25-08-2014, 11:50 AM
SPACE BASED SOLAR POWER ON SEMINAR REPORT
[attachment=66965]
ABSTRACT
The new millennium has introduced increased pressure for finding new renewable energy sources. The exponential increase in population has led to the global crisis such as global warming, environmental pollution and change and rapid decrease of fossil reservoirs. Also the demand 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 carried out to look into the possibility of building a power station in space to transmit electricity to Earth by way of radio waves-the Solar Power Satellites. Solar Power Satellites(SPS) converts solar energy in to micro waves and sends that microwaves in to a beam to a receiving antenna on the Earth.this methode is known as space based solar power{SBSP}, for conversion to ordinary electricity.SPS is a clean, large-scale, stable electric power source. Solar Power Satellites is known by a variety of other names such as Satellite Power System, Space Power Station, Space Power System, Solar Power Station, Space Solar Power Station etc. One of the key technologies needed to enable the future feasibility of SPS is that of Microwave Wireless Power Transmission.WPT is based on the energy transfer capacity of microwave beam i.e; energy can be transmitted by a well focused microwave beam. Advances in Phased array antennas and rectennas have provided the building blocks for a realizable WPT system.
INTRODUCTION
To address the future energy needs of an expanding population there is a growing need to find clean reliable sources of energy. The world population is expected to grow to 8.9 billion by 2050. The world’s energy demand is predicted to increase 44% by 2030. Currently, non-renewable resources such as oil, natural gas, and coal provide 85% of the world’s energy. Ground-based solar, wind, hydropower, and other renewable energy options are currently in place, but provide less than 1 percent of the world’s power. This percentage should grow but current renewable energy technology is limited and cannot provide enough power to match the growing need. Biomass plantations can produce carbon-neutral fuels for power plants or transportation, but photosynthesis has too low a power density for bio-fuels to contribute significantly to climate stabilization. Nuclear energy can supply power without emitting C02, but problems of waste disposal and weapons proliferation are well known. There are several new technologies being developed that all have the potential to contribute or even solve to the world’s future energy needs. This includes developing fusion reactors, high-altitude wind farms, and tidal energy These and many other options should all be explored. This paper focuses on one of the most promising of these other options; space based solar power (SBSP).
SBSP has the potential to fulfill the planets growing energy needs in the coming centuries. The concept of SBSP is simple. Satellites are sent into space fitted with solar panels that can convert the sun’s rays into electricity. This electricity is then converted into microwaves and is then transmitted back to a receiver on the planet’s surface. The receiver on the planet’s surface converts the microwaves back into electricity where it can be fed into the power grid. Any company or country seeking to implement this technology faces certain legal and technical challenges. However the promise of SBSP is worth the cost of overcoming these challenges
HISTORY OF SBSP AND RECENT DEVELOPMENTS
Peter Glaser and the NASA studies
Dr. Peter E. Glaser, a NASA consultant, first proposed the idea of SBSP in 1968.His proposal, of giant satellites beaming power to the earth from space, seemed extremely unconventional at the time. However various subsequent studies of his idea showed its promise and culminated into a $19 million dollar study from 1976-1980 conducted by the U.S. Department of Energy (DOE) and the National Aeronautics and Space Administration (NASA). The study concluded that no insurmountable technological hurdles stood in the way of solar power satellites as a major alternative energy source. However, the study also estimated creation of SBSP would require several decades with a cost-to-first power at over $280 billion The study recommended the issue be revisited in ten years to allow technology to catch up and potential costs to decrease’s a result, as a result all serious effort on solar power from space by the U.S. government ceased until the mid 90s.
