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Distillations magazine. First solar generator

Distillations magazine. First solar generator

    The Sun Queen and the Skeptic: Building the World’s First Solar Houses

    In the mid-20th century, colleagues-turned-rivals Maria Telkes and Hoyt Hottel engineered new ways of heating American homes.

    Before the bad blood and competition, before he agitated for her dismissal and her fame eclipsed his, Hoyt Hottel and Maria Telkes had been colleagues pursuing a common goal: to find new ways to use the energy radiated by the sun.

    Working together at MIT in the 1940s, they wrestled with basic questions solar engineers continue to confront. How can sunlight be efficiently converted into other forms of energy? How can the resulting heat or electricity be stored and put to use? Can solar technologies produce energy cheaply enough to be useful in everyday life and supplant the world’s finite supplies of polluting fossil fuels?

    Many Americans were particularly enthralled by the idea of using the sun to warm their homes. The prospect of free heating proved irresistible to a generation that had learned hard lessons about scarcity and thrift as they endured the Great Depression, wartime fuel rationing, and oil panics. A few enterprising architects had already garnered attention for building so-called passive solar houses, which used walls of south-facing Windows to maximize the homes’ warmth in winter.

    “No idea of the last 30 years has so fired the imagination of the American public as the one of letting the old sol reduce the winter fuel bill,” declared a 1942 article in House Beautiful.

    As interest grew at academic institutions and in private industry, scientists began designing materials and systems to better capture solar energy. Among the many animated by the idea of exploiting the sun’s seemingly endless bounty was Godfrey Lowell Cabot, an industrialist from an old Boston Brahmin family. Cabot had grown very wealthy manufacturing the carbon black used to strengthen and extend the life of car tires. In his later years he became obsessed with energy and solar energy in particular, funding research at both Harvard University and MIT.

    “Godfrey Lowell Cabot of Boston speaks to almost anybody, but his thoughts are definitely heavenward,” Time reported in 1938, soon after Cabot gave MIT a sizable donation. “He is 77, and in his old age he broods much about the vast stores of energy in sunlight which man does not utilize.”

    In 1939 MIT hired Telkes, a Hungarian immigrant and one of the very few women in engineering, to join its nascent solar program. Like Cabot she was a fervent believer in solar energy’s potential to replace potentially limited fossil fuels, such as coal and gas. Solar energy, she once wrote, “is the greatest untapped energy resource of the world and its utilization should be one of our most important and fruitful projects.” She was later dubbed the Sun Queen for her many groundbreaking solar inventions.

    Hottel, a chemical engineering professor and the leader of MIT’s solar project, was far more skeptical of the technology’s prospects. than once he criticized its proponents for what he considered fuzzy-headed optimism. He clashed with Cabot and Telkes, eventually driving her from the program. Yet, paradoxically, he too was a foundational figure in the field. He published seminal research and built some of the world’s first-ever “active” solar houses.

    The story of these scientists, their collaborations, and their clashes captures the history of a simple idea that proved difficult to realize in full but had the potential to fundamentally change the way we live.

    A Home to Live In

    Hottel came to solar technology almost by accident. A prodigy from Indiana, he graduated from college at 19 and became an assistant professor at MIT at 25. He mostly studied fire and industrial furnaces but was asked to help launch the solar project. He was the only participant who came up with a concrete proposal and so, as he later recalled, was made “the rather too-young chairman” of MIT’s solar energy committee.

    Hottel spent some of Cabot’s riches studying flat-plate collectors, simple glass-covered devices often used in California and Florida to produce hot water for homes. The first product of that research was an experimental structure erected on the MIT campus in 1939. Later dubbed MIT I, Hottel’s first solar house featured a rooftop collector where sunlight heated the water, which was then stored in a huge underground tank. Fans blew air over the hot tank and up into the building, keeping it warm through two Boston winters.

    A 1942 paper Hottel cowrote on the project became a classic in the field of solar heating and a guide for use of flat-plate collectors, influencing engineers and do-it-yourself homebuilders for decades to come. Not that anyone would want to exactly replicate MIT I; as Hottel was careful to explain, it was a scientific experiment and not a test model. Installing a 17,000-gallon underground tank would not be economically feasible for a real house.

    Yet real sun-heated houses were what the public increasingly wanted. Now that Hottel understood how to collect solar energy, he recognized that MIT needed to develop a more practical storage solution, perhaps a smaller tank that kept just a day’s supply of heated water. For Telkes this problem created her first opportunity to work on solar housing.

    Telkes had come to the field in a roundabout way, having first dabbled in biological and metallurgical research related to energy. After immigrating to the United States in 1924, she worked as a biophysicist at the Cleveland Clinic Foundation, where she helped surgeon George Washington Crile create a photoelectric device that recorded brain waves. In Crile’s darkened lab “brain tissues were made to glow by their own inner light, giving off a strange radiance that shown like a mystic halo,” the Chicago Daily Tribune reported in 1934.

    Telkes next worked at Westinghouse developing metal alloys for thermocouples that would turn heat into electricity. When she heard about MIT’s new solar-energy program, she wrote the university to ask for a job and was hired. With the outbreak of World War II she was assigned to work with Hottel designing a portable solar desalinator, a balloon-like device that aviators downed at sea could use to make drinkable water.

