Space Energy Options for Addressing the Energy Dilemma and the Climate Emergency

Arthur R. Woods (*) and Marco C. Bernasconi (**)

Keywords: The Space Option, Energy Dilemma, Climate Emergency, Space Energy Options, Space-Based Solar Power, Lunar Solar Power, Helium-3

Abstract
Humanity is facing an imminent Energy Dilemma in that the limited proven reserves of fossil fuels could reach exhaustion levels at mid-century and none of the alternative terrestrial energy options – nuclear – wind – ground solar (PV) – can be sufficiently scaled to achieve the goal of divesting from fossil fuels by the year 2050 as is being called for by the United Nations, many governments and numerous organizations to address the Climate Emergency. Providing energy to Earth from space – either from orbit or from the Moon – is the only feasible and scalable alternative currently available to humanity to divest from fossil fuels while meeting its future energy needs.  This Space Energy Option is seldom mentioned and rarely discussed as a way to address the interrelated climate and energy emergencies.

The Climate Emergency

Due to the many assessments and reports issued since 1990 by the United Nation’s IPCC – Intergovernmental Panel on Climate Change – and the subsequent international commitment to address the climate issue achieved in the 2015 Paris Agreement on climate change which, as of February 2020 has now been signed by 189 countries. Thus the world population has become increasingly alarmed that a period of global warming has commenced which may lead to environmental catastrophe by the end of this century.  Numerous scientific studies have shown that this warming is caused by rising levels of CO₂ in the atmosphere which is attributed to the continued dependence on the use of fossil fuels to satisfy most of humanity’s energy needs. A worldwide program to address the impending climate disruption has been incorporated into the United Nation’s Agenda 2030 [1] including the Paris Agreement and the 17 Sustainable Development Goals as well as through a number of international conferences [2],  sub-organizations and public-private partnerships.  Similar measures are being promoted, developed and adopted by environmental and scientific organizations worldwide [3]. Many prominent people such as former US vice-president Al Gore, British natural historian and broadcaster David Attenborough and the young Swedish activist Greta Thunberg have brought the Climate Emergency to the world’s attention [4].

As it is the Sun which warms the surface of Earth and drives the hydrologic cycle, it is the primary source of energy for the climate system which keeps Earth suitable for life. The sunspot cycle of the Sun also has much do with the changes in the climate and scientists report that the current long period of low sunspot activity may indicate that the Sun is entering a Solar Minimum which could lead to a severe cooling effect similar to the last Little Ice Age [5]. Solar activity which modulates the influx of galactic cosmic rays (high-speed particles that strike the Earth from space), has been shown to have a direct influence on cloud formation and has been correlated with warmer periods during high solar activity and cooling periods during low levels of solar activity [6].  Severe global cooling would probably be much worse for humanity than the predicted rise in global temperatures as this would directly affect food production and require additional energy for heating and maintaining all aspects of society. In either case, addressing the Climate Emergency will require massive amounts of clean energy production for a growing population to adapt and survive a severe warming or cooling situation [7].

The Energy Dilemma

There are several sources of energy data available in order to have a picture of the world energy demands now and in the future. One commonly used is the BP Statistical Review of World Energy 2019 which lists World Primary Energy Consumption by fuel, i.e. oil, natural gas, coal, nuclear energy, hydroelectricity and renewables by region and country. [8] For 2018, Fig.1 shows the World Total Primary Energy consumption at 13,864.9 million tonnes of oil equivalent (MTOE). Of that amount 11,743.6 MTOE came from oil, gas and coal, 611.3 MTOE from nuclear energy, 948.8 MTOE from hydroelectricity, and 561.3 MTOE from renewables (wind, terrestrial solar and other non-hydro renewables).

