In this article we will analyze the photovoltaic solar energy development and current research , we will see the technological advances in solar energy for the benefit of the human being.
Research and development of photovoltaic solar energy
Solar energy is a concept that we have pursued in recent years, if only to try to find a better way to address the problem of global energy supply without harming the environment .
For those who know very little about this source of energy, it is fundamentally that obtained from the sun and that can be converted into energy that we can use, that is, electricity or thermal energy for heating or cooling environments .
Solar energy is simply the energy that comes from the sun. The mother star of our solar system is a powerful source of energy. Without it, no life on Earth would have existed.
It is a renewable source , we are all free to use it, it is widely available and clean. Currently it is already used to satisfy the energy demand of homes and offices, but it also has other purposes, such as heating the domestic hot water that we all use to wash or feed the electricity grid in small countries.
How does solar energy work?
Now let’s take a closer look and see how solar energy works and, in particular, let’s see what solar panels are and how they can help us achieve our goals when it comes to using solar energy efficiently. . As one of the cleanest and safest renewable technologies , it is time for the general public to recognize the effectiveness of this type of solution.
Useful energy is derived from the conversion of energy from the sun. There are three main ways in which this transformation can be carried out:
- Photovoltaic processes take place with photovoltaic panels, which take sunlight and transform it into electricity. The elementary component of the generator is the photovoltaic cell in which the conversion of solar radiation into electric current takes place. It consists of a thin slice of semiconductor material, usually silicon. We will discuss this in more detail below.
- Solar panels are made predominantly of materials that naturally convert sunlight into electricity . These materials are known in the scientific field as semiconductors. When sunlight strikes these semiconductors, they release free-moving electrons, which are channeled through the device and produce an electrical current.
- Photovoltaic devices undergo constant technological development in this period because some wavelengths of sunlight, including UV rays and infrared rays, can not be converted by these devices. This can be problematic when the sun does not shine and, consequently, UV and infrared rays are the main rays that reach the surface of the earth.
- The energy that the sun creates is transformed into energy that can be used to heat or cool the devices that work . There are processes that can help in almost any imaginable context, from commercial buildings to homes, but also for pool heating.
- This time the fundamental element for energy conversion is the solar collector. It is very different from a solar panel, since its purpose is not to convert the sun’s energy into electrical energy, but rather to heat a fluid that passes inside its pipes. A collector is mainly formed by a heat transfer fluid that is inside the tubes, a transparent cover that allows the rays of the sun to pass through it, an absorbent plate that captures them and an insulator to avoid the most delicate components of the collector. Overheat too much
- The main reason why solar heating and cooling devices are needed is because we must reduce our dependence on natural gas and other fossil fuels . Heating systems, such as traditional boilers, mainly use natural gas or methane to feed. Air conditioning systems are a big problem, since conditioners use a lot of electricity to cool the rooms, and this is often produced with fossil fuels.
- Even in the thermal sector, technology is constantly evolving and adapting. The progress made in this area of science is significant and not a day goes by without discoveries on how to best use this type of energy.
Concentrated solar systems, generally called CSP (Concentrated Solar Energy), are one of the most recent technologies to exploit solar energy. The CSP technology is not yet fully developed, but it has its strength in the possibility of supplying electricity independently of the resource.
They are plants used to produce electricity by supplying high temperature heat to a plant based on a thermodynamic cycle. The process is called “indirect conversion of solar energy” as opposed to the direct transformation of solar energy into electricity (photovoltaic systems).
Mirrors are the main elements of a CSP system; They concentrate all the solar energy in a single point so that the whole system works more effectively. Without the mirrors, CSP systems would have no reason to exist. For this reason, the implants can have a point shape (they use a parabolic mirror to channel all the rays in the center of the parabola), with a central tower (the mirrors placed on the ground direct the sun’s rays to a point located in the upper part of a special tower) and for linear Parabolas (they are formed by parabolic tubes, that is to say, without upper cover, which heat a fluid contained inside the pipes).
The energy accumulated by the fluid is then made to expand in the steam turbines that ensure that electricity can be produced and stored. This makes CSP systems different from other types of solar energy exploitation because the energy storage system is much more advanced than those found in other types currently in use. By 2020, it is expected that there will be more than 5,000 concentration plant projects around the world, already in operation or under construction.
How do solar panels work?
Now that we have examined all the different types of solar energy conversion to useful energy, how they work and which are the basic components for transformation, let’s look at one of the most common devices used to obtain energy from the sun: solar panels.
- In short, the sun’s energy, which can be described as a specific amount of energy, composed of multiple particles called photons, passes through semiconductors, which in turn generate electricity and develop it so that it can be used effectively .
- The solar panels are capable of exploiting different types of solar radiation and not only from the sun, but also the light reflected from the roofs of houses, from snow and ice, which is called albedo.
- As mentioned above, solar panels are composed of a certain amount of solar cells. A single cell can not do much, but a group of cells can help create enough energy to power the most diverse devices. Solar cells are small discs, composed of semiconductor materials, among which the best known is silicon. Solar cells are capable of producing energy only when hit by solar radiation . Within these structures an electric field is created that opposes the propagation of free electric charges. This electric field gives the cell a structure called “diode”, in which the passage of the current, constituted by free charge carriers, for example electrons, is hindered in one direction and facilitated in the opposite direction.
