In 1975, an Arizona magazine had a vision of a solar future. See what

A painting of a white city, clustered around pearly towers and skirted by leagues of brilliant solar panels, wraps the front and back cover of Arizona Highways’ August 1975 edition. The painting, titled “Vision of Tomorrow,” was a commissioned work by Arizona artist Robert McCall, who painted scenes of space exploration for NASA during the race to the moon.

This time, his vision was not space, but Arizona, and the futuristic mission was not the moon landing, but the transition to solar energy.

“Tomorrow, new cities will rise on the Arizona desert,” the caption to McCall’s painting reads. “These cities will be free from much of the pollution that affects us today, thanks to an endless supply of pure, clean energy from the sun.”

Fifty years later, massive solar fields tile swaths of Arizona’s deserts, and clean energy has gone from being “alternative” to mainstream. Far from science fiction, a solar-powered world is now growing into a reality. In 2025, Arizona had a total of 11.4 gigawatts of solar power capacity installed across the state, equivalent to more than five Hoover Dams.

“We are now big business in this country,” said Frank Macchiarola, the chief advocacy officer of renewable energy advocacy group American Clean Power, at a June conference in Phoenix.

Arizona’s solar energy advocates encapsulated their hopes and dreams in that Arizona Highways solar edition, titled “Solar Center, Arizona, USA.” The edition was entirely dedicated to solar energy, with articles on solar home designs, solar energy research and the importance of the sun in ancient cultures.

How the role of solar energy has evolved

Arizona Highways released its special edition on solar energy because a contributing editor, Dan Halacy, was part of an active community of solar advocates in Arizona that included senators, scientists and writers. Following the 1973 oil embargo, the United States experienced a surge in interest in renewable energy sources. With its flat, sunny spaces and growing high-tech industry, Arizona seemed like the perfect place to become a global hub for solar energy research.

While they understood its fundamental appeal, early solar advocates couldn’t foretell the factors that would finally bring their prized technologies to global significance. In many ways, they underestimated the power of solar. Rather than a supplemental energy source to be deployed along with fossil fuels, renewables may soon become capable of replacing fossil fuels altogether. And rather than providing alternative methods of heating and cooling, solar can now provide huge amounts of electricity to power almost any aspect of human life.

Climate change and economics, not limits on fossil fuels, would ultimately drive the adoption of renewables in the United States. And perhaps the most unexpected element of solar’s progress for early advocates would have been the role of China, not the West, in making solar energy the global phenomenon it is today.

“What would looking back 50 years from now, besides teaching us a certain amount of humility about our predictive abilities, what does that tell us? … What I expected to see in 1975 is not what I see now,” said Frank Laird, a professor of public policy at the University of Denver.

The rise of solar technology has not been straightforward. The first solar active solar technology used in Arizona, installed in 1904, was a steam engine that used mirrors to superheat water and drive pumps for irrigation. It cost close to $90,000 in today’s dollars and broke down when it was destroyed by hail two years later.

That form of harnessing solar energy became obsolete when electricity generated from fossil fuels became cheaper than sun-powered steam and more practical than rooftop solar water heaters (non-electric methods of solar energy use). Today, that story has flipped. Electricity has become the main method of using sunlight and is now cheaper than power from fossil fuels.

But the appeal of a ubiquitous, clean and cheap energy source remained a through-line in solar’s meandering history. Arizona’s solar advocates saw that appeal in 1975, even if they couldn’t see how that appeal would manifest in a new millennium.

“I’m nervous about the word ‘inevitable,’” Laird said. “History has its way of taking funny little detours … But I think the economic argument has been a very powerful one for China … It all could have gone in a different direction, but as a consequence of China, things like solar and wind are cheaper now.”

‘It’s possible, go for it’

Solar advocates’ passion and curiosity must have played no small part in the technology’s success, according to Zachary Holman, solar technology specialist and vice dean for research and innovation at Arizona State University’s Fulton Schools of Engineering.

If he could send a message back in time to his predecessors in 1975, Holman said he would send a simple statement:

“It’s possible, go for it.”

The enthusiasm that buoyed solar energy and filled an entire edition of Arizona Highways with solar dreams ultimately faded after the 1970s, deflated by an influx of cheap oil and gas after conflicts ended in the Middle East.