Fig.1. Extract from BP Statistical Review of World Energy

Converted into SI units (International System of Units), 13,865 MTOE corresponds to approximately 18.4 terawatts (TW), of which 15.6 TW (85%) comes from fossil fuels, 1.26 TW (7%) from hydroelectricity, 811 gigawatts (GW)  (4%) from nuclear power, and 745 GW (4%) from renewables, as illustrated in Fig. 2. This estimate of world energy consumption was confirmed  by the International Energy Agency in their World Energy Outlook 2019 Launch Presentation which set the total amount at 14,300 MTOE which, when converted to electrical power, is approximately 19 TW. [9]

Fig. 2. Global Primary Energy Consumption by Fuel in Terawatts

Replacing Fossil Fuels with Terrestrial Energy Alternatives

Looking first at nuclear power as an alternative, most nuclear power plants in operation have a power capacity around 1 GW. [10] Thus, to replace current fossil fuel usage with nuclear power (assuming for the plants a 90% availability) would require the deployment of up to 17,530 new 1-GW nuclear reactors. On the average then, for the next 30 years, 572 new power plants would have to go on line each year – in other words, adding 1½ new 1-GW reactors each day. In 2018, world-wide nuclear power systems accounted for only 811 GW (4% of the total energy use) and, currently, building one nuclear power plant takes about 10 years. Furthermore, some estimates conclude that the uranium reserves may supply the currently-operating reactors only for some 90 years more. Accordingly, a nuclear solution to divest from fossil fuels seems highly unlikely [11].

Terrestrial fusion nuclear power has been under development for more than 50 years. Among the dozen or so fusion projects around the world, the largest effort is the International Thermonuclear Experimental Reactor (ITER) which is a 35 nation effort under development since 1985 that hopes to have a commercially viable reactor by the year 2050. ITER’s first plasma reactor demonstration experiment that should produce a net energy gain of 500 MW from 50 MW of input heating power is scheduled for 2025.  From the ITER website: “The ITER Tokamak and plant auxiliary systems will produce an average of 500 MW of heat during a typical plasma pulse cycle, with a peak of more than 1100 MW during the plasma burn phase; all of this heat needs to be dissipated to the environment”. [12] Thus, in addition to requiring geologically stable locations with sufficient access to cooling water where the substantial waste heat can be discharged into the local environment, scalable deployment of nuclear fusion faces the same obstacles as nuclear fission (17,530 new 1-GW reactors by the year 2050). Thus nuclear fusion is also not a near term energy option.

Wind and solar photovoltaic (PV) generators have significantly lower availability: the inherent intermittency and storage aspects, make it necessary to deploy multiples of their equivalent rated (peak) power levels to equal the output, e.g., of nuclear power systems. For wind, the generating capacity needs to be some 3.35 times higher [13] and for PV, 6-7 times higher. Thus, to replace 2018 use of fossil fuels with wind and solar, no less than 65 TW (depending on the assumed wind/ PV mix) of power generating capacity from these two renewable sources would need to be installed. Again, this translates into 2 TW of electrical generating capacity from wind and solar to be installed every year from now until the year 2050 – i.e., 5 GW per day – and this, too, would have to start immediately.

Published data shows that the world’s installed wind power capacity reached 597 GW in 2018. [14] Installed world terrestrial solar PV capacity was 401 GW in 2017 [15] and is predicted to reach 530 GW by 2024. [16] Thus, nuclear, wind, ground solar and other non-hydro renewables combined, contributed about 1.6 TW of current level of world energy consumption or approximately 8%.

With current world population of 7.7 billion expected to increase by 25% to 9.7 billion between now and 2050, at current energy consumption levels a very minimum of 23 TW (+25%) of power will be necessary to sustain civilization. However, based on the current average energy consumption increase of 1.5% per year, [17] more likely humanity will require more than 30 TW of continuous power by mid-century.

In his assessment of the U.S. energy needs in the year 2100, Michael Snead has reached a similar conclusion concerning the lack of scalability of terrestrial energy alternatives in his book Astroelectricity (2019) and on his Spacefaring Institute YouTube channel. [18]

In addition to the many environmental and geopolitical issues associated with the continued use of fossil carbon fuels, the limited nature of these resources needs consideration. For instance, the “BP: World Reserves of Fossil Fuel” report shows that the remaining proven extractable reserves of fossil fuels are critically finite. At current rates of consumption, humanity will exhaust said reserves of crude oil by the year 2066, natural gas by 2068 and coal by 2169. [19] Furthermore, EROI – energy return on investment – is also a critical issue for future production predictions as this will influence the price of fossil fuels as they become more difficult and thus less economical to produce. This aspect also significantly adds to the urgency of finding a viable alternative energy solution and underscores the imminent Energy Dilemma that humanity is facing.

Fig 3. Estimated years of extraction remaining for fossil fuels.

