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How much does a solar water heater cost. Solar water roof panels

How much does a solar water heater cost. Solar water roof panels

    How much does a solar water heater cost?

    A solar water heater costs 3,000 to 9,000 installed, depending on the system and tank size, type, and location. After tax credits and rebates, a solar hot water system costs 1,500 to 6,600 or 26% to 50% less. Solar-powered water heaters save 50% to 80% on energy costs and last 20 years.

    ,000 – 9,000 cost before tax credit and rebates

    A solar water heater costs 3,000 to 9,000 installed, depending on the system and tank size, type, and location. After tax credits and rebates, a solar hot water system costs 1,500 to 6,600 or 26% to 50% less. Solar-powered water heaters save 50% to 80% on energy costs and last 20 years.

    Solar water heater cost

    Solar water heaters for homes cost 3,000 to 9,000 with installation. Active solar water heating costs 2,300 to 6,000, and passive thermal water heaters cost 1,000 to 3,700 for the system alone. Solar hot water collector panels cost 800 to 1,500 each. Solar storage tank are 1,000 to 2,800.

    Solar water heater cost

    National average cost 6,000
    Minimum cost 1,000
    Maximum cost 13,000
    Average range 3,000 to 9,000

    In comparison, a conventional water heater installation costs 600 to 1,800, and a tankless water heater costs 800 to 3,500.

    All in this guide exclude the federal tax credit and rebates that save 26% to 50% on total costs, unless otherwise stated.

    Solar hot water heater system by type

    Active system types cost 2,300 to 6,000 and are more effective in colder climates. Passive systems cost 1,000 to 3,700, have no moving parts, and are easier to maintain. All solar water heater systems are either active (direct and indirect) or passive (integral collector-storage and thermosyphon).

    Active vs. passive solar water heater cost

    Type Average cost
    Active system 2,300 – 6,000
    Passive system 1,000 – 3,700
    Active vs. passive solar water heater features

    Feature Active direct Active indirect Drain back ICS (Batch) Thermosyphon
    Lightweight collector
    Low-profile collector
    Withstands freezing
    No extra storage tank needed
    Requires a controller
    Requires a pump
    No moving parts

    Active solar hot water system prices

    Active solar hot water system are 2,300 to 6,000 for the system alone. Active systems use a pump to circulate liquid from the solar collectors to a storage tank inside the home. Most active systems have a backup heating element to provide hot water on cloudy days.

    • Active direct systems, also called open-loop systems, pump the household water supply directly through the collector on the roof, where it is heated and circulated back into the home. Direct systems are susceptible to freeze damage.
    • Active indirect systems, also called closed-loop systems, pump an anti-freeze heat-transfer fluid through the collector and a heat exchanger, which transfers the heat to water in a storage tank. Indirect systems are ideal for homes in regions that experience freezing temperatures.
    • Active drain-back systems pump distilled water through the collector and use a heat exchanger to transfer heat to the home’s potable water supply. Drain-back systems prevent freezing by draining the water from the collector into a separate storage vessel when the pump is inactive.

    Passive solar water heating system cost

    Passive solar water heating systems cost 1,000 to 3,700 for the system alone. Passive systems don’t use pumps and rely on convection to circulate the water as heated water rises and cold water sinks. Passive systems are less efficient than active systems and are susceptible to freeze damage.

    • Integral collector-storage (ICS) passive systems, also called batch solar heaters, feature large, black storage tanks built into a collector box. Water in the tanks is heated directly by the sun before flowing into the home’s plumbing system.
    • Passive thermosyphon systems feature a rooftop tank mounted above a collector panel to store hot water as it rises from the collector. Thermosyphon systems work best in moderate to warm climates and require a roof strong enough to support the weight of a full water tank.

    Solar water heater installation costs

    Solar water heater installation costs depend on the system type, thermal collector and storage tank size, location, site conditions, and tax credits and rebates.

    Installation costs more for homes with complicated plumbing, roofs above two stories, or collectors located far from the storage tank.

    Solar water heater installation costs

    Factor Average cost
    Solar heating system 1,000 – 6,000
    Thermal collector 1,600 – 2,600
    Tank 1,000 – 2,800
    Parts (active systems) 800 – 2,200

    In the 1980s, solar water heaters took off in Israel, but stalled in the U.S. It’s a simple fix

    Despite the huge global opportunity for reducing fossil fuel demand, solar water heating is virtually unheard of in the U.S. Here’s why, and how to change that.

