The question is: where to start? First of all, in fact, you would like to understand how photovoltaic panels work and what are the various types available, in order to make the most careful choice possible.
Index
- How Solar Panels Work: Preliminary Information
- How does photovoltaic with storage work?
- How does photovoltaic work without storage?
- How Balcony Solar Panels Work
- How Solar Thermal Panels Work
- How photovoltaic works: revenues
- How Solar Panels Work Explained to Kids
- Which photovoltaic panels to buy
How Solar Panels Work: Preliminary Information
You may already know that photovoltaic is a renewable energy production system ( solar energy , specifically), adopted by companies and private citizens who increasingly decide to install solar panels on the roofs of their buildings. In fact, nowadays, this can be a very advantageous choice and from many points of view, not least that of saving on the bill . Then, undoubtedly, there is the environmental impact to consider (a system of this type does not produce any type of pollution), in addition to the surplus value brought to the property on which they are placed. Furthermore, the only maintenance required is cleaning , to be carried out every now and then to maximize the production of electricity. In itself, the system is little subject to wear, as it does not have moving parts.
switching to photovoltaics. This is in fact what is commonly said, regarding this technology, perhaps neglecting a little more technical comments . Your curiosity is more than legitimate, therefore, and in the following lines I will try to satisfy it.
Let’s start by clarifying what a solar panel is made of (a system, as you can easily imagine, is nothing more than a system of photovoltaic panels or modules, which also includes an electrical component – the cables – and an electronic component – an inverter, plus possibly also a mechanical-automatic part to allow the “tracking” of the sun).
A photovoltaic panel is in turn made up of smaller units, photovoltaic cells . These cells are made of silicon and have free electrons that “move”, receiving energy from light particles ( photons ). The movement, at the same time, produces the flow of electricity .
In fact, the matter is a little more complicated than that. The electrons hit by the photons are located between two layers of silicon, one negatively charged (with phosphorus) and the other positively charged (with boron). In this way, with the presence of two opposite poles , an electric field is established . The electric field, when the photons hit the electrons, will carry them towards the metal plates on the sides of the cell, and finally inside the electric wires .
A peculiarity of this system (taken “singly”, i.e. without an inverter) is that it produces electricity in direct current : this means that the electrons, inside the circuit, move in only one direction (their flow is “unidirectional”). Since alternating current costs less and travels more easily, it is usually preferred to alternating current. In fact, in our buildings, this mode is practically always used.
This is why it is necessary to transform direct current into alternating current, which can be achieved by means of an inverter . In addition to carrying out this work, in reality, the inverter is also useful for safety reasons (it protects against ground faults) and for monitoring operation (it provides data on voltage, current on both AC and DC circuits and also data relating to energy production and the maximum power point).
How does photovoltaic with storage work?
After having explained to you in general terms how photovoltaics work , I think it is appropriate to go into more detail, giving you at least some information on the various types .
The first distinction to make is undoubtedly between photovoltaic “with storage” and photovoltaic “without storage” . The first type includes a photovoltaic storage system, designed to “store” – precisely – the energy produced in excess during the day to then use it during the night and in the following days, if the weather conditions prevent adequate functioning. In practice, the accumulator consists of lithium batteries (often preferred for their higher energy density, longer life and smaller size compared to other storage technologies) that are charged in case of excessive production and then discharged when necessary (when the sky is grey, for example).
Batteries are charged second to the lights and appliances in the home, that is, only after they have stopped requiring energy. There are also energy management systems that establish a charging priority, optimizing energy use based on household needs and weather conditions.
How does photovoltaic work without storage?
You will have understood that photovoltaic with storage allows its users to be totally autonomous, and therefore to eliminate the costs in the bill. On the contrary, photovoltaic without storage requires a constraint with the traditional grid , and therefore – upstream – the stipulation of a contract with an electricity supplier . Being connected to the grid can have various advantages, such as the possibility of receiving or giving energy based on needs, and this can contribute to maintaining a certain level of reliability in the supply of energy.
In this regard, if you are wondering how photovoltaic works with Enel or other suppliers, after obtaining approval of the project relating to the system, you will have to submit a connection request to the energy provider, who will give you the necessary instructions to proceed.
