The following is an excellent short history of solar panels and solar power from guest contributor Dane Cross. I think you’ll thoroughly enjoy it — I did!
What do Archimedes, Einstein and Arnold Schwarzenegger all have in common? Answer: They’ve all contributed to the development of solar power.
From the 3rd Century BC when Archimedes fought off Roman ships by concentrating the suns rays at them with brass shields (they burst into flame), through work by some of the best known figures in the history of science, harnessing the power of the sun has long been a goal of human innovation. Let’s look at some of the highlights:
1767 – The Solar Oven
Swiss physicist, alpine explorer, and aristocrat Horace de Saussure is credited with inventing the first working solar oven, amongst other discoveries. Constructed from 5 layers of glass and measuring around 12 inches across, the oven worked by allowing light to pass through the glass before being absorbed by the black lining and turned into heat. The heat is then reflected by the glass, therefore heating the space inside the box up to 87.5 degrees Celsius.
He wrote that “Fruits… exposed to this heat were cooked and became juicy.”
1839 – The Photovoltaic Effect
Edmond Bequerel, born in Paris in 1820, discovered that when two electrodes were placed in an electrolyte (electricity-conducting solution), a voltage developed when light fell upon the electrolyte. The basic principles of solar power had been uncovered.
1873 – Selenium
An English Electrical engineer, Willoughby Smith, discovered the photoconductivity of selenium entirely by accident. He was developing a method for continually testing underwater telegraph cables as they were being laid and chose selenium rods as a semi-conductor with high resistance for his test circuit. Although selenium appeared to be up to the job, inconsistent results kept occurring. Smith realised that the conductivity of selenium was affected by the amount of light it was exposed to. He described the effect in a paper published in Nature in February of that year.
1876 – Electricity from Light
A King’s College Professor, William Grylls Adams, and his student, Richard Evans Day, found in 1876 that selenium produced electricity when exposed to light. They attached platinum electrodes to selenium and observed a current in the electrodes when the selenium was exposed to light. Although there was not enough electricity to power anything, they had shown that electricity could be generated from light without the use of any moving parts.
1883 – The First Working Solar Cell
American inventor Charles Fritts developed the first solar cell, applying selenium to a thin layer of gold. This method was only able to achieve 1% efficiency, making it impractical for general use.
1904 – Einstein’s Paper on Light & Electrons
In the snappily titled “On a Heuristic Viewpoint Concerning the Production and Transformation of Light,” Einstein set out for the first time the relationship between light and electrons. Although controversial at the time, it was gradually accepted by the scientific community and led to his winning of the Nobel Prize in 1921.
Later in 1916, Robert Millikan would experimentally prove Einstein’s theory of the photoelectric effect.
1918 – Accidental Crystals
Jan Czochralski, a polish scientist, discovers a method for creating single-crystal silicon entirely by accident — he mistakenly dipped his pen in a crucible of molten tin rather than an inkwell. The result was a thin thread of solidified metal. Single-crystal semi-conductors and metals became important throughout electronics — their efficiency and stability not only contributing to the development of silicon solar cells, but also crucial to the creation of transistors for microprocessor units.
1954 – A Major Breakthrough
Three researchers at Bell Labs — Daryl Chapin, Calvin Fuller, and Gerald Pearson — discover silicon solar cells.
Chapin had for several years been experimenting with selenium-based solar cells but was unable to achieve an efficiency above 1% (for comparison, internal combustion achieves around 20%). At the same time, Fuller and Pearson were developing silicon transistors and found that one of these, when exposed to light, generated electricity. The three scientists joined forces and in 1954 presented their ‘solar battery’, powering a small toy windmill and a radio, at an efficiency of 6%. The key to this was their ability to diffuse boron into silicon, a process known as doping. This first solar cell was the size of a small coin, and although not commercially viable, is the basis for solar cell development ever since.
1956 — 213 Truman N.E., Albuquerque, NM
In the mid-50s, engineer Don Paxton and architect Frank Bridgers designed the world’s first commercial solar building. Utilising a south-facing glass wall tilted to 30 degrees, alongside mechanical and “passive” solar technologies, the structure was well ahead of its time. Relying on mechanical solutions where computer control would nowadays be used, they achieved a remarkable level of efficiency through solar heating and thermal storage. The template that they created is still utilised in creating energy-efficient homes and commercial premises today.
Late 1950s – Increasing Efficiency
Throughout the late 50s, Hoffman electronics developed increasingly efficient solar cells. It started out initially at an 8%-efficient cell in 1957, before eventually increasing to a 14%-efficient, commercially available cell in 1960.
1950s and 60s – The Space Race
The burgeoning space industry’s need for a sustainable power source in the earliest satellites led to investment and development in solar technology. Satellites such as Explorer VI and VII and the first telecommunications satellite Telstar 1 (launched by Bell Labs) utilised the most cutting edge (at the time) solar cells, achieving up to 14 watts from their photovoltaic arrays.