    She also continued tinkering with thermocouples. A 1942 profile of Telkes in the Christian Science Monitor found her stirring solutions over a flame in an MIT lab and demonstrating a visionary assertiveness. “It is the things supposed to be impossible that interest me. I like to do things they say cannot be done,” she told the newspaper.

    By the end of the war she added another FOCUS to her research, becoming deeply engaged in the challenge of designing practical solar-heating systems. “Solar heat storage,” she later wrote in Science, is “the critical problem.”

    Water, which could only store so much heat per gallon, required large, expensive tanks, Telkes reasoned. Solid materials such as rock were even less efficient. promising were phase-change materials that absorb or release heat when they change from solid to liquid. She became fascinated with one such substance called Glauber’s salt, or sodium sulfate, which is widely used in the chemical industry.

    For MIT’s next solar experiment Hottel initially wanted to build a real house with occupants. Telkes proposed putting containers of Glauber’s salt behind a glass wall, where they would absorb large amounts of heat during the day and release it as the building cooled.

    “The idea looks very good,” Hottel wrote in response to her proposal. “Dr. Telkes’ contribution may make a big difference in the outcome of our project.”

    Clashing Worldviews

    Hottel and Telkes both aspired to build a livable solar house, but they approached the idea from very different perspectives.

    While Hottel would go on to lead MIT’s solar team for more than two decades, solar housing was just one of many different projects he worked on. Like many academic scientists, he accepted a variety of research tasks as they were offered by corporate or government sponsors. He studied ramjet engines and built a device to remove carbon monoxide from auto exhaust; during World War II he worked on tank-mounted flamethrowers and napalm bombs. He once developed a simulated skin to gauge the effect of atomic blasts on the body.

    Hottel approached solar-energy collection as just another engineering and economic problem rather than as a societal imperative. He frequently expressed skepticism about its prospects, given the world’s ample supply of relatively cheap fossil fuels and the emergence of nuclear power, and he mocked those who cited the seemingly vast amount of energy available in sunlight.

    “Figures such as these are almost irrelevant to the problem of practical utilization of solar energy,” he said in a 1940 lecture. “They have attracted uncounted crank inventors who have approached the problem with little more mental equipment than a rosy optimism.” In reality the amount of useful sun energy is limited by the weather and inefficiencies in energy collection, he explained.

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    Why Hottel continued to pursue solar experiments for years despite his belief in their ultimate futility is not entirely clear. He was surely driven in part by his restless scientific curiosity and industrious personality, as well as ambitions to break new ground, as he did with MIT I. Heading a well-endowed research group, especially at such a young age, also carried a measure of prestige and may have helped cement his position at MIT.

    Cabot’s solar grant funded Hottel’s and his graduate students’ research and helped them produce many scientific papers, a key measure of success. Academics are always on the hunt for funding; it would have made little sense for him to give up control of a well-resourced, long-lasting research opportunity, especially one that let him craft his own experiments rather than follow the dictates of corporate sponsors. Once launched, the solar fund just kept going, even if Hottel’s interest waned at times and MIT ultimately judged the program underproductive.

    Hottel sometimes sneered at breathless articles on solar houses, but he also may have enjoyed the greater public attention the projects attracted compared with his other work. Newspaper and magazine interviews gave him venues to demonstrate his hard-nosed fidelity to scientific and economic rigor.

    “He clearly took pride in his role as a skeptic, and believed he was making a contribution by broadcasting caution,” writes architectural historian Anthony Denzer.

    Telkes, meanwhile, squarely saw the exploitation of solar energy as a benefit to mankind, allying herself with Cabot and with such prominent advocates as scientists Farrington Daniels and Eugene Ayres. Unlike Hottel, Telkes would spend the rest of her career studying, proposing, or building solar-energy projects, and she vigorously defended their prospects against skeptics like him.

    “Conservative engineers treat this subject with near derision,” she wrote in a 1951 paper. She likened them to people who had preferred horses to early automobiles, focusing too much on tangible, short-term results over the likely long-term benefits. Yes, the United States had access to plenty of fuel, but what about places lacking in coal or oil? What about the “soot, fire hazards, and mining accidents” caused by the production and use of conventional fuels?

    Solar energy is “the cleanest and healthiest fuel,” she wrote. While the field still faced many challenges, “The total research and development expenditures made thus far in solar energy utilization are infinitesimal when compared with the expenditures made in the development of other natural resources. Sunlight will be used as source of energy sooner or later anyway. Why wait?”

    It was perhaps inevitable that Hottel’s and Telkes’s ideological differences would eventually make them adversaries. The seeds of the conflict, however, may have been planted early on, during Telkes’s first project for the team.

    magazine, first, solar, generator

    Telkes had completed a prototype of her desalination device for aviators in 1942 and won notice from government officials and private industry. But Hottel changed manufacturers three times to get the best deal and minimize costs, delaying delivery of the desalinators to the U.S. military until just after the end of the war. Telkes and Cabot expressed frustration that Hottel’s maneuvers had rendered the project much less useful than it might have been.

