The lunar electrical power utility
by V. Beldavs, D. Dunlap, J. Crisafulli, and B. Foing
|By 2030 and beyond, potential demand for power from lunar operations is likely to be in the megawatt range and eventually at gigawatt levels.|
Scores of projects are being proposed for the Moon by established spacefaring powers as well as new players. The far side “Moon Village” proposed by the head of the European Space Agency, Johann-Dietrich Wörner has drawn great interest (see “Building a Moon village”, The Space Review, November 2, 2015). Of particular note is the endorsement of the concept by George Nield, the head of the FAA’s Office of Commercial Space Transportation, who noted recently that no US agency has been authorized to supervise commercial space activities.
All of these initiatives will require electrical power. Rovers will require several kilowatt-hours per month for communications and instruments. Demand will grow as the Lunar Village becomes a reality with its own demand for power and electrical storage. The Moon’s two-week-long night creates additional challenges for rovers or other lunar infrastructure.
Jim Shier of NASA’s Space Communications and Navigation (SCaN) office has proposed beaming power via lasers from powersats in lunar orbit to instruments on the lunar surface to enable continuous operation during the lunar night.1 Consider the avenues of research that would open if the rovers had unlimited range or could drill deep into the surface or perform continuously on command.
In situ resource utilization (ISRU) is being increasingly discussed as a game changer in the economics of space. It may be possible to process water from craters at the lunar poles into fuel, radiation shielding, even for consumption. Analysis shows that lunar water could offer significant economic advantage to Mars mission planning in the recent NASA-funded evolvable lunar architecture study2 as well as through space logistics analysis.3
ISRU will require much more energy than the few kilowatt-hours per month that rovers, sensors, and communication gear will require on missions anticipated in the early 2020s. By 2030 and beyond, potential demand for power from lunar operations is likely to be in the megawatt range and eventually at gigawatt levels.
The initial target for ISRU is water, whose presence on the Moon has been confirmed. However, no samples of lunar water have yet been directly studied. We do not know how the water is bonded with the surrounding lunar materials. Thus far, the energy economics of ISRU projects has not been calculated because the nature of the resource is unknown and processing techniques can thus only be hypothesized.
|Given the availability of reliable electrical power on the Moon when and where needed, in the quantity and qualities desired, and at a competitive cost, many projects will become feasible that would otherwise not even be thinkable.|
As lunar activities pick up it will become compelling to examine all possible options for ISRU starting with low-hanging fruit such as water and structural materials made from lunar bulk materials, and soils for growing food and bio-based materials. Given the availability of ample, reliable, and competitively priced energy, the extraction of iron, aluminum, titanium, silicon, and other elements will become feasible; these can be used to manufacture products with high value. For example, the Compton-Belkovich Thorium Anomaly could potentially be a source of thorium4 for use as a fuel in nuclear reactors in space, avoiding the danger of launching significant radioactive mass from the Earth. Peter Schubert has proposed processing lunar regolith to isolate silicon to be processed into solar arrays.5 Lunar ilmenite, which is also widely present in regolith, has also been proposed as a source for producing solar arrays with particularly high radiation resistance and wide band gap.6 Helium-3 from the Moon has been widely discussed for fusion power, but interest has waned in recent years.
Poor availability of reliable electrical power can become a showstopper, particularly for projects that require continuous operation. Given the availability of reliable electrical power on the Moon when and where needed, in the quantity and qualities desired, and at a competitive cost, many projects will become feasible that would otherwise not even be thinkable.
Utilities build power plants and industry then builds the factories that use generated power. The Tennessee Valley Authority (TVA), launched by an act of Congress in 1933, built hydropower plants throughout the Tennessee Valley, providing power to seven southeastern US states. Future demand was hard to forecast insofar as the region had been largely without electrical power. TVA built the dams and industry emerged in the region to use the generated power.
In a 2013 article (see “Move over NASA and make room for the TVA of space”, The Space Review, April 8, 2013), I suggested a space development corporation modeled on the TVA to accelerate commercial development of space. However, at that the time I did not see a central role for energy itself as key to commercial development of the Moon. The key role of ISRU to enable NASA missions to Mars and many other initiatives in space suggests that an energy utility could play a central role in lunar development.
In principle, the only material that would need to be lifted off the surface of the Earth is people, some personal items that they treasure, and the living things people need or want in space. All else can be produced from materials in space. Given a scenario where interplanetary spacecraft can be built largely from asteroid and lunar materials, then it would be feasible to make such vessels much larger than presently planned to reach Mars or other bodies in space. In his Mars trilogy, Kim Stanley Robinson envisioned spacecraft carrying hundreds of people from Earth to Mars. The ships would have sufficient radiation shielding to protect their human cargo and sufficient size to provide artificial gravity without disorienting Coriolis force effects.