The U.S. government revisited the idea of SBSP in 1997 with NASA’s“Fresh Look Study” The “Fresh Look Study” sought to determine if recent technological advances could deliver SBSP to terrestrial markets at competitive prices. The study found that a huge global market had developed and concerns about greenhouse gas emission were growing. It also found that technological innovations had increased the potential of creating SBSP. NASA followed the initial positive results of the “Fresh Look Study” by initiating the Space Solar Power Exploratory Research and Technology (SERT) program in 1999.[51]
The National Security Space Office Study: A Different View on SBSP
The most recent study of SBSP occurred in 2007 when the National Security Space Office (NSSO), a division of the Department of Defense (DoD), conducted its own study on the feasibility of SBSP. The NSSO study requested input from numerous experts in the science and solar power community and with their help made a number of key findings. The NSSO study concluded SBSP presented a strategic opportunity that could significantly advance U.S. and partner security, capability, and freedom of action. Most studies till that point only focused on SBSP as a solution of the power needs of the global community at large. The NSSO study added an additional layer emphasizing the advantages SBSP could offer the U.S. military. In particular the study stated:
WIRELESS POWER TRANSMISSION (WPT) BACKGROUND
The vision of achieving WPT on a global scale was proposed over 100 years ago when Nikola Tesla first started experiments with WPT, culminating with the construction of a tower for WPT on Long Island, New York, in the early 1900s. Tesla's objective was to develop the technology for transmitting electricity to anywhere in the world without wires. He filed several patents describing wireless power transmitters and receivers. However, his knowledge of electrical phenomena was largely empirical and he did not achieve his objective of WPT, although he was awarded the patent for wireless radio in 1940. The development of WPT was not effectively pursued until the 1960s when the U.S. Air Force funded the development of a microwave-powered helicopter platform. Based on the development of the microwave tubes during the World War II, W. C. Brown started the WPT research and development in 1960sA successful demonstration of a microwave beam-riding helicopter was performed in 1965. This demonstration proved that a WPT system could be constructed and that effective microwave generators and receivers could be developed for efficient conversion of microwaves into DC electricity.
The growing interest in solar energy conversion methods and solar energy applications in the 1960s and the limitations for producing cost-effective base load power caused by adverse weather conditions and diurnal changes led to the solar power satellite concept in 1968 as a means to convert solar energy with solar cell arrays into electricity and feed it to a microwave generator forming part of a planar, phased-array antenna. In geosynchronous orbit, the antenna would direct a microwave beam of very low power density precisely to one or more receiving antennas at desired locations on Earth. At a receiving antenna, the microwave energy would be safely and very efficiently reconvened into electricity and then transmitted to users
SOLAR POWER SATELLITE
The solar power satellite concept would place solar power plants in an above the earth where they could convert sunlight to electricity and beam the ground based receiving station. The satellite would be placed in sow called geostationary or earth synchronous orbit. 24 hour orbit that is thus synchronous with earth rotation. so the satellite placed their will stay stationary overhead from earths receiving antenna
The solar power satellite will consist of a large number of solar cells mounted on a frame of steel reinforced lunarcrete. The solar cell produces electricity from sun by photovoltaic {pv) methods with no moving part. the only moving part of the satellite is the transmitter antenna, which slowly tracks the ground based rectenna while solar array keeps facing the sun. Each transmitter antenna is connected to solar array by two starry joints with slip ring
Photovoltaic
Photovoltaic (PV) is a method of generating electrical power by converting solar radiation into direct current electricity using semiconductors that exhibit the photovoltaic effect. Photovoltaic power generation employs solar panels composed of a number of solar cells containing a photovoltaic material. Materials presently used for photovoltaic include monocrystalline silicon, polycrystalline silicon, amorphous silicon, cadmium telluride, and copper indium gallium sulfide. Solar cells produce direct current electricity from sun light. Cells are electrically connected together to form photovoltaic modules, or solar panels.
A solar cell is essential a PN junction with a large surface area. The N-type material is keep thin to allow light to pass through to the PN junction. Light travels in packets of energy called photons. The generation of electric current happens inside the depletion zone of the PN junction. The depletion region as explained previously with the diode is the area around the PN junction where the electrons from the N-type silicon, have diffused into the holes of the P-type material. When a photon of light is absorbed by one of these atoms in the N-Type silicon it will dislodge an electron, creating a free electron and a hole.
ARCHITECTURE OF SPS
SPS2000
SPS2000 is a Strawman model of solar power satellites with microwave power output of 10 MW, which was proposed by the SPS working group of the Institute of Space and Astronautical Science (ISAS). The primary objective of SPS2000 research is to show whether SPS could be realized with the present technology and to find out technical problems.
GEO Heliostat/Concentrator
This architecture uses a geostationary orbit. This GEO Heliostat consisting of a mirror or system of mirrors that tracks the sun and reflects light onto a power generator/transmitter array. This architecture allows the Heliostat to be smaller and shorter than the Sun Tower architecture. This helps with power management and distribution.
