soler paower.docx

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ABSTRACTThe search for a new, safe and stable renewable energy source led to the idea of building a powerstation in space which transmits electricity to Earth. The concept of Solar Power Satellites (SPS)was invented by Glaser in 1968.Research is still going on in this field and NASA is planning toimplement one by 2040. SPS converts solar energy into microwaves and transmit it to a

receiving antenna on Earth for conversion to electric power. The key technology needed toenable the future feasibility of SPS is Microwave Power Transmission. SPS would be a massivestructure with an area of about 56 sq.m and would, weigh about 30,000 to 50,000 metric ton.Estimated cost is about $74 billion and would take about 30 years for its construction. In order toreduce the projected cost of a SPS suggestions are made to employ extraterrestrial resources forits construction. This reduces the transportation requirements of such a massive structure.

However the realization of SPS concept holds great promises for solving energy crisis.

The selling price of electrical power varies with time. The economic viability of space solarpower is maximum if the power can be sold at peak power rates, instead of baseline rate. Priceand demand of electricity was examined from spot-market data from four example markets: New

England, New York City, suburban New York, and California. The data was averaged to showthe average price and demand for power as a function of time of day and time of year. Demandvaries roughly by a factor of two between the early-morning minimum demand, and theafternoon maximum; both the amount of peak power, and the location of the peak, dependssignificantly on the location and the weather . The demand curves were compared to theavailability curves for solar energy and for tracking and non-tracking satellite solar powersystems, in order to compare the market value of terrestrial and solar electrical power. newdesigns for a space solar power (SSP) system were analyzed to provide electrical power to Earthfor economically competitive rates. The approach was to look at innovative power architecturesto more practical approaches to space solar power. A significant barrier is the initial investmentrequired before the first power is returned. Three new concepts for solar power satellites were

invented and analyzed: a solar power satellite in the Earth-Sun L2 point, a geosynchronous no-moving parts solar power satellite, and a nontracking geosynchronous solar power satellite withintegral phased array. The integral-array satellite had several advantages, including an initialinvestment cost approximately eight times lower than the conventional design.

INTRODUCTION

The new millennium has introduced increased pressure for finding new renewable energysources. The exponential increase in population has led to the global crisis such as globalwarming, environmental pollution and change and rapid decrease of fossil reservoirs. Also thedemand of electric power increases at a much higher pace than other energy demands as the

world is industrialized and computerized. Under these circumstances, research has been carriedout to look into the possibility of building a power station in space to transmit electricity to Earthby way of radio waves-the Solar Power Satellites. Solar Power Satellites(SPS) converts solarenergy in to micro waves and sends that microwaves in to a beam to a receiving antenna on theEarth for conversion to ordinary electricity.SPS is a clean, large-scale, stable electric powersource. Solar Power Satellites is known by a variety of other names such as Satellite PowerSystem, Space Power Station, Space Power System, Solar Power Station, Space Solar PowerStation etc.[1].One of the key technologies needed to enable the future feasibility of SPS is that


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of Microwave Wireless Power Transmission.WPT is based on the energy transfer capacity ofmicrowave beam i.e,energy can be transmitted by a well focused microwave beam. Advances inPhased array antennas and rectennas have provided the building blocks for a realizable WPTsystem .The Solar Power Satellite (or "Space Solar Power," SPS) is a concept to collect solar power in

space, and then transport it to the surface of the Earth by microwave (or possibly laser) beam,where it is converted into electrical power for terrestrial use [1]. The recent prominence ofpossible climate change due to the greenhouse effect from burning of fossil fuels has againbrought alternative energy sources to public attention, and the time is certainly appropriate toreexamine the economics of SPS. In the analysis of the economics of solar power satellites toprovide electric power for terrestrial use, past analyses have typically assumed an averaged (or"baseline") power pricing structure. In the real world, price varies with location, season, and timeof day; and the initial markets for satellite solar electricity need to be selected to maximizerevenue. It is important to design the system to service the real-world electrical power market,not to an unreal average-price model. The following criteria will have to be used for a credibleanalysis of solar power satellite economic benefits and rate of return:

he maximum selling price

WHY SPS

Increasing global energy demand is likely to continue for many decades. Renewable energy is acompelling approach both philosophically and in engineering terms. However, manyrenewable energy sources are limited in their ability to affordably provide the base load powerrequired for global industrial development and prosperity, because of inherent land and waterrequirements. The burning of fossil fuels resulted in an abrupt decrease in their .it also led to thegreen house effect and many other environmental problems. Nuclear power seems to be ananswer for global warming, but concerns about terrorist attacks on Earth bound nuclear powerplants have intensified environmentalist opposition to nuclear power. Moreover, switching on tothe natural fission reactor, the sun, yields energy with no waste products.Earth based solar panels receives only a part of the solar energy. It will be affected by the day &night effect and other factors such as clouds. So it is desirable to place the solar panel in thespace itself, where, the solar energy is collected and converted in to electricity which is thenconverted to a highly directed microwave beam for transmission. This microwave beam, whichcan be directed to any desired location on Earth surface, can be collected and then convertedback to electricity. This concept is more advantageous than conventional methods. Also themicrowave energy, chosen for transmission, can pass unimpeded through clouds andprecipitations.

SPSTHE BACKGROUND

The concept of a large SPS that would be placed in geostationary orbit was invented by PeterGlaser in 1968 [1].The SPS concept was examined extensively during the late 1970s by the U.SDepartment of Energy (DOE) and the National Aeronautics and Space Administration (NASA).The DOE-NASA put forward the SPS Reference System Concept in 1979 [2]. The centralfeature of this concept was the creation of a large scale power infrastructure in space, consisting


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of about 60 SPS, delivering a total of about 300GW.But, as a result of the huge price tag, lack ofevolutionary concept and the subsiding energy crisis in 1980-1981, all U.S SPS efforts wereterminated with a view to re-asses the concept after about ten years. During this timeinternational interest in SPS emerged which led to WPT experiments in Japan.

Space solar power is potentially an enormous business. Current world electrical consumptionrepresents a value at the consumer level of nearly a trillion dollars per year; clearly even if only asmall fraction of this market can be tapped by space solar power systems, the amount of revenuethat could be produced is staggering.To tap this potential market, it is necessary that a solar power satellite concept has the potentialto be technically and economically practical. Technical feasibility requires that the concept notviolate fundamental laws of physics, that it not require technology not likely to be developed inthe time frame of interest, and that it has no technological show-stoppers. Economic feasibilityrequires that the system can be produced at a cost which is lower than the market value for theproduct, with an initial investmentlow enough to attract investors, and that it serve a market niche that is able to pay.