Today, some analysts worry the United States will turn away from solar again. After years of heavy government investment in green energy, spurred by a desire to renew the U.S. industrial base and avoid the worst consequences of climate change, a new administration is throwing road blocks in front of the technology’s success.

These slowdowns could keep the country from quickly responding to climate change, exacerbating droughts and fires that already plague Arizona. But climate change has only ever been one component in the story of solar energy; many of its early advocates never mentioned it. What they saw was an opportunity for clean, abundant, democratized energy. And they thought Arizona was the perfect place to harness it.

Early advocates never mentioned climate change

For all the senators, scientists, and writers who gushed over solar energy in the Arizona Highways 1975 solar edition, none of them mentioned something we now almost implicitly associate with the technology: climate change.

Only one year after Arizona Highways published its solar edition, a group of environmentalists gathered by President-elect Jimmy Carter released the “Wolfcreek Statement,” a written case for “energy conservation,” including the adoption of alternative energy sources like solar. The authors offered a range of reasons for supporting solar, and nestled among them was danger from “climatic stability.”

Meanwhile, in the Arizona Highways solar edition, climate change isn’t mentioned once. Instead, the authors actually supported burning more coal, alongside solar power, to meet the nation’s energy needs. The magazine and the report both show that environmentalists, and their would-be pro-growth adversaries, had reasons to support solar energy well before public climate change boosted the technology’s profile again.

Advocates in the Arizona Highways edition supported solar for basic reasons: The sun is abundant, free and almost impossible to monopolize. As crises in the global oil and gas markets shook the United States in the 1970s, an energy source that didn’t rely on foreign governments or fluctuating markets seemed perfectly rational. And at a time when the Great Depression still loomed in popular memory, frugality through efficiency was seen as a moral goal.

“They were children of the Depression … I think it was a kind of mindset of just being frugal or having common sense about resources. But they weren’t thinking about sustainability or climate change,” said Anthony Denzer, a professor of architectural engineering at the University of Wyoming who has studied the history of solar house design.

Scientists were aware of the possibility of greenhouse gas-caused climate change in 1975, but its full impact had not been well analyzed and publicized.

Even in environmental circles, climate change was just emerging as an issue of note at that time. Many leading environmentalists strongly supported alternative energy sources, though they also focused more on thrift and constraints on rapacious energy use, not climate change.

“The keystone of a rational energy policy must be a national commitment to energy conservation. Such a commitment will provide the time we need to develop and deploy energy technologies that are safe and sustainable,” the authors wrote in the Wolfcreek Statement.

Changes in policy: Energy emergency? Trump cuts to efficiency, aid programs in AZ could create one

1970s ‘energy emergency’ gives solar a temporary boost

Because the public hadn’t registered climate change as an existential threat to the current way of life, alternative energy sources were often seen as a way to cut society’s active energy use, not as a way to replace fossil fuels and spur more economic growth.

Whether they were concerned with national security or the environmental costs of constant growth and fossil fuel consumption, most advocates saw solar as a way to sober up from a reckless and dangerous addiction to fossil fuels and adjust American society to a future where “outmoded ideas and extending past trends of exponential energy growth.”

“The harsh truth is that our country has seen the last of the era of cheap fuels when natural gas, oil, and coal were abundant and economical,” Sen. Paul Fannin, R-Ariz, wrote in the first pages of the Arizona Highways solar edition.

The so-called “energy emergency” gave solar energy an unprecedented boost. Congress passed the Solar Energy Research Development and Demonstration Act in 1974, spurring research into solar. President Jimmy Carter installed solar panels on the roof of the White House and held a “Sun Day” in 1978 to promote solar research. The federal government founded the Solar Energy Research Institute, the same center that Fannin hoped to lure to Arizona when he wrote his article in the Arizona Highways solar edition (the institute ultimately landed in Golden, Colorado, and is now known as the National Renewable Energy Laboratory).

But economic boosters and fossil fuels opposed both arguments; fossil fuel shortages were painful, they said, but temporary. When the oil shocks of the 1970s ended, and the United States began producing more of its own fossil fuel resources, oil became abundant, and calls for austerity and alternative energy, both environmental and national security-oriented, lost their luster.