RECTENNA
Rectenna is an acronym for RECTifying anTENNA. It is a special type of antenna that rectifies the incoming microwave radiation into DC current and hence the name Rectenna. A rectenna comprises of a mesh of dipoles and diodes for absorbing microwave energy from a transmitter and converting it into electric power. Its elements are usually arranged in a mesh pattern, giving it a distinct appearance from most antennae. A simple rectenna can be constructed from a schottky diode placed between antenna dipoles as shown in Fig. 1. The diode rectifies the current induced in the antenna by the microwaves. Rectenna are highly efficient at converting microwave energy to electricity. In laboratory environments, efficiencies above 90% have been observed with regularity. In future rectennas will be used to generate large-scale power from microwave beams delivered from orbiting SPS satellites
SPACE TRANSMITTING ANTENNA [SPACETENNA]
The transmitting antennas are large active electronically steerable phased array. These arrays are composed of radiation module that consists of a high gain phased locked magnetron and directional amplifier that supplies microwave power to slotted waveguide array.
The DC power must be converted to microwave power at the transmitting end of the system by using microwave oven magnetron. The heat of microwave oven is the high voltage system. The nucleus of high voltage system is the magnetron tube. The magnetron is diode type electron tube, which uses the interaction of magnetic and electric field in the complex cavity to produce oscillation of very high peak power. It employs radial electric field, axial magnetic field, anode structure and a cylindrical cathode
WIRELESS POWER TRANSMISSION TO THE EARTH
Solar power from the satellite is sent to Earth using a microwave transmitter. This transmission is transmitted to the relevant position via an antenna or spacetenna. The transmission is transmitted through space and atmosphere and received on earth by an antenna called the rectenna.
The power could be transmitted as either microwave or laser radiation at a variety of frequencies depending on system design. Whatever choice is made, the transmitting radiation would have to be non-ionizing to avoid potential disturbances either ecologically or biologically if it is to reach the Earth's surface. This established an upper bound for the frequency used, as energy per photon, and so the ability to cause ionization, increases with frequency. Ionization of biological materials doesn't begin until ultraviolet or higher frequencies so most radio frequencies will be acceptable for this.
DEALING WITH LAUNCH COAST
One problem for the SBSP concept is the cost of space launches and the amount of material that would need to be launched. Reusable launch systems are predicted to provide lower launch costs to low Earth orbit (LEO).
Much of the material launched need not be delivered to its eventual orbit immediately, which raises the possibility, that high efficiency (but slower) engines could move SPS material from LEO to GEO at an acceptable cost. Examples include ion thrusters or nuclear propulsion.
Power beaming from geostationary orbit by These sizes can be somewhat decreased by using shorter wavelengths, although they have increased atmospheric absorption and even potential beam blockage by rain or water microwaves carries the difficulty that the required 'optical aperture' sizes are very large. For example, the 1978 NASA SPS study required a 1-km diameter transmitting antenna, and a 10 km diameter receiving rectenna, for a microwave beam at 2.45 GHz. droplets. Because of the thinned array curse, it is not possible to make a narrower beam by combining the beams of several smaller satellites. The large size of the transmitting and receiving antennas means that the minimum practical power level for an SPS will necessarily be high; small SPS systems will be possible, but uneconomic. To give an idea of the scale of the problem, assuming a solar panel mass of 20 kg per kilowatt (without considering the mass of the supporting structure, antenna, or any significant mass reduction of any focusing mirrors) a 4 GW power station would weigh about 80,000 metric tons, all of which would, in current circumstances, be launched from the Earth. Very lightweight designs could likely achieve 1 kg/kW,[48] meaning 4,000 metric tons for the solar panels for the same 4 GW capacity station. This would be the equivalent of between 40 and 150 heavy-lift launch vehicle (HLLV) launches to send the material to low earth orbit, where it would likely be converted into subassembly solar arrays, which then could use high-efficiency ion-engine style rockets to (slowly) reach GEO (Geostationary orbit)
CONCLUTION
Space energy is not the only option for solving the world’s future energy needs, but it is one of the most promising. The idea of satellites sending clean continuous power from the sun may still sound like science fiction, but many of today’s technological marvels in the past likely did as well. The realization of SBSP will not happen overnight; in fact it is an idea over 40 years in the making. Launch costs need to be lowered. The international legal regime needs to develop further to accommodate SBSP. SBSP will likely also require substantial cooperation between different countries and private companies. All are difficult challenges but will be rewarded with a worthy prize.
