Why to use renewable energy sources?

The term renewable energy means the energy produced from renewable sources arising from particular natural resources. They are therefore forms of alternative energy to traditional fossil fuels (which are part of non-renewable) and many of them have the distinction of being too clean energy that not discharge harmful and / or greenhouse gases such as CO2, into air. They are thus the basis for the so-called green economy.

From the energy point of view solar energy is alternative to traditional fossil fuels, it is renewable and clean (green energy) as well as one of the strengths in support of so-called green economy in modern society. Solar energy can be properly exploited through different technologies and different purposes although in several of its technologies of exploitation suffers from variability and intermittency of production or not full programmability due to day-night cycles and the cloud cover.

The wind is exploited for the production of electrical energy using devices with blades, used in so-called Wind Farm "wind farms" to obtain large quantities of electrical energy. Three elements play, in particular, in favor of this type of energy: it is absolutely clean from the ecological point of view, it is renewable, and the raw material is at zero cost. This source is inexhaustible, free and produces no waste. The disadvantage is the large size of the installations.

A power plant for the conversion of the thermal energy of oceans produces energy by exploiting the difference in temperature between the different layers of ocean. The solar energy absorbed by the surface of the sea heats it, creating a temperature difference between the surface water, which can reach 25 - 28 degrees, and those located for example at a depth of 600 m, which do not exceed 6-7 degrees. The areas from yellow to red in the image below are suitable for the exploitation of the thermal gradient to produce electricity, the potential of this technology is considerable in the appropriate areas.

Geothermal energy is an important resource, not yet fully exploited, to obtain an efficient mix of sources towards sustainable development. This form of renewable energy derive from the heat present in the deeper layers of the Earth's crust.The exploitation of geothermal energy is to pipe the steam coming from the water sources of the underground routing to turbines used for the production of electricity. The water vapor is then reused for heating, the greenhouse cultivation and spas.

A biomass power plant is a power plant that uses renewable energy obtainable from biomass pulling through different techniques: by direct combustion of biomass, by pyrolysi, by gasification. The term biomass defines any organic matter such as waste industry residues of agricultural processing and forestry, firewood, food industry waste, dung and animal wastes, vegetable oils, waste but also plant species cultivated for the purpose, such as poplar, miscanthus, or other essences and fast-growing species and easy to grow, suitable for the purpose.

Ppt created by students in the 3A class

I.C. "A. D'Aosta" - Ottaviano (NA) - ITALY