    Brilliant Disasters

    If Hottel’s mishandling of the desalinator set the two engineers at odds, it was Telkes’s obsession with Glauber’s salt that would trigger a permanent rupture. Though initially promising, the substance turned out to be troublesome. During testing for the team’s second solar house in 1946, the material stratified into its different component substances and corroded the containers until they leaked.

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    Hottel and others blamed Telkes for “imprecise assessment” of the heat storage process, historian Daniel Barber writes. Telkes blamed Hottel for poorly supervising the graduate students who ran the experiment, saying they had failed to keep the building at a steady temperature as required. Her colleagues also clashed with Telkes on a personal level, in part because of her assertive personality but also, perhaps, because of a bias against the sole woman on the team.

    She is “a person of strong opinions which she expresses forcibly,” MIT dean George Harrison wrote in a report on the solar fund several years later. Even people outside the program “found it impossible to agree with her for any length of time.”

    MIT President Karl Compton took Telkes’s side in the squabble over the Glauber’s salt testing. “She does not like to see her ideas brushed aside based solely on this evidence,” he wrote to Hottel. He urged the solar committee to skip further testing and have an architect design a livable house with phase-change technology. “We should make a bold approach for a further big step forward in the matter of the solar heated house, rather than putter around with further measurements.”

    But despite support from Compton and from Cabot, who had become friendly with Telkes, Hottel not only rejected the idea of using Glauber’s salt but dismissed Telkes from the solar energy fund entirely. Telkes was reassigned to MIT’s metallurgy department, where she resumed her research on thermocouples.

    Instead of building a real house Hottel and the others put up another experimental shed, MIT II. It was made up of several adjoining cubicles, each with a different arrangement of glass Windows, walls of water-filled containers, and other elements.

    The water walls actually did a decent job of storing heat. (Decades later the idea would be taken up again by solar-home builders.) But Hottel believed the building’s leaky Windows had let out too much heat, basically ruining the project, and he apparently disowned it, according to Denzer. Cabot was again annoyed and suggested Hottel should be removed as chair of the solar energy fund in favor of someone who would go ahead and build a real house—someone like Maria Telkes.

    “I would like to see this solar energy research entrusted to someone who would give more attention to it,” he groused.

    Hottel recognized the threat. If an occupied house was the price of remaining in charge of the fund, he was ready to provide one. He and a collaborator, architecture professor Lawrence Anderson, moved quickly this time. They had an architecture student design a plan to convert MIT II into MIT III, a habitable house that used Hottel’s rooftop collector method.

    With a peaked roof, a backyard, and a water tank hidden in the attic, the structure looked like a typical house. It immediately drew national attention. In 1949 the Saturday Evening Post profiled the occupants—graduate student Harry Reid; his wife, June; and their two-year-old son, Toby—“who were elated with the house and eminently satisfied with its heating system,” according to Barber.

    “None of us has had a cold since we moved in, and Toby hasn’t even had the sniffles,” June was quoted as saying.

    At peak performance MIT III derived 82% of its heat from the sun and the rest from auxiliary heaters. Various inefficiencies kept it from achieving the builders’ goal of 90% solar heating, but the project confirmed the accuracy of Hottel’s earlier work on flat-plate collectors and boosted his public profile.

    “Hottel executed a brilliant subterfuge, using the architecture department and the Reid family to create an attractive Trojan horse which would accommodate his experiment and distract from controversies about his leadership,” Denzer writes in The Solar House, a history of passive and active solar homes.

    Telkes, though exiled from the solar energy fund, continued to look for opportunities to prove the utility of Glauber’s salt. She befriended a well-known modernist architect, Eleanor Raymond, who eventually put her in touch with Amelia Peabody, another wealthy Boston Brahmin. With encouragement from close friends Godfrey Cabot and Karl Compton, Peabody agreed to commission Telkes and Raymond to build a solar house on her estate in Dover, Massachusetts.

    Shortly after the debut of MIT III, the three women completed their Dover Sun House. Described in the press as looking like “an overgrown chicken coop,” it was dominated by a giant attic with a south-facing wall composed entirely of tall, glass-plated collectors. For heat storage warmed air was blown into spaces containing 3,500 gallons of Glauber’s salt housed in metal drums.

    The project appeared a huge success. Cousins of Telkes’s lived comfortably in the building for two winters, and front-page newspaper articles celebrated the house for dispensing entirely with conventional heating fuels. “A New House in Dover, Mass., Has Been Comfortably Warm All Winter Without a Furnace,” read a 1949 headline in Life. A cover story in Popular Science said the house might represent a more important scientific development than the atom bomb. Andrew Nemethy, who grew up in the house, later recalled that it drew 3,000 visitors—“society matrons, club members, reporters, and curious civilians”—until tours were suspended.

    “No other solar house received as much publicity as the Dover Sun House,” Denzer notes.

    The glowing reports missed a few important details, however. While the house did not use coal or oil for heating, the fans needed to circulate air ran up the electric bill. And as it had during the MIT tests, the Glauber’s salt stratified into liquid and solid layers, and the metal containers corroded and leaked. By the third winter Nemethy’s family was freezing.

    “After week-long strings of cloudy days, indoor temperatures sank to panic levels. My mother complained, and we soon had electric heaters in all the rooms,” he recalled. The solar heating system was removed, and an oil furnace was later installed in the attic.