1970s – Commercial Viability
Despite the great advances over twenty years or so, solar technology was still too expensive to be commercially viable in terrestrial installations. In the early 70s, Dr. Elliot Berman (with funding from Exxon Corp.) designed a much lower cost solar cell, using lower-grade silicon and cheaper housings which brought the cost per watt down from $100 to just $20. Installations far from mains electricity (i.e. oil rigs) used the cells over expensive and cumbersome batteries, giving terrestrial solar technology the capital boost it needed to become a viable mainstream solution.
1972 – The Institute of Energy Conversion
The first laboratory dedicated to the development of PV research is established at the University of Delaware. A year later, this leads to one of the world’s first PV-powered houses – ‘Solar One’. Using the model known today as the solar ‘feed-in’, surplus electricity generated during the day is fed back into the grid, while at night the house can draw purchased power from the grid.
1977 – 500 Kilowatts and Counting
Photovoltaic manufacturing production exceeds 500 kilowatts for the first time
1978 – First Feed-In Tariff Implemented
The first form of feed-in tariff was implemented in the US in 1978 under President Jimmy Carter, after signing the National Energy Act (NEA). Its purpose was to encourage energy conservation and the development of new energy resources, including renewables such as solar, wind, and geothermal power.
1980s – Solar Hits the Mainstream
Throughout the 1980s, solar developments continued at apace. Thin-film solar cells allowed for smaller, cheaper, and more-efficient solar installations, on buildings, vehicles, and consumer items (such as hand-held calculators).
1982 – Solar-Powered Vehicles
German automobile manufacturer Volkswagen start testing solar PV arrays on the tops of Dasher station wagons. An array generate approximately 160 watts for the vehicle’s ignition system.
1986 – Kramer Junction
World’s largest solar thermal facility scheduled to be built in Kramer Junction, California. The facility consisted of rows of mirrors that concentrated energy from the sun into a system of pipes that circulated a heat transfer fluid. This fluid was then used to produce steam, which would power a conventional turbine with which to generate electricity.
1990 — Start of the 1000 Roof Program in Germany, Accompanied by the National Power Feed-in Law
As in the case of the Carter feed-in tariff scheme, the tariffs were below end-consumer prices, with the high cost of PV at that time, and it did much for PV development.
1990s – Dawn of the Grid
First grid-supported photovoltaic system is completed and installed in Kerman, California by Pacific Gas & Electric, the world’s first ‘distributed power’ effort.
1996 – Flight of the Icare
The Icare, which at the time was the world’s most advanced solar-powered plane, flew over Germany in 1996. Over 3,000 super-efficient solar cells covered the wings and tail surfaces of the plane.
Later on that year, development began on Solar Two, an upgrade of its 1973 Solar One project. Solar Two was a huge advancement in that it demonstrated the ability to produce power even when the sun wasn’t shining. This also helped foster commercial interest in power towers.
1999 – 32.3% Efficiency
Spectrolab, Inc. worked with the National Renewable Energy Laboratory to develop a photovoltaic solar cell that converted 32.3 percent of received sunlight into electricity.
1999 — 100,000 Solar Roofs Program Starts in Germany
A “100,000 Solar Roofs” program was started in Germany with the goal of creating a PV power capacity of 300 MW within six years. The program was initiated by Dr. Hermann Scheer, member of the German Parliament and president of EUROSOLAR.
2000 — Hermann Scheer Introduces the National Renewable Energy Act in German Parliament
It’s unique property were technology-dependent feed-in tariffs. For PV, the tariff levels were way above end-consumer prices. This created an (artificial) market that allowed the PV industry to grow from a niche player to an adult industry. The second unique part is the continuous reduction in the tariffs baked into the law that forces the industry to stay on its toes.
2000s — Largest Residential Solar Installation Complete
A family in Colorado installed largest residential installation to be registered under the ‘Million Solar Roofs’ program. The system is measured at 12 kilowatts, providing most of the energy for the 6,000-square-foot home.
2004 — 1 GW of PV Installed in Germany
2004 – One Million Solar Roofs
California Governor Arnold Schwarzenegger proposes Solar Roofs Initiative for one million solar roofs in California by 2017.
2006 — Polysilicon Use in Photovoltaics Exceeds All Other Polysilicon Use for the First Time
Contributing to this is the lower cost of manufacture than monocrystalline counterparts.
Later that year, new world record achieved in solar cell technology when a new solar cell breaks the “40 Percent Efficient” sunlight-to-electricity barrier.
2007 — 42.8% Efficiency
University of Delaware claims to achieve new world record of 42.8% in solar cell technology without independent confirmation.
2008 — CleanTechnica Launched
CleanTechnica starts publishing articles on cheap solar panels and solar power. (OK, maybe not as notable as the above.)
2008 and Beyond
Solar power has seen a huge surge in popularity as a renewable form of energy in recent years, largely attributable to government incentives such as feed-in tariffs. Whilst the amount that the homeowner is paid for each kilowatt is being reduced in a number of countries this year, other companies are jumping into the game, and the incentives still make a lot of sense in terms of finances and the environment.
The amount of research and investment in the technology itself continues at a lightning fast pace, with no shortage of engineers and innovators daring to take risks.
I’m sure this timeline will be extended far into the future.
Dane Cross is a freelance writer and green aficionado currently writing on behalf of Ardenham Energy, a UK based provider of solar panels and heat pumps.
Image: solar farm courtesy shutterstock