Prospects and Challenges of the Space-Based Energy

This study examines the potential of space-based energy technologies, focusing on solar panel satellites and solar wind energy harvesting as sustainable alternatives to ground-based energy production. By conducting a comprehensive literature review, we assess the current technological state, economic viability, environmental impact, and regulatory needs of these systems. Our analysis reveals that solar panel satellites can provide continuous power independent of weather conditions, with decreasing launch costs and lighter technology. Solar wind satellites, while less developed, show promise for high energy output using abundant materials. However, both technologies face challenges, including energy transmission efficiency and environmental costs of launch. Addressing these obstacles through policy, technological innovation, and international cooperation could position space-based energy as a viable solution for clean, scalable energy in the future. In conclusion, space energy technologies such as satellite-based solar panels and solar wind harvesting systems represent promising alternatives to terrestrial energy sources. However, their successful implementation requires overcoming a number of technical, environmental and regulatory hurdles. Long-term investment in research and development, as well as active international collaboration, can help position space energy as a viable solution for providing clean and scalable energy in the future. Our study highlights the need for further exploration and development of these technologies and calls for changes in approaches to energy at the global level.   

Introduction

Most science fiction fans have heard of the Dyson Sphere: a cage of solar panels around our star that capture infinite, unfathomable amounts of energy for humanity. The idea, though far-fetched, sounds like a good one–but one would only have to think a little bit deeper to find the flaws in the concept: material gathering and cost being the main problems. But a much more reasonable proposal: a swarm of panels around Earth itself, has intrigued the minds of many science fiction fans turned astronomers and physicists.

Space-based energy technologies offer advantages and future prospects in attaining energy in a carbon-free, energy and cost-efficient way. These technologies promise low upkeep costs, scalability and international cooperation–a source of energy for both Earth’s energy needs and for potential use on off-planet bases. The strength of space-based energy comes from its rapid progress, growing global interest in its development, and its ability to provide endless, clean electricity efficiently. These technologies will be incredibly important for the future development of humanity if they are advanced in a way that is responsible–they don’t take up space on any livable land, provide an infinite energy source, and have the potential to be incredibly scalable and cheap to sustain. Launch costs are the lowest they have ever been and are only getting lower, the required technology is only getting lighter and simpler to produce. The global energy crisis is getting more dire, and energy is getting more expensive to produce, energy consumption has grown by about a third of what it was in 2000 [1]–these technologies offer both a lucrative investment and a way to fill the energy demand of humanity.

This paper provides a comprehensive analysis of space-based energy technologies, focusing on the promising potential of solar panel satellites and the emerging concept of solar wind energy harvesting. A literature review of the current works in the field is provided, along with a ‘current state’ section and a data analysis that seeks to explain the economic viability, environmental impact, and some of the more technological aspects of the technology. An overview of the regulations and policies that would need to be enacted in order to make the technology viable is also included.

Methodology

This study explores two key areas: solar panel satellites and solar wind power. Research involves looking at what previous, more technical studies have produced and compiling their conclusions for a more comprehensive look at the technology. Cost and environmental analysis will be resultant – a detailed look into the future and current state of the technology. A literature review was conducted for a more general overview of the areas, followed by a more detailed analysis of the cost and environmental repercussions that each of the technologies could have. The ‘current state’ section details the technology as it is today, and a policy and regulatory section describes the current regulations on the technologies and what regulations would need to be implemented in order for the technologies to be integrated effectively and consciously.

Literature Review

The Solar Satellite

Solar power produces about 6% of global electricity and is one of the quickest advancing renewable technologies. The ease of incorporation into open spaces, suburban, and urban infrastructures makes for one of the most visible and widespread clean energy sources-solar panels can be installed in large scale solar farms, on family home roofs, or, with the development of ultra-thin and transparent solar panels and glass, on sky-scraper facades. The main limitation of solar power is that it is very reliant on good weather conditions to be effective—solar satellites solve that issue.

Solar satellite technology involves placing solar arrays into Earth’s orbit and instructing them to harvest solar power throughout the 24-hour cycle. Because of this configuration, the panels can harvest energy for 99% of the day-night cycle. They continue to work in times of unfavorable weather on Earth as they are located above the mesosphere and thus above even the topmost clouds. These solar panels have the potential to be an incredibly efficient energy capture method–with development, they are growing increasingly thinner and lighter, and rocket launch costs are at an all-time low. The main issue with this technology is the present cost and lack of adequately developed efficient microwave beaming technology that is necessary to transport the captured solar energy to ground level.

Space-based solar panels stand out as an energy efficient, clean, advancing and inexpensive technology [2]. Existing research classifies it as viable for the future, as it “has the potential to dwarf all the other sources of energy combined with very little negative environmental impact” [3]. Materials have undergone cost and efficiency improvements: photovoltaics used to rely on crystalline silicon cells, but newer developments have switched to lighter, thin-film solar cells made from cadmium telluride and copper indium gallium selenide as well as cheaper Perovskite solar cells. Future scientific and industrial advancements could include installing solar batteries of greater capacity and implementing artificial intelligence in order to maximize the efficiency of energy generation and usage, oversee grid operations, and anticipate potential system malfunctions in advance.

Solar satellites as a technology are developing quickly–there is government support, which suggests more funding and research coming soon. The main issue of solar satellites is launching costs and impact on local ecosystems, but this can be solved with a cheap, ‘green’ propellant–something that has been in development for years by multiple unaffiliated groups. A cost analysis of solar satellite technologies is also promising–there are multiple options for financing, and the road taken will likely largely depend on what agencies end up funding the first and most prominent projects. It is expected that a government agency will take a more cost-effective route, while a private company would have more freedom to spend on a more costly but more energy efficient strategy. The precedent set by large and primary projects will likely be the one followed by most if the technology is successful.

The technological development required for solar satellites is minimal, though not insignificant–lighter solar panels need to be developed, as well as an effective way of beaming produced energy back to Earth–currently, the efficiency of transmission, while optimistic, is not optimal and progress still needs to be made in the area.

Solar Wind

Another means of solar power is solar wind—the release of protons and electrons being constantly emitted by the sun and their capture by technologies such as solar wind or e-sails. The two currently recognized types of satellites that collect solar wind are the Dyson Harrop and Solar Wind Power Satellite, both of which require being located far away from Earth’s orbit, creating a limitation that spurs ongoing discussions among scientists considering the most efficient ways of positioning such satellites, such that they can be maintained and cheaper to produce. Public data suggests that the main advantages of this technology are energy efficiency, (‘generating 100 billion times the power needed by humanity annually’ low costs (as the base technology is made from inexpensive and abundant materials, such as copper) [4], carbon-free and renewable energy, and independence from weather conditions. The technology at its current state requires solar sails to move hundreds of miles away in order to be viable, which proves inefficient when transmitting energy–a major problem for solar panel satellites as well.

Additionally, its disadvantages are space-inefficiency–the surface area has to be large in order to be energy efficient and detectable from large distances–and the additional difficulty of transporting the acquired energy back due to resistance from Earth’s magnetic field. Research is slow-going because of the lack of interest in the technology–solar panel satellites prove to be a more developed concept and, thus, safer to invest interest and money into–but solar wind harvesting has the potential to be cheaper to produce and maintain than solar panel satellites, while also requiring a lot of the same advancements as them–the development of one will prove progress for the other.

Current State

The Solar Satellite

Conceptually, solar panel satellites form a baseline, clean energy source for other technologies to build off of. Currently, the technology is progressing rapidly. NASA has a vested interest in the success of solar satellites [5], and so do dozens of other independent and corporation affiliated researchers. Multiple companies based around the concept have emerged [6], [7]; and some–like Reflect Orbital, have developed another system of transmitting solar energy to Earth: the concept involves using mirrors, not solar panels, to reflect sunlight to ground to be then captured by ground-based panels. This strategy is flawed in that, while it works at night, meaning that solar power can be harvested around the clock, it does not work in poor weather conditions. Visible and UV light waves both cannot travel through clouds, unlike microwaves, which are the transmission source used by more traditional solar satellite concepts. The advantage of this strategy is in the satellites themselves–by making them simply reflect light rays onto ground level, rather than collect them, the satellite itself is a lot cheaper to produce. They are also lighter than current solar satellite prototypes, and thus more of them can be launched for cheaper costs.

The main thing solar power satellites need is government backing. Most progress in the field is being made by companies and individuals, and while much progress is being made, in order to be truly viable a government body has to get involved in order to fund and create regulation for the technology.

Photovoltaics are more efficient than ever and only getting better–development for ultra-thin photovoltaics [8] is incredibly promising, these technologies would save on launch and material costs if they can be mass produced. Countries like the U.S., Japan, and China all have displayed considerable interest in the technology–a promising sign for future research and development. Where progress needs to be made is transmission technology–microwaves and high-power lasers are the two main contenders–microwaves being less powerful and therefore not as reliable but not as potentially dangerous as high-power lasers.

Proposals suggest two probable orbits: geostationary and Molniya, with geostationary requiring higher launch capabilities but promising a more reliable transmission system due to its largely constant distance from Earth, and Molniya offering very low-cost ground systems due to its high eccentricity and resultant predictable proximity to Earth.

Solar Wind

The current state of research done on Solar Wind technologies is sufficient, with plenty of data on the mechanics of how they collect energy from space. The constant releases of high-speed solar wind particles are captured by solar ion panels on e-sail ‘sailboat’ technologies (conceived in 2004 by P. Janhunen) [9], traveling thanks to the energy of the photons that propels them forward. With the main objective being their travel in the space medium, various e-sail models are constantly tested and launched into space, following solar sail technological advances. Only in the last two decades, NASA progressed in the development of ‘solar sail propulsion systems’ that increase the likelihood of further missions with the utilization of solar sails. Despite a $30 million investment, launches with the novel improved propulsion technology, NanoSail-D, failed without even reaching the orbit, sparking uncertainty in future solar sail exploration [10]. Other solar sail missions, however, such as IKAROS by The Japan Aerospace Exploration Agency, launched 10 years after NASA’s unsuccessful interplanetary mission, showed record-breaking e-sail acceleration thanks to solar power. While IKAROS did not reach Venus’s orbit, as had initially been planned, it proved to be a significant achievement in e-sail exploration, creating opportunities for solar wind power generation with the use of panels on e-sail models.

Organized by the ULTRASat payload are two Lightsail programs that were completely funded by sponsors. Lightsail-1 followed ‘18 days of on-orbit checkout and anomaly response actions,’ and ‘was successfully deployed on June 7, 2015’ [11] Lightsail-2 was responsible for controlling its movement and location in relation to the sun, and launched in June of 2019, bringing light to such limitations, as ‘partial solar panel deployment…and momentum wheel management.’ After several years in space, and as of 2022, Lightsail 2 re-entered Earth’s atmosphere [12]. After the return of Lightsail 2, NASA continued with the most up-to-date e-sail space mission- the launch of the ACS3 (Advanced Composite Solar Sail) that occurred in April of 2024 [13].

Considering the recent development of e-sails, there have been immense successes in the realm of exploration of solar wind power. Leading up to this day, space missions are still in progress with the objective of discovering the functionality of e-sails in regard to solar wind.

Data Analysis

Solar Wind

The two currently globally acknowledged potential technologies for collecting and transmitting solar wind energy are The Dyson Harrop satellite and the Solar Wind Power satellite. The Dyson Harrop technology (essentially, a metal wire pointed to the sun) is a sun-encircling megastructure, it is self-sustaining and works as to utilize the electrons generated by the sun to power the magnetic field mechanism, and is not only able to withstand degradation from powerful blows of solar wind but, hypothetically, could be more cost-efficient than the equivalent number of solar panels due to the great availability of copper over photovoltaic panels. According to Harrop himself, this system of solar wind power satellites has the potential to generate up to 100 billion more energy required by Earth every year. The reason this seemingly ideal system is unrealistic is because of the incredible amount of material that it would require. Proposals to disassemble Mercury for parts sound outrageous, but, when met with the facts of simply how much raw material would be required (a surface area of roughly ‘600 million times the surface area of the Earth’ [14]) they sound like a reasonable solution. Unfortunately, the funds for such an endeavor are highly unlikely to be provided, and the technological ability of humanity is far from sufficient to support the idea.

A more realistic idea for solar wind satellites is a swarm that circles Earth instead. This would require far less materials and technological prowess. A large problem with solar wind satellites is beaming energy back to Earth at such a great distance (as mentioned above, solar wind energy technology requires a much closer proximity to the sun to be efficient)–beam divergence is inevitable at these distances. The spreading out of energy from a tight beam to a radius that would be thousands of kilometers wide is resultant, causing the collected electrons to have most of their energy dissipated. In order to sustain the collected energy, the beam would have to be captured and refocused with a lens ten of kilometers across—mechanism humans are currently unable to produce. At the moment, the environmental impact of the hypothetical Dyson Harrop model is unknown, as its many properties are yet to be discovered.

