History of the discovery of the photovoltaic phenomenon
We are living in a period where the increasing environmental problems combined with the depletion of fossil energy resources and the huge advances in the technology of Photovoltaic Systems make their use feasible. But how did we get here and what is the history of photovoltaics?
Man's first introduction to the photovoltaic phenomenon was in 1839 when the French physicist Edmond Becquerel (1820 - 1891) discovered the photovoltaic phenomenon during his experiments with an electrolytic contact made of two metal electrodes.
The next important step was taken in 1876 when Adams (1836 - 1915) and his student Day observed that a quantity of electric current was produced by selenium (Se) when it was exposed to light.
In 1918, the Polish Czochralski (1885 - 1953) added the method of producing monocrystalline silicon (Si) semiconductor with his research, which is still used in an optimized form today.
An important discovery was also made in 1949 when Mott and Schottky developed the steady-state diode theory. In the meantime quantum theory had unfolded. The way was now open for the first practical applications.
The first solar cell was a fact at Bell Laboratories in 1954 by Chapin, Fuller and Pearson. Its efficiency was 6% exploiting incident solar radiation.
The first major photovoltaic systems, Evolution in prices and costs
Four years later, in 1958, photovoltaic system technology was annexed to the field of space applications when an autonomous photovoltaic system was installed on the Vanguard I satellite.
This system worked successfully for 8 years and was one of the first photovoltaic systems.
From this point onwards, photovoltaic systems began to be gradually integrated into various applications and the technology began to improve continuously.
In 1962 the world's largest PV installation is made in Japan by Sharp, in a lighthouse. The installed capacity of the system is 242Wp.
Photovoltaics started to make their appearance but due to the high cost of production their application was only possible in special cases of autonomous systems. However, research was progressing and the performance of PV was constantly improving. The main customer of PV in the decades that followed was NASA.
The high prices of photovoltaic panels were the most important reason why there was not more enthusiastic acceptance by the market. Indicatively, the price of photovoltaics starts at 500$ per installed Watt in 1956, and after 14 years , in 1970 it reaches 100$/Watt. In 1973 improvements in production methods bring the cost of photovoltaics to 50$/Watt.
The first PV installation to reach 1MW (megawatt) levels is made in California in 1980 by ARCO Solar using a dual-axis solar tracking system (dual-axis trackers).
Evolution is now starting to happen at a faster pace. In 1983 the world PV production reaches 22MW and the total turnover reaches 250.000.000$.
In 1999 the company Spectrolab in collaboration with NREL develops a photovoltaic cell with an efficiency of 32.3%!!!! This element is a combination of three materials (layers) and special for applications in concentrating CPV systems. In the same year the record for Thin Films efficiency reaches 18.8%. The production of all PV panel technologies reaches a total of 200 MegaWatts.
2004: the march is now unstoppable. The massive entry of large companies into the PV industry brings mass production and this in turn brings the price of interconnected systems to 6.5 Euro/Wp. Germany and Japan dominate PV panel manufacturing and now all developed countries are starting, in one way (equipment production) or another (PV plant construction), to adopt PV technologies and consolidate them in the minds of investors and energy consumers alike. The total production in 2004 reached 1 200 MegaWatts of PV components and the turnover of the same year reached 6 500 000 000$.
Today, large-scale economies of scale have achieved high yields in mainly crystalline materials and several countries, with Germany and Japan leading the way, have already invested huge funds in order to exploit photovoltaic technology more widely.
Already, of course, these countries have begun to enjoy the fruits of their advanced know-how.
Photovoltaics in Greece
However, none of this would have become a reality if the Kyoto Protocol and other international agreements that followed under the pressure of environmental problems had not been ratified.
The substantial impetus for photovoltaics, as for other renewable energy sources, was given through government programmes in the form of subsidies for energy production activities (mainly electricity) using "green" technologies (RES). The best known of these is the favourable pricing of energy produced from renewable energy sources, also known as feed-in tariffs.
Greece has also adopted incentives for the promotion of renewable energy sources, which were (and are?) VERY attractive for potential investors.
But the proverbial sloppiness, incompetence and corruption that plagues the state institutions, has managed to make the most promising technology of our time to be characterized as a "bubble" (and from the point of view of some, unfortunately rightly so).
Hundreds of applications for power generation licenses to the RAE and as many more applications for licenses - exemptions to subsidies from the investment law, are waiting patiently in some drawers at the time (or .... the year) of their crisis.
However, fortunately, the state mechanism does not seem to have "succeeded" in intercepting the global dynamics of photovoltaics in our country, since the ingenuity of the Greek manufacturer and the "foresight" of some investors have already "sent" some megawatt-hours to the PPC network.
Also, apart from investments in interconnected systems, another PV market that is developing is that of autonomous systems, since the price of photovoltaic kilowatt-hour now competes with that of oil and even presents several advantages over it. Most autonomous systems are currently located on Mount Athos, but there are now many PV installations in country houses, remote telecommunications stations, lighthouses, livestock farms, etc.
*Note: To see the returns of photovoltaic systems (investments) in various regions of Greece you can use the free calculation forms of selasenergy.gr
The future of photovoltaics
However, many consider that the penetration of photovoltaics has been very slow, taking inspiration from the explosive way in which another semiconductor materials industry, that of computers, has evolved. This delay is mainly due to the technical (and economic) difficulties faced by manufacturers in the production process when trying to create pure semiconductor materials (crystalline silicon).
In photovoltaic systems the volume of the required material (crystalline silicon) is very large and its production is very energy-intensive. In addition, the cost of the equipment and the energy consumed in the production process is very high.
For this reason, the trend that seems to occupy a large share of the photovoltaic market after some years (compared to what it has today) is thin film technologies in which a significant reduction in the required volume of silicon (or other technologies used) is achieved and therefore a reduction in the price of photovoltaic panels.
In any case, the leadership of crystalline silicon technologies will not be challenged. This is also confirmed by the hundreds of millions of euros - dollars - and yuan that have been invested worldwide in the construction of production plants:
- polysilicon (polysilicon)
- crystalline silicon (solar ingot) ingot (single and polar)
- photovoltaic cells (solar wafers)
- photovoltaic cells (solar cells)
- and photovoltaic panels (solar panels - modules) or otherwise (panels - windows - mirrors etc.).
The forecasts for the near future regarding the photovoltaic market are particularly promising, both for the universal spread of photovoltaic technology worldwide and for the downward trend in the prices of photovoltaic panels.