Updated 2 weeks ago
What Did the “Most Advanced Solar Home” Look Like 50 Years Ago?
Written by
Catherine Lane

Solar energy has been shaping the way we think about sustainability for almost a century. In 1939, the very first home heated with solar energy, Solar I, was built. But, it wasn’t until the 1970s that solar energy started to make its way into more American homes, as the environmental movement and the ‘70s energy crisis increased demand for alternatives.
1977 marked a turning point. The Solar Research Foundation was created, the first iteration of a residential solar energy tax credit was on its way, and Popular Science crowned a beachside Long Island residence “The Most Advanced Solar Home” in its July issue.
Fast-forward 47 years, and a copy of this magazine found its way to my local antique shop, where I found it among vintage issues of National Geographic. I was fascinated by it, thinking back on how far solar technology has come since I started working in the industry less than a decade ago. How could this house, nearly 50 years old, differ from the most advanced solar homes of today?
Advanced solar homes: 1970s vs. today

Images courtesy of Popular Science and Tesla, Inc.
Popular Science’s “Most Advanced Solar Home” was owned by the Barbash family in Quogue, New York. Built with the explicit purpose of harnessing solar energy, the home followed design principles of other solar homes of the time — like steep roofs and angular exterior walls — so it could maximize the sun exposure to its solar thermal collectors. The collectors sent hot water to a large storage tank that then heated the home and its water supply using a sophisticated computer control system.
Fifty years later, a solar home of today looks a little different than the one installed on the Barbash’s roof. A truly advanced, modern solar home would be equipped with a Tesla Solar Roof and Powerwall battery system. It would also use smart technology like a smart electrical panel and a smart home management system to better control energy usage, maximizing the benefits of solar.
Function Then: Heating the home
The biggest difference between solar homes of today versus those of the ‘70s lies in what the systems actually do. Back in the 1970s, solar homes were primarily designed to harness the sun’s energy through heat. Solar thermal systems could heat and potentially cool homes and provide hot water, but that's about where the capabilities stopped.
Special solar collectors were installed on the home’s roof. The collectors heated water (or another liquid) that was then stored in a tank that heated coils of copper pipe. These were connected to “radiator-like” units within the home’s ducts that blew the hot air surrounding the coils into the home.
Though not used in the Barbash household, this system could reach temperatures of up to 240°F, which is enough to power absorption-type air conditioners.
Function Now: Powering the home
Modern solar systems use photovoltaic (PV) solar cells, which convert sunlight into an electrical current. With a Tesla Solar Roof, a number of the roof shingles contain these solar cells. The electric current they generate is sent to an inverter, where it’s converted into electricity that can be used not only by your HVAC system, but by all of your appliances.
Photovoltaic technology makes it possible for homes today to run entirely on clean energy. This means modern solar homes can provide greater electric bill savings, and the homes are even greener as they run more appliances with the power of the sun.
Design Then: Solar collectors

Images courtesy of Popular Science
The Barbash home relied on a 384-collector array spread across 20% of its roof, with each module measuring 4 feet by 8 feet. These collectors provided enough thermal energy to heat the home, but their bulky design made them impossible to ignore.
The collectors, manufactured by Owens-Illinois, were coated with a patented selective material that maximized solar thermal absorption. They were also equipped with aluminum backing to allow the collectors to absorb reflected light. A vacuum between the inner and outer layers minimized heat losses and increased the system’s overall efficiency.
The collectors contained a heat-absorbing liquid, like water, which was heated by the sun. You can think of it like leaving a water bottle in your car on a hot day. The car traps the heat from the sun, and the water in the bottle gets hotter as the day goes on.
Design Now: Solar shingles

Image courtesy of Tesla, Inc.
Today, the same home could be outfitted with Tesla’s Solar Roof, a sleek system where the roof shingles themselves work as a power source. Instead of dominating the roof with large, noticeable modules, modern solar shingle technology can generate enough electricity to power the entire home through a seamless design.
A unique feature of the Tesla Solar Roof is that, while every shingle looks the same, not every one has solar cells. Installers strategically place the solar-enabled shingles around the roof to maximize sun exposure. On average, it takes just 34% of the available roof space to provide enough solar to power the whole home, and the rest of the roof is covered by identical, non-solar shingles.
What was once a functional but loud statement about sustainability is now an almost invisible installation, blending into the look of almost any home while providing even more benefits.
Storage Then: Thousand-gallon tank

Image courtesy of Popular Science
At the heart of the system was a hulking 1,000-gallon storage tank equipped with a heat exchanger to preheat domestic hot water and water-filled copper coils. Liquid was sent from the collectors on the roof to the storage tank.
The tank not only allowed the system to complete its core function of heating the coils that eventually warmed the house, but it also made it possible to store solar energy for use on cloudy mornings or chilly nights when the sun wasn’t shining.
Storage Now: Solar batteries