    Prejudice and Persistence

    After MIT III the solar energy fund went dormant. In 1953 dean Harrison undertook a review to understand why it was not more productive. His report briefly mentioned Hottel’s spotty leadership but largely took the professor’s side, laying much of the blame on meddling by Cabot under the influence of Telkes.

    The review heavily reflected Hottel’s perspective, according to historian Sara Shreve. Hottel was hostile toward Telkes from early on because of her tenacious commitment to the idea of solar housing as well as her eagerness to engage with the public and the press. The report even went as far as disparaging Telkes’s intellect and character.

    “She has a wide circle of influential acquaintances, who are impressed with her enthusiasm for solar heating and her apparent intelligence,” Harrison wrote. She supported outside experiments (namely, the Dover Sun House) that “proved to be either grossly over-engineered or to be failures.” This is the report that described Telkes as having strong opinions that she expressed “forcibly” and that stated several people had found it “impossible to agree with her.”

    “She has for some time been at outs with the Committee, and especially with Professor Hottel,” Harrison wrote.

    For Shreve these criticisms reveal an underlying sexism. The “assertiveness” that a woman would need to earn a doctorate in engineering in Hungary in the 1920s, emigrate to the United States, and get a job at MIT “were at odds with prevailing societal expectations about female behavior,” she writes, especially in the post–World War II return to traditional gender roles.

    Barber notes that the dean cites Telkes’s “rather radical opinions” and supposed “ultra-radical tendencies.” These Комментарии и мнения владельцев describe her solar advocacy but may also betray Harrison’s suspicions of a Hungarian woman amid the McCarthyist anti-Communism of the early 1950s.

    After the review MIT fired Telkes. Hottel and Anderson made one more big solar-housing push, building a home in Lexington, Massachusetts, that was meant to be sold on the open market. The main distinguishing feature of MIT IV was a large wall of solar collectors that sloped down from the top of the roof to a high berm behind the house.

    The house made the cover of Popular Mechanics, but it was burdened by complex systems: multiple water tanks, a forced-air system, and automated controls designed to turn on the solar collection only when it offset the cost of pumping the water. MIT staff struggled to keep up with repairs and maintenance, and nobody would buy the home. Denzer calls the structure “a public relations success, a noteworthy aesthetic effort, an inefficient machine, and an economic tragedy.” After four years the solar system was ripped out.

    Hottel quit trying to build solar housing. While a number of scientists, architects, and do-it-yourselfers built innovative and successful solar homes in the ensuing decades—using a wide variety of both active and passive designs—Hottel remained a skeptic until the end of his life. In a 1995 interview he said he favored continued solar research and believed photovoltaic panels would eventually prove valuable, but he still thought people were far too optimistic about solar energy.

    “We’re kidding the public about the sun. It’s not worth as much as claimed,” he said in a 1985 oral history interview with the Chemical Heritage Foundation (now the Science History Institute). “The cost of doing something using the sun has always been a little higher than if you do it some other way.” Nonetheless, when he died in 1998, the New York Times described him as “a leader in the development of alternative fuels.”

    Telkes, meanwhile, became a star in the lively but increasingly irrelevant world of solar-heating research, which gradually faded in prominence as nuclear power and cheap Middle Eastern petroleum conquered the energy industry. She presented at conferences and proposed a version of the Dover Sun House for Manhattan, which won her a job at New York University.

    She kept busy, consulting on the construction of several homes around Princeton, New Jersey, and helping plan residential developments in upstate New York and the Dallas suburbs. (Neither of the developments was built.) In the late 1950s she designed an ambitious demonstration project, the Princeton Sun House, using Glauber’s salt, but it was plagued with the usual corroding containers and other problems and never worked very well. Another project, a stand-alone heat generator called the Solar Wall, didn’t go anywhere.

    After briefly teaching at the University of Pennsylvania and working in industry, she found a home at the University of Delaware, where she expanded her research to include a new breed of solar technology—electricity-generating photovoltaic cells. In 1971 she and her colleagues built Solar One, the first house to generate both heat and electricity from the sun, helping kick off a nationwide solar boom.

    By the time photovoltaic solar panels entered the market, the active heating systems that Telkes, Hottel, and many others designed had largely faded away. They had become technological dead-ends. Just a few examples of these systems survive in homes custom-built by tinkerers and home-efficiency enthusiasts.

    In that respect Hottel was right: it was always going to be a little cheaper (not to mention easier) to use some other fuel to create heat. Solar methods did not get good enough fast enough to meet the demands of the massive housing boom of the 1950s and 1960s, which erected millions of tract homes heated by gas radiators and cooled by electric air conditioners. The federal government and the energy industry spent billions promoting traditional fuels, sweeping solar heating aside.

    But in another way Hottel was wrong to foreclose the possibilities of solar heating, and Telkes deserves the praise she received for her determined prescience and eagerness to innovate.

    Mid-century solar houses were less expensive to heat than conventional homes, some by a large margin. They also had environmental benefits whose significance was not fully appreciated until half a century later, when the threat posed by greenhouse gases became widely known. With well-sealed Windows and better insulation, homes can be made even more efficient, as builders of today’s highly insulated “passive houses” have shown. Telkes was on the right track, but the technological and social transformations she sought were just out of reach.