[attachment=66965]
ABSTRACT
The new millennium has introduced increased pressure for finding new renewable energy sources. The exponential increase in population has led to the global crisis such as global warming, environmental pollution and change and rapid decrease of fossil reservoirs. Also the demand 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 carried out to look into the possibility of building a power station in space to transmit electricity to Earth by way of radio waves-the Solar Power Satellites. Solar Power Satellites(SPS) converts solar energy in to micro waves and sends that microwaves in to a beam to a receiving antenna on the Earth.this methode is known as space based solar power{SBSP}, for conversion to ordinary electricity.SPS is a clean, large-scale, stable electric power source. Solar Power Satellites is known by a variety of other names such as Satellite Power System, Space Power Station, Space Power System, Solar Power Station, Space Solar Power Station etc. One of the key technologies needed to enable the future feasibility of SPS is that of Microwave Wireless Power Transmission.WPT is based on the energy transfer capacity of microwave beam i.e; energy can be transmitted by a well focused microwave beam. Advances in Phased array antennas and rectennas have provided the building blocks for a realizable WPT system.
INTRODUCTION
To address the future energy needs of an expanding population there is a growing need to find clean reliable sources of energy. The world population is expected to grow to 8.9 billion by 2050. The world’s energy demand is predicted to increase 44% by 2030. Currently, non-renewable resources such as oil, natural gas, and coal provide 85% of the world’s energy. Ground-based solar, wind, hydropower, and other renewable energy options are currently in place, but provide less than 1 percent of the world’s power. This percentage should grow but current renewable energy technology is limited and cannot provide enough power to match the growing need. Biomass plantations can produce carbon-neutral fuels for power plants or transportation, but photosynthesis has too low a power density for bio-fuels to contribute significantly to climate stabilization. Nuclear energy can supply power without emitting C02, but problems of waste disposal and weapons proliferation are well known. There are several new technologies being developed that all have the potential to contribute or even solve to the world’s future energy needs. This includes developing fusion reactors, high-altitude wind farms, and tidal energy These and many other options should all be explored. This paper focuses on one of the most promising of these other options; space based solar power (SBSP).
SBSP has the potential to fulfill the planets growing energy needs in the coming centuries. The concept of SBSP is simple. Satellites are sent into space fitted with solar panels that can convert the sun’s rays into electricity. This electricity is then converted into microwaves and is then transmitted back to a receiver on the planet’s surface. The receiver on the planet’s surface converts the microwaves back into electricity where it can be fed into the power grid. Any company or country seeking to implement this technology faces certain legal and technical challenges. However the promise of SBSP is worth the cost of overcoming these challenges
HISTORY OF SBSP AND RECENT DEVELOPMENTS
Peter Glaser and the NASA studies
Dr. Peter E. Glaser, a NASA consultant, first proposed the idea of SBSP in 1968.His proposal, of giant satellites beaming power to the earth from space, seemed extremely unconventional at the time. However various subsequent studies of his idea showed its promise and culminated into a $19 million dollar study from 1976-1980 conducted by the U.S. Department of Energy (DOE) and the National Aeronautics and Space Administration (NASA). The study concluded that no insurmountable technological hurdles stood in the way of solar power satellites as a major alternative energy source. However, the study also estimated creation of SBSP would require several decades with a cost-to-first power at over $280 billion The study recommended the issue be revisited in ten years to allow technology to catch up and potential costs to decrease’s a result, as a result all serious effort on solar power from space by the U.S. government ceased until the mid 90s.
