Our hunger for energy is growing daily, every day we need hundreds of TWh of electricity and most of this comes from fossil fuels with a massive CO2 emission and other pollutants that kill our atmosphere. To deal with the energy problem and the consequent emissions, we must act following two paths, the first wants to re-invent our way of life with the setting up of so-called smartcities, the second wants to rely on clean energy sources and here we find, among the others, the concentrating photovoltaics.
To meet our energy needs, the concentration photovoltaics, it will have to combine with other renewable energy sources which overall can significantly affect our energy hunger. What changes betweenphotovoltaic energy conventional and the concentrating photovoltaics?
First of all we can make a distinction of costs. Systems forphotovoltaic energy they have an estimated cost ranging between 6,000-7,000 Euro / kWp. Much cheaper is the case of wind energy where, each kW of energy produced costs less than half of a kW from photovoltaic panels, but we certainly cannot install an 80-meter wind turbine in the backyard; but when do we decide to install a conventional photovoltaic system? We need authorizations, permits and above all there are problems for the design and maintenance of the plants. The concentrating photovoltaics he wants prose as a remedy for these difficulties.
The ideal would be to join forces between conventional photovoltaic and concentrating solar energy, we have seen it with CSP technology with solar concentrating system but it is a solution created for large solar parks, while those who are thinking of exploiting solar energy for their home, because they could not orient themselves on solar concentrating system for home use?
Consisting of a large system of mirrors, the so-called "primary concentrator " which has the purpose of projecting all the sunlight in a single point where the photovoltaic receiver is positioned, placed on the optical focus of the system. The large-scale production of this technology is simple: it would be enough to use injection or thermoforming molds, this is a development within the reach of most Italian companies.
The photovoltaic conventional waste a lot of energy, what a plant would not do concentrating photovoltaics, designed to follow the movements of the sun so as to operate when the sun's rays are always on the optical axis of the "primary concentrator". The concentrating photovoltaics could exploit a movement system using electronic and electromagnetic technologies for the precise positioning of the parabolic systems.
So far we have focused on the function of "primary concentrator ", that is, that system of mirrors that "concentrates" all solar energy in a single point. At this point the photovoltaic receiver, the heart of the system, consisting of a small panel of highly efficient photovoltaic cells designed to operate under concentration. The photovoltaic receiver, for many years has been a limitation of the diffusion of concentrating photovoltaics due to its high costs, only in recent years have photovoltaic cells for concentrations arrived on the market that guarantee high performance and affordable prices.
Let's imagine this "fire point" where is the "primary concentrator"Concentrates all the solar power, certainly the photovoltaic receiver will reach very high temperatures! This is why a cooling system has been devised that can keep the temperature of the photovoltaic cells below 90 ° C.
The advances made by technology over the past 10 years are able to offer systems concentrating photovoltaics at reasonable prices and capable of guaranteeing high performance. As too often happens, it is not the technology that slows down the development of a sector but the market itself. L'photovoltaic energy could coexist and be implemented with the concentrating photovoltaics for the creation of very high efficiency solar fields, the problem is that the groups that market the solar panels they want their own market share, as the developers of the concentrating photovoltaics. In this regard, you may be interested in reading the article "Solar panels and Solar Thermal“.
edited by Anna De Simone