The baseline "power tower" developed by the "Fresh Look" study in 1996 and 1997 [1,2.7] onlypartially satisfies these criteria. One difficulty is the power distribution system. The distributionsystem required to transfer power from the solar arrays to the microwave transmitters, consistingof a long high voltagetether system, can not operate in the environment of near-Earth space at the voltages requiredwithout short-circuiting to the space plasma. Lowering the voltage to avoid plasma dischargewould result in unacceptable resistive losses.Power distribution is a general problem with all conventional solar power system designs: as adesign scales up to high power levels, the mass of wire required to link the power generationsystem to the microwave transmitter becomes a showstopper. A design is required in which thesolar power can be used directly at the solar array, rather than being sent over wires to a separatetransmitter. (The "solar sandwich" design of the late 70's solved this problem, but only with theaddition of an unwieldy steering mirror, which complicates the design to an impractical extent).In addition to technical difficulties, the baseline concept does not meet economic goals. Asshown in table 6-4 of the "Fresh Look" final report [1], even with extremely optimisticassumptions of system cost, solar cell efficiency, and launch cost, each design analyzed results ina cost which is either immediately too expensive, or else yields a cost marginally competitive(but not significantly better) than terrestrial power technologies, with an internal rate of return(IRR) too low for investment to make money. Only if an "externality surcharge" is added to non-space power sources to account for the economic impact of fossil-fuels did space solar poweroptions make economic sense. While "externality" factors are quite real, and represent a true costimpact of fossil-fuel generation, it is unlikely that the world community will artificially imposesuch charges merely to make space solar power economically feasible. The value of the solarpower concept, howeverboth the dollar value and the potential value of the ecologicalbenefitsis so great that the concept should not be abandoned simply because one candidatesystem is flawed. It is important to analyze alternative concepts in order to find one that presentsa workable system. At the technical interchange meeting which kicked off the "Fresh Look"study of solar power satellites in 1995, innovative concepts for solar power satellites weresolicited in the "brainstorming" sessions [1,2,8]. However, none of the new concepts weredeveloped in detail.


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RECENT NASA EFFORTSFresh look StudyDuring 1995-96, NASA conducted a re-examination of the technologies, system concepts of SPSsystems [2],[3].The principal objective of this Fresh Look Study was to determine whether a

SPS and associated systems could be defined. The Fresh Look Study concluded that theprospects for power from space were more technically viable than they had been earlier.SSP Concept Definition StudyDuring 1998, NASA conducted the SSP Concept Definition Study which was a focused one yeareffort that tested the results of the previous Fresh Look Study. A principal product of the effortswas the definition of a family of strategic R&T road maps for the possible development of SSPtechnologies.SSP Exploratory and Research Technology ProgramIn 2000, NASA conducted the SERT Program which further definednew system concepts. TheSERT Program comprised of three complementaryelements:

System studies and analysis Analysis of SSP systems and architecture concepts to address the

economic viability as well as environmental issue assessments.SSP Research and technology Focused on the exploratory research to identify system concepts

and establish technical viabilitySPS technology demonstration Initial small scale demonstration of key SSP concepts and / or

components using related system / technologies.

SPS-A GENERAL IDEA

Solar Power Satellites would be located in the geosynchronous orbit. The difference betweenexisting satellites and SPS is that an SPS would generate more power-much more power than itrequires for its own operation. The solar energy collected by an SPS would be converted into

electricity, then into microwaves. The microwaves would be beamed to the Earths surface,where they would be received and converted back into electricity by a large array of devicesknown as rectifying antenna or rectenna.(Rectification is the process by which alternatingelectrical current ,such as that induced by a microwave beam , is converted to direct current).This direct current can then be converted to 50 or 60 Hz alternating current [4]. Each SPS wouldhave been massive; measuring 10.5 km long and 5.3 km wide or with an average area of 56sq.km.The surface of each satellite would have been covered with 400 million solar cells. Thetransmitting antenna on the satellite would have been about 1 km in diameter and the receivingantenna on the Earths surface would have been about 10 km in diameter [5].The SPS wouldweigh more than 50,000 tons.The reason that the SPS must be so large has to do with the physics of power beaming. The

smaller the transmitter array, the larger the angle of divergence of the transmitted beam. A highlydivergent beam will spread out over a large area, and may be too weak to activate the rectenna.Inorder to obtain a sufficiently concentrated beam; a great deal of power must be collected and fedinto a large transmitter array.


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Figure 1 Configuration of SPS is space.The day-night cycle ,cloud coverage , atmospheric attenuation etc.reduces the amount of solarenergy received on Earths surface.SPS being placed in the space overcomes this .Anotherimportant feature of the SPS is its continuous operation i.e,24 hours a day,365 days a year basis.Only for ma total of 22 in a year would the SPS would be eclipsed for a period of time to amaximum of 72 min.If the SPS and the ground antenna are located at the same longitude, theeclipse period will center around midnight [7]. The power would be beamed to the Earth in theform of microwaves at a frequency of 2.45 GHz. Microwaves can pass unimpeded throughclouds and rain .Microwaves have other features such as larger band width , smaller antenna size,sharp radiated beams and they propagate along straight lines. Because of competing factors such

as increasing atmospheric attenuation but reducing size for the transmitting antenna and the othercomponents at higher frequency , microwave frequency in the range of 2-3 GHz are consideredoptimal for the transmission of power from SPS to the ground rectenna site[7].A microwavefrequency of 2.45 GHz is considered particularly desirable because of its present uses for ISMband and consequently probable lack of interference with current radar and communicationsystems. The rectenna arrays would be designed to let light through, so that crops or even solarpanels could be placed underneath it. Here microwaves are practically nil .


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The amount of power available to the consumers from one SPS is 5 GW.the peak intensity ofmicrowave beam would be 23 mW/cm.So far, no non thermal health effects of low levelmicrowave exposure have been proved, although the issue remains controversial [4]. SPS has allthe advantage of ground solar, plus an additional advantage; it generates power during cloudyweather and at night. In other words SPS receiver operates just like a solar array. Like a solar

array, it receives power from space and converts it into electricity. If the satellite position isselected such that the Earth and the Sun are in the same location in the sky, when viewed fromthe satellite, same dish could be used both as solar power collector and the microwave antenna.This reduces the size and complexity of satellite [8]. However, the main barrier to thedevelopment of SPS is social, not technological. The initial development cost for SPS isenormous and the construction time required is very long. Possible risks for such a large projectare very large, pay-off is uncertain. Lower cost technology may be developed during the timerequired to construct the system. So such a large program requires a step by step path withimmediate pay-off at each step and the experience gained at each step refine and improve the riskin evolutionary steps [9].


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WIRELESS POWER TRANSMISSION

Transmission or distribution of 50 or 60 Hz electrical energy from the generation point to theconsumer end without any physical wire has yet to mature as a familiar and viabletechnology.However, the reported works on terrestrial WPT have not revealed the design method

and technical information and also have not addressed the full-scale potential of WPT ascompared with the alternatives, such as a physical power distribution line [10]. However themain thrust of WPT has been on the concept of space-to-ground (extraterrestrial) transmission ofenergy using microwave beam.Fig.3 shows the block diagram of a conceptual WPT system annexed to a grid [10].

Figure 3. conceptual model for a WPT system annexed to a grid.