President Ronald Reagan cut funding for SERI, removed the solar panels from the White House roof, and rolled back government support for solar companies. The dozens of companies that sprang up to reduce U.S. households’ dependence on fossil fuels went out of business. American growth, fueled by oil and gas, became easy and obvious. The economic boosters had won, and the environmentalists and renewable energy advocates had not.

That dynamic changed as climate change became a global talking point and cheap solar panels hit the market decades later. The two forces provided a rare opportunity for economic boosters and environmentalists to join forces, and they have since claimed real victories.

Slower solar? Rooftop solar growth dims in sunny Arizona as regulators clash and costs climb

Reduce consumption or increase renewables?

As the 2020s opened, the United States suddenly gained access to a cheap supply of abundant solar energy that could power more economic activity while satisfying environmentalist’s greatest fear about a warming climate (while also reducing the air and water pollution associated with fossil fuel consumption).

“The renewable energy advocates now enthusiastically embrace the economic narrative, and they’re partly right; the price of wind turbines and the price of solar panels have dropped a lot,” Laird said.

Bill McKibben, an environmentalist author and climate activist, calls the new climate-economic nexus a “future-oriented angle” on renewables, one that suddenly merges environmental, political, and economic arguments in a way he has rarely seen before.

When he started writing about environmental issues in the 1970s, McKibben said, his primary concern was for the natural environment. His first book, “End of Nature,” was all about the deep impacts climate change would have on ecosystems and natural processes. Now, he says that love for the natural world may have to allow for human impacts on the landscape that fight climate change.

“(Environmentalists) are going to have to adapt their aesthetic to allow for a windmill on the horizon, or whatever it is. And truthfully, I find most people easily able and enthusiastic about doing that. I think now most people have come to think that windmill on the horizon is something beautiful,” McKibben said in an interview about his new book about solar energy, “Here Comes the Sun.”

McKibben said the moment has put environmentalists in a strange new position of saying “yes” rather than saying “no.” There are two ways, McKibben said, that the earth can avoid the worst effects of climate change: to rapidly reduce global emissions through a slowdown in consumption, or to reduce them by “ripping out the guts” of the global fossil fuel economy and replacing them with renewables.

Slowing people down, McKibben said, is too unattractive and ineffective, while cheap renewable power makes the latter option enticing.

“I still think that 100 years from now, humans will have figured out better ways to amuse themselves than buying more stuff,” McKibben said. “But I don’t think that’s going to happen in the next four or five years, which seems to be the crucial time frame for doing something about climate change.”

Renewable hurdles: Trump plan to deregulate climate pollution could make Arizona hotter, drier and more fiery

Today, climate change is a driving force in the engineering and research that has made renewable energy affordable and accessible. Holman said climate change motivated him to begin his career in renewables in the early 2000s.

“I loved that I could contribute with material science and physics and engineering to something that seemed like it was important to the future of humanity,” Holman said.

Since then, Holman has helped his graduate students launch five companies from his department at ASU, often bringing new technologies to the market with each one.

Holman said his students come from an array of majors, including physics, engineering, and chemistry. Holman said they rarely fall into solar energy research by chance.

“Those students come to renewable energy sources as a topic where they feel like they can contribute meaningfully,” Holman said.

They believed oil prices would push people to solar

Two years before Arizona Highways published its solar edition, oil prices in the United States quadrupled in less than a year as Arab governments stopped selling the country oil, protesting its support for Israel in the Yom Kippur War.

“With alarming suddenness, we joined long lines of vehicles waiting for gasoline that too often was gone almost immediately. Many people had to bundle up against the cold as heating oil, natural gas, and other fuels were also severely curtailed,” Fannin, the Arizona senator, wrote in Arizona Highways.

The Arizona Highways solar edition emerged at a time when shortages in fossil fuels, not the negative impacts of their use, was the driving argument for solar energy adoption. National security-oriented thinkers argued that the United States would suffer more oil shocks from international conflicts. Environmentalists argued that the United States’ recoverable fossil fuel deposits were running out, a theory that would echo through the decades in different forms.

“More than half of our recoverable domestic supply of our two choicest fuels has been exhausted. The future holds inevitable conflicts between habits and prices, between convenience and vulnerability, between the broad public good and narrow private Interests,” the statement reads.