The U.S. government revisited the idea of SBSP in 1997 with NASA’s“Fresh Look Study” The “Fresh Look Study” sought to determine if recent technological advances could deliver SBSP to terrestrial markets at competitive prices. The study found that a huge global market had developed and concerns about greenhouse gas emission were growing. It also found that technological innovations had increased the potential of creating SBSP. NASA followed the initial positive results of the “Fresh Look Study” by initiating the Space Solar Power Exploratory Research and Technology (SERT) program in 1999.[51]
The National Security Space Office Study: A Different View on SBSP
The most recent study of SBSP occurred in 2007 when the National Security Space Office (NSSO), a division of the Department of Defense (DoD), conducted its own study on the feasibility of SBSP. The NSSO study requested input from numerous experts in the science and solar power community and with their help made a number of key findings. The NSSO study concluded SBSP presented a strategic opportunity that could significantly advance U.S. and partner security, capability, and freedom of action. Most studies till that point only focused on SBSP as a solution of the power needs of the global community at large. The NSSO study added an additional layer emphasizing the advantages SBSP could offer the U.S. military. In particular the study stated:
WIRELESS POWER TRANSMISSION (WPT) BACKGROUND
The vision of achieving WPT on a global scale was proposed over 100 years ago when Nikola Tesla first started experiments with WPT, culminating with the construction of a tower for WPT on Long Island, New York, in the early 1900s. Tesla's objective was to develop the technology for transmitting electricity to anywhere in the world without wires. He filed several patents describing wireless power transmitters and receivers. However, his knowledge of electrical phenomena was largely empirical and he did not achieve his objective of WPT, although he was awarded the patent for wireless radio in 1940. The development of WPT was not effectively pursued until the 1960s when the U.S. Air Force funded the development of a microwave-powered helicopter platform. Based on the development of the microwave tubes during the World War II, W. C. Brown started the WPT research and development in 1960sA successful demonstration of a microwave beam-riding helicopter was performed in 1965. This demonstration proved that a WPT system could be constructed and that effective microwave generators and receivers could be developed for efficient conversion of microwaves into DC electricity.
The growing interest in solar energy conversion methods and solar energy applications in the 1960s and the limitations for producing cost-effective base load power caused by adverse weather conditions and diurnal changes led to the solar power satellite concept in 1968 as a means to convert solar energy with solar cell arrays into electricity and feed it to a microwave generator forming part of a planar, phased-array antenna. In geosynchronous orbit, the antenna would direct a microwave beam of very low power density precisely to one or more receiving antennas at desired locations on Earth. At a receiving antenna, the microwave energy would be safely and very efficiently reconvened into electricity and then transmitted to users
SOLAR POWER SATELLITE
The solar power satellite concept would place solar power plants in an above the earth where they could convert sunlight to electricity and beam the ground based receiving station. The satellite would be placed in sow called geostationary or earth synchronous orbit. 24 hour orbit that is thus synchronous with earth rotation. so the satellite placed their will stay stationary overhead from earths receiving antenna
The solar power satellite will consist of a large number of solar cells mounted on a frame of steel reinforced lunarcrete. The solar cell produces electricity from sun by photovoltaic {pv) methods with no moving part. the only moving part of the satellite is the transmitter antenna, which slowly tracks the ground based rectenna while solar array keeps facing the sun. Each transmitter antenna is connected to solar array by two starry joints with slip ring
Photovoltaic
Photovoltaic (PV) is a method of generating electrical power by converting solar radiation into direct current electricity using semiconductors that exhibit the photovoltaic effect. Photovoltaic power generation employs solar panels composed of a number of solar cells containing a photovoltaic material. Materials presently used for photovoltaic include monocrystalline silicon, polycrystalline silicon, amorphous silicon, cadmium telluride, and copper indium gallium sulfide. Solar cells produce direct current electricity from sun light. Cells are electrically connected together to form photovoltaic modules, or solar panels.
A solar cell is essential a PN junction with a large surface area. The N-type material is keep thin to allow light to pass through to the PN junction. Light travels in packets of energy called photons. The generation of electric current happens inside the depletion zone of the PN junction. The depletion region as explained previously with the diode is the area around the PN junction where the electrons from the N-type silicon, have diffused into the holes of the P-type material. When a photon of light is absorbed by one of these atoms in the N-Type silicon it will dislodge an electron, creating a free electron and a hole.
ARCHITECTURE OF SPS
SPS2000
SPS2000 is a Strawman model of solar power satellites with microwave power output of 10 MW, which was proposed by the SPS working group of the Institute of Space and Astronautical Science (ISAS). The primary objective of SPS2000 research is to show whether SPS could be realized with the present technology and to find out technical problems.
GEO Heliostat/Concentrator
This architecture uses a geostationary orbit. This GEO Heliostat consisting of a mirror or system of mirrors that tracks the sun and reflects light onto a power generator/transmitter array. This architecture allows the Heliostat to be smaller and shorter than the Sun Tower architecture. This helps with power management and distribution.