    This article originally was published on Ensia.

    For Gershon Grossman and Ed Murray, 1978 was a big year. Grossman, then a solar energy pioneer at the Technion, Israel’s premier technological institute, was launching the first International Conference on the Application of Solar Energy. Murray, an idealist attending college, joined an upstart solar heating company in Sacramento, California’s capital, drawn by a prescient concern about climate change and, as he puts it, an impulse to save the world.

    For both, the excitement was palpable. Solar water heaters were surging into the market, solar thermal energy showed broad potential, and the two were riding the wave.

    much, does, solar, water, heater, cost

    Four decades later, however, they live in two different worlds. In Israel, 85 percent of households get hot water from a dud shemesh, or sun boiler. But in the U.S., despite decades of advocacy by Murray and others, the number of households that have a solar water heater is less than 1 percent. In California, many people don’t even know the technology exists.

    America’s solar water heating deficit is often portrayed as a historical accident driven by the vagaries of politics and comparatively cheap fossil fuels. However, interviews with academic and commercial players on the front lines of the solar thermal industry, and a recent in-depth report on the now-expired California Solar Initiative–Thermal (CSI-T) program, suggest that the desire for simple, magic bullet solutions to climate change also has played a significant role in relegating this practical technology to the sidelines.

    A mandate, an election and two roads diverged

    Heating water accounts for 25 percent of residential energy use worldwide, mostly achieved by burning fossil fuels. Solar water heaters do the job without combustion. Unlike solar photovoltaic (PV) systems, which convert sunlight into electricity, solar thermal systems collect solar energy as heat.

    Solar water heaters transfer this heat to water in a holding tank. Other energy sources, such as natural gas or electricity from a power grid, serve as a backup for cloudy days.

    By tapping the sun, solar water heaters can reduce a household’s water heating fuel consumption 50 percent to 70 percent. Israel is just one of dozens of countries with a variety of climates where this technology has been deployed. Solid performance and wide applicability have made the technology one of Project Drawdown’s top 50 climate change solutions.

    So why did solar thermal technology soar in Israel and sputter in California, setting Grossman and Murray on such different life paths? A pair of political decisions in the 1970s and 1980s had dramatic impact.

    In 1976, Israel mandated solar water heaters for all new residential buildings up to eight stories tall.

    The Yom Kippur War of 1973 and subsequent oil embargo made energy independence a matter of national security worldwide, but the pinch was particularly painful in countries lacking oil production. For Israel, the threat was existential; as former Israeli prime minister Golda Meir famously quipped, [Moses] took us 40 years through the desert in order to bring us to the one spot in the Middle East that has no oil. In 1976, Israel mandated solar water heaters for all new residential buildings up to eight stories tall — a mandate extended to all residential buildings last December.

    For Grossman, now a professor emeritus at the Technion and head of the Energy Forum at the Neaman Institute for National Policy Research, mandating solar water heaters made sense environmentally, even beyond Israel’s political agenda. You just can’t argue with the numbers on how much [energy] you can save using solar water heating instead of electrical heating.

    The U.S. also felt the jolt of the oil embargo and feared running out of domestic oil. Supported by President Jimmy Carter’s 1978 federal tax credits for renewable energy, Americans installed nearly 1 million solar thermal systems by 1990, supplied by more than 200 U.S. manufacturers, including leading corporations such as Grumman Aerospace Corporation and Sears Roebuck.

    Renewable solar heats 85 percent of households in Israel, who get hot water from a dud shemesh, or sun boiler. In the U.S., it’s a different story. Photo courtesy of Yaniv Hassidof.

    However, in contrast to Israel, America’s commitment to renewable energy proved ephemeral. Under President Ronald Reagan, the federal incentives lapsed, dealing the solar thermal industry a body-blow. We went from 650 companies in California that were installing solar [water heaters] to about 37 overnight, recalls Murray, currently president and CEO of two California companies dedicated to manufacturing, distributing and installing solar thermal systems, as well as president of the California Solar and Storage Association.

    Recent attempts to revive the residential solar water heater industry have had limited success. The CSI-T program, begun in 2010 as a larger push to incentivize solar installations statewide, aimed to add 200,000 systems, but received only 6,237 applications for residential retrofits in 10 years, according to the program’s December report. I could put a sign over the front door of my office that says ‘free solar water heating,’ and they’d probably still stay away in droves, Murray says with a wry laugh.