Solar energy couldn’t replace gasoline in cars at that point, but passive solar heating could replace the heating oil that most Americans used to warm their homes.

“Back in the 70s, a lot of parts of the country used a lot of fuel oil to heat houses,” Laird said. “(Replacing heating oil) was kind of the major goal. Solar electricity at that point was super expensive compared to what the utilities could produce. So it wasn’t really a competitor for electricity.”

At the time, deploying solar energy in that way would have been a step backward. Solar water heaters were common in the United States in the early 1900s, before electricity and cheap oil and gas replaced them with more on-demand methods of heating. As a result, solar was described not as a step forward in productivity, but as a release from the country’s dangerous overreliance to cheap oil.

But the oil embargo ended, the United States ramped up production of its own fossil fuels, and, as the Economist wrote in a 2023 article, “the world slipped into complacency as the disruptions of the 1970s faded from memory.”

Laird attributed part of that process to the new attitude Reagan brought to the White House when he was elected in 1981.

“Then Reagan came into office and more or less declared the crisis over … the very high prices of the 70s had encouraged (exploration and drilling). So oil production was going up in the 80s, so that crisis was alleviated,” Laird said. “And (new high interest rates caused a recession). When you have a recession, demand for gasoline and diesel goes down.”

Solar energy retreated to a niche interest after the threat of oil shocks dissipated. It returned briefly in the 1990s as the Gulf War interrupted global oil supplies for a moment, but then retreated again, according to Laird.

Every time the United States suffered a shock to its oil supplies, foreign policies would loosen and domestic drilling would grow, bringing back cheap energy supplies and sidelining arguments for alternative energy sources. In the early 2000s, a group of hobby theorists, along with some notable economists, started ringing alarm bells about a phenomenon they called “peak oil.”

Theorists like Jeff Rubin, a Canadian economist and author, held that the world was running out of its easily accessible oil supplies, and that harder-to-reach supplies wouldn’t be economical to reach. The issue became a “darling of liberals,” in the words of peak oil denier Michael Lynch, and was sometimes paired with climate change as a justification for weaning Americans off of fossil fuels, largely by reducing their travel.

New administration: How Trump’s actions on energy could worsen climate change in Arizona

Oil companies find ways to access new supplies

Peak oil theorists didn’t believe alternative energy sources could replace oil in the United States. Rubin, for instance, would argue that electrification couldn’t replace fossil fuels because his home city of Toronto struggled to keep air conditioning units running during the summer. Instead, Rubin’s allies saw a smaller, or at least leaner world of constrained energy use, one where air travel gave way to video calls.

But the world never ran out of oil. Instead, oil companies accomplished exactly what the peak oil theorists thought they couldn’t—they invested in new technologies that could access new supplies. The invention of fracking spurred the “shale revolution,” which flooded the market with new oil and gas supplies and made the United States the world’s largest oil producer.

“It’s debates like these, where so many are so certain without expertise or knowledge of the subject, and agitate for often-costly policies to cope with their assumed crisis, that make the public skeptical of warnings about our imminent doom,” Lynch wrote in 2019.

Ironically, energy experts are now debating when the world will see peak oil demand, not peak supply. Fatih Birol, executive director of the International Energy Agency, who once argued that the world would reach peak oil supply before 2020, is now under fire from the Trump administration for predicting that the world could hit peak oil demand before 2030, long before the globe can exhaust its supplies. The agency may now be walking that prediction back, as it assumes some governments will implement policies that may not materialize.

Regardless of when peak oil demand hits, the culprit that could bring it about is the same energy source that peak oil theorists dismissed in the first place: solar energy.

Slower solar? Arizona’s clean energy industry falls silent as Trump bill threatens progress

China emerges as a solar leader

While the United States had managed to overcome most of its oil shocks, partly by expanding its domestic production, China took the national security threats of an overdependence on foreign oil seriously. China, unlike the United States, has limited oil and gas reserves, and nearly all its oil imports travel through the narrow Strait of Malacca, meaning the country and its booming economy were potentially more vulnerable to oil shocks than the United States.

China identified “new energy” as a strategic industry in the early 2010s, launching decades of government investment in the space. American and German companies had already vastly improved the technology for commercial and industrial applications, proving that solar energy could not only replace heating oil in homes, but also power batteries in cars and electrify cities and industries.

