One area that utilize solar energy, the Department of Promotion of passive solar systems in buildings for heating and air conditioning. The CRES provides the necessary technical assistance and technology, study the feasibility and benefits of the facility and conducts research with many applications.
The possibility of producing electricity both in remote and populated areas, without impact on the environment, make attractive the use of photovoltaic systems in Greece.
The photovoltaic systems are able to convert solar energy into electricity. A typical PV system consists of:
the PV framework (type solar collector)
system of energy storage (batteries)
iletronika the systems that control the electricity generated by PV array.
A typical array consists of one or more N / B under electrically connected to each other. When the F / B part exposed to sunlight they convert 10% of solar energy into electricity. Moreover, the conversion of solar energy into electricity is quietly, reliably and without any burden on the environment.
The PV framework consisting of properly processed silicon disks (solar data = solar cells) which are hermetically sealed in plastic to protect from the weather conditions (eg humidity). The front side of the protected context of rigid glass. This structure, not exceeding a thickness of 4 to 5 mm, usually mounted in a frame of aluminum, such as windows of buildings. The interior is interconnected in series and parallel depending on the application. In most applications in our own parallel, many benefits provided by the stable assembly of F / B, towards the south and of course on condition that the allowance is less than adequate torque angle. The advantages are:
Cheap and easy assembly with the lowest cost.
Good mechanical stability of the installation even under strong winds.
Variety of opportunities for a satisfactory aesthetic integration into existing building structures.
On the other hand, the performance of PV energy can be improved with the appropriate direction to the sun and there is even greater improvement with higher extent of direct radiation throughout the radiation.
Tech continued to turn the sun requires a stable structure and regulation of movement direction.
This course is always linked to higher costs in relation to the fixed assembly, but with the additional power consumption. The conduct of two axes in two thrusters to adjust the direction (ie the rotation around vertical axis) and inclination (torque around a horizontal axis) of the F / B in the position of the sun and bring the best performance.
Instead, use the Single conduct a curved, polar (ie directed towards the north) with a single axis thruster. Such conduct has lower energy efficiency in relation to the conduct of the two axes.
The sunlight on the solar generator enhanced, mainly with a mirror, ie the concentration of sunlight. Certainly the use of reflectors has meaning only in the mobile facility. This form could not prevail in our country because:
The concentration of sunlight is worth only under conditions of mounting and moving directly from high radiation.
The fotokypseles strongly heated by concentrating the radiation, so that when the concentration is greater than 2, without active cooling in cells from Silitium, caused damage to cells.
The output mirror is cheaper than the production of PV, but it brings so much additional return. Also, in addition, require much space in the assembly when a mobile facility.
In our parallel, we further strengthened the disadvantage of moving mount. When the existence of direct (immediate) radiation is high, ie mainly in the summer, produced a stream, but where are the low radiation with high proportion of diffuse radiation in the winter, does not achieve additional efficiency.
The integration of F / B frames in buildings can have multiple benefits. Apart from the electricity production of PV framework can be used as building blocks to cover the roof, the lining of the front or as sunblinds. This new element in the architecture, could lead to innovative solutions for the appearance of buildings.
For proper fitting a solar system, first calculated the size of the generator power, according to the current need for action in each case. The solar system should provide energy in sufficient quantity to cover the electricity consumed during the day lamps, appliances, and energy consumption of the same installation.
Passive solar systems:
With the use of passive solar systems can get hot water:
In industries that require hot water during the production process, such as soap industries, tanneries, dairy production, dyeing, breweries etc.
In greenhouses for space heating and soil.
In large private and public buildings such as hospitals, apartment buildings, etc.
While the potential for passive heating and cooling systems are very large, the applications in Greece is very low. Until now numbering just over 250. The largest percentage of private buildings is the home area while in the second step size are educational buildings. The remaining applications cover other uses. Most buildings are built in Zone A (as defined by the existing thermal insulation), and most of them in Crete. The rest are found in Macedonia in Thessaloniki and principal and its surroundings and in Attica.
The systems used are the most part very simple. We have used materials or components, advanced technology, even in buildings that have received funding from the demonstration projects of 17 DG the European Union.
The key factors halting the application of the following:
Lack of knowledge among architects and engineers in general.
Lack of public information.
Lack of manufactured goods necessary for the proper construction and operation of passive systems and standardization of components.
General trend of private and public placement in the smallest possible initial capital consistently increased operating costs of buildings.
Energy consumption in the building sector accounts for 30% of total final consumption at the national level. There is a serious trend which is mainly due to high rate of installation of air conditioning equipment. At the same time it should be noted that the building sector contributes 40% of CO2 emissions at the national level. Thus a policy of CO2 reduction by the state to follow the commitments of the Rio Conference should address primarily the building sector. Such a policy creates very good conditions for the expansion of their
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