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ESA SSP concept
As the European Space Agency and other governments fund space solar power initiatives, the US government may be showing renewed interest. (credit: ESA)

With a tweet, America has joined the race to develop astroelectricity—hopefully!

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In a September 21 tweet, US Department of Energy (DOE) Secretary Jennifer Granholm suggested that space(-based) solar power (SSP) was now a part of the clean energy mix DOE is pursuing. This off-the-cuff announcement followed preliminary work begun last year by NASA—for the third time—to study SSP. While this announcement has not yet been characterized as an admission by DOE that their decades-long quest for practicable terrestrial sustainable energy has failed, this is exactly what the formal expansion of DOE’s clean energy mandate to include SSP really is. The world is now entering the “Age of Astroelectricity” where SSP-generated astroelectricity will not only substantially power the world (and America) with abundant clean energy, but it will, as Gerard O’Neill forecast a half-century ago, necessitate the permanent human settlement of the central solar system.

How we got here—a personal view

This important recent step by DOE is the result of a quest for more than a decade by many around the world to advocate for SSP. In early 2007, I was invited to support a small, informal study of SSP undertaken by the National Security Space Office (NSSO) in the Department of Defense (DOD). Aware of John Mankins’ past efforts at NASA and his ongoing private efforts to advance SSP-enabling technologies, NSSO recognized the game-changing nature of powering America and the world with SSP. The opening paragraph of the forward to that study’s report, “Space-Based Solar Power as an Opportunity for Strategic Security”, stated:

Preventing resource conflicts in the face of increasing global populations and demands in the 21st century is a high priority for the Department of Defense. All solution options to these challenges should be explored, including opportunities from space.

My joining the Mankins-led study team was to provide support for the space logistics capabilities (astrologistics) needed to jumpstart the in-space research and development of key SSP technologies and in-space manufacturing and assembly. While the Space Shuttle was then still operational, it was recognized that more robust and safer astrologistics capabilities were needed. I was asked to join the study team based on my previous astrologistics concept exploration efforts while working as a civilian engineer at the Air Force Research Laboratory (AFRL) and as having been the chairman of the American Institute of Aeronautics and Astronautics (AIAA) Space Logistics Technical Committee.

This important recent step by DOE is the result of a quest for more than a decade by many around the world to advocate for SSP.

Recall that in 2007 the United States was still in the grips of its decades-long substantial dependence on imported oil and natural gas, a national energy security dependency that had dragged America into persistent and very costly warfare in the Middle East. The commercial fracking revolution that has since substantially increased America’s oil and gas technically-recoverable resources, enabling America to, at least temporarily, return to domestic energy independence was still in the future. The geopolitical importance of oil, along with oil’s global market price, was near an historic high point. Consequently, America was committing tremendous national resources to sustain America’s precarious foreign oil and gas economic lifeline through both military expenditures and substantial foreign oil and gas purchases. (At that time, as shown below, America was importing around 60% of its oil.)

oil import chart

Later in 2007, the geographically dispersed study team gathered to report our findings. At the “meet everyone” dinner, as the study lead, John Mankins spoke to the assembled group. He gave a very encouraging talk on the future potential and need for SSP. In his presentation, Mankins presented top-level estimates of the growing global need for energy and how SSP could significantly help to meet these needs—a topic first addressed in the 1970s by Professor Gerard O’Neill in his still inspiring book, The High Frontier: Human Colonies in Space. So convincing were his explanations that it left me wondering why SSP was not enthusiastically embraced by the federal government, then still seeking long-term sustainable energy security as it is today. After all, America’s 2007 oil insecurity was comparable to that of America’s first oil supply crisis 40 years earlier that prompted the original extensive NASA and DOE SSP investigations in the late 1970s and early 1980s. So, why wasn’t SSP in 2007 a DOE and NASA priority? (In fact, why isn’t it today?)