The Space Option

The Space Option concept was first introduced in 1993 at the 44^th International Astronautical Congress in Graz, Austria and subsequently developed by the authors. [20] It is an evolutionary plan to meet the basic and anticipated needs of humanity with the addition of utilizing near Earth resources -­ not only for the in-situ support of science or exploration – but rather to apply these resources and/or their products for use on Earth at a conspicuous level. Most immediately, the harnessing of inexhaustible amounts of clean energy from space would replace humanity’s dependence on the continued use of fossil fuels while insuring humanity’s future energy needs. This would also provide the basic means for restoring the environment, sustaining the world economy, reducing poverty and stimulating progress in the developing countries while preserving the living standards of the developed nations. Additionally, plentiful energy from space could also power desalination plants and contribute to solving the water crises and likewise produce hydrogen for future transportation scenarios.

In current discussions about transiting from fossil fuels to some other alternative energy source, it is surprising that energy from space or SBSP, a technologically feasible idea that was introduced as the Solar Power Satellite by Peter Glaser in 1968 [21] and patented in 1973, is rarely considered or even discussed as a possible alternative to terrestrial energy sources. The standard objection to SBSP has been the cost to implement such a space power system. When considered in the context of the increasing demand for CO₂-neutral energy and the value of the global energy market by the year 2050, this criticism should have lesser relevance as terrestrial energy alternatives prove to be insufficient, impractical or undesirable and the magnitude of Energy Dilemma becomes apparent.

Space Energy Options

Peter Glaser described the basic SPS concept in terms of actual technological capabilities. Intriguingly, several science-fiction authors had presented related schemes since the 1940’s. In particular, Isaac Asimov had a space station near the Sun collecting energy and transmitting it to various planets using microwave beams in his short story “Reason” [22].

Following Glaser’s publication, several technical studies assessed the feasibility of supplying Earth with solar power from space. To date, the most extensive study remains the “Satellite Power System Concept Development and Evaluation Program,” conducted from 1977 to 1981 by the (US) Department of Energy (DoE) and NASA, with a $19.7 million budget. [23] Ralph Nansen, at the time with the Boeing Corporation, participated in this study. In his book: Sun Power: The Global Solution for the Coming Energy Crises (1995), he writes that the study had come to a conclusion that Space Solar Power relying on large reusable rockets and automated assembly systems in orbit was technically feasible. Nansen writes, had the project gone forward, an investment of $2 trillion would have saved the United States $22 trillion by 2050 and this would have adverted the energy crises we are now facing forty years later.[24]

More recently, a study by the International Academy of Astronautics (IAA) – completed in 2011 [25] and subsequently published in the book The Case For Space Solar Power (2014) by the IAA study’s lead author John Mankins [26] – realistically describes how a SPS located in Earth orbit would use the latest technologies and be built by robots out of modular components – a concept that has both economic and maintenance advantages.

There are a number of technological approaches to building the optimal SPS. These range from very large structures placed in Geosynchronous orbit (GEO) to smaller satellites in Middle Earth Orbit (MEO) and in Low Earth Orbit (LEO). The size and mass of the satellite and the choice of orbit will have much impact on the overall efficiency and cost of an eventual SPS system. In addition to the aforementioned DoE/NASA study, various approaches to SPS are discussed in detail in these five books about Space-Based Solar Power:

• Frank P. Davidson, L.J. Giacoletto, & Robert Salked, Eds. (1978) Macro-Engineering and the Infrastructure of Tomorrow. AAAS Selected Symposium 23, Westview Press, Boulder (CO), 131-137
• P Glaser, F Davidson, & K Csigi, (1998) Solar Power Satellites, Wiley
• Ralph Nansen, (1995, 2012) Sun Power: The Global Solution for the Coming Energy Crisis, Ocean Press 1995,  Nansen Partners 2012
• John Mankins, (2014) The Case for Space Solar Power, Virginia Edition Publishing LLC
• Michael Snead, (2019) Astroelectricity,  Spacefaring Institute LLC

For comparison with terrestrial energy alternatives, one may build on the 5-GW power level used e.g. in the DoE/NASA reference study. The power generated by the orbital plant must cover the losses in the transmission chain: (i) in the conversion from DC electrical to microwave power, (ii) in relation with the beam’s space and absorption losses, and (iii) with the microwave capture and conversion to AC power at the ground “rectenna” (rectifying antenna). One also has to account for the time the station passes through the Earth’s shadow (<1% for a geostationary orbit). For 1 TW of continuous power, then, some 202 solar power satellites would be necessary.  Scaling this to meet humanity’s energy needs, about 3,030 of such power plants would be necessary to deliver 15 TW, which is approximately what is needed to replace fossil fuels today. Twice this number would be required to provide 30 TW of continuous clean solar power in the year 2050.

