Today the concept of renewable energy sources is spreading more and more, thanks to the progress made in the energy sector and to the problems of climate change and global warming that lead to look for valid alternative sources.
Since the era of the first industrial revolution in the mid-700s and up to a few years ago, the energy resources of our planet have been quickly consumed and this has led to the consequences we know. For this reason, the renewable sources, which can be naturally regenerated, are the right answer to an increasingly dramatic environmental transformation.
Even if the energy produced by renewable sources is a clean energy, some natural resources can end if no action is taken in time. The use of wood, for example, brings to the problem of wild deforestation. Wooden houses with solar energy, the main renewable source that turns into electricity and heat for humans, are prefabricated houses that use photovoltaic panels and solar thermal energy.
Other examples of renewable energy sources are the wind energy produced through the wind – as well as the marine energy generated through the sea and the oceans, the geothermal energy that uses the heat of the earth, the energy of the hydrothermal water and the energy produced by the vegetable and animal waste (biomass).
The currently used non-renewable sources, such as fossil and nuclear energy, have proven to be the cause of the critical climatic conditions we are currently experiencing. Furthermore, these energy sources are being exhausted quickly, so if we want to improve the conditions of the planet, as well as our own lives, we need to change our lifestyle. A solution could be to replace fossil resources with renewable energy sources, thus contributing to save our planet.
WHAT ARE THE SOURCES OF RENEWABLE ENERGY?
Renewable energies are inexhaustible natural energy resources, such as solar, wind and hydroelectric energy. Other renewable resources depend on human cultivation and exploitation, such as biomass. In this case, we refer to “sustainability”.
However, when is a renewable energy source sustainable? In the case of exhaustible energy resources, such as biomass, a rational use of energy flow over time is necessary, as in the case of forest exploitation. In this case, the man must make sure that the growth of the new trees planted is equal to or greater than the number of trees felled. This is an example of sustainability.
The energy that comes from the sun is the primary energy source on Earth. The sun, in fact, is a green, inexhaustible energy resource, and the amount of energy it produces can, by itself, meet the energy needs of the entire humanity. Its limits are large-scale production, collection and processing difficulties and intermittent production. However, solar energy remains an excellent form of energy for business and domestic use, especially when it is supported by any financing. In fact, it involves considerable savings and does not require excessive maintenance.
The energy generated by the wind is also a form of renewable and inexhaustible energy. The power of the wind, in fact, generates mechanical energy. The energy produced by windmills, for example, is spread in the windiest places and can in turn be transformed into electricity.
The energy produced by wind power is a stable alternative over the long term, but it records important variations in daily production, making it necessary to have storage facilities and other alternative energy sources. As for the profits, instead, the installation of these plants requires very little maintenance and at the same time guarantees a significant saving on the energy bill. Wind energy is growing in Italy, but in some countries it has already achieved excellent results. This is the case of Holland and of its trains that travel thanks to wind energy since 2017.
Hydroelectric energy is produced by the force of water masses in motion, such as water flowing or falling from a gradient (just think of the rivers and waterfalls), which first generate kinetic energy, later transformed into mechanical energy from turbines and finally in electricity from electric generators. The amount of energy produced may depend on both the flow of water and the position of the plant or of the existing gradient. The green energy produced is one of the clean energies that have a reduced impact on the environment, so the building of large hydroelectric basins would have a significant environmental and socio-economic impact.
The geothermal energy is extracted from the subsoil, and it exploits the natural heat of the Earth.
It is an excellent investment because it is available throughout the whole day and produces green energy thanks to long-term guaranteed installations. Nevertheless, today it is used to satisfy a very small percentage of the world demand.
Geothermal energy is different from thermal energy, which is obtained from any body that has a temperature above zero. Not all thermal energy is likely to become mechanical energy, but any energy can become thermal energy in the long run.
THE RENEWABLE ENERGY SOURCES OF THE FUTURE, ADVANTAGES AND FUNCTIONING
Inexhaustible and clean renewable energies reduce the environmental impact and are spreading rapidly, so as to cover half of the world’s energy by 2050. Beyond the initial investment, the benefits of these energy sources are obvious:
RENEWABLE ENERGY SOURCES AGAINST NATURAL GAS
In the future scenario of renewable energy sources, a key role is played by the natural gas. In fact, according to the International Energy Agency, the consumption of natural gas has recorded the highest growth rate of all fuels since 2006. This is due to the increase in demand in China and other Asian countries, in which the “Blue Sky” policy imposes rigid goals on air quality, as well as the mandatory transition from coal to gas. In fact, gas produces energy thanks to its abundance and versatility, while polluting less than other fossil fuels. Think of coal, which emits 40% fewer substances.
For all these reasons, today natural gas is the most widely used renewable energy source, together with solar panels and wind farms. In the industrial processes, for example, natural gas is the raw material for petrochemical products and, together with the associated liquids, it represents about 29% of all fossil fuels used as raw materials in the chemical industry.
However, what is the future of natural gas? In fact, even if this fuel emits fewer particles of oil and coal, it is not a totally clean energy source and therefore it does not reduce the risk of global warming. Rather, the extraction of shale gas is very polluting and requires large amounts of water. In doing so, groundwater levels are lowered and chemicals are injected into the soil to fragment the rock. In this way, the access to drinking water in rural communities is seriously endangered.
Renewable energies, on the other hand, are cheaper than natural gas, whose costs are more unstable. Electricity consumption grows thanks to the digital economy and the progress in electric mobility. Demand could still increase by 90% by 2040. Despite the benefits of electrification that reduces pollution, it is also urgent to “decarbonise” electricity production, to prevent harmful emissions and aggravate global climate conditions.
We can conclude by saying that the future of natural gas is strongly threatened by the renewable energy sources that protect the planet.
The 2018 World Energy Outlook of the International Energy Agency outlines three possible scenarios for the future of the energy system:
On this proposal, the strategy to undertake will depend on the action of the Governments of the different Countries. In fact, each year more than 70% of the 2 thousand billion dollars of investments in energy supply comes from entities controlled by the States. The need, however, is to choose clean technologies to limit climate change.
While the European Union wants to reach 20% in 2020 and 30% in 2030, today Europe and the United States no longer represent 40% of the energy demand. The Asian continent, in fact, is the one with the most energy demand in the world, and up to 2040 the demand is destined to rise globally by 25%. The choices and policies of governments will decide the world energy scenario and the future health status of the planet. Meanwhile, it may be interesting to know that Italy and Germany are the only European countries in the world top 5 for installed solar power.
Although coal is still at the forefront of energy production, renewable sources grow thanks to the reduction of the production costs of photovoltaic and wind energy, and thanks to the increase in oil prices. The level of CO2 emissions caused by energy consumption and its influences on climate change and global warming remain worrying given their constant increase.
If you are interested in finding out more about the universe of renewable energy sources, read more about our JOurnal!