In our last learning series on the history of solar energy, we started from the very beginning and ending with the launching of solar energy into space!

What came next? That’s exactly what you’re about to find out in part 2 of the history of solar energy.

Still on the search for a useable solar cell

history of solar energy Photo by David Monje on Unsplash

The last time we left off we were still on the search for an efficient silicon solar cell (the components in solar panels that make them able to use sunshine for energy). Solar cell efficiency was a very gradual process through the years, but eventually led to the solar cells used in our solar panels today.

By the way, are you wondering what exactly solar cell efficiency is? Simply put, it’s a measurement of how well a solar cell converts sunshine into energy.

In 1960 the silicon solar cell was still only 14% efficient. And it wasn’t until 1985 that the researchers at the University of South Wales finally break the 20% efficiency barrier!

Solar cell efficiency is determined by a lot of factors and has a lot to do with what type of solar cell you’re talking about, what material you’re using and how thick it is, along with other, more complicated, factors. If you’re interested, you can read more about it.

Continued Evolution of Solar Cells

solar cell research Silicon Crystal Growth and Wafer Technologies – Scientific Figure on ResearchGate.

One of the types of solar cells that developed in the 1970’s was thin-film solar cells.

The Next Thing: Thin-film Solar Cells

Thin-film solar cells are exactly what they sound like, a very thin layer of material that contains solar converting cells. Think about the tiny solar panels in a calculator. In fact, it was shortly after in 1978 the first solar-powered calculators were introduced.

In 1972 the Institute of Energy Conversion was established at the University of Delaware and became the world’s first laboratory dedicated to solar cell research and development. Their research and development focused on thin-film solar cells and solar thermal systems.

And in 1980, thin-film solar cells exceeded 10% efficiency thanks to the University of Delaware’s research. (Efficiency for thin-film solar cells tends to be lower than the cells used in solar panels.)

In 1986 ARCO Solar released the world’s first commercial thin-film power module (like a small panel). And six years later, the University of South Florida hit 15.9% efficiency with cadmium telluride thin-film.

While the popularity of thin-film solar cells have dropped in recent years, this technology continues to be important for the future of solar energy products like building-integrated installations (BIPV) and vehicle charging systems. Stay tuned for future parts of this series to learn more about this.

The Solar Cell Efficiency Dilemma

solar cell efficiencies Image source: NREL

Development of the silicon solar cell continued in research labs, but commercialization was slow to adopt this new technology. This was mostly due to the low efficiency of silicon solar cells at the time.

Solar cells had been used successfully in space since 1958, with the launch of a solar-powered transmitter aboard the satellite Vanguard 1. And by 1960, most of the solar technology at the time was being used in space for shuttles and satellites.

A Push to Make Solar a Consumer Option

In 1963, Sharp successfully started mass-producing solar cells, which made them theoretically more available to the general consumer. However, the solar cell was still a ways from being widely accessible to consumers.

What was needed next was help from… the oil industry?

How Big Oil Was Important in Forming the Solar Industry

oil and solar industries Photo by Zbynek Burival on Unsplash

Yes, that’s right. Oil was a huge reason solar took off when it did in the late 1970’s to early 80’s.

In the 1970s, a few breakthroughs helped make the solar cell more widely available, and a few of those breakthroughs were pioneered by none other than some of the largest oil corporations.

The breakthrough happened due to the oil crisis of 1973 in the US in which the oil embargo sparked fuel shortages and long lines at gas stations. Oil companies started looking to invest in other arenas.

Enter Elliot Berman: Solar Energy Pioneer

“Dr. Elliot Berman was among those who believed that solar photovoltaic technology had great potential on Earth, where millions of people lacked electricity.”  – John Perlin, author of Let It Shine: The 6,000-Year Story of Solar Energy

With help from Exxon Corporation, Berman designed a significantly less costly solar cell, bringing the price down from $100 a watt to $20 a watt. This was extremely important at the time because it demonstrated that solar could be a viable option for manufacturing products for the consumer level.