Lunar demand for power in the megawatt-and-more range is unlikely to emerge until after significant ISRU operations are underway, which is unlikely until 2030 or later. So our development scenario should address maximum potential power demand to the mid-2020s when planning will need to be underway for larger scale power generation for ISRU involving mining and materials processing.
David Dunlop and Al Anzaldua, in a 2014 article, present an approach to use the International Space Station as a stepping stone and development center for developing space-based solar power for terrestrial applications, starting with emergency relief where power can be $3 or more per kilowatt-hour, ten or more times typical power costs in the US (see “Building a bridge to space solar power for terrestrial use”, The Space Review, May 12, 2014). The cost of power on the Moon will be significantly higher until a lunar power utility is formed that can deliver reliable power at competitive prices. There are lunar orbits from which power can be beamed via lasers to surface customers. Solar power arrays the size of the ISS system could deliver 84 kilowatts. Since two powersats are required, assume that two such arrays, for a total of 168 kilowatts of generating capacity to meet total power demand through 2030. A rough estimate on development and construction costs would be $250 million, including the development of standardized beamed power receivers for deployment on the lunar surface. An accurate estimate would require specification of the launch mass including assembly robots and the solar arrays, interconnect wiring, and packaging.
|If electrical power could be readily delivered to any point on the Moon or in lunar orbit at a defined price that is less than what it would cost the facility to develop its own power system, then a lunar utility would have a bright outlook.|
Given the deployment of the two powersats that could beam power to most points on the lunar surface, rovers could then be designed with unlimited range to accelerate lunar exploration. This would also enable pilot-scale ISRU operations anywhere on the lunar surface at much lower cost due to the availability of power from the lunar utility. The potential would also open up the use of laser-assisted launch technology to reduce the amount of fuel spacecraft would need to carry. Other customers could be facilities in orbit, to which power could be beamed from either of the two powersats.
The lunar power utility’s future growth will depend on meeting the needs of customers for reliable electrical power delivered at costs competitive with alternatives. Alternatives might emerge in the form of supercapacitors that can store electrical power for the duration of the lunar night, with the additional requirement that the facility have its own power-generating capacity. It would be unlikely that a competing powersat system would be deployed in the 2020–2030 timeframe, giving the lunar utility a monopoly advantage to develop its technologies and power distribution capacity.
Other potential competition includes nuclear power. Both the US and Russia have supported significant development of nuclear power for space. The US Prometheus program, initiated in 2003, was intended to develop nuclear as both a source of power as well as for space propulsion, but was later cancelled by NASA.7 According to published information, Russia is working on packaged nuclear reactors for space both for propulsion and for facility power for space stations and lunar operations that could operate at up to the megawatt level. Information from 2011 speaks of initial launches by about 2020.8
Electrical power utilities build generating plants to meet anticipated long-term demand. In regulated markets the utilities, as monopoly suppliers, can be guaranteed a market decades into the future to recoup their long-term investment. This article proposes a similar model for the lunar power utility through 2050, where the monopoly supplier position is built on the basis of economics of power generation and distribution to the lunar surface and cislunar space operations. If the utility was controlled by the US or any other nation, though, this could not be sustained. No nation powerful enough to send spacecraft to the Moon and to operate there is likely to accept being subject to the risk of a competing nation controlling its source of power, even if the power is priced competitively. An international structure similar to the original Intelsat, owned by multiple nations, may resolve such a concern.
It is unlikely the lunar power utility would remain dependent solely on solar energy. Nuclear was the power source of choice in the “Space Imperative” vision of space pioneer Krafft Ehricke.9 Hydropower is the primary source of power for TVA, but the TVA also has three large nuclear plants that generate 6.8 gigawatts of power. For lunar needs, the primary form of power generation within this scenario is expected to be solar. The choice of photovoltaic or Brayton or Stirling cycle solar power generation in the long term will be determined by the ability to convert lunar or asteroid materials to power-generating equipment, largely eliminating mass to launch from Earth as needs for power increase. Solar photovoltaic would have the significant advantage that solar arrays are highly scalable. To add incremental power, simply add more solar cell modules. However, access to highly concentrated thorium on the Moon also opens the possibility of nuclear energy from a thorium reactor.
The design, development, and commissioning of new nuclear reactors can take 12 or more years to meet anticipated future demand in the US market. If a decision were reached today to build a new nuclear power station in the US, it could easily be 2030 before the power plant is commissioned and produces power. This is not much different from meeting future electrical power demands on the Moon, where foreseeable demand will be for uses requiring a few kilowatts in the initial decade. However, materials processing tends to be energy intensive and we should expect the same for lunar industrial processes. Post-2030 demand is likely to rise to the megawatt range and could rise significantly higher as industrial operations get underway. Packaged nuclear reactors such as are used in ships could be suitable but multiple issues would arise in delivering such a system to lunar orbit or to the lunar surface that could be avoided through solar technology.