    Larger installations for apartment complexes, hotels and universities and home pool heating have helped keep Murray’s solar thermal businesses afloat despite the lack of other residential demand. Ironically, the commercial sector isn’t as robust in Israel because the country’s original mandate only applied to residential properties — a move Grossman views as a significant oversight. Indeed, Grossman believes that an industrial mandate could increase Israel’s renewables usage up to fivefold.

    much, does, solar, water, heater, cost

    The limiting psychology of renewables

    The woes of the American solar water heater industry go far beyond politics, however. The industry also suffers a more insidious challenge: For the average consumer, going solar means just one thing: solar PV.

    Solar thermal technologies, including solar water heating, provide a direct, thermodynamically efficient and cost-effective method for decarbonizing heating. And for households in mild climates with low electricity bills, solar water heating can be one of the simplest ways … to use renewable energy and save on energy bills, says the CSI-T report.

    But solar PV has exploded into the global electricity sector, thanks to manufacturing innovations and strong government support. Leveraging economies of scale, the price of solar PV panels has dropped by over an order of magnitude in the past decade. In California, additional boosts came from government-instituted solar feed-in tariffs, cheap financing plans and private-sector investments. And, in a major coup for the industry, California mandated solar PV on new residences up to three stories starting 2020.

    California’s residential solar water heater industry finds itself in a vicious cycle of low consumer demand and high prices.

    On the other hand, California’s residential solar water heater industry finds itself in a vicious cycle of low consumer demand and high prices. As the CSI-T report notes, In contrast to conventional gas and electric water heaters, which are typically installed by plumbers, solar water heaters are installed by a range of firms and public entities. In other words, consumers actively must seek out solar water heaters by relying on nonstandard sales channels.

    This additional friction reduces consumer demand among all but the most motivated consumers, leading to higher marketing costs that drive up the customer’s bottom line. in California are further exacerbated by past industry failures, which have led to strong, self-imposed regulations in the name of consumer satisfaction, says Murray. For example, after many cheaper solar water heating systems froze during the unprecedented 1990 freeze in California, only more expensive systems were allowed through the CSI-T program.

    All told, the cost of the average solar water heater sold in California through the CSI-T program was 7,400, compared to less than 1,000 for a fossil fuel alternative. By contrast, a solar water heater in Israel can cost as little as 700.

    Going all-in on one technology available to solve the carbon emissions problem satisfies the very human need for ‘magic bullets.’

    Today, drumming up excitement for solar thermal remains difficult. According to CSI-T report interviews with solar water heater adopters, Some interviewees remarked that it seemed tough to get others interested, theorizing that PV was so dominant in neighbors’ minds that solar water heating hardly registered.

    It’s just the sizzling, sexy PV [that] really captivates the audience, says Murray.

    Portfolios, not magic bullets

    Entrepreneurs routinely caution, Fall in love with the problem, not the solution. In this case, the problem is carbon emissions, and, against entrepreneurial advice, individual governments have tended to fall in love with just one solution. For Israel, Cyprus, Hawaii and others, solar water heaters were that solution. For California, it’s solar PV.

    By committing to a specific technology, governments fall prey to a conceptual error that science journalist Ed Yong recently referred to as a monogamy of solutions. (Interestingly, he argues this fallacy also shapes the government’s response to COVID-19.) Rather than embracing the growing portfolio of technologies available to solve the carbon emissions problem, going all-in on one satisfies the very human need for magic bullets.

    Europe’s Green Deal may model such a portfolio approach for the rest of the world, according to Bärbel Epp, a German physicist-turned-journalist with nearly two decades of experience studying the global solar thermal market.

    According to Epp, representatives from the European solar thermal market have lobbied the European Commission for over a decade to use solar thermal technologies to decarbonize the heating sector. It took [the solar thermal industry] I don’t know how many years, at least 10, of just continuously repeating the sentence that heat is 50 percent of our final energy consumption in Europe. … It was hard to lobby in Europe, but it’s now obvious that we have to do something for heat. Whether these efforts will succeed in providing solar thermal a seat at the table remains to be seen.

    To Grossman, solar water heaters are the first piece of Israel’s portfolio. As Israel struggles to meet its Paris Agreement goals, Grossman says he believes solar PV panels will take their place alongside solar water heaters on Israel’s rooftops.