Once connected, you will have to register your system with the GSE (Energy Services Manager) , the body that administers incentives for renewable energy in Italy. Registration will give you the right to economic incentives, provided for the energy produced by the photovoltaic system.
How Balcony Solar Panels Work
If for any reason you do not consider it convenient to install a “classic” photovoltaic system, of large dimensions, you can still evaluate the choice of balcony photovoltaic . This is the ideal solution for those who live in an apartment building, for example, or in any case cannot decide independently to cover the roof with panels. Just keep in mind that balcony photovoltaic panels are by definition (by law) without storage , which means having to give up the dedicated benefits (such as that of the exchange on site).
So, how does a plug and play , portable , balcony or camper solar panel work (all terms applicable to these mini-panels)? Well, in truth, there is not much to say: just connect the electronic devices to be powered directly to it, such as smartphones, tablets and small appliances. These panels are in fact equipped with USB connectors or ports to which you can “hook” the devices to exploit the energy produced in real time. Clearly, we are talking about devices capable of managing a limited amount of energy, and therefore suitable for the specific uses mentioned above.
Alternatively, it is possible that the panel includes an energy storage device such as a small external battery, useful for storing energy during the day and then providing it in the evening/night hours. How long it can power a device or how long it can store energy, obviously depends on the case.
In some configurations, it may be possible to use the energy produced to power devices or charge batteries while the panel is also connected to the electrical grid. This way, if solar power is insufficient, the device could draw energy from the grid .
How Solar Thermal Panels Work
After explaining how plug and play photovoltaics work , I would suggest focusing on another particular type of photovoltaics, moving on to illustrate how solar panels for hot water work .
A solar thermal panel is designed to capture the sun’s thermal energy and use it to heat a heat transfer fluid , which is in turn used to produce domestic hot water or heat spaces.
Sometimes, when talking about systems used to produce heat, we talk about photovoltaic with heat pump . The operation is substantially identical to that described above; only that, instead of using the heat directly for heating, the heat transfer fluid can be connected to a heat pump , useful for amplifying the heat taken from the solar panels and therefore further heating the water or air. More info here .
How photovoltaic works: revenues
Regarding photovoltaic without storage, we are talking about a series of advantages from an economic point of view that can be summarized in four points.
- Energy Account . The Energy Account is one of the main incentive mechanisms for energy produced by photovoltaic systems in Italy. It provides a fixed payment for each kWh of energy produced by the system, and the rate can vary based on various parameters, including the power of the system and the date of entry into service. The Energy Account can have different time bands and rates (the mechanism can change over time due to regulatory updates, so it is a good idea to stay informed).
- Net metering . How does photovoltaic net metering work ? Simple: first of all, net metering is a mechanism that allows you to self-consume the energy produced by the photovoltaic system, avoiding storing it, as is instead the case with photovoltaic with storage. The excess energy produced during the day is fed into the electricity grid , and the owner of the system receives a credit in terms of kWh that he can use when the system does not produce enough energy, such as at night. The possibility of using net metering depends on local regulations and may not be available everywhere. Furthermore, the accumulated credit may vary depending on local rates and conditions.
- Regional and local incentives . In some regions or municipalities, additional incentives may be available to promote the installation of photovoltaic systems.
- Tax Credit . In some cases, you may be eligible for tax credits or tax breaks related to the installation of photovoltaic systems. In this regard, I recommend that you consult a tax professional for detailed information.
The incentive landscape may change over time due to national and regional energy policies. To obtain updated information on the various incentives available, I recommend that you consult the latest energy regulations and policies in force at the GSE and other competent authorities . You can contact the GSE directly by following the instructions in this guide .
How Solar Panels Work Explained to Kids
How can we simply explain how solar panels work? Well, we could imagine them as large “machines” that use sunlight to do something magical: produce energy! Apparently, they are somewhat special “tiles” that are placed on the roofs of houses or in other sunny places so that they capture the sun’s rays. Inside them, however, there is a whole world… or a whole sun !
In fact, inside the panels there are small things called “solar cells” . These cells are responsible for doing the magic , that is, transforming the light that hits the panel into electricity.
When the sun isn’t shining much, solar panels can still work a little, but they don’t produce as much electricity as when the sun is strong. At those times, you can use the energy that has been stored during sunny days, as long as the panels are “helped” (supported) by special batteries .