◊ This is part of the ‘solar energy’ series of articles ◊
Solar energy in the broadest sense is primarily responsible for life on our planet through various processes including photo synthesis and heat generation. As far back as the 7th century BC various cultures used the thermal properties of light to start fires by using mirrors and glass. Since the discovery of the photovoltaic effect of light there has been significant advancement of the technology.
Here is a glimpse of the timeline of photovoltaic (PV) devices:
| Year | Milestone |
|---|---|
| 1839 | Alexandre Edmond Becquerel discovered that the Sun’s energy produced a photovoltaic effect. Certain materials can generate small amounts of electric current when exposed to light. |
| 1873 | Willoughby Smith discovered the photoconductivity of selenium. |
| 1876 | William Grylls Adams along with a student of his, Richard Day, discovered that when selenium was exposed to light, it produced electricity. The selenium cells were not efficient enough to power electrical equipment, however proved that light could be directly converted into electricity. |
| 1883 | Charles Fritts, an American inventor, described the first solar cells made from selenium wafers. |
| 1921 | Albert Einstein awarded the Nobel Prize in Physics for his work on the photoelectric effect. |
| 1953 | Calvin Fuller, Gerald Pearson, and Daryl Chapin, discovered the silicon solar cell. |
| 1954 | Calvin Fuller, Gerald Pearson, and Daryl Chapin develop the silicon photovoltaic cell at Bell Labs. This cell was efficient enough to run small electrical devices |
| 1956 | The first solar cells are available commercially at 2% efficiency. The cost however is far from the reach of everyday people |
| 1957 | Hoffman Electronics creates an 8% efficient solar cell. |
| 1959 | Hoffman Electronics creates a 10% efficient solar cell. |
| 1950’s (late) and early 1960’s | Satellites in the USA’s and Soviet’s space program were powered by solar cells. By the late 1960’s solar power was the standard for powering space bound satellites. |
| 1960 | Hoffman Electronics creates a 14% efficient solar cell. |
| 1970’s (early) | A way to lower to cost of solar cells was discovered. This brought the price down from $100 per watt to around $20 per watt |
| 1976 | David Carlson and Christopher Wronski of RCA Laboratories create first amorphous silicon PV cells, which have an efficiency of 2.4%. |
| 1980 | The Institute of Energy Conversion at University of Delaware develops the first thin film solar cell exceeding 10% efficiency using Cu2S/CdS technology. |
| 1983 | Worldwide photovoltaic production exceeds 21.3 megawatts |
| 1985 | 20% efficient silicon cells are created by the Centre for Photovoltaic Engineering at the University of New South Wales. |
| 1992 | University of South Florida fabricates a 15.9% efficient thin-film cell |
| 1994 | National Renewable Energy Laboratory develops a GaInP/GaAs two-terminal concentrator cell (180 suns) which becomes the first solar cell to exceed 30% conversion efficiency. |
| 1999 | Total worldwide installed photovoltaic capacity reaches 1,000 megawatts. |
| 2006 | New World Record Achieved in Solar Cell Technology – New Solar Cell Breaks the “40 Percent Efficient” Sunlight-to-Electricity Barrier. |
| 2007 | University of Delaware claims to achieve new world record in Solar Cell Technology without independent confirmation – 42.8% efficiency. |
| 2011 | Fast-growing factories in China push manufacturing costs down to about $1.25 per watt for silicon photovoltaic modules |
| 2018 | Alta Devices, a US-based specialty gallium arsenide (GaAs) PV manufacturer, claimed to have achieved a solar cell conversion efficiency record of 29.1%, as certified by Germany’s Fraunhofer ISE CalLab. |
Development of PV modules is continuing as the implementation of renewable energy sources grows. The unit-cost of PV devices continues to trend lower which is driving an increase in installed capacity worldwide.
Sources:
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