After the NSSO study concluded and the team went their separate ways—and with the Pentagon losing interest in SSP as warfare in the Middle East intensified—I focused on answering the implicit “why” question. In 2008, I published the white paper, “The End of Easy Energy and What to Do About It”. It was an extensive 127-page quantitative assessment of energy needs and sustainable energy options. The paper’s abstract summarizes my findings:

Easy energy refers to the current oil, coal, and natural gas energy sources that provide about 86% of the U.S.’s and the world’s energy. An increasing average world per capita demand for easy energy combined with a growing U.S. and world population will exhaust recoverable resources of easy energy this century, probably within the lifetime of today’s young children. Current sustainable nuclear and renewable energy sources provide only about 14% of the world’s electricity and modern fuel needs. To meet the world’s projected 3X increase in energy needs by 2100, if not decades earlier, today’s sustainable energy production must expand by a factor of over 24X. This paper’s assessment of the energy production potential of conventional nuclear, geothermal, wind, ground solar electric, and land biomass finds that these will fall significantly short of both the U.S.’s or the world’s 2100 sustainable energy needs. To fill the substantial sustainable energy shortfall that will emerge by 2100 as the era of easy energy ends, space solar power and algae biodiesel—absent the extensive use of advanced nuclear energy and/or undersea methane hydrates—will need to be substantially developed. Space solar power will be needed to supply most of the U.S.’s and the world’s dispatchable electrical power generation capacity while hydrogen produced with off-peak space solar power electricity and algae biodiesel will be needed to fill the fuels shortfall.

Noting that algae-based fuels have not developed as a viable energy source and that sustainable clean carbon fuels produced from clean hydrogen and captured carbon dioxide are better for general use than hydrogen alone, my paper’s findings have generally remained valid. Given these clear quantitative findings justifying why SSP was needed (updated as discussed below), I remained puzzled on why the federal government, particularly DOE and NASA, were not aggressively pursuing SSP. Perhaps, I thought, the 2008 presidential election, bringing a change in administrations and, potentially, energy policies would correct this oversight.

The outcome of the 2008 presidential election was substantially influenced by the oil price-driven banking crisis immediately preceding the election. Unfortunately, with the election of Barack Obama and Joe Biden, the “green movement” long hidden in the shadows of the federal government took unabashed administrative control of US energy and environmental policies. At the same time, renewed growth of DOE’s “nuclear roots” aimed to make good on the half-century-old goal of acceptably safe nuclear fission power. In addition, fervent opposition from the environmental movement arose to renewing America’s domestic fossil carbon fuel energy security using the new emerging commercial technology of guided drilling and hydraulic fracturing, aka “fracking”. Consequently, advancing terrestrial renewable energy sources and pursuing renewed nuclear fission power plant designs moved to center stage in terms of DOE research and development priorities. Meanwhile, the organizationally aging NASA was generally happy with conducting repeated Space Shuttle “expeditions” to the International Space Station (ISS).

In 2011, the Obama/Biden administration retired the shuttle. As a result, America was relying on Russia for access to the ISS. Indicative of the general technological planning ineptitude of that administration, for the first time in US history, a key national logistics infrastructure capability was ended without a better replacement taking its place. (This “accomplishment” is about to be repeated with the planned abandonment of the ISS in 2031.) Ending the shuttle without an improved, fully reusable, and airworthiness-certified human space access capability ready to replace it, something that has been achievable by America’s aerospace industry since the mid-1980s, effectively closed the door on federal support for SSP. Without the ability to safely reach and operate in space, something NASA’s first SSP studies clearly identified in the 1970s and 1980s as being essential, SSP remained a dream.

The possibility of focused federal support for SSP diminished further when President Obama signed the Paris Agreement in 2015 in which SSP was glaringly absent—in fact, any real technological solution to the world’s need for abundant clean energy was absent. (I was informed that some in the Obama Administration were aware of my earlier SSP efforts.) Regrettably, the Paris Agreement made repressive global energy policies, now exemplified by the “Great Reset” and the “Green New Deal”, the focus of US and global misnamed “progressive” politicians. (In 2021, the Biden Administration renewed America’s pledge to support the Paris Agreement, illustrating the green movement’s continuing, carefully hidden, almost subversive control of US energy policies.) With the Paris Agreement, SSP was essentially a “dead” topic in the federal government.