China threw the force of its government and national security interest behind further development and scaled up solar panel production beyond what was previously possible. Today, China is not only the leading producer of solar technology but also a leading center for solar research and innovation.

Holman, the ASU professor who works on solar technology, said this was the period when solar energy research shifted from exploration to mass production, and from Western countries to China.

“Lately, it hasn’t been a lot of exploration. It’s been kind of cutthroat competition, with everybody doing the same thing. Now the question is, who can do it better?” Holman said.

As a result, solar panels plummeted in cost, making them an even cheaper energy source than the fossil fuels that had driven U.S. markets for more than a century. Of the renewable power generation added in 2020, about 62% was cheaper than the cheapest new fossil fuel option, according to a 2021 report from the International Renewable Energy Agency.

“If you were to look around yourself right now, maybe have a window near you, some wall material, maybe some brick … All of the materials that you could look around and see are basically more expensive per square foot than solar panels,” said Holman.

Cheap solar panels (and cheap wind power) began exploding onto power grids all over the world, including Arizona. Electric vehicle adoption exploded, too. The economic and climate-related benefits of solar power motivated the Biden Administration to push legislation extending tax cuts for renewable energy projects, build American-made panels and other electrified energy system components and craft a new energy system. The administration saw that it could tackle climate change while investing cheap power that could be run through a unified electric energy system. The new energy system would be more independent of foreign or market influence, and it would create new jobs.

Though the Trump administration has since rolled back many of those efforts, solar power remains cheaper and cleaner than fossil fuels. Utilities can’t build out entire grids on renewable energy yet, because the sun and wind don’t always produce electricity, but improvements in battery technology, including components built in Arizona, could address much of the problem.

Salt River Project’s power utility and Google announced a partnership in September to install and monitor new long-duration batteries on SRP’s grid so the patterns can identify weaknesses and “accelerate the advancements needed to deploy LDES at scale.” The goal is part of both organizations’ commitments to phase away from fossil fuels and switch to more renewables.

“Through our collaboration with SRP, we aim to accelerate the innovation and technological advancements necessary to deploy LDES solutions at scale so communities in Arizona and beyond can meet their power needs reliably and cost-effectively for years to come,” said Lucia Tian, Google’s Head of Advanced Energy Technologies, in a press release.

Room in the desert: Solar energy bills target Arizona’s La Paz County, with bipartisan support in Congress

Some foresaw the massive solar fields in Arizona’s deserts

Most of the visions for solar energy in the Arizona Highways solar edition never worked out. Passive solar-heated houses are rarer today than they were then, and few houses use sunlight to heat their water.

There was one vision mentioned in the Arizona Highways that did pan out, the vision of a couple of scientists at the University of Arizona, whose fascination with solar energy literally became a labor of love.

Aden and Marjorie Meinel, a married couple, were some of the first people to understand the true future of solar energy in Arizona: ranks of power-generating panels, tiling the state’s desert expanses. While other solar advocates were pushing for special home designs that used sunlight as a form of climate control, the Meinels understood that electricity would become the most important form of solar energy.

Solar technology was part of the Meinels’ relationship from the get-go. Aden and Marjorie met in Pasadena, California, where Marjorie cooked Aden hot dogs using a solar steam engine her father had built to run a shop lathe. The couple would later become two of the country’s foremost experts on solar energy, fostering a love that defined their relationship and their careers are researchers at the University of Arizona.

While many solar advocates pushed for passive methods that could be deployed in the 1970s, the Meinels believed solar electricity generation was the future. They created Helio Associates, a research company, and earned financing and partnerships from Arizona Public Service, Salt River Project and Tucson Gas & Electric (now Tucson Electric Power), Arizona’s largest power utilities, to explore their ideas.

Their first concept was to create a massive solar farm out of the western Arizona desert. Later, they envisioned sunken reflectors, with Marjorie even proposing that the Lavender Mine Pit outside Bisbee could become a mirror-covered solar energy-generating facility. The Meinels believed the mine pit could have produced 80-100 megawatts of electricity.

The Meinels’ ideas appear in Arizona Highways through McCall’s paintings, who depicted vast tracts of mirror-like panels, girding cities, overlaying entire desert landscapes. McCall envisioned space-age command centers for managing the solar arrays, with officers in sharp uniforms harnessing the power of the sun.

