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CO2 　 Emission 　 from Solar Power satellite (SPS)Multi-Tether Satellite System

Keiichiro AsakuraFaculty of Economics , Ryutsu Keizai University

120 , Ryugasaki City, Ibaraki 301-8555, JapanE-mail:asakura@rku.ac.jp

Satoshi NakanoKeio Economic Observatory (KEO) , Keio University

2-15-45 Mita, Minatoku, Tokyo 108-8345, Japan

Kanji YoshiokaKeio Economic Observatory (KEO) , Keio University

2-15-45 Mita, Minatoku, Tokyo 108-8345, Japan

Multi-Tether Satellite system is developed by Professor Susumu SASAKI, Japan Aerospace Exploration Agency: JAXA .We would like to thank him for giving us technical information and helpful comments. We are solely responsible for any errors.

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Concept of SPS

Earth’sSurface

Low Earth Orbit

Geo-Stationary Orbit36,000km

Reusable Launch Vehicle（ RLV ）Payload ： 50 ｔPropellant ； LH2,250t LO2,1,500t1unit;2,000tTotal:14unit,1000 round trips

Orbital Transfer Vehicle（ OTV ）Payload;50 ｔPropellant ； LA ｒ ,30t1unit;145tTotal ： 171unit,600 round trips

Microwave

Photo-voltaic panel2.5km ×2.5km

Upper panel:2.8GWLower panel:2.5GW

Electric power

1GWRectennaDiameter;3.5km

Satellite

Tether

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Model　　and　Data

1.Model - Environmental I-O Analysis

　　　 CO2 k= C (I-A)-1 fk ・・・（ 1 ）

　　　　 　　 C ： CO2 emission coefficient (diagonal)

　　　　 　 (I-A)-1　： Leontief Inverse Matrix

　 　 　 　 　 　 　 　 f k: final demand vector of k-th SPS components

　 　 　 (e.g. Satellite,Orbital Transfer Vehicle, Rectenna ・・・ )

　　　　　　　 CO2 k :CO2 emission of k-th SPS component

2.Data (a) Japanese Environmental I-O Table (b)SPS Material data

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Making SPS Final Demand

Si l i con Transi stor a p_aSi l i con di ode b p_b ＭＰＵ

CPU（ ） c p_c ＤＲＡＭ d p_d

・ ・ ・・ ・ ・・ ・ ・

① Materi al I nput i nformati on (e. g. Satel l i te)

ResourceRequi rements Uni t pri cemateri al

i nput

② I O sector

Semi conductor devi ces a× (p_a)Semi conductor devi ces b× (p_b)I ntegrated ci rcui ts c× (p_c)I ntegrated ci rcui ts d× (p_d)

・ ・・ ・・ ・

I O cl assi fi cati on pri ces

③ Add Margi n (FD)

Semi conductor devi ces a× (p_a)Semi conductor devi ces b× (p_b)I ntegrated ci rcui ts c× (p_c)I ntegrated ci rcui ts d× (p_d)

・・ ・

trade and transport margi n m1・ m2・ ・

pri cesI O cl assi fi cati onMain data source of FD vectors estimated are;DOE/NASA(1980),Society of Chemical Engineers(1995)Yearbook Machinery Statistics,Unit price information in IO DatabasesNaruo(1996) and Sasaki(2006)

Overview of the CO2 Emission from SPS

CO2 Emission by main components

CO2 Emission by sector

OTV; Orbital Transfer VehicleRLV; Reusable Launch VehiclePV; photovoltaics cellLAr; Liquid argonLH2; Liquid hydrogenLO2; Liquid oxygen

sector thousand ton share(%)1 Electricity 5,927.6 52.72 private power generation 727.8 6.53 road freight transport 575.9 5.14 coal products 455.5 4.15 pig iron 454.6 4.06 compressed gas, liquefied gas 437.6 3.97 coastal and inland watertransport 266.6 2.48 self-transport by private cars 206.9 1.89 sheet glass, safety glass 200.7 1.8

10 petroleum refinery products 163.8 1.5others 1,826.6 16.2

Total 11,243.7 100.0

thousand ton share(%)Satellite Structure 1,116.9 9.9%

PV 2,659.7 23.7%OTV Structure 74.6 0.7%

LAr 61.0 0.5%PV 184.6 1.6%

RLV Structure 46.6 0.4%LO2,LH2 6,406.9 57.0%

Recttna 693.4 6.2%11,243.7 100.0%Total

component

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Comparison of CO2 emission of different electricity generation systems

*Figures on Coal,Oil,LNG,Nuclear and PV1 are estimated by Hondo(2000) .Figure on PV2 is recalculation on Nakano(2006),using eq.(1). Figures on several types of SPS are estimated by our group.*Life time assumption on Multi-Tether Satellite system; 40 years.*Total repair ratio of Multi-Tether Satellite system is assumed to be 2.5%,CO2 emission /kWh becomes 33g, if it is permitted to assume it simply. *CO2 emission in distributing the electricity generated is not included in the SPS figures (since the data is not available) but is included for the other systems.

g-CO2/kWh

→several types of SPS