The tide is now changing due to growing international support for SSP

Implementation of the Paris Agreement evolved into national “net-zero by 2050” pledges—referring to ending anthropogenic carbon dioxide emissions from the use of fossil carbon fuels by 2050. Over the last decade, advancing the Paris Agreement/net-zero agenda have become a key progressive litmus test not only for politicians but also for journalists, climate scientists, social media magnates, CEOs, and many of the world’s rich and famous. Undergirding this net-zero political pressure has been incessant claims blaming supposed anthropogenic-driven global warming and climate change for just about any disaster that comes along.

Many European countries, faced with increased energy costs and heightened energy insecurity due to Russia’s invasion of Ukraine, are facing consumer backlash in upcoming elections about aggressive net-zero transition plans.

However, recently this misinformation-driven propaganda has been collapsing. For the last several decades, the Intergovernmental Panel on Climate Change (IPCC)—created to summarize key climate-related research—has been the primary governmental organization warning of pending environmental catastrophe should the repressive net-zero policies arising from the Paris Agreement not be met. In July 2023, Jim Shea was elected as the new IPCC chair. Following Shea’s election, he was widely quoted as saying, “Climate change is an existential threat to our planet.” Yet, just four days later, Shea was quoted as clarifying his remarks with, “If you constantly communicate the message that we are all doomed to extinction, then that paralyzes people and prevents them from taking the necessary steps to get a grip on climate change. The world won’t end if it warms by more than 1.5 degrees," Shea told Der Spiegel. “It will however be a more dangerous world.” (More on this point later.)

What has happened is that the need for repressive energy policies has not been supported by tested scientific hypotheses. To make up this deficiency, the IPCC staff’s own opinions have largely become the substantive basis of their intended policy-influencing reports. As one recent scientific paper’s author publicly admitted, slanting the results of the published summary of their scientific work to match the expectations of editorial staffs has apparently become common to get one’s work published to advance one’s career and secure future funding. If true, then the IPCC has become a self-licking ice cream cone.

Recently, Bill Gates, speaking at British Prince William’s Earthshot Prize Innovation Summit, said, “There’s a lot of climate exaggeration… The climate is not the end of the planet. So the planet is going to be fine.” (Gates apparently uses “climate” in these remarks in place of “climate change” and “global warming”.)

In remarks following that summit, Gates emphasized that climate policies will not be successful using what he characterized as “brute force” approaches. “If you try to climate brute force, you will get people who say, ‘I like climate but I don’t want to bear that cost and reduce my standard of living,’” said Gates. “With innovation, it’s unlikely, particularly in middle-income countries, that the brute force approach will be successful.”

Recently, Britain—a longtime leading “net-zero by 2050” supporter—has backed off its previously announced transition plans due to added costs and unrealistic goals. On September 20, 2023, British Prime Minister Rishi Sunak, in his speech on net zero, said:

But what I have concluded during my time so far as Prime Minister, is that those decisions - the decisions that could bring real change, change that could alter the trajectory of our country - can be so caveated, so influenced by special interests, so lacking in debate and fundamental scrutiny that we’ve stumbled into a consensus about the future of our country, that no one seems to be happy with.

And this is because too often, motivated by short term thinking, politicians have taken the easy way out. Telling people the bits they want to hear, and not necessarily always the bits they need to hear.

We must reduce our emissions. And when I look at our economic future, I see huge opportunities in green industry. The change in our economy is as profound as the industrial revolution and I’m confident that we can lead the world now as we did then. So, I’ll have no truck with anyone saying we lack ambition.

But there’s nothing ambitious about simply asserting a goal for a short-term headline without being honest with the public about the tough choices and sacrifices involved and without any meaningful democratic debate about how we get there.

The Climate Change Committee have rightly said you don’t reach net zero simply by wishing it. Yet that’s precisely what previous governments have done – both Labour and Conservative. No one in Westminster politics has yet had the courage to look people in the eye and explain what’s really involved. That’s wrong – and it changes now.

Now I believe deeply that when you ask most people about climate change, they want to do the right thing, they’re even prepared to make sacrifices. But it cannot be right for Westminster to impose such significant costs on working people especially those who are already struggling to make ends meet and to interfere so much in people’s way of life without a properly informed national debate.