McCall’s science fiction style would have been familiar to readers at the time, as he had painted promotional artworks for Stanley Kubrick’s 1968 film, “2001: A Space Odyssey,” and worked on  postage stamps and murals documenting the space race for NASA. McCall was an apt illustrator for the job: at that time, photovoltaic solar panels were so expensive that powering satellites was one of their only real-world applications.

Along with the images of solar panels covering the Arizona landscapes, he also depicted huge arrays that could be launched into space, where they would power long-distance exploration.

“These products of space-age technology (the Meinels) thought might make solar energy feasible not only for heating and cooling, but for generating vast amounts of electricity as well,” reads an article in Arizona Highways.

The first large solar facility to feed electricity into Arizona’s grid was not a giant pit of mirrors, but an 82-kilowatt solar field constructed near Flagstaff and operated by Arizona Public Service in 1997. The facility was a different kind of solar technology than the Meinels predicted: photovoltaic cells use sunlight to excite electrons in silicon slabs, directly creating electricity, while the Meinels were focused on solar thermal energy, which uses sunlight to heat water, creating steam that turns a turbine. Still, the image remained the same: Arizona could use its vast, sunny, flat land surface for power.

Solar facilities now provide roughly 15% of the electricity generated in Arizona. The state has added roughly four gigawatts of solar power capacity to its grid since the beginning of 2023, roughly equivalent to building two Hoover Dams in three years. The state is ranked fourth in the country for total solar power capacity.

Holly Irwin, a La Paz County supervisor, said solar farms could give her rural local government enough revenue to fill out the “skeleton crews” in its county departments. Connecticut-based Lotus Infrastructure Partners installed the Ten West Link transmission line in La Paz County in 2023, and Solar developer 174 Power Global is now constructing the Atlas Energy Park, a massive 700 MW solar farm.

Meanwhile, the Bureau of Land Management approved permits for another massive solar farm — the 600 MW Jove Solar Project. Both facilities will produce tax revenue for La Paz County, where small towns and a tiny slice of privately owned land produces little tax revenue for local services.

“We have to create our own revenue stream, and this is a great way of doing that in an area that is undisturbed, it’s out in the middle of nowhere, but it’s generating revenue for the county and for our businesses,” Irwin said.

Irwin said local hotels and restaurants served the workers who arrived to build the facility, while local contractors pitched in on the construction. La Paz County’s representative in Congress, Paul Gosar, R-Ariz, passed bills to get federal land under the facility transferred to the county, and he has introduced another bill to give counties more of the revenue from solar facilities on federal land.

On the other end of Gosar’s district, in Goodyear, Arizona, an American company is now producing some of the components used in the huge solar facilities nearby. Fluence, an American grid-scale battery systems company, opened its new battery enclosure factory, complete with AI-powered automated machinery, in May. One of the guests at the opening was Michael Alvarez, chief operating officer of Longroad Energy, which has installed Fluence’s battery systems only 20 miles away from where they’re manufactured, at one project within Longroad’s 900 MWdc Sun Streams complex.

“We are very proud of Fluence here because of their dedication and commitment to seeing America rebuilt greater and better … bringing that energy component back to our shores here in America, bringing manufacturing jobs back to America, bringing high-skilled labor jobs to this community, that is something we love to see,” a spokesperson from Gosar’s office said at the factory’s ribbon cutting.

Lying on 5,000 acres of state land in the West Valley, the whole Sun Streams complex will have the capacity to generate close to 900 MWdc of electricity, with Arizona Public Service contracting more than 650. The complex is among the largest solar developments anywhere in the United States. A Longroad spokesperson said the company found an ample, qualified pool of employees in Arizona and plans to develop more projects in the state.

Meanwhile, Mohave County, also part of Gosar’s district, hasn’t been as eager about the benefits of a new solar economy like its neighbors. The county lifted a moratorium on major solar projects in 2024, but left stringent zoning restrictions in place. According to Irwin, Mohave County didn’t bite on solar like La Paz did because of “one simple reason: money.” Irwin said Mohave County has enough of a tax base that it doesn’t need solar energy to fund its operations.