    Meir Rindeis a reporter at WHYY in Philadelphia.

    First Solar acquires Swedish perovskite specialist Evolar

    First Solar has agreed to pay 38 million to buy Swedish manufacturing startup Evolar AB, as it seeks to expand development of high-efficiency tandem PV tech.

    Evolar’s turnkey production lines can be combined with customers’ silicon PV lines.


    First Solar said it is buying Swedish manufacturer Evolar AB in a bid to accelerate its efforts to develop tandem PV technology. The US solar module maker will initially pay around 38 million, but it might later pay an additional 42 million, subject to certain technical milestones being achieved in the future.

    First Solar said in a statement on Friday that the acquisition will accelerate the development of next generation PV technology, including high efficiency tandem devices. It aims to integrate Evolar’s know-how with its existing research and development streams, intellectual property portfolio, and expertise in developing and commercially scaling thin-film PV.

    “This acquisition supplements our existing RD streams with expertise in thin film semiconductors that complement CadTel. We expect that it will accelerate our efforts to develop tandem technology that continues our commitment to ultra-low carbon, responsibly produced solar,” said Mark Widmar, chief executive officer of First Solar.

    Evolar, which was founded in 2019 by now-insolvent CIGS thin-film manufacturer Solibro, focuses on developing solutions, including manufacturing equipment, to commercialize tandem solar technology with perovskite thin films.

    The company says that its unique evaporation technology enables it to apply a thin-film layer of perovskite, known as “PV Power Booster” technology, to increase cell energy yield by 25% at a minimal cost. It is currently in the process of commercializing its turnkey production line for perovskite cells, which can be seamlessly integrated into silicon production lines to upgrade tandem cell production.

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    Last year, Evolar put its encapsulated, semitransparent standalone perovskite modules through a series of industry-standard accelerated reliability tests. The results suggested that the cells could stand up to 25 years if deployed outdoors.

    Evolar holds the current world record for CIGS research solar cells with an efficiency of 23.6%. The company collaborates closely with Uppsala University and has established a research laboratory in Uppsala, Sweden. This marks First Solar‘s first RD facility in Europe, although the terms of the agreement were not disclosed.

    After the transaction closes, around 30 of Evolar’s RD staff will join First Solar and collaborate with the company’s team of approximately 60 scientists at its research technology center in Santa Clara, California, and development teams in Perrysburg, Ohio.

    The Perrysburg facility, representing an investment of up to 370 million announced in October 2022, is believed to be the first of its scale in the Western hemisphere. It is expected to accelerate the development and production of advanced thin film PV and tandem PV modules and is scheduled to be completed in 2024.

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    Marija Maisch

    Marija has years of experience in a news agency environment and writing for print and online publications. She took over as the editor of pv magazine Australia in 2018 and helped establish its online presence over a two-year period.

    Investing in Solar Energy Stocks

    The solar energy industry builds and installs devices to capture energy from the sun and convert it into electric power. Companies in the industry are working to transition the global economy from fossil fuels such as oil and natural gas to renewable energy sources. It will take trillions of dollars and many years to complete the transition, making the solar energy industry a compelling opportunity for long-term investors.

    The sector encompasses a wide variety of companies with the following functions:

    Best solar stocks to invest in 2023

    Solar energy represents an enormous market opportunity. The U.S. needs to invest an estimated 1.2 trillion through 2050 on solar energy developments alone to decarbonize the economy. Meanwhile, the global investment opportunity for solar is even larger.

    Many companies FOCUS on solar energy and should benefit from the sector’s growth. However, not all have strategies designed to enhance value for their shareholders. Three solar energy stocks that stand out as the most worthy of investors’ consideration are:

    SolarEdge Technologies

    Here’s why these solar stocks shine brightly in this rapidly expanding industry:

    First Solar

    First Solar is a global leader in developing solar energy solutions. It develops, manufactures, and sells advanced solar modules.

    One thing that sets First Solar apart from other solar panel makers is its FOCUS on manufacturing a proprietary, advanced thin-film module. In less than ideal conditions such as low light and hot weather, its panels perform better than competing silicon modules. They’re also larger in size, which helps reduce the cost per watt. Those factors make them ideal for utility-scale solar energy projects.

    First Solar also distinguishes itself from its peers in the solar sector by having one of the strongest balance sheets. It routinely has more cash than debt, giving it the financial flexibility to continue executing its strategy of developing and building thin-film solar modules for utility-scale customers, including expanding its manufacturing capacity. First Solar is in an excellent position to thrive as the solar industry continues expanding.

    First Solar also has lots of growth lined up. The company has sold out its manufacturing capacity through 2024 and has signed sales contracts through 2026. It’s investing heavily to expand its solar panel manufacturing capacity to capitalize on the sector’s growth. The investments should enable First Solar to expand its revenue and earnings at Rapid rates in the coming years.

    Brookfield Renewable

    Brookfield Renewable is a renewable energy yieldco created by leading alternative asset manager Brookfield Asset Management ( BAM 0.87% ). The energy company generates renewable energy that it sells under long-term power purchase agreements. Brookfield’s business model provides it with steady cash flow to pay an attractive dividend yield, hence the yieldco designation.

