Download presentation

Presentation is loading. Please wait.

Published byChloe Claydon Modified over 3 years ago

1
UNCLASSIFIED Space Power Station First Order Assessment 22 Apr 2007

2
UNCLASSIFIED Objective Provide a perspective on viability of Space Solar Power for a variety of applications Big down to small applications System charateristics - how big/massive, how many launches, how many years … Scope: Addresses only orbital hardware required to collect solar energy - will not address: Hardware to convert to w power and transmit to Earth Terrestrial hardware to receive w power and conversion to electrical power

3
UNCLASSIFIED Space Power Station - Concept GEO Solar Power Stations (SPS) Converts solar flux into electrical power using photovoltaics Converts electrical power to microwave ( w) power Beams (transmits) w power to Earth Earth Receive Station (ERS) Receives w power Converts w power to electrical power Feeds National Power Grid (NPG) Motivation - become hydrocarbon independent Total annual US energy consumption is ~ 10 16 W Hourly US consumption rate is ~ 1.14x10 12 Wh (Watts/hour) ~ 85% of US energy is hydrocarbon based Hourly US hydrocarbon consumption is ~ 9.7x10 11 Wh

4
UNCLASSIFIED Space Power Station – Assumptions What is efficiency of conversion process is – use ~20% < 28% solar flux to electrical conversion in SPS < 90% electric to microwave conversion in SPS < 90% transmission efficiency < 90% microwave to electric conversion in ERS Solar flux is ~ 1370 Wh/m 2 Effective flux is therefore ~ 275 Wh/m2 US hydrocarbon consumption is ~ 9.7x10 11 Wh Surface area of GEO photovoltaic array needed to generate ~ 9.7x10 11 Wh is ~ 3.5x10 9 m 2 (~ 60 km on a side) Assumed volume of array is 3.5x10 7 m 3 (1.0 cm thick) Mass of array is ~ 9.5x10 10 kg (using Al as basis @ 2.7x10 3 kg/m 3 ) or ~ 8.2x10 10 kg (using silicon @ 2.33x10 3 kg/m 3 )

5
UNCLASSIFIED Space Power Station – A Small Problem EELV Heavy can place ~5x10 3 kg in GEO Deploying ~ 9.5x10 10 kg using current Heavy EELV would require ~1.9x10 7 launches - assuming no replacement require for wear-out – no maintenance … Deployment would require ~ 51,781 years at a launch rate of one EELV Heavy a day Numbers do not include any w hardware

6
UNCLASSIFIED Space Power Station – A Big Problem If all conversion efficiencies were 100% and the effective thickness of the array remained 1 cm, system would require ~ 1/5 the mass and therefore 1/5 the launches … would only take >10,356 years to deploy as long as all parts had MTBFs on the order of 10,000 years At 100% efficiency and effective array thickness of 0.001 m (1 mm) mass on-orbit would be down by factor of ten – so it would only take ~ 1000 years to deploy at one EELV Heavy launch a day If array needs to be replaced every 100 years because of radiation damage, etc … deployment and never closes

7
UNCLASSIFIED Space Power Station – Terrestrial Alternative Max solar flux in desert regions approaches 1000 Wh Overall terrestrial efficiency for a 24 hour day is less than orbital efficiency … ~ 5% … about a quarter if well sited 50% daylight 50% weather 70% trapped by tracking arrays 28% solar to electrical conversion efficiency Yields ~ 50 Wh/m 2 average for a 24 hour day Solar collector array area needs to be about 5.6 times space based alternative or ~2.0x10 10 m 2 or ~2.0x10 4 km 2 That corresponds to about a terrestrial patch that is about 140 km on a side – relatively easy to site as smaller parts in a variety of Western States – but still big by any standard – about 6% of New Mexico ~315,194 Km²

8
UNCLASSIFIED Space Power Station – Tactical Application What is efficiency of conversion process is ??? – use ~20% Solar flux is ~ 1370 Wh/m 2 - effective flux ~ 275 Wh/m2 Target tactical consumption at ~ 9.7*10 7 Wh (97 Mega Wh) Why? ~ 100 M1-A1 tanks ~ 100 MWh Surface area of a GEO photovoltaic array needed to generate ~ 9.7x10 7 W/hr is ~ 3.5x10 5 m 2 (~ 0.6 km on a side) Assumed volume of array is 3.5x10 3 m 3 (1.0 cm thickness) Mass of array is ~ 9.5x10 6 kg (using Al as basis @ 2.7x10 3 kg/m 3 ) or ~ 8.2x10 6 kg (using silicon @ 2.33x10 3 kg/m 3 ) If thickness were 1.0 mm, mass would be 95,000 kg

9
UNCLASSIFIED Space Power Station – Tactical Application Heavy EELV can place ~5x10 3 kg in GEO Deploying ~ 9.5x10 6 kg using current Heavy EELV would require ~1.9x10 3 launches - assuming no replacement require for wear-out – no maintenance … Deployment would require 5.2 years at a launch rate of one a day At a rate of 1/month … takes >62 years If effective array thickness was 1 mm, time to deploy would drop by factor of 10 to 6.2 years at one launch per month – but need to add in w hardware

10
UNCLASSIFIED Space Power Station – Going the Other Way Heavy EELV can place ~5x10 3 kg in GEO Let 50 EELVs be dedicated to deploying array at one launch/month – yields 2.5x10 5 kg in GEO in ~ four years If array has an effective structural thickness of: 1 cm and a density near that of Aluminum (~2700 kg/m 3 ) – yields 27 kg/m 2 or 9,259 m 2 of solar array 1 mm and a density near that of Aluminum (~2700 kg/m 3 ) – yields 2.7 kg/m 2 or 92,590 m 2 of solar array If 1.0 cm array provides 275 Wh/m 2 on the ground – get 2,546,296 Wh or ~ 2.5 mWh = output from 2.5 M1-A1s 1.0 mm array would yield 10x or ~25 M1-A1s Now, need to discount output by mass (and $$$) of w hardware

Similar presentations

Presentation is loading. Please wait....

OK

Metric System Basic Units

Metric System Basic Units

© 2018 SlidePlayer.com Inc.

All rights reserved.

Ads by Google

Company brochure ppt on architectural firm Ppt on linux shell scripting Ppt on software project management by walker royce Ppt on home automation using rf Ppt on event driven programming ppt Ppt on diode family matters By appt only Ppt on travelling salesman problem branch and bound Ppt on model united nations Ppt on traction rolling stock