The 50 Hz ac power tapped from the grid lines is stepped down to a suitable voltage level forrectification into dc. This is supplied to an oscillator fed magnetron. Inside the magnetronelectrons are emitted from a central terminal called cathode. A positively charged anodesurrounding the cathode attracts the electrons. Instead of traveling in a straight line, the electronsare forced to take a circular path by a high power permanent magnet. As they pass by theresonating cavities of the magnetron, a continuous pulsating magnetic field i.e., electromagneticradiation in microwave frequency range is generated. After the first round of cavity-to-cavity tripby the electrons is completed the next one starts, and this process continues as long as themagnetron remains energized. Fig.4 shows the formation of a reentrant electron beam in a typicalsix cavity magnetron. The output of the rectifier decides the magnetron anode dc voltage. This inturn controls the radiation power output. The frequency of the radiation is adjusted by varying

the inductance or capacitance of the resonating cavities. Instead of traveling in a straight line, theelectrons are forced to take a circular path by a high power permanent magnet. As they pass bythe resonating cavities of the magnetron, a continuous pulsating magnetic field i.e.,electromagnetic radiation in microwave frequency range is generated. After the first round ofcavity-to-cavity trip by the electrons is completed the next one starts, and this process continuesas long as the magnetron remains energized. Fig.4 shows the formation of a reentrant electronbeam in a typical six cavity magnetron.


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Figure 4. Re-entrant electron beam in a six-cavity magnetron

The microwave power output of the magnetron is channeled into an array of parabolic reflectorantennas for transmission to the receiving end antennas. To compensate for the large loss in freespace propagation and boost at the receiving end the signal strength as well as the conversionefficiency, the antennas are connected in arrays. Moreover, arrayed installation of antennas willnecessitate a compact size.A series parallel assembly of schottky diodes, having a low standing power rating but good RF

characteristics is used at the receiving end to rectify the received microwave power back into dc.Inverter is used to invert the dc power into ac. A simple radio control feedback system operatingin FM band provides an appropriate control signal to the magnetron for adjusting its output levelwith fluctuation in the consumers demand at the receiving side. The feedback system wouldswitch of the supply to the oscillator and magnetron at the sending end if there is a total loss ofload. The overall efficiency of the WPT system can be improved by

Increasing directivity of the antenna arrayUsing dc to ac inverters with higher conversion efficiencyUsing schottky diode with higher ratings.

MICROWAVE POWER TRANSMISSION IN SPS

The microwave transmission system as envisioned by NASA and DOE would have had threeaspects [5]:1. The conversion of direct power from the photovoltaic cells, to microwave power on thesatellites on geosynchronous orbit above the Earth.2. The formation and control of microwave beam aimed precisely at fixed locations on the Earthssurface.3. The collection of the microwave energy and its conversion into electrical energy at the earthssurface.


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The ability to accomplish the task of efficiently delivering electrical power wirelessly isdependent upon the component efficiencies used in transmitting and receiving apertures and theability to focus the electromagnetic beam onto the receiving rectenna. Microwave WPT isachieved by an unmodulated, continuous wave signal with a band width of 1Hz. Frequency ofchoice for microwave WPT has been 2.45GHz due to factors such as low cost power

components, location in the ISM band, extremely low attenuation through the atmosphere [2].The next suggested band centered at 5.8GHz system reduces the transmitting and receivingapertures. But this is not preferred due to increased attenuation on higher frequency.The key microwave components in a WPT system are the transmitter, beam control and thereceiving antenna called rectenna .At the transmitting antenna, microwave power tubes such asmagnetrons and klystrons are used as RF power sources. However, at frequencies below 10 GHz,high power solid state devices can also be used. For beam safety and control retro directivearrays are used. Rectenna is a component unique to WPT systems. The following sectiondescribes each of these components in detail.

TRANSMITTER

The key requirement of a transmitter is its ability to convert dc power to RF power efficientlyand radiate the power to a controlled manner with low loss. The transmitters efficiency drivesthe end-to-end efficiency as well as thermal management system i.e., any heat generated frominefficiencies in the dc-RF conversion, should be removed from the transmitter as it reduces thelife time of RF devices and control electronics .Passive inter modulation is another field whichrequires critical attention. Filtering of noise and suppression of harmonics will be required tomeet he regulatory requirement.The main components of a transmitter include dc-to-RF converter and transmitting antenna. .The complexity of the transmitter depends on the WPT application. For the large scale WPTapplication such as SPS, phased array antennas are required to distribute the RF power sourcesacross the aperture and electronically control the power beam. Power distribution at the

transmitting antenna= (1-r), where r is the radius of antenna There are mainly three dc-to-RFpower converters: magnetrons, klystrons and solid state amplifiers.Klystron Fig.5 shows the schematic diagram of a klystron amplifier .

Figure 5 Klystron amplifier schematic diagram.


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Here a high velocity electron beam is formed, focused and send down a glass tube to a collectorelectrode which is at high positive potential with respect to the cathode. As the electron beamhaving constant velocity approaches gap A, they are velocity modulated by the RF voltageexisting across this gap. Thus as the beam progress further down the drift tube,bunching of electrons takes place. Eventually the current pass the catcher gap in quite pronounce

bunches and therefore varies cyclically with time. This variation in current enables the klystronto have significant gain. Thus the catcher cavity is excited into oscillations at its resonantfrequency and a large output is obtained.Fig.6 shows a klystron transmitter. The tube body and solenoid operate at 300C and thecollector operates at 500C. The overall efficiency is 83%. The microwave power density at thetransmitting array will be 1 kW/m for a typical 1 GW SPS with a transmitting antenna apertureof 1 km diameter. If we use 2.45 GHz for MPT, the number of antenna elements per squaremeteris on the order of 100. Therefore the power allotted to the individual antenna element is of theorder of 10 W/element. So we must distribute the high power to individual antenna through apower divider .

BEAM CONTROLA key system and safety aspect of WPT in its ability to control the power beam. Retro directivebeam control systems have been the preferred method of achieving accurate beam pointing. Asshown in fig.7 a coded pilot signal is emitted from the rectenna towards the SPS transmitter toprovide a phase reference for forming and pointing the power beams [2]. To form the powerbeam and point it back forwards the rectenna, the phase of the pilot signal is captured by thereceiver located at each sub array is compared to an onboard reference frequency distributedequally throughout the array. If a phase difference exists between the two signals, the receivedsignal is phase conjugated and fed back to earth dc-RF converted. In the absence of the pilot


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signal, the transmitter will automatically dephase its power beam, and the peak power densitydecreases by the ratio of the number of transmitter elements.

RECTENNABrown was the pioneer in developing the first 2.45GHz rectenna [2]. Rectenna is the microwaveto dc converting device and is mainly composed of a receiving antenna and a rectifying circuit.Fig .8 shows the schematic of rectenna circuit [2]. It consists of a receiving antenna, an input lowpass filter, a rectifying circuit and an output smoothing filter. The input filter is needed tosuppress re radiation of high harmonics that are generated by the non linear characteristics ofrectifying circuit. Because it is a highly non linear circuit, harmonic power levels must besuppressed. One method of suppressing harmonics is by placing a frequency selective surface in

front of the rectenna circuit that passes the operating frequency and attenuates the harmonics.