    Back in Sacramento, Murray is still battling for solar thermal. This year, he’s lobbied the California legislature to extend the state’s recently expired solar thermal subsidy program for one more year, citing COVID-19 as a barrier. The legislature hasn’t budged, but Murray vows he’ll keep going. He may be a lot older than he was in 1978, but the idealism is still alive.

    Editor’s note: Dina Berenbaum and Manoshi Datta wrote this story as participants in the Ensia Mentor Program. The mentor for the project was Peter Fairley.

    much, does, solar, water, heater, cost

    Editor’s note, Nov. 3: This story was updated to give more information about Gershon Grossman’s current role.

    Solar Water Heaters Explained (2023)

    See how you can save money on utility bills and support clean energy by installing a solar water heater system to heat your home’s water.

    Leonardo David is an electromechanical engineer, MBA, energy consultant and technical writer. His energy-efficiency and solar consulting experience covers sectors including banking, textile manufacturing, plastics processing, pharmaceutics, education, food processing, real estate and retail. He has also been writing articles about energy and engineering topics since 2015.

    Tori Addison is an editor who has worked in the digital marketing industry for over five years. Her experience includes communications and marketing work in the nonprofit, governmental and academic sectors. A journalist by trade, she started her career covering politics and news in New York’s Hudson Valley. Her work included coverage of local and state budgets, federal financial regulations and health care legislation.

    A solar water heater can reduce your water heating bills by around 50% to 80%, according to the U.S. Department of Energy (DOE). Plus, a high-quality solar heater can last for around 20 years, whereas traditional gas and electric heaters normally need a replacement after 10 to 15 years. In other words, you can save money on both energy bills and new equipment by investing in a solar water heater.

    In this article, we at the Guides Home Team will cover how solar water heaters work, how much a system costs and if replacing your traditional water heater is worth it.

    • What Is a Solar Water Heater?
    • Cost
    • Solar vs. Traditional Water Heaters
    • Pros and Cons
    • Are They Worth It?
    • Where To Purchase
    • FAQ

    Offers a range of financing options 24/7 customer service line Panel insurance protects against theft and damage

    Packages include 24/7 system monitoring 25-year warranty guarantees power production, product performance and workmanship Installation process is handled 100% in-house

    What Is a Solar Water Heater?

    In simple terms, solar water heaters use large collector panels exposed to direct sunlight to warm your water. These collectors are generally installed on roofs and use dark colors to absorb as much solar radiation as possible. When water flows through your system, it absorbs thermal energy produced by the collector panels, and its temperature increases. Solar water heating systems require zero energy consumption. However, since collector panels are often installed in elevated places such as a roof, homeowners may need circulating pumps to keep water flowing. These pumps consume a small amount of electricity, but the operating cost is minimal compared to the potential heating savings you can achieve. Although they use the same energy source, solar water heaters and photovoltaic (PV) panels should not be confused. A solar water heater system gathers sunlight directly to heat water, while residential solar panels convert sunlight into electricity. If your property gets decent sunshine, both types of systems can save you thousands of dollars in bills over time.

    Types of Solar Water Heaters

    You can classify solar water heaters into two systems: active and passive. Active systems use circulating pumps and controls to transfer heat from the collector panels to a storage tank, while passive systems operate without these components. Generally, you can use a passive solar heater if your water supply has enough pressure to transfer water on its own. Otherwise, you will need an active solar water heater. A solar water heater includes one or more storage tanks, equipped with adequate insulation to prevent heat loss. The system may also include a conventional water heater as backup, for times when solar heating is not enough to cover your domestic hot water needs.

    Active Solar Water Heaters

    • Direct circulation heaters:Cold water flows directly into the solar collector, where the sun heats it up. This hot water is then delivered to your home’s potable water system.
    • Indirect circulation heaters: Water never flows directly into the solar collector. Instead, the unit uses a heat transfer fluid such as ethylene glycol, which is sent to an insulated tank with a heat exchanger coil. Water flows into the tank, where it heats up without mixing with the fluid. These are also known as closed-loop systems since the heat transfer fluid circulates between the collector and heat exchanger in a closed loop.

    Direct circulation heaters have a much simpler design but are vulnerable to freezing temperatures. Indirect systems are recommended in cold climates since they can use an antifreeze solution as the heat transfer fluid.