In contrast, the Solar Wind Power satellite is constructed using a ring-shaped solar sail that faces the sun. This satellite, unlike the Dyson Harrop model, can be constructed with the currently available materials, making it by far the more feasible and realistic solar wind technology. Among its many advantages are protection from solar wind decay, nearly 100% efficiency, laser-directed energy output to faraway satellites, space stations or planetary installations, and the use of supercooled metals (proved to be less sensitive to aging or extreme effects than the relatively delicate systems of solar panels [4]). Similarly to the Dyson Harrop model, current Solar Wind Power satellites are not being researched enough or manufactured and launched into space, making it hardly possible to identify plausible information on their impact on the environment.

The Solar Satellite

While a solar satellite system still needs technological development to function on a large scale, there are already plans on how to make a space-based solar system compatible and fund-efficient. The main advantage of space-based solar power is that it can provide power even when ground-based systems can’t–at night and in poor weather conditions. This could be accomplished with satellites stationed at Lagrange point 2 (Fig. 1).

Fig. 1. Diagram displaying Lagrange points–L2 is where a solar satellite could be stationed to provide solar power at night.

A compatible ground-space solar system could include space satellites, creating a baseline for ground-based panels to be supported by space-based panels that can be the sole producer at night, when energy demand dwindles, and can support ground-based panels when demand peaks during the day. This, however, would necessitate a tracking system to be installed on satellites–a compilation that could be avoided by only instructing satellites to produce during peak demand. Energy is at a premium when demand peaks, with energy prices going up by a factor of two to four, and selling the only energy produced by simplified satellites during those times could be more economically efficient. This trade off would mean that satellites would not be a viable baseline for ground-based systems, but it is a significant enough cost saving measure that it should be considered. Ground solar facilities could be easily converted to space solar receiving and integrating facilities, as an SPS receiver functions almost exactly like a solar array–this would save on costs and land. Short-term energy markets (spot markets) could also be a place where solar satellites have an advantage–they would need to be able to quickly (within a tenth of a second) switch to transfer to an area of short but high demand. Jobs like this are highly lucrative and would also make solar satellites more cost effective, but the base technology would have to be developed further to make such a quick time of transition possible, possibly making the satellite itself more expensive to produce. The prime advantage of solar satellites, however, is their ability to work around the clock and in poor weather–it is also possible to take complete use of this and make solar satellites a baseline for ground solar to build off.

A solar satellite could also service two locations at once, as long as they are separated by no more than 80 degrees apart on the equator–a relay satellite could be used to achieve a higher degree of separation (Fig. 2).

Fig. 2. Solar satellite can service two places at once either directly (top) or by utilizing a relay satellite (bottom) [15].

The environmental impact of solar satellites is an area that needs to be looked into further–though solar energy is clean and practically infinite, there is something to be said about the environmental impact of launching the satellites into orbit. It is well known that rocket launches impact local ecosystems [16], release harmful pollutants into the atmosphere [17], and deplete the ozone layer. Currently, “decline in global stratospheric O₃ is small (0.01%), but reaches 0.15% in the upper stratosphere” [18]—this statistic could grow with the growing space market, and we should be cautious before expanding the industry much further. There have been proposals for a ‘green’ rocket propulsion system (hydrogen peroxide HTP-class [19], Al and Mg powders and water [20], and HAN-based liquid propellant [21], among others, have been brought forward) but so far the limitations of these potential ‘green’ rocket fuels are too great–some, like HTP-class hydrogen peroxide, are too strenuous to produce in large quantities, others, such as Al and Mg powders and water, are promising but under researched. Electric propulsion for small satellites is also promising, but needs more development in order to be reliably installable on a large scale.

The main question of environmental impact is: will the clean energy produced by solar satellites be enough to offset the impact of producing and launching them? If clean propulsion systems for these satellites turn out to be viable ways of launch this technology would already be incredibly promising–solar panels are cheap to produce and, if a light and simple solar satellite is developed for mass production (an effort that is already underway) than there is a functionally infinite source of clean, free energy–the expenses of launch and production can be payer off by servicing markets during peak periods, spot markets, or by being a baseline for ground solar panels to build off of.