Figure 8 Schematic of rectenna circuit.For rectifying Schottky barrier diodes utilizing silicon and gallium arsenide are employed. Inrectenna arrays, the diode is the most critical component to achieve higher efficiencies because itis the main source of loss.Diode selection is dependent on the input power levels. The breakdown voltage limits the powerhandling capacity and is directly related to series resistance and junction capacitance through theintrinsic properties of diode junction and material .For efficient rectification the diode cut off


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frequency should be approximately ten times the operating frequency. Diode cut off frequency isgiven by =1/ [2RsCj], where is the cut off frequency, Rs is the diode series resistance, Cj isthe zero-bias junction capacitance.

RECENTLY DEVELOPED MPT SYSTEMS

The Kyoto University developed a system called Space Power Radio Transmission System(SPORTS) [1]. The SPORTS is composed of solarpanels, a microwave transmitter subsystem, anear field scanner, a microwave receiver. The solar panels provide 8.4 kW dc power to themicrowave transmitter subsystem composed of an active phased array. It is developed to simulate the whole power conversion process for the SPS, including solar cells, transmittingantennas and rectenna system. Another MPT system recently developed by a team of Kyoto University ,NASDA and industrial companies of Japan , is an integrated unit called the SolarPower Radio Integrated Transmitter (SPRITZ),developed in2000 [1]. This unit is composed of asolar cell panel, microwave generators,transmitting array antennas and a receiving array in onepackage. This integrated unit as shown in fig.9 could be a prototype of a large scale

experimental module in the orbit

CONSTRUCTION OF SPS FROM NON TERRESTRIAL

MATERIALS: FEASIBILITY AND ECONOMICSSPS, as mentioned before is massive and because of their size they should have been constructedin space [5]. Recent work also indicate that this unconventional but scientifically well basedapproach should permit the production of power satellite without the need for any rocket vehiclemore advanced than the existing ones. The plan envisioned sending small segments of thesatellites into space using the space shuttle. The projected cost of a SPS could be considerablyreduced if extraterrestrial resources are employed in the construction [9].One often discussedroad to lunar resource utilization is to start with mining and refining of lunar oxygen, the most


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abundant element in the Moons crust, for use as a component of rocket fuel to support lunarbase as well as exploration mission. The aluminum and silicon can be refined to produce solararrays [12]. A number of factors combine to make the concept of using non conventionalmaterials appear to be feasible. Among them are the shallow gravity wells of the Moon andasteroids; the presence of an abundance of glass, metals and oxygen in the Apollo lunar samples;

the low cost transport of those materials to a higher earth orbit by means of a solar-poweredelectric motor; the availability of continuous solar energy for transport, processing and living[12]. Transportation requirement for SPS will be much more needed for known for knowncommercial applications. One major new development for transportation is required: the massdriver [12].The mass driver is a long and narrow machine which converts electrical energy intokinetic energy by accelerating 0.001 to 10 kg slugs to higher velocities. Each payload-carryingbucket contains superconducting coils and is supported without physical contact by means ofdynamic magnetic levitation. As in the case of a linear synchronous motor-generator, buckets areaccelerated by a magnetic field, release their payload, decelerate with return energy and pick upanother pay load for acceleration. The power source can be either solar or nuclear. The massdriver conversion efficiency from electrical to kinetic energy is close to 100 percent. The mass

driver can be used as a launcher of lunar material into free space or as a reaction engine in space,where payloads are transferred from orbit to orbit in a spiral trajectory. The performance of themass driver could match that of the space shuttle main engines. But the mass driver has theadvantage that any material can be used as fuel and continuous solar power in space is thecommon power source. An alternative to the use of lunar resources for space manufacturing isthe use of earth-approaching asteroidal materials.

MICROWAVES-ENVIRONMENTAL ISSUESThe price of implementing a SPS includes the acceptance of microwave beams as the link of thatenergy between space and earth. Because of their large size, SPS would appear as a very brightstar in the relatively dark night sky. SPS in GEO would show more light than Venus at its

brightest.Thus, the SPS would be quite visible and might be objectionable. SPS posses manyenvironmental questions such as microwave exposure, optical pollution that could hinderastronomers , the health and safety of space workers in a heavy-radiation (ionizing) environment, the potential disturbance of the ionosphere etc.The atmospheric studies indicate that theseproblems are not significant , at least for the chosen microwave frequency [13].On the earth, each rectenna for a full-power SPS would be about 10 km in diameter. Thissignificant area possesses classical environmental issues. These could be overcome by sitingrectenna in environmentally insensitive locations, such as in the desert, over water etc. Theclassic rectenna design would be transparent in sunlight, permitting growth and maintenance ofvegetation under the rectenna.

However, the issues related to microwaves continue to be the most pressing environmentalissues. On comparing with the use of radar, microwave ovens , police radars, cellular phones andwireless base stations, laser pointers etc. public exposures from SPS would be similar or evenless. Based on well developed antenna theory, the environmental levels of microwave powerbeam drop down to 0.1W/cm [12]. Even though human exposures to the 25 mW/cmwill, ingeneral, be avoided, studies shows that people can tolerate such exposures for a period of at least45 min. So concern about human exposure can be dismissed forthrightly [4]. Specific researchover the years has been directed towards effects on birds, in particular. Modern reviews of this


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research show that only some birds may experience some thermal stress at high ambienttemperatures. Of course, at low ambient temperatures the warming might be welcomed by birdsand may present a nuisance attraction [13]. Serious discussions and education are required beforemost of mankind accepts this technology with global dimensions. Microwaves, however is not apollutant but , more aptly , a man made extension of the naturally generated electromagnetic

spectrum that provides heat and light for our sustence

DEMAND AND COSTElectrical Power Demand

While international and third-world markets for electricity are significant (and rising third-worldpower needs may eventually be the driving force for development of satellite solar power) dataon price and demand is most easily available for the U.S., where a spot market for electricalpower exists. Figures 14 show data on electrical power demand and price for urban andsuburban New York and for the Boston area graphs the average electrical power demand versustime of day, showing the total demand from ten selected utilities serving New York City, LongIsland, and some of the surrounding communities. (This graph averages demand across several

days in May and June 2000). The period of high demand is seen to run from approximately 9AM to 9 PM, when people are awake and using power, and when industrial use is maximum. Formany U.S. markets, peak power usage comes in the summer, when air-conditioning loads arehigh. Figure 2 shows demand data as a function of time of day from the New England ISO,serving the Boston area. This data compares June 16, a day when the outdoor temperature washigh, with June 19, a comparatively cool day.

Figure 1. Power demand in MW for New York and Long Island (sum of power production fromten utilities) as a function of time of day (summer 2000 data).


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Electric Demand (MW-hr)New England ISO

June 16 (hot day) and June 19 (cool day)

hot summer day (upper curve). Time is Daylight Savings Time.The difference between the power required for these two days illustrates the role of airconditioning loads in the peak power demand. The high demand period is skewed toward theafternoon, particularly during the hot day, and runs from about 8 AM to 11 PM. A secondaryevening peak, representing home use of electricity for cooking, television, and so forth, is alsovisible. Published data from southern California [3] shows the same trends, with the summertimedemand fluctuating by roughly a factor of two between day and night. The night demand isapproximately the same in winter and summer, but the daytime demand is higher in the summer,peaking in the early afternoon. In the winter, the afternoon peak vanishes, and a smaller peak at 6to 7 PM (presumably due to electric stoves and ovens) is the highest power use.