Image courtesy of Tesla, Inc.
Today, the large storage tank is replaced with sleek lithium-ion battery systems like the Tesla Powerwall 3, designed to store excess solar energy generated throughout the day for later use. Unlike the storage tank, batteries can power more than just the heating system, running everything from your lights to your refrigerator after the sun sets.
The Powerwall is an excellent storage system that can seamlessly integrate with the Tesla Solar Roof while still having an easy user interface and useful operating modes. However, there are some more advanced batteries you might see in modern solar homes, like those from FranklinWH, that offer greater customization and an extra level of control.
Controls Then: Computerized control
If the storage tank was the heart of the system, the Sunkeeper computer system was the brains. This computer regulated water flow, managed heat distribution, and activated a propane-powered backup heating system when needed.
With zoning capabilities and temperature sensors, the system was considered ultra-modern technology in the 1970s.
Controls Now: Smart home systems
The innovative technology used in the Sunkeeper computer offered a glimpse into the future of smart home management. Today, homes have become far more intelligent, with full networks of connected systems that allow you to manage your home’s energy exactly how you want to. And there are a whole host of smart home devices and management systems to choose from.
Smart thermostats, for example, don’t just keep your home at the desired temperature. They can learn your habits and create customized heating and cooling schedules that balance comfort and efficiency.
Whole-home automation software, like Home Assistant, offers highly customizable management hubs that allow you to control everything from a security system to your home’s lighting in one place.
Even electrical panels are becoming smarter, allowing you to remotely control what circuits you're using when, minimize your electricity bills, and get the most out of your solar energy system.
When used correctly, smart home systems can help you manage your energy usage effectively and maximize the value you get from a solar system.
Cost Then: $500,000+
Having an advanced home has never been cheap. In 1977, the Barbash family’s solar collector modules cost about $548 each, but the computer system was what really tipped the price tag over the edge. Owens-Illinois commissioned the computer system for $100,000 (about $520,000 today) to prove that solar thermal homes of this kind were possible.
According to Popular Science, Owens-Illinois estimated the computer system’s cost could come down to just $1,000 over the following five years as a result of the Barbash home’s success. In total, the 1977 solar thermal setup, including the collectors, computer, and installation, would cost somewhere in the ballpark of $585,000 today.
Cost Now: $200,000+
A modern solar home also costs a pretty penny. We estimated how much a complete Solar Roof and smart home upgrade would cost for the Barbash house today, coming up with a cost of about $225,000.
The Tesla Solar Roof is expensive, with an estimated price of about $200,000 for a 13.61 kW installation on a 3,386-square-foot roof. A Powerwall battery adds another $15,700, and a basic smart home upgrade, including a smart electrical panel, tacks on almost $7,000.
Even so, installing a state-of-the-art solar PV system today that produces electricity for your entire home plus a battery and smart home automation upgrades is nearly half the cost of installing a solar thermal system that only provides heating and hot water, illustrating just how far technology has come.
There are cheaper ways to go solar. Back in the ‘70s, plenty of homeowners installed simpler home solar thermal systems to provide hot water and ease the burden of the energy crisis. These more basic systems cost a few thousand dollars.
Now, traditional solar panels are also substantially cheaper than the Tesla Solar Roof, with a typical solar installation costing an average of $22,000 before incentives. Smart home and battery storage systems are optional add-ons that make it possible to maximize your solar energy usage, but they aren’t required to power your home with solar.
Looking ahead
It’s clear that solar technology has come a long way since 1977. I’ve even seen significant changes since I entered the solar industry in 2019. Just six years ago, PERC solar cells were all the rage, and every major storage system used NMC batteries. Today, it’s TOPCon cells and LFP batteries for as far as the eye can see.
While solar thermal systems have fallen out of fashion, both because of improvements in photovoltaics and President Reagan letting the original solar tax credit expire in the 1980s, one thing has remained constant: People want solar. The energy crisis of the ‘70s caused homeowners to turn to solar, and frequent power outages and higher-than-ever electricity prices are doing the same today.
The solar industry has been shaky in the past and is in a more precarious position today than it has perhaps ever been. But solar provides something that utility companies and governments have historically failed to: reliability. As we continue to innovate and the industry expands, the future for solar, though a bit cloudy at times, seems bright.
Catherine has been researching and reporting on the solar industry for five years and is the Written Content Manager at SolarReviews. She leads a dynamic team in producing informative and engaging content on residential solar to help homeowners make informed decisions about investing in solar panels. Catherine’s expertise has garnered attention from leading industry publications, with her work being featured in Solar Today Magazine and Solar ...
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