    Passive Solar Water Heaters

    You can classify passive solar water heaters based on their construction:

    • Integral collector storage (ICS) systems:These solar water heaters have a very simple design. Water is delivered to a storage tank that is exposed to the sun, where it heats up before reaching your plumbing fixtures. In other words, the solar collector and storage tank are combined into a single component.
    • Thermosyphon systems: These systems use a rooftop solar collector to heat water, which flows when you turn on a faucet or other fixtures. The storage tank and solar collector are separate components in this case, and water flows from the tank into the collector by gravity.

    Types of Solar Collectors

    You can also classify solar water heaters based on the solar collector. There are three main types of collectors:

    Solar Collector TypeDescription

    The Cost of a Solar Water Heater

    According to the U.S. DOE, a solar water heater costs, on average, around 100 per square foot of collector area. For example, if your system uses a solar collector that measures 4 feet by 10 feet (or 40 square feet), the average price is around 4,000. Depending on the complexity of your system, the price can range from around 50 per square foot to more than 400.

    The U.S. DOE determined that water heating represents 14% to 18% of utility bills. equivalent to 400 to 600 per year. For a homeowner spending 600 on utility bills each year, a solar water heater that covers 50% of hot water demand would save 300. So if you purchased this system for 4,000, your payback period would be 13.3 years.

    The above example is very simplified — the actual costs of a solar water heater can vary depending on the type of system and your home’s hot water needs. Solar collector can range from around 1,500 for small basic systems to over 13,000 for high-end units, according to EcoWatch.

    Incentives and Tax Credits

    Thanks to the Inflation Reduction Act of 2022, solar energy systems qualify for a federal tax credit equal to 30% of the total cost of your solar water heater. Considering the 4,000 solar water heater example above, the tax credit would be 1,200, which reduces the net system cost to 2,800. Thanks to this incentive, the expected payback period drops from 13.3 years to 9.3 years in this example.

    Depending on your location, additional solar incentives may be available from the state government or local utility company. You can check the Database of State Incentives for Renewables and Efficiency (DSIRE) to find rebates and other incentives by state.

    Solar vs. Traditional Water Heaters

    The main advantage of a solar hot water system is using a free energy source that reaches your home all year long. Solar collectors cannot heat water at night, but you can solve this by using an insulated tank to store hot water during the day.

    Traditional water heaters run using gas or electricity and have the advantage of being able to heat water at any time. However, since these heaters depend on utility services, they can have a high operating cost. The U.S. DOE determined that the typical American home spends 400 to 600 per year on water heating.

    There is also an environmental impact when using traditional water heating. Gas-fired water heaters release carbon emissions directly, and electric water heaters result in indirect emissions unless the local grid uses renewable energy.

    Pros and Cons of Solar Water Heaters

    Solar water heaters have advantages and disadvantages, like any piece of equipment. These systems can save you hundreds of dollars over time, but you should know their limitations.

    Pros Service life of around 20 years Can help you save 50% to 80% on water heating costs Qualifies for a 30% federal tax credit

    Cons Cannot heat water on demand without sunshine Upfront costs can be high Longer payback period than solar panel systems

    Are Solar Water Heaters Worth It?

    Solar water heaters can be cost-effective for homeowners who use large amounts of hot water, especially if local electricity and gas are high. Solar panels offer a higher return on investment (ROI) and shorter payback period than solar water heaters in most cases. Solar panels generate electricity that you can use to power any device, while solar collectors can only heat water. You can combine solar panels with an efficient heat pump water heater to accomplish the same role as a solar collector — meaning your solar panels can heat water while also providing electricity. Solar power systems and heat pumps also qualify for the federal solar tax credit. which means you wouldn’t miss out on this benefit. To learn more about home solar panel installation, check out our guide to the top solar providers.

    Why aren’t solar water heaters more popular in the U.S., even in solar-friendly states like California?

    Despite widespread global success and huge opportunity for reducing fossil fuel demand, solar water heating is virtually unheard of in the U.S. Evidence suggests our demand for simple fixes is to blame.

    Photo © iStockphoto.com | AlSimonov

    Writer Dina Berenbaum Data scientist and environmental technology enthusiast

    Writer Manoshi Datta @DattaManoshi Computational biologist and freelance writer

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    October 28, 2020 — For Gershon Grossman and Ed Murray, 1978 was a big year. Grossman, then a solar energy pioneer at the Technion, Israel’s premier technological institute, was launching the first International Conference on the Application of Solar Energy. Murray, an idealist attending college, joined an upstart solar heating company in Sacramento, California’s capital, drawn by a prescient concern about climate change and, as he puts it, an impulse to “save the world.” For both, the excitement was palpable. Solar water heaters were surging into the market, solar thermal energy showed broad potential, and the two were riding the wave.