Many of these moratoria come from debates about land use. Sunlight is ubiquitous, but it is also diffuse, according to Holman, meaning solar facilities will “always be about covering wide areas.” Cattle ranchers protest the installation of solar farms on federal grazing lands, and neighbors resist the effects on their views.

But other reasons have crept into local governments’ paranoia about solar technology also. Autumn Johnson, executive director of Arizona solar advocacy group AriSEIA, said myths about solar energy have flourished in communities across the state, stalling the construction of cheap, deployable electricity when the state needs it most.

“No, they’re not going to make your horses sterile. No, solar panels are not going to blow up and leach toxins into your water … these are things we actually have to spend time refuting,” Johnson said.

Misinformation about solar energy has spread so far that Columbia Law School’s Sabin Center for Climate Change Law dedicated a 60-page report to busting solar myths in 2024.

Irwin said La Paz County has only found one land-use issue with its solar developments so far — a plan to send a transmission line through part of the Arizona Peace Trail, a rugged offroading destination in the Mojave Desert— and that plan was changed to satisfy complaints.

“So they worked it out, and it was fine,” Irwin said.

Energy debate: A solar ban, a gas power plant and the rural retirees firing back at dirty energy

They believed sunlight would heat homes without panels

The Tempe Municipal Building looks like it was built upside down, and that’s kind of the point. Architects Michael Kemper Goodwin and Rolph Oswald designed the building like an inverted pyramid so that none of the walls would receive direct sunlight, keeping the building cool in Arizona’s scorching summers. There seems to be no downside to being upside-down, a clever workaround for expensive summer air conditioning bills, according to city staff.

“They’re able to clean all the windows,’ said Eric Iwerson, Tempe’s director of transportation and sustainability.

One might imagine, as the solar advocates in Arizona Highways did, that this kind of building design would become popular in Arizona. But 55 years after Tempe unveiled its upturned pyramid, the building remains a rare breed. Passive solar designs, either for heating or cooling, soak up much of the page space in the 1975 solar edition, but they take up almost none of solar energy’s real-world applications in 2025.

The Tempe Municipal Building is an example of “passive” solar design, which uses the arrangement of walls and windows to let sunlight heat or cool a space without exerting any extra energy. “Active” solar heating means using solar panels to heat water or air and circulate it around the house, or to generate electricity that powers a heater or AC unit.

One section of the Arizona Highways solar edition is filled with designs from students of Jeffrey Cook, a professor of architecture at ASU, who taught arid region design and emphasized energy conservation. “(Cook’s students) feel very positive about energy conservation. Their design concepts show a strong feeling of sympathy with the natural environment,” the anonymously written section of the magazine reads.

Cook and his students had good reason to believe they were onto something big. A few years after their designs appeared in Arizona Highways, the Carter administration launched a huge campaign of support for passive solar designs. Over 1.1 million people used the credits between 1978 and 1984, and a 1979 report by Carter’s Department of Energy projected that 41-48% of new homes built in the year 2000 would be passive solar.

Arizona was already a hub for solar design at the time, along with Chicago and Boston, according to Denzer, the architecture professor at the University of Wyoming. Solar advocates like to point out that Ancestral Puebloan structures — including the Montezuma Castle south of Sedona — used alcoves in canyon walls to capture warm sunlight in the winter and create shade in the summer. Later, Tucson architect Arthur T Brown took inspiration from those designs, experimenting with solar designs throughout the 1940s and through the 1970s.

“Arthur Brown was kind of on his own out here in Arizona doing this, and he said it was also counterintuitive, because nobody cared about saving fuel at that time, electricity was cheap … So he, he, he kind of was proud that he was, you know, doing things that were against the grain,” Denzer said.

Later, Brown was joined in a proliferation of passive solar enthusiasts. Architects Guilford Rand and Rod Frier laid out designs for passive solar houses and hospitals to be designed all over Arizona.

The concept was so exciting that the Copper Development Association, a nonprofit that boosts the use of copper, built a passive solar house with an all-copper roof in Tucson as a kind of marketing showcase — “surely the most elegant example of solar architecture in the world,” the Arizona Highways reads.

The house included an all-copper roof, a copper fireplace, and an entire wall mirrored with brass. The copper roof used sunlight to heat water, and the home, in the winter, and cool the home through absorption-type refrigeration units in the summer. It also included a solar battery that provided some electricity.