    Brookfield Renewable has a diversified renewable energy portfolio. It’s a global leader in hydroelectric power plants. It complements those facilities with rapidly expanding onshore and offshore wind energy, utility scale and distributed generation (e.g., rooftop) solar, and energy storage platforms.

    The clean energy company believes solar could make up the majority of its production capacity within the next decade.- not because it doesn’t see a bright future for wind or hydro, but because it sees greater opportunity in solar. Declining costs are making solar development projects increasingly lucrative.

    Brookfield has made several acquisitions in recent years to increase its solar energy development capabilities. In 2022, it purchased Urban Grid, a leading developer of utility-scale solar and energy storage projects in the U.S. The acquisition tripled its U.S. renewable energy development pipeline.

    Brookfield’s solar-powered development pipeline has it on track to expand cash flow per share at a 6% to 11% annual rate through 2026. On top of that, it sees as much as 9% of additional growth potential per year from future acquisitions, which should support the company’s plan to increase its high-yielding dividend by 5% to 9%. Its dividend growth makes it one of the top renewable energy dividend stocks. Meanwhile, its overall combination of growth and income should enable Brookfield Renewable to generate attractive total returns in the coming years.

    SolarEdge Technologies

    SolarEdge Technologies manufactures power optimizers and inverters used to convert the sun’s energy into electricity. Its components have improved the way solar panels convert DC power produced by the sun into the AC electricity used by the electrical grid. A system that utilizes SolarEdge’s power optimizers will cost less than one that uses a microinverter built by a company such as Enphase Energy ( ENPH.0.91% ), for example, and with minimal efficiency loss.

    SolarEdge’s FOCUS on manufacturing low-cost power optimizers has enabled it to win market share from competitors as solar project developers emphasize cost. The company has also invested money to acquire and develop new products in the energy storage and energy management spaces, as well as Smart modules to help increase its average revenue per installation.

    SolarEdge complements its leading market position with a strong, cash-rich balance sheet, giving it the financial flexibility to invest in expanding its manufacturing capacity and its technological lead over competitors.

    Its strong balance sheet has also given SolarEdge the flexibility to expand into other Smart energy market segments. The company has made investments and acquisitions in storage, electric vehicle (EV) charging, batteries, uninterruptible power supply (UPS) systems, EV powertrains, and grid services solutions. The initiatives could accelerate its growth in the coming years and have set SolarEdge up for success as it works to capitalize on the fast-growing clean energy sector.

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    Investing in Renewable Energy Stocks

    Clean energy is the future, and these companies are leading the way.

    Selling Solar Panels: The How, Why, And Where

    The solar market is booming right now. In Q2 2021, the U.S. installed 5.7 GW of solar capacity, a 45% increase over the second quarter of 2020 and the largest Q2 ever recorded.

    With these additions, the U.S. officially surpassed 3 million installations — the vast majority of which are residential systems. Plus, solar accounted for 56% of all new electricity-generating capacity added in the U.S. in the first half of 2021.

    So if you’re thinking about getting into solar, now is the time. In this guide, we’ll cover everything you need to know about selling solar panels, including the how, the why, and the where to do it.

    Why bother selling solar panels in the first place?

    According to the Solar Energy Industries Association (SEIA), the pace of solar installations across all market segments has been steadily increasing over the past decade. Check out these 3 reasons why it’s worth your while to get into the solar game:

    Reason #1: Falling equals growth

    One of the biggest strikes against solar for the past several decades has been the cost. But that’s all changed. The cost to install solar has dropped by more than 70% over the last decade, leading the industry to expand into new markets and install thousands of systems across the U.S.

    Specifically, an average-sized residential system has dropped from 40,000 in 2010 to roughly 20,000 today (both are pre-incentive prices). And recent utility-scale range from 16/MWh – 35/MWh, meaning solar is now competitive with all other forms of electricity generation.

    Reason #2: Solar is leading in new electric capacity additions

    In 2020, 43% of all new electric capacity added to the grid came from solar. This is the largest share in history and marks the second year in a row that solar has added the most capacity to the grid compared to other sources.

    And it’s no fluke. Solar has ranked 1st or 2nd in new electric capacity additions in the last 8 years — increasing its share of total U.S. electrical generation from just 0.1% in 2010 to nearly 4% today.

    Reason #3: It’s now a 50-state market

    For years, the state of California dominated the solar market with over 8 million homes powered by solar. But other markets are expanding rapidly and in 2020, other states reached their largest share of the market than at any point over the last decade.

    Data from the SEIA shows that Rapid growth in Texas and Florida has led to this shift. In fact, Texas now ranks highest in terms of growth projection with 26,995 MW expected to be installed over the next 5 years.

    And Florida ranks #3 (right behind California) with 12,046 MW of growth expected over the next 5 years. As continue to drop, more and more states are expected to increase their share of the national market.

    And now that you know why you should sell solar panels, here’s the how.

    How to start selling solar panels

    If those reasons have you wondering how to get started, here are five steps to take right away.

    Learn what makes people buy solar panels

    When it comes to buying solar panels, there are a few key motivators for buyers. The first is the cost savings in terms of reduced electricity bills.

