HOW DOES SOLAR ENERGY WORK

Today, one of the most valuable renewable solar energy sources we have is solar energy , although not everyone knows exactly how it works. Here we explain everything you need to know.Surely you have ever wondered what it is and how energy is obtained from sunlight. Now we will explain how solar energy works and how we can take advantage of it.

Currently there are two ways developed to obtain solar energy . One as a source of heat energy for solar thermal energy equipment, and the other as a source of electricity obtained through a photovoltaic solar energy installation.

We will talk about this last option. Basically, to get solar energy from sunlight and transform it into electricity that we can take advantage of, we need a photovoltaic solar panel . This panel is responsible for transforming light energy (photons) into electrical energy (electrons), thanks to the groups of cells or solar cells by which they are formed and that transform them.

These cells obtain electricity in 12 or 24V thanks to their series connection, which allows them to increase the output voltage of the electricity. Simultaneously, several networks of circuits installed in parallel linked together, increase the electrical production of the solar energy .

One of the drawbacks of the energy produced by solar panels is that the type of electric current they provide is direct current, and therefore, a power converter or inverter is often used , in order to modify said direct current in this way. alternating current, which is what we usually use in our homes, businesses ...

Solar cells

We will first explain the operation of a solar cell . The method is simple and consists of the following: solar panels take advantage of the photons that hit the cells that come from radiation or sunlight. After impact, materials such as silicon, which is a semiconductor, absorb these photons. These subsequently hit the electrons, thus freeing them from the atoms to which they previously belonged. In this way, the released electrons begin to circulate through the material, producing electricity.

The process explained previously is repeated regardless of the material that is used to manufacture the solar cells, of course, as long as the material used has conductive properties and is capable of absorbing light. At present, the solar panels that we can find on the market contain cells made of silicon, a material that is quite abundant on the planet, although with considerable difficulty in extraction and synthesis . Due to this, the solar energy that we obtain is usually quite heavy, expensive, and with quite a few difficulties when it comes to installation.

Due to the previously explained, many scientific experts in the world are working tirelessly trying to find new materials that result in cheaper solar panels , less heavy, with greater efficiency, finer, and with greater capacities or applications to improve their utility.

At present, there are companies that work in the study and manufacture of solar panels with cells based on indium, gallium, copper, selenium, or germanium . For example, entities such as NASA use germanium for their panels since the resulting efficiency is the highest of all, with the main drawback of its high manufacturing cost.

In addition to the aforementioned, nanotechnology is also being applied to solar panels , technology sensitized by dye or solar energy cell and hybrid materials, for cells called double or triple union, which use several elements simultaneously.

We define electricity self-consumption as the use of energy produced by a renewable installation (photovoltaic, wind, ...) for the purpose of own consumption . During 2019, photovoltaic energy self-consumption experienced an extraordinary stimulus in Spain after RD 244/2019 was legalized, which regulated the terms of the sector, including utilities and innovations when developing it.

The electricity self-consumption law mainly decrees two self-consumption models: connected to the grid (self-consumption with surpluses) or without discharge (self-consumption excluded).

Electricity self-consumption connected to the electricity grid

Self-consumption with surpluses under compensation: they allow the energy to be transferred in the pool or to balance the surpluses every month (installations less than 100 kWh) through the estimation of the excess hourly energy (called simplified compensation). This remuneration will be reflected in the electricity bill for that period.

Self-consumption with surpluses not eligible for compensation: they have the obligation to sell the surpluses in the market. This variant can transfer all leftovers without limitation every month. Of course, it is implicit to associate as a power generator and take responsibility for fiscal and administrative management.

Electricity self-consumption not connected to the electricity grid

Isolated self-consumption: installations without connection to the electricity grid. It is necessary to install a zero injection kit in order to avoid dumping into the network. Energy self-sufficiency is achieved thanks to this type of installation and with the help of accumulation methods ( batteries or solar energy accumulators). This self-consumption prototype is common in remote locations where it is difficult to get power lines.

How to achieve electricity self-consumption.

Before starting to install the photovoltaic solar panels , a preliminary study needs to be carried out in order to analyze the suitability of the project. Some houses are different from others and the peculiarities of each one depend on the characteristics of the solar panels .

What does the installation require?

Mainly to carry out a photovoltaic installation is to have the right place, that is, that the roof of our house is available.

There are two alternatives to carry out the installation: one would be to hire a specialist company installing equipment for the collection, storage and supply of solar energy, and the other would be to do it yourself (self-installation). In both cases it will be necessary to make an investment at the beginning, about 10,000 euros that will be subject to the measures you have.

The amount of the installation since the new regulations in 2018, has decreased by around 75% and the period during which it is amortized has also decreased by half, 7 years. When 7 years have passed, electricity will be free ( solar panels have 25 years of useful activity, which can mean saving more than 3,000 euros).