Solar Power from the Moon

In the mid-1980s, David Criswell introduced a significant variation of the SPS concept called the Lunar Solar Power (LSP) System. Instead of building the photovoltaic system in Earth orbit using materials transported from Earth, he proposed a potentially more efficient approach by using an existing orbiting platform – the Moon – for the location of the solar collectors and to use lunar materials for their construction. Criswell contends that generating power from the Moon would be at least 50 times more cost efficient than competing approaches such as large solar arrays on Earth or solar power satellites deployed to orbit about the Earth either from the Earth or from the Moon. The sunward hemisphere of the Moon continuously receives 13,000 TW of solar power. In addition, all of the main resources for power generation – reliable solar power, lunar real estate, and appropriate materials – are readily available on the Moon [27]. Thus, instead of sending tons of materials from Earth into space at great environmental and financial cost, and constructing these enormous and complex power satellites in orbit, one would send a small team of humans accompanied by the necessary robots to the lunar surface to carry out the job on site.

The primary material necessary for the manufacture of photovoltaic collectors is silicon, which, as on Earth, is in great quantity on the Moon. The solar converters would be thin-filmed photovoltaics made out of lunar glass. Robots would mine the lunar soil for silicon and the photovoltaics would be manufactured in an automated factory constructed for this purpose. The basic technology for manufacturing photovoltaics with a conversion efficiency factor of less than 10% already exists and the engineering aspects are typical of major construction techniques. Of course these activities would be carried out in a new environment but thanks to Apollo, there exists substantial information about the lunar environment. The photovoltaics would be mounted on a grid that would also be constructed from of lunar materials.

Criswell estimated that within 10 years from startup, a LSP system could be providing 50 GWe (Gigawatt electric) per year of electric power and a small scale 100 GWe demonstrator system could show a net profit within 10 years. This would be steadily increased in average yearly installments of 560 GWe/year over a 30 year period eventually reaching a 20,000 GWe or 20 TWe which, at 2 kW per person, is considered as a minimum sustainable energy level for a population of 10 billion if the energy is equally distributed. In 2002 Criswell stated: “Prosperity for everyone on Earth by 2050 will require a sustainable source of electricity equivalent to 3 to 5 times the commercial power currently produced.” [28] 3 kW per person would equal the 30 TW currently projected for an expected population of 10 billion in the year 2050.

Following in Criswell’s footsteps, the Shimizu Corporation in Japan has proposed the Luna Ring – a gigantic, 400km-wide and 11,000 km-long mirrored structure positioned on the lunar equator which would capture solar energy and beam it back to Earth with lasers. [29]

Helium-3 Astrofuel

Helium-3 is sometimes referred to as Astrofuel. Helium-3 is transmitted with the solar wind, but Earth’s magnetic field pushes the isotope away so that only extremely small quantities of it are found on Earth. It is seen as an ideal isotope for nuclear fusion reactors on Earth once these become operational since helium-3 reaction produces no radioactive byproducts.  Thanks to the Moon’s negligible magnetic field, it is estimated that up to 1,100,000 metric tonnes of helium-3 have been deposited in the lunar regolith, however in concentrations of less than about twenty parts per billion.

Extracting helium-3 from the lunar regolith will require the mining and processing of hundreds of millions of tons of regolith. This would also require a very large lunar operation which would also depend on large amounts of energy such as Lunar Solar Power to heat the regolith to a temperature of about 600 degrees centigrade. It has been estimated that 1 million metric tonnes of helium-3, reacted with deuterium, would generate about 20,000 terawatt-years of thermal energy. To put this into perspective, 25 tonnes of helium-3 would power the United States for one year at current consumption levels [30].