Policy and Regulatory Considerations

There are several things that need to be regulated in order for the solar satellite industry to be truly viable. Orbital slots need to be allocated, regulations on launch times and rocket fuels, space debris mitigation, cyber security measures, and international collaborative means all need to be controlled and regulated. Regulation and policy take a long time to create, but the technology required for maximum efficiency also takes years to develop. If the legal process starts soon, by the time new technology will be created there will be a legal framework that it has to follow, mitigating potentially dangerous and irresponsible technology from being created.

Orbital slot allocation needs to be handled by either a government or by a large body that all bodies wishing to launch satellites into orbit are obligated to follow the regulation of. This needs to be an international effort, as Earth orbit is not any sole country’s sovereign property but instead an internationally agreed common space. Satellites, by the nature of being in orbit, will circle the Earth in its entirety and fly over all the territory under its path. There are already regulations and international agreements for non-Earth territory [22], but with the potential introduction of even more satellites into orbit more regulation about orbit allocation needs to be created in order to decrease potential crashes and the creation of more space debris.

The space debris that is created also needs to be dealt with. Space debris, space trash, or space junk is essentially what is left behind from crashed and useless satellites, lost nuts and bolts, and all the other things that get left up in orbit by humans. As they lose angular momentum, they will eventually crash to Earth and burn up in the atmosphere much like meteors–it is estimated that about one piece of debris falls to Earth per day [23]. Though the problem eventually takes care of itself, the amount of debris in orbit will become more and more problematic with time: it will be harder to find uninterrupted orbits for satellites and harder to launch rockets into interplanetary and interstellar space. This is a problem that will affect any effort to expand off of Earth but will also affect any industry that relies on in-orbit objects to do its job: internet and communications will be affected, along with meteorological predictions, navigation technologies, and television will all be affected. Space debris needs to be mitigated in order to keep order and peace.

There are several proposals for mitigating space debris and only loose guidelines for dealing with it. Some regulation like the UN Committee on the Peaceful Uses of Outer Space, The Federal Communications Commission, and the Clean Space Initiative are either non-binding agreements or simply requirements for satellite launchers to submit their plans for mitigating and dealing with their defunct satellites. Others, like the Liability Convention [24] and the Inter-Agency Space Debris Coordination Committee are either old and unrevised for modern times and technologies, or have been left ineffective because of the tense relations of the participating agencies’ countries today. “Policy has not kept pace with the rapid growth of the emerging commercial space industries,” says the Federation of American scientists [25]. Proposals for technology that could mitigate space debris are great and widespread, but most of them are currently very expensive and have not started serious development.

The type of rocket fuel used in a launch greatly impacts how environmentally impactful it is, in order for solar satellites to not turn into a purely economic venture that continues impacting the environment in detrimental ways–governments need to regulate types of fuels used. A metanalysis should be conducted in order to determine the least environmentally impactful fuel that can be produced cheaply, and that fuel should be implemented as the baseline for most rocket launches.

Cyber security for solar power satellites should also be considered in regulation. Because of the detached nature of satellites, it is nearly impossible to make physical adjustments to technology after it is launched. Companies should be wary of hackers harming energy production and thus impacting profits, but if solar satellites become a widely relied upon energy source, then serious measures need to be taken in order to protect civilians from being impacted by space-crime. Disruptions in baseline energy flow could influence the daily lives of ordinary people, leaving them without power for lengthy periods of time.

Conclusion

The purpose of this study is to provide a thorough review, analysis, and viability assessment of future energy technologies and their implementation. We shed light on the economic, energetic, and environmental prospects of space-based energy, such as solar wind and solar power satellites, by reflecting on previous investigations and comprehensive studies on current and future states of these technologies. It explored the potential of space-based power machines and the possibilities of their further exploration, amelioration, and scalability, considering the current expenses in production and launching, as well as their power efficiency and environmental impact. The key points explored in this paper include space-based energy technologies and the efficiency, scalability and the challenges of those technologies. It discusses the future potential and the policies and regulations that should be created in order to have the space-based energy industry grow in a way that is beneficial to both the environment and the public. By acknowledging the limitations, categorizing, and assembling existing information on space-based power technologies, the research findings contribute to available studies and underscore the vitality of further research in this area.