    Four decades later, however, they live in two different worlds. In Israel, 85% of households get hot water from a dud shemesh, or “sun boiler.” But in the U.S., despite decades of advocacy by Murray and others, the number of households that have a solar water heater is less than 1%. I n California, many people don’t even know the technology exists.

    America’s solar water heating deficit is often portrayed as a historical accident driven by the vagaries of politics and comparatively cheap fossil fuels. However, interviews with academic and commercial players on the front lines of the solar thermal industry, and a recent in-depth report on the now-expired California Solar Initiative–Thermal (CSI-T) program, suggest that the desire for simple, “magic bullet” solutions to climate change has also played a significant role in relegating this practical technology to the sidelines.

    A Mandate, an Election and Two Roads Diverged

    Heating water accounts for 25% of residential energy use worldwide, mostly achieved by burning fossil fuels. Solar water heaters do the job without combustion. Unlike solar photovoltaic (PV) systems, which convert sunlight into electricity, solar thermal systems collect solar energy as heat. Solar water heaters t ransfer this heat to water in a holding tank. Other energy sources, such as natural gas or electricity from a power grid, serve as a backup for cloudy days.

    By tapping the sun, solar water heaters can reduce a household’s water heating fuel consumption 50% to 70%. And Israel is just one of dozens of countries with a variety of climates where this technology has been deployed. Solid performance and wide applicability have made the technology one of Project Drawdown’s top 50 climate change solutions.

    So why did solar thermal technology soar in Israel and sputter in California, setting Grossman and Murray on such different life paths? A pair of political decisions in the 1970s and 1980s had dramatic impact.

    The Yom Kippur War of 1973 and subsequent oil embargo made energy independence a matter of national security worldwide, but the pinch was particularly painful in countries lacking oil production. For Israel, the threat was existential; as former Israeli prime minister Golda Meir famously quipped, “[Moses] took us 40 years through the desert in order to bring us to the one spot in the Middle East that has no oil.” In 1976, Israel mandated solar water heaters for all new residential buildings up to eight stories tall — a mandate that was extended to all residential buildings in December 2019.

    For Grossman, now a professor emeritus at the Technion and h ead of the Energy Forum at the Neaman Institute for National Policy Research. mandating solar water heaters made sense environmentally, even beyond Israel’s political agenda. “You just can’t argue with the numbers on how much [energy] you can save using solar water heating instead of electrical heating.”

    The United States also felt the jolt of the oil embargo and feared running out of domestic oil. Supported by President Jimmy Carter’s 1978 federal tax credits for renewable energy. Americans installed nearly 1 million solar thermal systems by 1990, supplied by more than 200 U.S. manufacturers, including leading corporations such as Grumman Aerospace Corporation and Sears Roebuck.

    In Israel, 85% of households get hot water from a dud shemesh, or “sun boiler.” In the U.S., it’s a different story. Photo courtesy of Yaniv Hassidof

    However, in contrast to Israel, America’s commitment to renewable energy proved ephemeral. Under President Ronald Reagan, the federal incentives lapsed, dealing the solar thermal industry a body-blow. “We went from 650 companies in California that were installing solar [water heaters] to about 37 overnight,” recalls Murray. who is currently the president and CEO of two California companies dedicated to manufacturing, distributing and installing solar thermal systems, as well as president of the California Solar and Storage Association.

    Recent attempts to revive the residential solar water heater industry have had limited success. The CSI-T program, begun in 2010 as a larger push to incentivize solar installations statewide. aimed to add 200,000 systems, but received only 6,237 applications for residential retrofits in 10 years, according to the program’s December 2019 report. “I could put a sign over the front door of my office that says ‘free solar water heating,’ and they’d probably still stay away in droves,” Murray says with a wry laugh.

    Larger installations for apartment complexes, hotels and universities, and home pool heating have helped keep Murray’s solar thermal business es afloat despite the lack of other residential demand. Ironically, the commercial sector isn’t as robust in Israel because the country’s original mandate only applied to residential properties — a move Grossman views as a significant oversight. Indeed, Grossman believes that an industrial mandate could increase Israel’s renewables usage up to fivefold.