These data are representative of region where the highest electrical use is in the summer; itshould also be noted that in some markets (e.g., Florida), the maximum power demand comes inwinter, when electrical heaters are used.

Electrical Power Cost The cost (i.e., the market price of electricity to the distribution utility)follows the demand. When the demand is low, then the lowest-cost generators are used,generating continuous baseline power. At high demandperiods, higher-cost "peak power"generation is required, with spinning reserve needed to dealwith instantaneous demand spikes.Figure 3 shows the cost of electrical power in New York City, graphed at one-hour intervalsthrough the day for a typical day in June 2000. This is the price of electricity sold to the electricdistribution system, not the consumer price. (The actual spot market price fluctuates significantly

from this, as discussed later.).The cost can be roughly divided into two periods, a "low" cost period running from roughlymidnight to 7 AM, with a cost of under one cent per kilowatt hour, and a "high" cost periodrunning from roughly 8 AM to 8 PM, where the cost is about 4 cents per kilowatt hour. Duringthe lowest demand period, from 1 to 6 AM, the cost is under a quarter of a cent per kilowatt-hour.


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Figure 4. Power cost ($/MW-hr) for New England, comparing a hot summer day with a coolerday. The difference between high and low cost periods is about a factor of 4.5. The cost tracksdemand: when demand is low, at night, only the low-cost baseline production is required, whilewhen demand is high, higher-cost peaking-power supplies are brought on line to fill the demand.Figure 4 shows cost data for New England, for the two days with demand graphed earlier. Again,there is a significant difference in the cost of power between the low usage time, 1 AM to 9 AM,


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and the high usage time, although the difference is only a factor of two for this service region.The cost remains high until midnight for the cooler day, and until 1 AM for the hot day.

Short-term Price FluctuationsAt high-demand periods, spinning reserve is needed to deal with instantaneous demand spikes

[5]. The term "spinning reserve" comes from the fact that for short-duration demand spikes,energy stored in the rotation of the generator can be drawn. Inadequate spinning reserve requiresload shedding by the utility, with consequent loss of revenue, or else results in temporary"brown-out" conditions and loss of frequency regulation. To avoid this, electricity can bepurchased on the spot market. Instantaneous spot-market electricity prices can skyrocket to veryhigh values, an order of magnitude higher than baseload prices, due to instantaneous demand, butin general these price spikes are short lasting, and not easily predictable. To avoid these spikes,the data shown earlier was averaged.Figure 5 shows the hourly fluctuation of the actual price to the utility for seven different days. Asis shown, over this period the instantaneous price paid by the utility briefly hit spikes of over 14cents per kilowatt-hour, considerably higher than the 4 cents per kilowatt-hour average for the

high demand period. The timing of the price fluctuations are not correlated from day to day,although they only occur during the high-demand period, since the reserve is high during the lowdemand period. This instantaneous price can, for brief periods, be as high as ten times theaverage, or occasionally even higher.

Price of Electric Power

(New York City)

Figure 5. Short-term price fluctuations in the New York market.


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Analysis

It is clear from these figures that, although conventional designs for a solar power satellite willproduce a constant amount of power independent of the demand, the actual demand forelectricity varies with time of day and with the day of the year, and hence the price that electrical

power can be sold for varies as well, by an amount that varies from roughly a factor of two toover a factor of four, depending on market. The conventional solar power satellite design tracksthe sun, and provides continuous power, except for a period near the spring and autumnalequinox, when it is eclipsed by the Earth around midnight.Since a solar power satellite beams power long distances, would it be possible to use a singlepower satellite to provide power to two different geographical markets that are substantiallyseparated in longitude (and hence buy peak-rate power at different times)? This would be thepower-beaming equivalent of "wheeling" power from one geographic location to another. Sincethe peak price period lasts nearly twelve hours (e.g., 8 AM to 8 PM for New York), for a singlesatellite to provide power to two separate markets at peak rates for both markets would requirethe two markets be at longitudes separated by nearly 180 degrees. If the downlink power beam is

allowed to reach the Earth at 90-degree incident angle (i.e., from a satellite on the horizon), thena single geosynchronous satellite could service two sites on the equator separated by no morethan 162 degrees of longitude. In reality, grazing-incidence is not practical. (Among other things,it would require a verticallyoriented rectenna.)For a more practical case, assume that the maximum allowable zenith angle is 45 degrees. In thiscase two locations served by the same geosynchronous orbit solar power satellite can be at most80 degrees (5.3 hours) apart. This geometry is shown in figure 6 (top). The maximum separationis lower if the sites are not on the equator. This would be sufficient separation to extend theperiod over which the satellite is providing high-price power from roughly 12 hours per day toroughly 17 hours per day. Note that in this case, the ground infrastructure of rectenna, land, anddistribution system is doubled. This trade-off is only reasonable if the ground infrastructure costis not the major fraction of the power cost.If the beam could be diverted through a relay satellite (figure 6, bottom), then larger separationscould be achieved; in principle up to the most desirable case of a 180 degree separation. (In thegeometry shown in figure 6, where the relay satellite is in a lower orbit than the beamingsatellite, several relay satellites would be required to provide continuous coverage; each relaysatellite, however, can sequentially service several markets.) Although a power relay satellite inprinciple is just a passive microwave mirror, in practice it will have to contain tracking,guidance, and orbit maintenance avionics of a sophistication equal or greater that of the solarpower satellite. If the cost is a substantial fraction of the cost of the solar power satellite itself,then it makes more sense to simply build a second SPS, rather than the relay satellites.While it is not currently clear that a power relay satellite will be enough lower in cost to makeservicing two markets with a power relay practical, the fact that this would allow power to besold at high price during a period when otherwise the satellite would be selling power at lowprice means that this concept deserves study.

Servicing the Spot MarketEven higher revenue could be achieved if the solar power satellite could service the spot market,where instantaneous price of electricity can, for brief periods, rise to an order of magnitudehigher than the peak-power cost. This would require a power satellite with the ability to switchbeams from one ground location to a different ground location rapidly (within a few tens of


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seconds). Since instant spot demands are short, such a satellite would have to serve perhaps tendifferent utilities or more to average enough high-price demand markets; the cost of the groundinfrastructure may make this prohibitive.A satellite which serves the short-term spot market cannot, between high-price spikes, sell powerat peak power rates, since the ability to command premium rates is contingent on reliability of

power supply. If the power is taken offline to service a peak demand elsewhere, the servicecannot be relied on, and hence cannot sell for premium rates; conversely if the power is suppliedto a utility at peak-power rates, the beam cannot be momentarily diverted to service a utility witha temporary demand spike. There is probably not enough money represented by the brief high-price spikes to make this concept worthwhile in light of the cost of replicating the groundinfrastructure over ten or more sites, but if the ground infrastructure is low enough in cost, it maybe worthwhile.