    The average electric bill in the U.S. is between 100 to 200 per month so that’s a lot of savings. And as solar fall, more and more consumers are taking the plunge.

    Another big motivator is government incentives and subsidies. As of now, the federal solar tax credit is worth 26% of the cost of solar installation, including equipment and labor. So, based on the current average cost of panels, a typical homeowner can expect a tax credit of between 4,000 and 6,000.

    magazine, first, solar, generator

    Plus, there are 10 states that offer state solar tax incentives that consumers can use besides the federal tax credit, providing an additional 1,000 to 6,000 in savings. As of now, these states are Arizona, Hawaii, Idaho, Iowa, Massachusetts, Montana, New Mexico, New York, South Carolina, and Utah.

    Decide who you’ll be selling to

    You have to decide if you want to sell to commercial businesses or residential homeowners.

    Here are a few things to consider:

    • Project time: Commercial roofs are usually flat, making for a simpler installation process. But commercial roofs also tend to be much larger, meaning installation can take anywhere from a week to several months to complete. Residential panels usually only take one or two days.
    • Property ownership: There are some complexities with commercial property ownership that don’t exist in the residential market. From least to most complex, these include owner-occupied buildings, buildings with a single tenant, and multi-tenant buildings.

    Owner-occupied buildings are the least complex commercial solar projects because the building occupant (who benefits from a lower electric bill) and the owner (who can make purchasing decisions) are one and the same.

    All in all, know the dynamics you’ll face selling to different groups and choose the one(s) you’re best fitted to sell to.

    Get certified and register your business

    First, it’s important to understand that certification and licensing are different.

    Licensing is something that’s required (by some states), whereas certification is voluntary. So if you’re operating in a state that requires licensing (you can check that in this database), you’ll have to do that first to run your business.

    Whether or not you need to get licensed, you should also consider getting certified to distinguish your business from the competition. The North American Board of Certified Energy Practitioners (NABCEP) is considered the leading certifying authority in the solar industry.

    And to become NABCEP-certified, installers must pass an exam, sign a code of ethics, and take continuing education courses for recertification every three years. You also need to have some experience in the field (the amount varies by type of certification) and you must document all training and installations.

    In addition to demonstrating your expertise (or perhaps because of it), becoming certified can increase your earning potential by an average of more than 11,000 per year, according to the NABCEP. You’ll also want to register your business in your state with the Secretary of State’s office, a Business Bureau, or a Business Agency. For most small businesses, the SBA says it’s usually as simple as registering your business name with state and local governments. Some states allow you to register online, and some make you file paper documents in person or through the mail.

    Know how many panels your customer needs

    Determining the number of panels your customer needs depends on a variety of factors — the size of their roof, their electricity consumption, and the amount of sun their roof is exposed to. This means that you need to get a good look at the roof before you can tell them how many panels they’re going to need and where they should put them.

    Traditionally, roofers and solar panel installers had to pull out their ladder and climb the roof — taking measurements and performing shade calculations by hand. And while this still works, it’s not the fastest, safest, cheapest, or most accurate strategy.

    Instead, many solar installers are embracing remote technology like EagleView’s aerial imagery (yep, that’s us) that allows them to get a bird’s eye view of the roof without ever setting foot on the property.

    David Williamson, CEO at Titan Solar Power, says, “Remote processes and technological adoption are two of the biggest trends facing the solar installation market today. By using EagleView’s always-accurate reports, we’re able to get ahead of these trends and create designs and plan sets much faster without having to set foot on the property.”

    One example of an advantage of aerial imagery is that when inspectors climb a roof with a handheld shade calculation device, they typically collect data from 15 to 30 measurement points. However, virtual inspections using EagleView’s remote technology can capture 13,000 – 15,000 measurement points for shading data, far exceeding industry standards.

    Having this type of precise data at your fingertips allows you to estimate the number of panels homeowners need with speed, accuracy, and confidence.

    Know where you’ll be getting your supplies from

    As a solar installer, you’ll need to establish relationships with distributors to get your supplies.

    In the supply chain, solar distributors generally fall between equipment manufacturers like Panasonic, SolarEdge, etc., and solar installers.

    Distributors store and deliver equipment as needed by residential and commercial contractors, alleviating the need for individual solar installers to carry large amounts of inventory. Instead, solar contractors can wait to purchase the equipment they need until a homeowner moves forward with a project.

    The major solar distributors sell to all types of solar installers — residential, commercial, and utility-focused. Some of the biggest distributors in the U.S. include BayWa r.e., Wesco, and CED Greentech.

    Where to sell solar panels

    Now that you know the why and the how, it’s time to get in front of customers. Here are great 5 places to sell solar panels.


    Going door-to-door is a great place to start selling solar — even though it might sound a bit old-fashioned at first.

    Take Vivint, the home security company, for example. Vivint entered the solar market way back in 2013 and canvassed entire neighborhoods, door-to-door, quietly amassing a 9% share of the U.S. residential solar installation market in just two years.

    One of the reasons going door-to-door is so effective is that your salesperson can see the homeowner’s roof and answer questions the homeowner has in real-time.

    Another benefit of being able to see the roof is that your salespeople can prioritize “roofs with promise.” Experienced California solar salesman, Matt Fox, explains that a prospective client should have a roof that isn’t falling apart, isn’t too shaded, and doesn’t have too many vents.