Coincidentally with the Prime Minister’s speech, the British non-profit Civitas: Institute for the Study of Civil Society released “Net Zero: an analysis of the economic impact”. The study predicted that the UK’s cost to implement “net-zero” would rise from the UK Government’s projected £1.3 trillion to, “at least”, £4.58 trillion. This is for a UK population of only about 70 million.

Many European countries, faced with increased energy costs and heightened energy insecurity due to Russia’s invasion of Ukraine, are also facing consumer backlash in upcoming elections about aggressive net-zero transition plans. As a result, backing off on “net-zero” pledges is not exclusive to Britain. In Europe, Germany is restarting coal plants to help ensure that their future electricity generation needs are met. Germany is also delaying the imposition of climate protection-related building codes due to affordable middle-class housing shortages. Britain and France are delaying announced bans on gas-fired boilers while Britain will also delay an announced ban on conventional petrol-fueled cars.

Similarly, Australia is also wrestling with how to achieve net zero. One recent news article included an estimate for Australia—with a population of only 26 million—that switching from coal to small nuclear fission power plants for electricity generation would cost an estimated $249 billion (US). That’s $10,000 per person for eliminating just a modest percentage of their overall use of fossil carbon fuels.

This growing political honesty in achieving “net-zero” has now opened the door to official renewed interest in SSP-generated astroelectricity.

As the peoples of the free nations of the world are now coming to understand, the post-World War II progressive political movement is failing on a broad range of important policy areas, particularly regarding protecting the environment while enabling robust global sustainable energy development. As mentioned, Sunak questioned the veracity of “simply asserting a goal for a short-term headline without being honest with the public about the tough choices and sacrifices involved and without any meaningful democratic debate about how we get there.” This failure has been very evident in both the Obama and Biden Administrations’ fervent pursuit of the Paris Agreement and net-zero environmental and energy policies.

It is important to segregate the goals of achieving net-zero anthropogenic carbon dioxide emissions and global robust sustainable energy supplies from the abusive and ineffective progressive political Great Reset and Green New Deal means of achieving these goals. While the goals are moral and warrant political support, the mentioned means are not and must be abandoned. Honorable politicians will recognize this to be true and respond accordingly, like Sunak.

This growing political honesty in achieving “net-zero” has now opened the door to official renewed interest in SSP-generated astroelectricity—the enabling “innovation” that Gates mentioned. Japan has expressed interest in SSP, as has China. Both Japan and China seek an in-space substantial SSP demonstration in the coming years. The European Space Agency has created the Solaris project with similar goals. It is noteworthy that they recently sponsored a substantive study of a lunar SSP architecture undertaken by Astrostrom (German for astroelectricity). Clearly, the world’s “go clean” political momentum is shifting away from terrestrial options towards astroelectricity. In fact, a new SSP-focused space race is getting underway as the world comes to understand that astroelectricity is the world’s new “oil” in terms of its future geopolitical importance.

My current quantitative-based findings favoring SSP

Several times since completing the 2008 white paper, I have updated the underlying quantitative analysis justifying the need for SSP. I summarized my most recent effort in a four-part series published in the fall of 2022 in The Space Review. Here are the key findings and conclusions:

  • To achieve the United Nations’ Sustainable Development Goals (SDG), an orderly worldwide transition to globally available clean energy should be the world’s primary peace- and prosperity-focused priority. Without abundant and middle-class affordable clean energy, the SDGs are unachievable.
  • Enabling free peoples, through their earnest efforts, to achieve the equivalent of a European middle-class standard of living should, as a minimum, be the target outcome of achieving the SDGs.
  • To implement an orderly transition to clean energy to enable a European middle-class standard of living, each one million people will require seven to nine gigawatts of equivalent continuous electrical power—abbreviated as GWc.
  • For a population of 10 billion, the world will need 70,000 to 90,000 GWc of clean energy to achieve the SDGs. For perspective, this is equivalent to 35,000 to 45,000 Hoover Dams operating continuously.
  • For a world population of 10 billion using terrestrial wind and ground solar power, a land area three times the size of Africa covered in wind farms, or 1.5 times the area of Australia covered in ground solar farms, would be needed to meet the SDGs. Obviously, these are impracticable solutions highlighting that the current terrestrial renewables-focused net-zero efforts will fail.
  • For a world population of 10 billion, if using nuclear fission power—with a plant capacity factor of 90%—the world would need roughly 78,000 one-gigawatt reactors. Each year, roughly 80 million kilograms of plutonium or U-233—both capable of being used for nuclear weapons—would need to be bred to fuel these reactors. For many reasons, “going nuclear” is extremely unwise and clearly not a scalable “clean energy” solution.
  • To fully embrace nuclear fission power today as America’s clean energy solution would require more than 10,000 one-gigawatt reactors or, perhaps, as many as 100,000 small modular reactors. These would need to be fueled with 10 million kilograms of bred plutonium or U-233 each year.
  • For a world population of 10 billion using a combination of 80% SSP-generated astroelectricity and 20% ground solar-generated electricity, the total land area needed would be roughly 2.3 million square kilometers—substantially less than either the wind or ground solar solutions. Further, the combined terrestrial astroelectric/ground solar plants can be geographically widely located to enable a robust global clean energy equitable solution, as shown below.
land area map

Note that current US per-person energy use is more than twice that of Europe. In fact, current European per-person energy use is about where the US was in the 1920s. This fact emphasizes the need for America to adopt practicable means and timelines for its orderly transition to clean energy to avoid the repressive “brute force” approaches currently sought by fervent environmentalists with the willing support of the Biden Administration.

How the clean energy political winds (pardon the pun) need to shift at DOE

Drawing on my quantitative estimates summarized above, the Energy Secretary’s tweet must grudgingly reflect acknowledgement that its past prioritization of terrestrial renewable and nuclear fission energy has been in error. Otherwise, there would be no quantitative basis for including SSP.

DOE’s stated mission is “to ensure America's security and prosperity by addressing its energy, environmental and nuclear challenges through transformative science and technology solutions.” As my analysis shows, scaling up wind and ground solar power or nuclear fission power to enable America to achieve net-zero, while keeping America energy secure and prosperous, is not practicable. Hence, the quantitative-driven need for DOE to now embrace SSP is clear.

In doing so, DOE policy emphasis and funding priorities will necessarily shift to SSP at the expense of wind power and nuclear power. With this shift, America will be entering the new space race to master the Age of Astroelectricity that will enable the world to peacefully achieve the UN SDGs with globally abundant clean energy. Moreover, America will be fulfilling the “freedom from want” pledge made by President Franklin D. Roosevelt in 1941 that requires free peoples to have abundant, middle-class affordable supplies of industrial energy.

Continued research advancing solar photovoltaic power generation will benefit both the space- and ground solar-components of the integrated space/ground solar power solution discussed above. Continued research into small modular molten-salt thorium-based nuclear fission reactors is also warranted to replace current aging reactors and for their possible use in space.

Regarding Shea’s “dangerous world” remark

Recall Shea’s remarks, “Climate change is an existential threat to our planet” and “It will however be a more dangerous world.” A key failure of the IPCC was its attempt to associate “climate change” with only possible anthropogenic-driven climate changes. It is clear that climate scientists still poorly understand the natural forcing functions dominating the Earth’s changing climate. Over the past several million years, the global climate has been driven by these forcing functions to oscillate between lengthy periods of extreme glaciation interspersed with much shorter periods of abnormally warm temperatures such as we are now experiencing. A natural climatic return to glaciation will destroy much of our industrial culture and, thus, is a true existential threat. For this reason, we still live in a “dangerous world”.

The Energy Secretary’s off-the-cuff tweet may turn out to be the important first step for DOE to recast its priorities and policies to favor the development of astroelectricity as the primary means for an orderly transition to clean energy.

At this time, we are unable to do anything to prevent a natural return to glaciation. However, that is not the only existential threat we face. As everyone understands, fossil carbon fuels are non-sustainable. The prosperity and peace of our industrial culture requires abundant middle-class supplies of affordable energy. As the history of the last 120 years shows, global energy insecurity prompts warfare. And, as Gates noted, the current “brute force” approaches of the fervent environmental movement to move to clean energy—whole-heartedly embraced by the Biden Administration—are not working.