    The Limiting Psychology of Renewables

    The woes of the American solar water heater industry go far beyond politics, however. The industry also suffers a more insidious challenge: For the average consumer, “going solar” means just one thing: solar PV.

    Solar thermal technologies, including solar water heating, provide a direct, thermodynamically efficient and cost-effective method for decarbonizing heating. And for households in mild climates with low electricity bills, “solar water heating can be one of the simplest ways … to use renewable energy and save on energy bills,” says the CSI-T report.

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    But it’s solar PV that has exploded into the global electricity sector, thanks to manufacturing innovations and strong government support. Leveraging economies of scale, the price of solar PV panels has dropped by over an order of magnitude in the past decade. In California, additional boosts came from government-instituted solar feed-in tariffs, cheap financing plans and private-sector investments. And, in a major coup for the industry, California mandated solar PV on new residences up to three stories starting 2020.

    On the other hand, California’s residential solar water heater industry finds itself in a vicious cycle of low consumer demand and high prices. As the CSI-T report notes, “In contrast to conventional gas and electric water heaters, which are typically installed by plumbers, solar water heaters are installed by a range of firms and public entities.” In other words, consumers must actively seek out solar water heaters by relying on nonstandard sales channels.

    This additional friction reduce s consumer demand among all but the most motivated consumers. leading to higher marketing costs that drive up the customer’s bottom line. in California are further exacerbated by past industry failures, which have led to strong, self-imposed regulations in the name of consumer satisfaction, says Murray. For example, after many cheaper solar water heating systems froze during the unprecedented 1990 freeze in California, only more expensive systems were allowed through the CSI-T program.

    All told, the cost of the average solar water heater sold in California through the CSI-T program was US7,400, compared to less than US1,000 for a fossil fuel alternative. By contrast, a solar water heater in Israel can cost as little as US700.

    Rather than embracing the growing portfolio of technologies available to solve the carbon emissions problem, going all-in on one satisfies the very human need for “magic bullets.”

    Today, drumming up excitement for solar thermal remains difficult. According to CSI-T report interviews with solar water heater adopters, “Some interviewees remarked that it seemed tough to get others interested, theorizing that PV was so dominant in neighbors’ minds that solar water heating hardly registered.”

    “It’s just the sizzling, sexy PV [that] really captivates the audience,” says Murray.

    Portfolios, Not Magic Bullets

    Entrepreneurs routinely caution, “Fall in love with the problem, not the solution.” In this case, the problem is carbon emissions, and, against entrepreneurial advice, individual governments have tended to fall in love with just one solution. For Israel, Cyprus, Hawaii and others, solar water heaters were that solution. For California, it’s solar PV.

    By committing to a specific technology, governments fall prey to a conceptual error that science journalist Ed Yong recently referred to as a “ monogamy of solutions . ” (Interestingly, he argues this fallacy also shapes the government’s response to Covid-19.) Rather than embracing the growing portfolio of technologies available to solve the carbon emissions problem, going all-in on one satisfies the very human need for “magic bullets.”

    Europe’s Green Deal may model such a “portfolio” approach for the rest of the world, according to Bärbel Epp, a German physicist-turned-journalist with nearly two decades of experience studying the global solar thermal market. According to Epp, representatives from the European solar thermal market have lobbied the European Commission for over a decade to use solar thermal technologies to decarbonize the heating sector. “It took [the solar thermal industry] I don’t know how many years, at least 10, of just continuously repeating the sentence that heat is 50% of our final energy consumption in Europe. … It was hard to lobby in Europe, but it’s now obvious that we have to do something for heat.” Whether these efforts will succeed in providing solar thermal a seat at the table remains to be seen.

    To Grossman, solar water heaters are the first piece of Israel’s portfolio. As Israel struggles to meet its Paris Agreement goals, Grossman says he believes solar PV panels will take their place alongside solar water heaters on Israel’s rooftops.

    Back in Sacramento, Murray is still battling for solar thermal. This year, he’s lobbied the California legislature to extend the state’s recently expired solar thermal subsidy program for one more year, citing Covid-19 as a barrier. The legislature hasn’t budged, but Murray vows he’ll keep going. He may be a lot older than he was in 1978, but the idealism is still alive.

    Editor’s note: Dina Berenbaum and Manoshi Datta wrote this story as participants in the Ensia Mentor Program. The mentor for the project was Peter Fairley.

    Editor’s note, 11/3/20: This story was updated to give more information about Gershon Grossman’s current role.

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