Weather conditions in the Mediterranean area favor the profitable use of some renewable energy sources, such as solar energy. The abundant solar radiation and the simple structure of the photovoltaic systems offer the possibility to decentralize solar energy, converting it into electricity.
Solar energy is a clean, endless, soft and renewable energy source. It is controlled by no one and represents an endless domestic energy resource, providing energy supply independence, predictability and security.
Photovoltaics, which convert solar energy into electric current, are considered to be the ideal energy conversion systems, since they use the most available energy source in the planet, they don't have moving parts and they produce electricity, which is the most useful energy form.
Our state provides incentives for the installation of photovoltaic systems, the most important being the guarantee of fixed selling price for the energy produced in the power supply network. The harmonization of the institutional framework to that of the other European states is expected to lead to the fast development of the photovoltaic area.
1. What is a photovoltaic system?
It is a system converting the abundant solar energy into electric current. It is one of the fastest developing renewable energy source technologies in the world. In 2004, for example, the photovoltaic production increased by 60% compared to 2003, while it is estimated that the last 5 years the photovoltaic facilities have been steadily increasing by 40% per year. First of all, photovoltaic systems consist of solar collectors, which are big flat surfaces (mostly made of crystalline silicon technology), similar to solar-powered water heater collectors. The photovoltaic system produces low voltage direct current. Thanks to an electronic device, known as inverter, this current is converted into a corresponding quality current, like the one produced by the Public Power Corporation S.A.
2. What is its operation principle?
Solar light consists essentially of elementary energy particles, called photons. Photons contain different amounts of energy, depending on the solar spectrum wave length. For instance, light blue or ultraviolet colors contain more energy than red or infrared colors. As a result, when photons collide onto a photovoltaic element (which is essentially a “semiconductor”), some of them are reflected, others penetrate it and others are absorbed by the photovoltaic element. The latter are the ones that produce electric current. These photons force the photovoltaic element electrons to move to another place, producing this way the electricity phenomenon. This is the simple physics’ principle on which one of the most advanced electricity production technologies of our time is based.
The photovoltaic system is the cheapest solution for energy and money saving!
A photovoltaic system consists of:
Τhe collector The inverter The baterry