    “What you want is a big, open plane without a lot of obstructions,” he told Sierra, the national magazine of the Sierra Club.

    Targeted online communities

    These days, you can find like-minded communities online for just about any interest or niche — including solar energy. For solar companies, these solar communities are a great place to soft sell your business.

    After all, the people in these communities are already sold on their idea of using solar to generate power and are looking forward to using it. This means selling to them is typically easier because you don’t have to sell them on solar energy itself, freeing you up to FOCUS on the value your particular business brings compared to the competition.

    One of the best ways to approach this strategy is by joining the communities and providing your insight and expertise for free. Then, when members are ready to install or someone asks them for a recommendation, they’ll likely remember you. You can also reach out directly to people in these groups who ask questions like “Does anyone know a good solar installer near me?”

    Here’s a list of popular online forums that you can check out:

    • Solar Panel Talk
    • Simply Solar
    • EcoRenovator
    • Homesteading Today
    • Green Building Advisor
    • Field Lines | Other Power
    • Energy Matters
    • Power Forum

    Local Google and Ads

    Another good place to sell solar online is through Google and ads. Using these platforms, you can run ads aimed at people actively shopping for solar. You can do that using the following tools in Google Ads:

    • In-market: Show ads to users who have been searching for products and services like yours.
    • Remarketing: Target users that have already interacted with your ads, website, or app so that they’ll see your ads more often.
    • Content keywords: Show ads to users who are searching on Google for specific keywords or phrases (e.g, solar panel companies near me).
    • Topics: Target ads to multiple pages about certain topics (i.e, solar energy). Topic targeting lets you reach a broad range of pages on the Display Network.
    • Placement: Show ads on specific websites that potential customers are visiting (like directories).

    On. the platform will automatically show your ads to people who are most likely to find them relevant. But you can further target your ad delivery with 3 audience selection tools.

    • Core Audiences: Define an audience based on criteria like age, interests, and geography/location.
    • Custom Audiences: Get back in touch with people who have previously engaged with your business, online or offline.
    • Lookalike Audiences: Reach new people whose interests are similar to those of your best customers.

    groups for homeowners

    You can use groups in two different ways. The first is to join existing groups of homeowners that FOCUS on solar energy — a strategy nearly identical to the previous section about joining online communities.

    The second way is to start your own group. With this strategy, you’ll want to be extra careful not to try to sell your product since it’s your own group. You’re playing the long game with this strategy.

    With that in mind, you should only post helpful and relevant information, answer questions, and offer expertise. The goal is to help group members solve their problems without being overtly salesy or sleazy.

    Customer referrals

    As with any business, existing customers are a great place to go to generate more sales. And when it comes to big, expensive products like solar panels, existing clients are typically more motivated to refer.

    After all, people have to front a lot of money to install the panels and they’re going to be motivated to earn anything back on it that they can. Plus, existing customers will have a relationship with your company for decades, possibly resulting in multiple referrals if you make it worth their while.

    Incentives like discounts or cash rewards are great motivators, especially if you offer tiered rewards for sending multiple solar leads. If a customer knows they will earn more with every referral, they will be more likely to send more your way.

    FAQs on selling solar panels:

    What does it take to sell solar panels?

    To sell solar equipment, you just need to be prepared and understand the why, how, and where. Here’s a quick recap:

    • Falling equals growth.
    • Solar is leading new electric capacity additions.
    • It’s now a 50-state market.
    • Learn what makes people buy solar panels.
    • Decide who you’ll be selling to (commercial vs residential).
    • Get certified and register your business.
    • Know how many panels your customer will need.
    • Figure out where you’ll get supplies.
    • Door-to-door.
    • Targeted online communities.
    • Local Google and ads.
    • groups for homeowners.
    • Customer referrals.

    Is selling solar panels hard?

    Thanks to the rising popularity of solar energy in the U.S., it’s not really a hard sell anymore. In fact, a Pew Research Center survey from 2019 found that 46% of U.S. homeowners had given serious thought to adding solar panels to their homes in the past year.

    How contractors improve close rates using EagleView

    Eagleview’s remote aerial imaging helps solar installers close deals faster because you don’t have to get someone up on the roof first.

    Jake Wachman, VP of Software at SunPower, explains that “EagleView reports help us to eliminate in-person site surveys and shorten project lifecycles by up to two weeks. Everyone wins: homeowners go solar faster, our dealers avoid an additional site visit, and we reduce project overhead.”

    What EagleView does to help

    EagleView compliments or eliminates your site survey process, delivering the external property data you need to plan a solar project quickly. We help contractors with the following:

    • Comprehensive remote measurement solutions, including pitch, azimuth, and remote shade analysis.
    • Design solutions that allow you to create precise digital models instead of drawing over 2D images and estimating the size and location of obstructions.
    • Determine optimal panel placement for energy production based on solar access values derived from sophisticated shade analysis.
    • Create proposals, permit sets, and project plans faster with digital file exports for popular design programs.

    Sell solar panels fast!

    Try EagleView’s aerial imagery tool to get fast, accurate roof measurements — no ladder required. Learn more about EagleView’s imagery tool.

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