Meanwhile, famed utopian designer Paolo Soleri was still drafting concepts for Arcosanti, an energy-efficient community with passive solar concepts at its heart (Soleri has said he was directly inspired by Ancestral Puebloan designs).

The Arizona Highways issue, which includes images of some initial Arcosanti designs, was published five years after Soleri’s students and followers began constructing the community near Interstate 17 north of Phoenix, where it still stands today. The building uses a concave half-dome, much like an alcove in a canyon wall, to regulate temperature in its workshops and common areas.

Today, Arcosanti has installed air conditioning units to deal with increasingly hotter summers; the so-called “Decade 80” house no longer exists at its previous location in Tucson, and Tempe has not continued building inverted pyramids. But that doesn’t mean Arizona has abandoned the idea of solar power in buildings — Arcosanti’s AC units run partly on electricity from solar panels, and Tempe has kept its power bills flat as it adds new facilities by installing solar on the roofs of its buildings.

For more great environmental journalism: Sign up for AZ Climate, The Republic’s weekly environment newsletter.

Installing solar, recouping the costs

Modern houses use better insulation and airtight window technology to be more energy efficient, instead of using passive solar designs that use sunlight for climate control, according to Denzer. When paired with electric heat pumps and solar panels, the modern home can exceed the energy conservation goals that old solar house designs aimed for.

“A lot of the best zero-energy houses I see are not so worried about passive solar heating, because if it’s very well insulated and airtight, you can heat your house with the equivalent of a hair dryer, and you’re better off putting that extra $10,000 into some solar panels,” Denzer said.

Affordable electricity generation was just a “gleam in the eyes” of 1970s solar advocates, Denzer said. Today, the technology is so cheap that the panels themselves only account for a small component of the cost to install solar on a person’s roof (the labor, racking materials, and electrical work make up the bulk of the price tag), according to Holman.

Pete Hladek installed solar panels on his roof in Surprise, estimating he saves $240 per month on his power bills because of the panels (at current power rates), saying he thinks he’ll recover the cost of the panels about nine years after installing them. Hladek has pages of hand-written calculations estimating the time it will take to recover the money he spent on his panels. 

“I have three or four friends I play pickleball with, who came down here as snow birds and decided they wanted to buy a bigger house. And one of the things that they demanded was that the house had solar,” Hladek said.

Along with his panels, Hladek uses some old-school passive solar as well: he installed two skylights in his bathroom and hallway to light those rooms without electricity during the day (the skylights also have a small internal solar panel that turns them into dim nightlights during dark hours).

Hladek is one of thousands of Arizonans with residential solar. The state ranks fourth in the country for the number of solar panels on residential rooftops (per capita). Just as an industry bloomed in the United States for installing solar water heaters in homes following the oil embargo, a new industry has popped up in Arizona for installing photovoltaic panels.

That success is being tested now. Residential solar installations have plummeted consistently since 2023, even as utility-scale installations have kept solar power rising overall. Arizona utilities, as with others around the country, have reduced the rates they pay for power from residential solar panels, and some utilities like SRP have even started charging fees for customers that put solar on their roofs.

Utilities argue that solar owners don’t pay enough into the system through power bills, meaning other customers end up shouldering the burden of paying for grid maintenance. Meanwhile, Republicans in Congress are ending a tax credit for residential solar installation at the end of 2025, nine years before it was initially set to expire.

Utilities are experimenting with some new ideas that could adapt residential solar to the needs of the grid. “Virtual Power Plants” are networks of solar panels, electric vehicle chargers, thermostats, and electric water heaters in individual homes that utilities can harness together to meet their needs. Instead of one big field of panels, utilities can use a neighborhood of solar homes and individual batteries to produce power.

“We have rising energy demand, an aging grid, more extreme weather, and rising energy costs,” said Sheila Hallstrom, Arizona regulatory lead at renewable energy advocacy group Advanced Energy United. “Advanced energy technologies can help address all of these concerns. They are fast to deploy, affordable, flexible, and give residents control over their energy sources and use.”

Austin Corona covered environmental issues for The Arizona Republic and azcentral.

Environmental coverage on azcentral.com and in The Arizona Republic is supported by a grant from the Nina Mason Pulliam Charitable Trust.