Fixed orientation SPS

Since power during the peak period is priced at nearly twice the average price, and power at theoffpeak is nearly valueless, it is worth considering whether it might be possible to simplify thepower satellite design by eliminating the tracking. A flat-plate, non tracking solar array will

much power as a tracking satellite, but in principle could be directed toproduce that power at the most optimum period of the day, when the value of the power isroughly double the average value. If the reduction in cost due to the gain in simplicity of such asatellite is large, this might be a worthwhile trade. Figure 7 shows, as an example, the powerproduced by such a fixed orientation solar power satellite, compared with the power demand ofNew York from figure 1. In this graph, the peak amount of power produced has been scaled sothat at the maximum power production by the satellite, the generation capacity not met by thespace solar power system does not fall below the lowest value during the daytime.In the example, this would result in reducing the maximum amount of power produced by theutilities by 850 MW, representing a peak-shaving to the utilities of 4%. Higher power productionfrom the satellite would result in the peak power production at solar noon overfilling the peakdemand, and thus, since the (non-solar) production at noon is lower than the lowest night value,the solar power satellite will be selling at minimum price, rather than maximum.

Figure 6. A single solar power satellite can service two markets on the Earth either directly (top)or by a relay satellite (bottom).


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Figure 7. Power Demand for New York, showing a 6.5GW(peak) solar power station used forpeakshaving.

Synergy With Terrestrial Solar

Space and Ground Solar Power Analyses of space solar power often assume that ground solarpower is a competing technology, andshow that space solar power is a preferable technology ona rate of return basis. In fact, however, space solar power and ground solar power arecomplementary technologies, not competing technologies. These considerations were initially

discussed in 1990 [4]. Low-cost ground solar power is a necessary precursor to space solarpower: Space solar power requires low cost, high production and high efficiency solar arrays,and these technologies will make ground solar attractive for many markets. The ground solarpower market, in turn, will serve develop technology and the high-volume production readinessfor spacesolar power.Since ground solar is a necessary precursor to space solar power, an analysis of space solarpower should consider how it interfaces with the ground-based solar infrastructure that will bedeveloping on a faster scale than the space infrastructure. Some possible ways that this interfacecould be optimized include:1. Integrate solar and microwave receivers on ground. This will allow the space solar power touse the pre-existing land that has already been amortized by ground solar power receivers, and

tie in to power conditioning and distribution networks that are already in place.2. Use solar power satellites to beam to receivers when ground solar is unavailable. By "fillingin" power when ground solar is unavailable, space solar power will serve as the complement tosolar. This requires an analysis of the match between solar availability, power demand, andpower availability from space. So in addition to the five requirements for economic analysisgiven earlier, a desirable additional requirement is:

wer system keeping in mind that it must complement the groundsolar infrastructure.


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Satellite Power for Night SupplementIn 1997, Landis proposed to locate a solar power satellite at the Earth-sun L2 Lagrange point,where it has a constant view of the night side of the Earth [6,7]. The proposed benefit of thislocation would be that the satellite could supplement daytime ground solar power by providingnight power. From the demand graphs, however, it is clear that this approach would result in

power supplied during the low demand (and hence low price) portion of the day.If in the future ground solar generation becomes a large fraction of the electric supply of theEarth, the price curve will shift to make this the high-price period. However, it is unlikely thatthis system design would be economically favorable in the near term.

Demand With Ground Solar SupplementFigure 6 compares the power required for New York with the power produced by a fixed solarplant designed to supply power during this daytime peak. This power production is nowenvisioned as a ground-based 7.5 GW solar field, tilted slightly to the west to shift the peak to 2PM (i.e., 1 hour after solar noon, including daylight savings correction). The ground solarinstallation produces power almost entirely during the peak cost time.The demand not filled by ground solar now is a two-peaked distribution, instead of a single

peaked power distribution.A design to produce power to optimally fit the two-peak distribution shown might be a fixed,two sided array. The simplest version of such a solar power satellite geometry [7] is shown infigure 8. In this power satellite concept the 6 AM/6 PM timing of the power peaks is notoptimally matched to the demand curve, even after the solar production is subtracted, since muchof the power is produced too early or too late in the day. A better match could be achieved if thetwo arrays are tilted relative to each other, in a "V" configuration. This is shown in figure 9. Asthe power produced by the solar power satellite grows, and eventually supplants the groundsolar, the two-panel system shown in figure 9 can be optimized to supply the peaking loads.Figure 10 shows the output from a V-shaped solar power satellite optimized to supply the peak-power loads of New York City. As is clear from the graph, the power production profile is muchsmoother after the solar power satellite's contribution fills in the peak power.


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ADVANTAGES AND DISADVANTAGESThe idea collecting solar energy in space and returning it to earth using microwave beam hasmany attractions.1. The full solar irradiation would be available at all times expect when the sun is eclipsed by theearth [14]. Thus about five times energy could be collected, compared with the best terrestrialsites2. The power could be directed to any point on the earths surface.


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3. The zero gravity and high vacuum condition in space would allow much lighter, lowmaintenance structures and collectors [14].4. The power density would be uninterrupted by darkness, clouds, or precipitation, which are theproblems encountered with earth based solar arrays.5. The realization of the SPS concept holds great promises for solving energy crisis

6. No moving parts.7. No fuel required.8. No waste product.The concept of generating electricity from solar energy in the space itself has its inherentdisadvantages also. Some of the major disadvantages are:1. The main draw back of solar energy transfer from orbit is the storage of electricity during offpeak demand hours [15].2. The frequency of beamed radiation is planned to be at 2.45 GHz and this frequency is used bycommunication satellites also.3. The entire structure is massive.4. High cost and require much time for construction.

5. Radiation hazards associated with the system.6. Risks involved with malfunction.7. High power microwave source and high gain antenna can be used to deliver an intense burst ofenergy to a target and thus used as a weapon[15].


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CONCLUSIONThe SPS will be a central attraction of space and energy technology in coming decades.However, large scale retro directive power transmission has not yet been proven and needsfurther development. Another important area of technological development will be the reductionof the size and weight of individual elements in the space section of SPS. Large-scale

transportation and robotics for the construction of large-scale structures in space include theother major fields of technologies requiring further developments. Technical hurdles will beremoved in the coming one or two decades. Finally, we look forward to universal acceptance ofthe premise the electromagnetic energy is a tool to improve the quality of life for mankind. It isnot a pollutant but more aptly, a man made extension of the naturally generated electromagneticspectrum that provides heat and light for our sustenance. From this view point, the SPS is merelya down frequency converter from the visible spectrum to microwaves.


