Renewable energy plays a vital role in designing a sustainable and green home, one that is as respectful of the environment as possible.
What are renewable energies, what are they and how do they work?
Renewable energy sources are alternatives to traditional energy sources such as fossil fuels: oil, coal, and natural gas. The term “renewable” is what truly distinguishes them from those previously mentioned: their ability to regenerate, and therefore their inexhaustibility. According to Italian law, Legislative Decree No. 28/2011, renewable energy sources include the sun, wind, hydroelectric and geothermal resources, tides, and wave motion.
Renewable Energy: How It Works
Their mechanism is the complete opposite of that of traditional energy sources: coal, natural gas, and oil have a long and tortuous regeneration time, are highly polluting, and have a significant environmental impact. Renewable energy, on the other hand, is inherent in the physical structure of our planet and has a continuous and infinite capacity for regeneration. Furthermore, its environmental impact is minimal and significant.
Main sources of renewable energy
There are many renewable energies available: solar, wind, geothermal, biomass, hydroelectric, and marine energy.
Solar energy: This is undoubtedly the best-known green energy. Obtained from the sun, it is converted into electricity using solar panels and photovoltaic systems. It is used to heat and cool homes and offices.
Wind energy: Thanks to wind turbines, the mechanical energy produced by the amount of air moved by the wind is converted into electricity that can be used in our homes.
Geothermal energy: An alternative to more common energy sources, it collects and stores the earth’s heat from natural phenomena such as geysers and transforms it into usable energy in our homes.
Biomass energy: This type of renewable energy is probably the first used by humans and derives from biological components, such as firewood.
Hydroelectric power: uses water as a source of energy through the installation of vertical and horizontal axis generators.
Marine power: generated by ocean currents, it harnesses the energy of the sea and converts it into electricity using vertical and horizontal axis generators, as is the case with wind power.
The advantages of renewable energy
These energies offer numerous benefits to human health and the environment. First and foremost, they offer a sustainable alternative to traditional energy sources, producing clean energy and improving well-being.
Derived from readily available and inexhaustible sources, these energy sources foster domestic economic development, increasingly reducing dependence on external suppliers. Thanks to increasingly efficient and cutting-edge technological systems, electricity bills are significantly reduced, while still guaranteeing energy needs comparable to those obtained from non-renewable sources.
Renewable energy: domestic use
The use of renewable energy sources in the residential sector aims to increase energy savings, while keeping a close eye on the cost of the investment.
Renewable energy solutions that can be considered within a home include photovoltaic systems, solar thermal systems, geothermal and micro-wind systems, and heat pump systems.
Photovoltaic panels generate electricity by harnessing solar radiation and are the most common solution in residential buildings. The energy produced by photovoltaic systems is consumed on-site, and excess energy is fed into the public grid. Because they rely on solar energy, in the event of a lack or limited solar radiation, this limit can be overcome through the development of storage solutions.
The second system, solar thermal, uses solar radiation to produce hot water through the transfer of heat between the fluid circulating in the panel and the water used in the home. The last system is the heat pump, whose operation and existing types need to be explained in detail in a dedicated article.
Obligation to use renewable energy
In Italy, Legislative Decree 28 of 2011 introduced the obligation to use renewable energy sources in specific cases: in new construction and in significant and major renovations. This decree clarifies what is meant by a new building, which includes not only new buildings but also extensions of existing ones, provided that the excess volume is no more than 15% of the existing portion. The second case concerns renovations of buildings with a very large surface area, approximately 1,000 square meters, subject to complete renovation or demolition with renovation.
Furthermore, depending on the type of property—private or public—and whether it is located in the historic center, the percentage of electricity production varies. For example, in the case of a private home, the percentage of energy for heating, cooling, and domestic hot water production is 50%, while in the case of a public building, it is 55%.
If you’d like to delve deeper into the topic, it’s a good idea to consult with designers and heating engineers who can guide you through the design and installation process for renewable energy systems.