The term renewable energy means the forms of energy produced from energy sources derived from particular natural resources that by their intrinsic characteristic regenerate at least as quickly as they are consumed or are not exhaustible on the scale of geological eras and, by extension, whose use does not affect the same natural resources for future generations.
Below are the latest articles on renewable energy published in Green Planner Magazine.
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What are renewable energies?
They are alternative forms of energy to traditional fossil fuels (which are instead part of non-renewable energy) and many of them have the peculiarity of being also clean energy, i.e. they do not release harmful and/or climate-altering substances such as CO2 (carbon dioxide) into the atmosphere.
They are therefore the basis of the so-called green economy. If you are interested in further technical and regulatory information on these issues, we recommend the Wikipedia page on renewable energy sources and the Renewable Energies section of Legambiente.
Types of renewable energy sources available
However, some renewable energy sources may be exhausted in the near future, for example wood, which is threatened in its survival by continuous deforestation.
Let us see what renewable energy sources exist and are already used for electricity production.
This type of energy is used in technologies related to solar and photovoltaic systems; the former allow the production of electricity through the use of solar panels equipped with a water storage tank while photovoltaic systems exploit solar radiation.
The advantages of using a photovoltaic system in economic terms are the offer of considerable savings on the electricity bill; there are offers and facilitations in the financing for the purchase of photovoltaic systems; they are also zero-risk investments with a guaranteed life span of at least 30 years; they do not require maintenance work apart from the change every ten years of the inverter (the only electrical component); finally, they fill unused spaces in the house so they do not involve encumbrance and disturbance.
The composition of the solar panel is normally in silicon as it is a material that receives the light of the sun rays and produces electricity. The use of solar energy is typical for domestic purposes, i.e. to heat water and homes or to supply refrigerators and air conditioners; a frequent use is for the distillation of sea water and the obtainment of fresh water.
Thanks to the power of the wind, it is possible to generate mechanical energy and later also electricity.
The mechanical energy obtained from the wind is that obtained for example in windmills used for grinding grain and other agricultural products; the millstone does its work thanks to the thrust received from the wind which, moving the mill blades, drives the mechanism’s activation gears.
The electrical energy is obtained thanks to the action of the wind on wind blades installed on top of a pole and connected to a mechanical rotor equipped with a dynamo, the latter allows the transformation of mechanical energy into electrical energy.
Usually the positioning of wind power plants is ideal in lowland areas where the wind remains constant, but one of the latest innovations in technology is the installation of wind turbines in the middle of the sea.
For the production of wind energy by individuals and companies is available the solution of the mini-wind turbine with small blade size and ease of installation: steel support poles from 5 to 30 meters, the turbine and electronic equipment that allow the management of the system.
The convenience of installing such systems has a positive effect on the payment of electricity, the general environmental impact and almost non-existent maintenance works.
Biomasses are biological products used as fuels or combustibles for the purpose of creating electricity; through biomass and therefore waste from agricultural and industrial products (urban waste, waste from livestock farming, firewood and so on), electricity is produced at low cost and with a minimum environmental impact; the quantities of carbon, nitrogen and sulphur released into the air by the combustion of these materials are lower than those emitted by fossil fuels. The use of biomass includes the chemical transformation of organic material into biogas, i.e. ready-to-use methane; the combustion of wood or vegetable oils to create electricity or produce heat; and the production of agricultural products such as compost used to fertilise fields.
This is the energy that can be obtained from the earth’s subsoil thanks to the heat coming from its depths and used to supply heating systems and air conditioners; through the installation in the subsoil of the evaporator of a refrigerant circuit burying a coil of several meters, the refrigerant can be transformed into gaseous form. Another type of exploitation of geothermal energy is useful for heating the house with the installation of underfloor systems that include a series of coils placed under the radiant floor. There are two types of geothermal energy: the classical type, which exploits geological and volcanological anomalies; the low-temperature type, which exploits the subsoil for the production of electricity. The geothermal plant can be equipped with vertical probes inserted in the ground at several tens of metres; horizontal probes for both trench systems and those distributed over large areas; spiral probes that are horizontal at a depth of about 4 or 6 metres and require large spaces; or energy poles, i.e. vertical probes inserted in the foundation piles. The advantages deriving from the use of geothermal energy involve, first of all, low levels of pollution for the environment; its constant availability over time throughout the day; the systems installed also have a guaranteed life span of at least 50 years so it is an extremely advantageous long-term investment.
It is the energy generated by the force of water with its waves and tides; to understand how energy can be created from water just think of the energy emitted by the sun that causes the heating of the water, this evaporating is then destined to fall on the earth’s surface in the form of rain or snow and this generates a movement of the masses of water falling from a height difference involves the creation of kinetic energy; the latter, in turn, is transformed into mechanical energy through the aid of turbines, and still you get to electricity by associating an electric generator. This method is used in hydroelectric power plants located mainly on mountain areas in order to exploit the earth’s gravity in a natural way but can also be obtained from rivers, natural and artificial waterfalls. The strength of hydroelectric plants is determined by the positioning of the plant itself, by the difference in height between the altitude where the water resource is located and the level to which it returns after passing through the turbine, and again by the mass of water flowing through the plant. The most exploited hydroelectric plants are those with reservoirs that exploit the natural or artificial reservoirs of lakes; storage or reservoir plants, on the other hand, obtain the availability of water in the reservoir with an electromechanical lift given by pumps or by the production turbine itself. New types of plants provide water supplies from canals and pipelines, exploiting the energy produced also for reclamation channel systems, condenser cooling circuits and other various water systems.
More information on renewable energy on Green Planner
The use of renewable sources is recommended for various reasons, from the economic savings that the purchase of a plant powered by natural sources involves, to the lower environmental pollution produced by the emission of clean energy and not harmful to health. Another aspect that should not be underestimated is the use of technologies that exploit renewable energy sources to produce electricity – which so far still comes largely from the use of fossil fuels that by their nature are exhaustible – is the possibility of continuing to use these sources without worrying about their exhaustion. Just think of oil, which has now reached high costs and still involves a higher rate of pollution than the choice of a natural and renewable energy source such as the sun, wind, water and earth. Do you need more information on renewable energy? Check out all Green Planner Magazine articles already published on renewable energy sources.