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REFERENCE

Remuneration and charging procedures for competitive procurement of reactive

power capacity

Frias, P.; Gomez, T.; Soler, D.Power and Energy Society General Meeting - Conversion and Delivery of Electrical Energy inthe 21st Century, 2008 IEEEDigital Object Identifier: 10.1109/PES.2008.4596759Publication Year: 2008 , Page(s): 1 - 6

Carrier kinetics in quantum dots through continuous wave photoluminescence

modeling: A systematic study on a sample with surface dot density gradient

de Sales, F. V.; Cruz, J. M. R.; da Silva, S. W.; Soler, M. A. G.; Morais, P. C.; da Silva, M. J.;Quivy, A. A.; Leite, J. R.Journal of Applied PhysicsVolume: 94 , Issue: 3Digital Object Identifier: 10.1063/1.1586953Publication Year: 2003 , Page(s): 17871794

Land Use and Land Cover Mapping in the Brazilian Amazon Using Polarimetric

Airborne P-Band SAR Data

Freitas, C.; Soler, L.; Sant'Anna, S.J.S.; Dutra, L.V.; dos Santos, J.R.; Mura, J.C.; Correia, A.H.

Geoscience and Remote Sensing, IEEE Transactions onVolume: 46 , Issue: 10 , Part: 1Digital Object Identifier: 10.1109/TGRS.2008.2000630Publication Year: 2008 , Page(s): 2956 - 2970Cited by: 4

Robotic maintenance of the EDF transmission (63 to 400 kV) network: feasibility

study and effects on tower design

Soler, R.; Guillet, J.Transmission and Distribution Construction and Live Line Maintenance, 1993. Proceedings from

ESMO-93., Sixth International Conference onDigital Object Identifier: 10.1109/TDCLLM.1993.316226Publication Year: 1993 , Page(s): 459468

Highly stable W/pIn0.53Ga0.47As ohmic contacts formed by rapid thermalprocessing
http://ieeexplore.ieee.org/xpl/articleDetails.jsp?tp=&arnumber=4596759&contentType=Conference+Publications&queryText%3Dsoler+power+setelitehttp://ieeexplore.ieee.org/xpl/articleDetails.jsp?tp=&arnumber=4596759&contentType=Conference+Publications&queryText%3Dsoler+power+setelitehttp://ieeexplore.ieee.org/xpl/mostRecentIssue.jsp?punumber=4584435http://ieeexplore.ieee.org/xpl/mostRecentIssue.jsp?punumber=4584435http://dx.doi.org/10.1109/PES.2008.4596759http://ieeexplore.ieee.org/xpl/articleDetails.jsp?tp=&arnumber=5037168&contentType=Journals+%26+Magazines&queryText%3Dsoler+power+setelitehttp://ieeexplore.ieee.org/xpl/articleDetails.jsp?tp=&arnumber=5037168&contentType=Journals+%26+Magazines&queryText%3Dsoler+power+setelitehttp://ieeexplore.ieee.org/xpl/RecentIssue.jsp?punumber=4915369http://ieeexplore.ieee.org/xpl/tocresult.jsp?isnumber=5037093http://dx.doi.org/10.1063/1.1586953http://ieeexplore.ieee.org/xpl/articleDetails.jsp?tp=&arnumber=4637976&contentType=Journals+%26+Magazines&queryText%3Dsoler+power+setelitehttp://ieeexplore.ieee.org/xpl/articleDetails.jsp?tp=&arnumber=4637976&contentType=Journals+%26+Magazines&queryText%3Dsoler+power+setelitehttp://ieeexplore.ieee.org/xpl/RecentIssue.jsp?punumber=36http://ieeexplore.ieee.org/xpl/tocresult.jsp?isnumber=4637826http://dx.doi.org/10.1109/TGRS.2008.2000630http://ieeexplore.ieee.org/xpl/articleDetails.jsp?tp=&arnumber=316226&contentType=Conference+Publications&queryText%3Dsoler+power+setelitehttp://ieeexplore.ieee.org/xpl/articleDetails.jsp?tp=&arnumber=316226&contentType=Conference+Publications&queryText%3Dsoler+power+setelitehttp://ieeexplore.ieee.org/xpl/mostRecentIssue.jsp?punumber=1075http://ieeexplore.ieee.org/xpl/mostRecentIssue.jsp?punumber=1075http://dx.doi.org/10.1109/TDCLLM.1993.316226http://ieeexplore.ieee.org/xpl/articleDetails.jsp?tp=&arnumber=4859788&contentType=Journals+%26+Magazines&queryText%3Dsoler+power+setelitehttp://ieeexplore.ieee.org/xpl/articleDetails.jsp?tp=&arnumber=4859788&contentType=Journals+%26+Magazines&queryText%3Dsoler+power+setelitehttp://ieeexplore.ieee.org/xpl/articleDetails.jsp?tp=&arnumber=4859788&contentType=Journals+%26+Magazines&queryText%3Dsoler+power+setelitehttp://ieeexplore.ieee.org/xpl/articleDetails.jsp?tp=&arnumber=4859788&contentType=Journals+%26+Magazines&queryText%3Dsoler+power+setelitehttp://ieeexplore.ieee.org/xpl/articleDetails.jsp?tp=&arnumber=4859788&contentType=Journals+%26+Magazines&queryText%3Dsoler+power+setelitehttp://ieeexplore.ieee.org/xpl/articleDetails.jsp?tp=&arnumber=4859788&contentType=Journals+%26+Magazines&queryText%3Dsoler+power+setelitehttp://dx.doi.org/10.1109/TDCLLM.1993.316226http://ieeexplore.ieee.org/xpl/mostRecentIssue.jsp?punumber=1075http://ieeexplore.ieee.org/xpl/mostRecentIssue.jsp?punumber=1075http://ieeexplore.ieee.org/xpl/articleDetails.jsp?tp=&arnumber=316226&contentType=Conference+Publications&queryText%3Dsoler+power+setelitehttp://ieeexplore.ieee.org/xpl/articleDetails.jsp?tp=&arnumber=316226&contentType=Conference+Publications&queryText%3Dsoler+power+setelitehttp://dx.doi.org/10.1109/TGRS.2008.2000630http://ieeexplore.ieee.org/xpl/tocresult.jsp?isnumber=4637826http://ieeexplore.ieee.org/xpl/RecentIssue.jsp?punumber=36http://ieeexplore.ieee.org/xpl/articleDetails.jsp?tp=&arnumber=4637976&contentType=Journals+%26+Magazines&queryText%3Dsoler+power+setelitehttp://ieeexplore.ieee.org/xpl/articleDetails.jsp?tp=&arnumber=4637976&contentType=Journals+%26+Magazines&queryText%3Dsoler+power+setelitehttp://dx.doi.org/10.1063/1.1586953http://ieeexplore.ieee.org/xpl/tocresult.jsp?isnumber=5037093http://ieeexplore.ieee.org/xpl/RecentIssue.jsp?punumber=4915369http://ieeexplore.ieee.org/xpl/articleDetails.jsp?tp=&arnumber=5037168&contentType=Journals+%26+Magazines&queryText%3Dsoler+power+setelitehttp://ieeexplore.ieee.org/xpl/articleDetails.jsp?tp=&arnumber=5037168&contentType=Journals+%26+Magazines&queryText%3Dsoler+power+setelitehttp://dx.doi.org/10.1109/PES.2008.4596759http://ieeexplore.ieee.org/xpl/mostRecentIssue.jsp?punumber=4584435http://ieeexplore.ieee.org/xpl/mostRecentIssue.jsp?punumber=4584435http://ieeexplore.ieee.org/xpl/articleDetails.jsp?tp=&arnumber=4596759&contentType=Conference+Publications&queryText%3Dsoler+power+setelitehttp://ieeexplore.ieee.org/xpl/articleDetails.jsp?tp=&arnumber=4596759&contentType=Conference+Publications&queryText%3Dsoler+power+setelite