If electrical power could be readily delivered to any point on the Moon or in lunar orbit at a defined price that is less than what it would cost the facility to develop its own power system, then a lunar utility would have a bright outlook. Given a predictable price for reliable electrical power, the economics of tourist facilities, lunar mining, materials processing facilities, spaceports, and other operations could be more precisely estimated, decreasing project risk. This would lead to more projects undertaken in less time across a broader range of opportunities, playing a similar role on the Moon as electrical power has played in economic development on the Earth.
Electrical power utilities possess the key attributes needed for a successful lunar power utility:
Thus far, there has been very little involvement of power utilities in space energy projects other than the agreement signed by Pacific Gas and Electric several years ago to purchase electricity generated in space.10 However, the role of the lunar power utility is very similar to development needs on Earth. A lunar electric utility could accelerate overall lunar development by broadening the financial base, technical expertise, and customer-oriented business management. Additionally, the Electrical Power Research Institute (EPRI) could support such an initiative, bringing radically different perspectives to the challenge.
If the lunar power utility was an initiative of the electrical utility industry, the support base for space initiatives would broaden to include all the companies involved, which would be helpful with the politics of the public-private partnerships that will be required.
Insufficient R&D has been conducted to demonstrate the feasibility of space-based solar power for terrestrial applications as a viable option to meet terrestrial demand for electrical power. The lunar utility offers a pathway to demonstrate the viability of beaming power to the surface from a powersat. Customers on the Moon will be willing to pay a much higher price for reliable power than customers on Earth, making the Moon an ideal environment to pilot the space-based solar energy option. Given good results, then emergency relief and military applications on Earth, where $3 or more per kilowatt-hour is an acceptable price for power, could be the next step. Given satisfactory performance in high-value applications with limited power needs, the larger-scale applications, such as providing power to Africa and other regions with underdeveloped infrastructure, could then emerge as target markets. Other possibilities include major disasters such as the Fukushima nuclear disaster, where multiple gigawatts of power could be required quickly. Power beaming to mobile rectennas mounted to aerostats may emerge as part of the solution.
The International Lunar Decade (ILD) is the framework for a process to achieve breakthrough to a sustainable space economy.11 The idea was initially conceived by Louis Friedman and the Planetary Society in 2006 and received the endorsement of COSPAR, the International Lunar Exploration Working Group (ILEWG) that includes all parties active in lunar exploration, and ESA. The first ILD started in 2007, the 50th anniversary of the International Geophysical Year and of the launch of Sputnik. The goals set for ILD in 2006 that related to collaboration in lunar exploration have been met. The larger goal of engaging the global space community has not yet been achieved. As a result, the promise of space development still lies in the future.
|We welcome the utility industry to explore this idea and to join the community of businesses, research centers, and space agencies in meeting the challenge of opening the solar system to humankind through industrial development of the Moon, our nearest neighbor in space.|
We are now seeking to launch the next stage of the ILD process to engage the global space community as well as organizations that have heretofore not been active in space to achieve an economic breakthrough. The launch of this ILD will be in 2017, marking the 60th anniversary of both the International Geophysical Year and the launch of Sputnik that heralded the dawn of the Space Age. The ILD decade that lies ahead will see concurrent action to develop international agreement on policies to govern commercial space development on the Moon and beyond as well as to develop the enabling technologies, infrastructures and financing methods to enable industrial development of the Moon and cislunar space.
A lunar utility managed as a business that is oriented towards economic development can be a key element of the ILD process. We welcome the utility industry to explore this idea and to join the community of businesses, research centers, and space agencies in meeting the challenge of opening the solar system to humankind through industrial development of the Moon, our nearest neighbor in space.
The ILD Campaign can be a stimulus for the national space agency members of International Space Exploration Coordination Group to look at collaborative options for national space agencies to be both investors as well as customers, working together with private capital in forming the “Lunar Electrical Power Utility.” A possible model is how the global commercial satellite industry developed. The rapid successful development of COMSAT, followed by INTELSAT, knit the world together in the 1960s. A similar success can be repeated on the Moon. Public-private partnership models have been proposed in the Evolvable Lunar Architecture previously mentioned. The lunar electrical power utility idea can be logically extended to communications and lunar positioning services as well.
The ILD will create numerous opportunities to engage young scientists and engineers in early development projects that will create a hopeful economic future, rather than the dystopian scenarios often portrayed in popular media and films. The ILD can be a catalyst for the planning and investment needed to open this global frontier to every nation and aspiring individual on Earth.