Today, the primary existential threat the world faces is another world war by nuclear-armed nations should middle-class affordable supplies of fossil carbon fuels diminish without replacement by affordable supplies of practicable clean energy becoming globally available. Candidly, the Obama Administration’s on-going legacy of “brute force” poor energy and environmental policies—currently continuing in the Biden Administration—are the root cause of this threat. This is because America’s political proxy war against fossil carbon fuels energizes the global fervent environmental movement and backstops many progressive politicians’ “climate” misinformation.

This clear political existential threat must now be removed while we have the time and the needed economic resources to bring abundant clean energy to the world. The Energy Secretary’s off-the-cuff tweet may turn out to be the important first step for DOE to recast its priorities and policies to favor the development of astroelectricity as the primary means for an orderly transition to clean energy.

Setting net-zero by 2100 as the rational global goal

The primary global treaty addressing environmental protection and possible anthropogenic-caused climate change is the UN Framework Convention on Climate Change (UNFC3). Following that treaty’s adoption in 1992, a second formal treaty was pursued to define the specific actions needed to achieve the UNFC3’s goals. After several aborted attempts, the Paris Agreement was created in 2015 for this purpose.

While the UNFC3 treaty intentionally did not include any legally mandated carbon dioxide emission reduction actions, the Paris Agreement would require nations to adopt specific targets. While President Obama signed the agreement, it was not submitted to the Senate for consideration due to its expected lack of sufficient Senate support. Instead, the Obama/Biden Administration generally pursued implementing the agreement through regulatory and non-legislative judicial means sidestepping the legislative power of Congress. These have become the failing “brute force” methods aimed at achieving the highly ambitious net-zero by 2050 goals mentioned earlier.

When the Paris Agreement was signed, then-president of the World Bank, Jim Yong Kim, desired that the agreement would establish a “clear path to net zero before 2100”. Hence, instead of the unrealistic “net-zero by 2050” goal, the more achievable “net-zero by 2100” goal should be adopted to provide sufficient time for an orderly transition from fossil carbon fuels to clean energy. However, to be clear, this does not mean just ending the use of fossil carbon fuels by 2100 but replacing these with the abundant global clean energy needed to enable a universal European middle-class standard of living necessary to achieve the SDGs.

Can net-zero by 2100 be achieved?

Is net-zero by 2100 feasible? Technologically, I would argue in the affirmative. Recall that it was only 22 years from breaking the sound barrier in 1947 to Neil Armstrong and Buzz Aldrin landing on the Moon in 1969. Today, the US aerospace industry has substantial industrial and operational mastery that past efforts by NASA and the space side of the Air Force—now the Space Force—have not effectively utilized since the 1980s. There is substantial American industrial prowess yet to be tapped that can be used to aggressively pursue the development of SSP.

To look at feasibility from an economic perspective, an engineer’s “back of the envelope” estimate will be helpful. Recall the Civitas estimate of £4.58 trillion ($5.59 trillion) to achieve net-zero by 2050 for a UK population of about 70 million today. For a world population of 10,000 million, this would equate to $800 trillion. The current size of the world economy is about $100 trillion. Assuming no growth through 2100, the total economic activity grows to $7,500 trillion. Of this total, the transition cost to net-zero would require about 10 percent of the world’s economic activity.

Of course, the world’s economy will continue to grow, typically about 4% per year provided there is ample affordable energy during the transition. Thus, it is reasonable to expect the needed clean energy transition cost percentage will fall significantly while the cost of implementation will also fall due to technological advancements.


For reasons not now known, DOE may have entered the United States into the forthcoming global space race to pursue the world’s new oil—astroelectricity. A simple, short tweet was all it took. The result will be an exciting future for America as we reorganize our immense national resources to participate—if not lead—the world’s transition to a true human spacefaring civilization, permanently settling and industrializing the central solar system to make the Earth clean energy secure with abundant astroelectricity. What America needs to do now is to chart an effective path spaceward to make this goal achievable!

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