26/26

Katz, A.; Weir, B. E.; Maher, D. M.; Thomas, P. M.; Soler, M.; DautremontSmith, W. C.;Karlicek, R. F.; Wynn, J. D.; Kimerling, L. C.Applied Physics LettersVolume: 55 , Issue: 21Digital Object Identifier: 10.1063/1.102066

Publication Year: 1989 , Page(s): 2220 - 2222

Sniffing out problems for humans in space

Nix, M.B.; Homer, M.L.; Kisor, A.K.; Soler, J.; Torres, J.; Manatt, K.; Jewell, A.; Ryan, M.A.Potentials, IEEEVolume: 26 , Issue: 4Digital Object Identifier: 10.1109/MP.2007.4280328Publication Year: 2007 , Page(s): 1824

Calculation of the Elastic Demand Curve for a Day-Ahead Secondary Reserve

Market

Soler, D.; Frias, P.; Gomez, T.; Platero, C.A.Power Systems, IEEE Transactions onVolume: 25 , Issue: 2Digital Object Identifier: 10.1109/TPWRS.2009.2033604Publication Year: 2010 , Page(s): 615 - 623Cited by: 2

Regulating electricity demand peaks for home appliances using reversible fair

scheduling

Kardaras, G.; Rossello-Busquet, A.; Iversen, V.B.; Soler, J.; Dittmann, L.Internet Multimedia Services Architecture and Application(IMSAA), 2010 IEEE 4thInternational Conference onDigital Object Identifier: 10.1109/IMSAA.2010.5729405Publication Year: 2010 , Page(s): 16

A Lab Setup Illustrating Thyristor-Assisted Under-Load Tap Changers

Monroy-erjillos, . Gmez-Expsito, . achiller-Soler, A.Power Systems, IEEE Transactions on

Volume: 25 , Issue: 3Digital Object Identifier: 10.1109/TPWRS.2009.2039717Publication Year: 2010 , Page(s): 1203 - 1210Cited by: 1
http://ieeexplore.ieee.org/xpl/RecentIssue.jsp?punumber=4816218http://ieeexplore.ieee.org/xpl/tocresult.jsp?isnumber=4859767http://dx.doi.org/10.1063/1.102066http://ieeexplore.ieee.org/xpl/articleDetails.jsp?tp=&arnumber=4280328&contentType=Journals+%26+Magazines&queryText%3Dsoler+power+setelitehttp://ieeexplore.ieee.org/xpl/RecentIssue.jsp?punumber=45http://ieeexplore.ieee.org/xpl/tocresult.jsp?isnumber=4279551http://dx.doi.org/10.1109/MP.2007.4280328http://ieeexplore.ieee.org/xpl/articleDetails.jsp?tp=&arnumber=5342455&contentType=Journals+%26+Magazines&queryText%3Dsoler+power+setelitehttp://ieeexplore.ieee.org/xpl/articleDetails.jsp?tp=&arnumber=5342455&contentType=Journals+%26+Magazines&queryText%3Dsoler+power+setelitehttp://ieeexplore.ieee.org/xpl/RecentIssue.jsp?punumber=59http://ieeexplore.ieee.org/xpl/tocresult.jsp?isnumber=5452108http://dx.doi.org/10.1109/TPWRS.2009.2033604http://ieeexplore.ieee.org/xpl/articleDetails.jsp?tp=&arnumber=5729405&contentType=Conference+Publications&queryText%3Dsoler+power+setelitehttp://ieeexplore.ieee.org/xpl/articleDetails.jsp?tp=&arnumber=5729405&contentType=Conference+Publications&queryText%3Dsoler+power+setelitehttp://ieeexplore.ieee.org/xpl/mostRecentIssue.jsp?punumber=5724109http://ieeexplore.ieee.org/xpl/mostRecentIssue.jsp?punumber=5724109http://dx.doi.org/10.1109/IMSAA.2010.5729405http://ieeexplore.ieee.org/xpl/articleDetails.jsp?tp=&arnumber=5401063&contentType=Journals+%26+Magazines&queryText%3Dsoler+power+setelitehttp://ieeexplore.ieee.org/xpl/RecentIssue.jsp?punumber=59http://ieeexplore.ieee.org/xpl/tocresult.jsp?isnumber=5512898http://dx.doi.org/10.1109/TPWRS.2009.2039717http://dx.doi.org/10.1109/TPWRS.2009.2039717http://ieeexplore.ieee.org/xpl/tocresult.jsp?isnumber=5512898http://ieeexplore.ieee.org/xpl/RecentIssue.jsp?punumber=59http://ieeexplore.ieee.org/xpl/articleDetails.jsp?tp=&arnumber=5401063&contentType=Journals+%26+Magazines&queryText%3Dsoler+power+setelitehttp://dx.doi.org/10.1109/IMSAA.2010.5729405http://ieeexplore.ieee.org/xpl/mostRecentIssue.jsp?punumber=5724109http://ieeexplore.ieee.org/xpl/mostRecentIssue.jsp?punumber=5724109http://ieeexplore.ieee.org/xpl/articleDetails.jsp?tp=&arnumber=5729405&contentType=Conference+Publications&queryText%3Dsoler+power+setelitehttp://ieeexplore.ieee.org/xpl/articleDetails.jsp?tp=&arnumber=5729405&contentType=Conference+Publications&queryText%3Dsoler+power+setelitehttp://dx.doi.org/10.1109/TPWRS.2009.2033604http://ieeexplore.ieee.org/xpl/tocresult.jsp?isnumber=5452108http://ieeexplore.ieee.org/xpl/RecentIssue.jsp?punumber=59http://ieeexplore.ieee.org/xpl/articleDetails.jsp?tp=&arnumber=5342455&contentType=Journals+%26+Magazines&queryText%3Dsoler+power+setelitehttp://ieeexplore.ieee.org/xpl/articleDetails.jsp?tp=&arnumber=5342455&contentType=Journals+%26+Magazines&queryText%3Dsoler+power+setelitehttp://dx.doi.org/10.1109/MP.2007.4280328http://ieeexplore.ieee.org/xpl/tocresult.jsp?isnumber=4279551http://ieeexplore.ieee.org/xpl/RecentIssue.jsp?punumber=45http://ieeexplore.ieee.org/xpl/articleDetails.jsp?tp=&arnumber=4280328&contentType=Journals+%26+Magazines&queryText%3Dsoler+power+setelitehttp://dx.doi.org/10.1063/1.102066http://ieeexplore.ieee.org/xpl/tocresult.jsp?isnumber=4859767http://ieeexplore.ieee.org/xpl/RecentIssue.jsp?punumber=4816218

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