Welcome everybody!!! Bau Bau BauDo you remember me? I’m IGOR!!!
SOLARTHERMAL ENERGYSolar Energy is the primary source forexcellence. Every year the sun radiates onthe Earth 19.000 billions of TEO (tonnesequivalents oil), while the Energy annualdemand is about 10 billions of TEO.In Italy the annual demand is about 190millions of TEO. Practically all the Energytoday we use, it has originated from solarradiation, including fossil fuels. Thepotential of energy obtained by heatderived form sun is able to satisfy goodpart of the thermal necessities and ashare non – marginal of electric energy,and finally it is possible to have thenecessary heat in the production of thebiological fuels.
The quantity of solar energy that arrives on the ground is so huge, about 10 000times more than all the energy used from the humanity, but it is not veryconcentrated, because it is necessary to gather energy from areas widest inorder to have significant quantities and, instead, it is difficult to convert intoenergy easily exploitable with acceptable efficiencies. For its exploitation needtechnology products of high cost that now make the solar energy much expensivecompared with others methods of energy production at present. The developmentof technologies that can make economic the use of the solar energy is a sector ofthe research very active but, in this moment it didn’t had revolutionary resultsyet.
This is a picture of the European situation regarding the use of the principal sources of alternative energy.
In Italy the principaltowns favourable to theinstallation of solarthermal power plants arein Sicilia, Sardegna,Calabria, Puglia, Basilicataand Campania. They arelands not cultivable andthey’re generally locatedalong the coast and in thelevel hinterlandimmediate.
In these sites, where the directsolar radiation reaches 1650 kWhyear for square meter, it ispossible to produce with thethermoelectric solar, a mediumterm, the 30% of electricityconsumed in Italy at present. Toachieve this result need an areaof about 800 square kilometres(including a space between amirror and the other): a area notbig, that can be split between sixcountries, and into eachcountries, in multiple sites. Thetechnology usable is that of thelinear parabolic mirrors. Toinstall a sufficient number toproduce the 30% of theelectricity consumed in Italy,need an area of about 30 squarekilometres each side (including aspace between a mirror and theother): a area not big, that canbe split between six countries,and into each countries, inmultiple sites.
SOLAR CENTRALMIRROR CENTRALThe solar central to mirror is constitutedfrom a field of mirrors,which attract the solarrays sending them tothe boiler.The solar rays thatarriving to the boiler,overheat the presentwater makingevaporating: the vapourstarts up a turbinethat, connected to analternator produceelectric energy.
PHOTOVOLTAIC CENTRALThe Photovoltaic central is constituted by a series of panels called solar cellsor photovoltaic cells. In them it is present a particular element, the siliconthat, suitably treated, it has the capacity to generate directly electricenergy when it’s hit by sunlight. The photovoltaic cell is like a circle of 10 cmof diameter and it’s supported by many others until you obtain the quantityof electricity required.
SOLAR THERMAL Solar thermal is a system able to transform the radiates energy from sun in thermal energy, usually called heat, that can be used in daily use, as for example the water heating services or the heating of the environments. In the buildings, the solar thermal systems are devices that allow capturing the solar energy, storing it and using it in various ways. They’re made from thermal solar modules commonly called solar collectors. This simple devices use the heat of the sun to heat the water for household use (shower, dish, washing machine, etc). The solar thermal system consists in the set of components whose the solar collector is one of the principal elements. The collectors allow to heat water and to use them in the best way. The minimum system consists in: • solar collector •theat Exchange •ank that allows to store the hot water produced • plant engineeringd on how the panel does circulate the liquid inside it, the panels are divided into:ar collactors to natural circulationar collactors to forced circulation
FORCED CIRCULATIONSystems to forced circulation are usefor production of sanity water andthey’re particularly suitable forsystems which integrate the heating.The solar panels have inside some tubeswhere slides a liquid that when it isexposed to the sun gets heat. Acontroller measures the temperaturereached by the liquid and that of watercontained inside the tank. If the liquidinto the panels è more hot than watercontained in the tank, the controllerstarts a pump that pushes the liquidinto the circuit with the objective of topass trough an internal coil to the tank.Trough the coil there is the passage ofheat from liquid to the water of thetank, that arrives in the circuit of thehouse’s sanitary water.Advantages: high efficiency, withminimum visual impact from the momentthat the tank staying within a boilerroom.
NATURAL CIRCULATIONThe natural circulation systems are systems suitable to the production ofsanitary water. They’re characterised by a tank on the top of the solarpanel. The rays of the sun heats the liquid contained into the tubes of thesolar panel, this goes up in a natural way until reaching the tank. Here theliquid gives heat to internal water to tank that, heated, enters into thesanitary hydraulic circuit of the house.Advantages:•limited cost,•don’t use circulatory or other electric elements.Environmental benefits:are multiple and go from emissionsabsent of carbon dioxide, sulphur,nitrogen oxides and dust as well asheat. The collectors help to don’tincrease the planet heating, whichnow reached critics levels in recentyears.
ADVANTAGESSolar water heating is a renewable energy source non polluting substancesenter and is at no cost. DISADVANTAGESSolar water heating require large areas for the installation of the panels,high cost of the plants, due to a poor diffusion of technology.