Because of this, solar cells began to power navigation warning lights and horns on many offshore gas and oil rigs, lighthouses, railroad crossings and domestic solar applications began to be viewed as sensible applications in remote locations where grid connected utilities could not exist affordably.

Image: Robert Willis/Solar Power Corp. via John Perlin via NPR

The Government Steps In

Right around this time, research in solar technologies started to catch the attention of the government due to the energy crisis.

And in 1977, President Jimmy Carter warned the nation: “The oil and natural gas we rely on for 75% of our energy are simply running out.”

Shortly after in 1977, the U.S. The Department of Energy launched the Solar Energy Research Institute. This lab, which later became known as the National Renewable Energy Laboratory (NREL), started to receive funding from Congress each year for solar research and development.

Read and listen about this story on NPR.

Solar Starts Expanding Across the World

solar panel farm in the desert Photo by Antonio Garcia on Unsplash

Solar Powers a Lighthouse in Japan

Solar for commercial use started its expansion across the world in the 1960’s. Japan was one of the first to conceive of how to use large solar panel array installations on a lighthouse.

At the time it was the world’s largest array.

Space-Based Solar Station Predicted by Science Fiction

In 1968 Peter Glaser was the first to conceive of a space-based satellite solar power station, and in 1973 received the patent.

And guess what? The idea was really first conceived in 1941 in a short story by science fiction writer Isaac Asimov called “Reason“! In the story a space station transmits energy collected from the Sun to various planets using microwave beams.

Solar Powered Homes

Solar power for home use? What a concept! But in 1973 you wouldn’t find solar panels on homes everywhere like you do now. In fact, the University of Delaware built one of the world’s first solar powered residences named Solar One that year. It was the first experimental house to convert sunlight into both heat and electricity for domestic use and drew thousands of visitors.

solar one Image of Solar One via University of Delaware

Solar Installed Across the World

That very same year in 1973 solar power systems were installed on every continent except Australia by the NASA Lewis Research Center.

These systems provided such diverse applications as vaccine refrigeration, room lighting, medical clinic lighting, telecommunications, water pumping, grain milling, and classroom television.

This was a massive project that was finally completed in 1995.

And Made Its Way to Reservations

Another huge advancement in the history of solar energy systems led by NASA Lewis Research Center in 1978 when they installed a massive solar system on the Papago Indian Reservation located in southern Arizona. This marked the world’s first village solar system.

The system was used to provide for water pumping and residential electricity in 15 homes until grid power finally reached the village in 1983.

First Solar Power Stations

solar power stations Photo by American Public Power Association on Unsplash

Arco Solar was the first to build two megawatt solar stations in California in the early 80’s. In 1980 ARCO Solar became the first company to produce more than 1 megawatt of photovoltaic modules in one year.  Two years later, the solar company installed the first megawatt-scale solar project in California.

Shortly after the company was sold and Arco turned its focus back into fossil fuel energy production, but the advancements made to solar during this time set a strong foundation for the future of solar energy.

In the 1980s, the largest power plants were yet to be built, but you’ll have to hold on to your seats to find out how we get there!

What’s Next?

That’s it for now. Stay tuned for next time when we will bring you the history of solar used for cars, spacecraft, satellites, and in flight.



  1. Thin-film Solar Cells:
  2. History Solar Panel Technology:
  3. History of Solar Power:
  4. Solar Timeline:
  5. Amorphous Silicon Solar Cell:
  6. NPR: How Big Oil Helped Launch the Solar Industry:
  7. Timeline of Solar Cells:
  8. Long History of Solar PV:
  9. Silicon Crystal Growth and Wafer Technologies: [accessed 8 Sep, 2020]
  10. Space Based Solar Power:
  11. Solar One:
  12. Solar Cell Efficiency chart: