of the time, and may keep it in continuous sunlight much of the
year. However, the delta-V to launch to a highly inclined MEO orbit may actually
be greater than that for GEO.