RECTENNA
Rectenna is an acronym for RECTifying anTENNA. It is a special type of antenna that rectifies the incoming microwave radiation into DC current and hence the name Rectenna. A rectenna comprises of a mesh of dipoles and diodes for absorbing microwave energy from a transmitter and converting it into electric power. Its elements are usually arranged in a mesh pattern, giving it a distinct appearance from most antennae. A simple rectenna can be constructed from a schottky diode placed between antenna dipoles as shown in Fig. 1. The diode rectifies the current induced in the antenna by the microwaves. Rectenna are highly efficient at converting microwave energy to electricity. In laboratory environments, efficiencies above 90% have been observed with regularity. In future rectennas will be used to generate large-scale power from microwave beams delivered from orbiting SPS satellites
SPACE TRANSMITTING ANTENNA [SPACETENNA]
The transmitting antennas are large active electronically steerable phased array. These arrays are composed of radiation module that consists of a high gain phased locked magnetron and directional amplifier that supplies microwave power to slotted waveguide array.
The DC power must be converted to microwave power at the transmitting end of the system by using microwave oven magnetron. The heat of microwave oven is the high voltage system. The nucleus of high voltage system is the magnetron tube. The magnetron is diode type electron tube, which uses the interaction of magnetic and electric field in the complex cavity to produce oscillation of very high peak power. It employs radial electric field, axial magnetic field, anode structure and a cylindrical cathode
WIRELESS POWER TRANSMISSION TO THE EARTH
Solar power from the satellite is sent to Earth using a microwave transmitter. This transmission is transmitted to the relevant position via an antenna or spacetenna. The transmission is transmitted through space and atmosphere and received on earth by an antenna called the rectenna.
The power could be transmitted as either microwave or laser radiation at a variety of frequencies depending on system design. Whatever choice is made, the transmitting radiation would have to be non-ionizing to avoid potential disturbances either ecologically or biologically if it is to reach the Earth's surface. This established an upper bound for the frequency used, as energy per photon, and so the ability to cause ionization, increases with frequency. Ionization of biological materials doesn't begin until ultraviolet or higher frequencies so most radio frequencies will be acceptable for this.
DEALING WITH LAUNCH COAST
One problem for the SBSP concept is the cost of space launches and the amount of material that would need to be launched. Reusable launch systems are predicted to provide lower launch costs to low Earth orbit (LEO).
Much of the material launched need not be delivered to its eventual orbit immediately, which raises the possibility, that high efficiency (but slower) engines could move SPS material from LEO to GEO at an acceptable cost. Examples include ion thrusters or nuclear propulsion.
Power beaming from geostationary orbit by These sizes can be somewhat decreased by using shorter wavelengths, although they have increased atmospheric absorption and even potential beam blockage by rain or water microwaves carries the difficulty that the required 'optical aperture' sizes are very large. For example, the 1978 NASA SPS study required a 1-km diameter transmitting antenna, and a 10 km diameter receiving rectenna, for a microwave beam at 2.45 GHz. droplets. Because of the thinned array curse, it is not possible to make a narrower beam by combining the beams of several smaller satellites. The large size of the transmitting and receiving antennas means that the minimum practical power level for an SPS will necessarily be high; small SPS systems will be possible, but uneconomic. To give an idea of the scale of the problem, assuming a solar panel mass of 20 kg per kilowatt (without considering the mass of the supporting structure, antenna, or any significant mass reduction of any focusing mirrors) a 4 GW power station would weigh about 80,000 metric tons, all of which would, in current circumstances, be launched from the Earth. Very lightweight designs could likely achieve 1 kg/kW,[48] meaning 4,000 metric tons for the solar panels for the same 4 GW capacity station. This would be the equivalent of between 40 and 150 heavy-lift launch vehicle (HLLV) launches to send the material to low earth orbit, where it would likely be converted into subassembly solar arrays, which then could use high-efficiency ion-engine style rockets to (slowly) reach GEO (Geostationary orbit)
CONCLUTION
Space energy is not the only option for solving the world’s future energy needs, but it is one of the most promising. The idea of satellites sending clean continuous power from the sun may still sound like science fiction, but many of today’s technological marvels in the past likely did as well. The realization of SBSP will not happen overnight; in fact it is an idea over 40 years in the making. Launch costs need to be lowered. The international legal regime needs to develop further to accommodate SBSP. SBSP will likely also require substantial cooperation between different countries and private companies. All are difficult challenges but will be rewarded with a worthy prize.