- Photovoltaic panels are sold with a guarantee of 80% initial performance after 25 years . They have been developed as aerospace technology (satellite power supply) and for security applications (light signaling), where reliability is one of the priorities. The tests are carried out exposing the modules to thermal cycles (from -40 to + 80 ° C), exposure to humidity and electrical tests. The rate of degradation of efficiency is estimated between 0.5% and 1% per year .
- As mentioned, solar panels are the main way for a space station, along with other astronomical technologies, to obtain the electricity needed by astronauts. A curiosity: sometimes, solar panels in space are damaged by small meteorites or other elements called “space junk”; this requires that the astronauts leave the cabin where they are and make the appropriate repairs if necessary
How to check the performance of a photovoltaic panel?
An interesting thing to do to verify the real efficiency of a photovoltaic panel is the energy balance of a single cell, since it describes the percentage of incident solar energy that is not converted into electricity. As an example, if you consider that the incident solar energy is equal to 100%, there are the following typical losses:
- Of the 20% to maintain in position the electric field in the transition region of the cell;
- Of 8.5% in carrier recombination free charge (electrons do not follow the flow direction);
- Of 23% for photons with high wavelength, with insufficient energy to release electrons;
- Of 3% for reflection losses and shading of contacts placed between the environment and the cell (eg protective glass);
- Of 0.5% for electrical transmission losses (due to circuit resistance);
- Of 45% of the photons with a short wavelength that are absorbed, but whose 32% is excess energy (heat production);
In the end, in this example, only the remaining 13% of solar energy is absorbed and transformed into electricity , which means that the yields of solar panels are currently too low to be competitive with traditional forms of energy production.
Recently there has been talk of 3D printers and the impact that this “invention of the century” could have on the development of the energy industry. Building photovoltaic panels in 3D is no longer a mirage, but represents a convincing challenge.
The first step towards a revolution in the concept of energy, also in view of the goals set for 2030 in terms of savings and efficiency.
Among the 17 Sustainable Development Goals (SDGs – Sustainable Development Goals) included in the UN Agenda is also the one of:
Ob. 7) Ensure that everyone has access to affordable, reliable, sustainable and modern energy systems.
Today, the costs for the installation of photovoltaic energy on the roofs of houses, buildings and warehouses have been reduced considerably, compared to a few years ago. Partly because more and more people have decided to switch to this renewable energy source, aware of how photovoltaic energy represents a profitable and sustainable solution to save on their bills. Partly thanks to tax deductions and tax deductions for the purchase of photovoltaic panels and storage batteries , which reduce initial investments.
And all this without negative repercussions on the technological quality of the products.
The photovoltaic panels, inverters and batteries currently on the market have a high performance and guarantee high yields.
However, technology never stops. That is why more and more innovative solutions are being studied, which allow the creation of flexible, lightweight and easily transportable products, at even cheaper prices.
Photovoltaics and 3D printers: studies and research.
In recent months there has been much talk about 3D-printed photovoltaic panels.
- The Air Force Research Laboratory presented a research demonstrating the possibility of producing high quality thin films with a 3D printer, without compromising energy efficiency and costs.
- The same was also confirmed by an Australian research team at the University of Newcastle, which tested flexible and innovative solar panels, printed with 3D technology, at a very low cost: only 10 euros / m². At the base of its operation, there is a revolutionary solar ink that is used as an energy conductor and applied directly during printing.
- Even so, a recent investigation of the Technological University of Michigan has tested the 3D printer to make plastic supports to support the battery of the photovoltaic panels. According to the research, this technique saves between 83% and 92% of the costs generally used for the production of metal supports. And the benefits to the environment would be incalculable if we could exploit the recycled plastic.
- According to researchers at MIT (Massachusetts Institute of Technology), 3D solar panels are 20% more efficient than traditional panels, thanks also to the materials used for their construction. Among them is perovskite, a mineral of titanium dioxide and calcium discovered in 1839 with excellent driving skills.
Therefore, the most modern materials, innovative design and ease of production could lead to a cost reduction of 50%. Tomorrow, buying a photovoltaic system could cost half that today.
The future of solar energy is NOW.
However, the road to achieving this coveted goal is still long. Stopping the wait (probably years) for a new fall in prices is a risk that it is better not to run.
However, the current situation with regard to photovoltaic energy is already very advanced.
Think, for example, of photovoltaic storage batteries. The models with the highest performance have an efficiency of 99%. This means that they save you a lot on the bill, reducing the costs of electricity almost to zero.
Read the testimonies of those who achieved complete energy independence.
What about electric cars ? They really represent the future of mobility. Within the next twenty years, 600 million vehicles will be powered by electricity, circulating on the world’s roads.
Why not think about how to produce the necessary energy to fill, perhaps at a zero cost? The installation of the photovoltaic system on the roof of your home allows you to operate lights and appliances, and also recharge your electric car, free of charge and in comfort.
More than the future, photovoltaic energy is already present.
Do not stay behind.
Find out how much you can save by installing a system for self-production of electricity on the roof of your home. Try our configurator.