This technology may become viable once nuclear fusion has been demonstrated at a commercial level and eventually, there may be some synergies once this technology advances. The most comprehensive book about mining helium-3 is “Return to the Moon” by Apollo 17 astronaut and geologist Harrison Schmitt [31]. Once humanity has become a true spacefaring species, helium-3 could perhaps be easier obtained from the four giant gas planets, Jupiter, Saturn, Uranus and Neptune; all of which have very large amounts of helium-3 in their atmospheres [32]. The movie “Moon” (2009) directed by Duncan Jones is about an astronaut on the Moon who has been managing the mining facilities extracting helium-3 from the lunar surface to be sent to Earth for use in fusion power generators.

Helium-3 and Lunar Solar Power are discussed in some detail in the following:

• John S. Lewis, (1996) Mining the Sky, Basic Books
• Dennis Wingo, (2004) Moonrush: Improving Life on Earth with the Moon’s Resources, Apogee Books Space
• Charles Proser (ed.), (2005 – DVD) Gaia Selene, Celestial Mechanics
• Harrison Schmitt, (2006) Return to the Moon, Praxis Publishing
• Robert Zubrin, (2019) The Case for Space: How the Revolution in Spaceflight Opens Up a Future of Limitless Possibility, Prometheus Books
• Leonard David, (2019) Moon Rush: The New Space Race, National Geographic

Next Steps

Although the engineering and logistical challenges would be formidable, except for the case of helium-3 fusion power, no new technology needs to be invented and no scientific breakthroughs are necessary for the SBSP/LSP approaches. The generation of electrical power in space and the transmission of power via microwaves have been demonstrated. Additional research is needed to control and direct these low-intensity beams over the required distances of space. The logistics of establishing and supplying a manned lunar base community – though a large task – is comparable to similar large scale engineering projects that have been accomplished on Earth.

It should be pointed out that the money spent to finance and construct a SPS/LSP system would be spent on Earth and flow through the global economy. Considering the value and ever increasing demand for energy, the potential revenues of such a clean energy producing system would certainly be immense and the initial investment quickly amortized. The real challenge of implementing this system is this initial financial investment and gaining the public’s confidence in the system.

China has recently signaled its interest in developing an Earth-Moon economic zone by 2050 and mining of helium-3 may appears to be the economic motivation to do so [31]. If any one nation dominates and the controls the source of energy powering the world economy this will obviously become a reason for conflict. Also, power generation stations in orbit or on the Moon would become targets in case of war and this aspect would lead to further militarization of space activities and the fallout of any large scale destruction of space assets could result in making the space environment unusable and in the worst case, forever trapping humanity on its home planet.  Therefore an international consortium of nations dedicated to jointly developing any of the Space Energy Options would seem to be the way forward. This concept is discussed in this article: GEEO – Greater Earth Energy Organization [33].

Conclusion

Humanity is facing an imminent Energy Dilemma which, in addition to the Climate Emergency, deserves the focus of world attention. As energy is the key element of both of these issues, the solutions to solving both or either are interrelated and interconnected.  Addressing the Climate Emergency will require massive amounts of clean energy production to adapt and survive a severe warming or cooling situation. Addressing the Energy Dilemma will require massive amounts of clean energy production for restoring the environment and meeting the energy needs of a growing population. None of the alternative terrestrial energy options – nuclear, wind and ground solar (PV) – can be sufficiently scaled to achieve the goal of divesting from fossil fuels and achieve net-zero CO₂ levels by the year 2050 as is being called for by the United Nations, many governments and numerous organizations. The various Space Energy Options represent the only technically feasible alternatives to addressing these two emergencies – if any of these can be implemented in time. Although the up-front investment would be significant it is comparatively reasonable to other industrial projects of similar scale. Once any of the Space Energy Options become operational they would likely become profitable in a very short time. An international consortium of nations could combine resources to jointly select and mutually develop the best Space Energy Option which would avoid future conflict over control and distribution of this essential resource to the ultimate benefit of all humanity.

Authors:

(*) Arthur R. Woods is an astronautical artist and independent researcher with two art projects successfully flown on the Mir space station. He is a member of the International Academy of Astronautics.

(**) Marco C. Bernasconi is an astronautical engineer and expert in lightweight structures, astronautical systems, and astronautics and society assessments. He is a member of the International Academy of Astronautics.

References and Notes

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