How does solar panels works?


How does solar panels works?

How does solar panels works?

Energy Lumisa Self-consumption Saving 7

How do solar panels work? How much does the photovoltaic installation cost? Is self-consumption profitable? What are the current trends in the sector? In this article we are going to review what it means to bet on electricity self-consumption and why it is an attractive option.

Spain is one of the countries of the European Union with more hours of sunshine, we are known as the destination of every foreigner who seeks his spiritual retreat after a hard life of constant work in a climate much less grateful than that of our country. Putting what we have in perspective helps us understand how lucky the people of this country are when it comes to the climate. This situation of so many hours of sunshine, more than 2,500 hours throughout a calendar year, makes us think of photovoltaic installation as a possible real option to obtain electricity, although the latest published data do not follow this theory. It seems that the pandemic and the good communication of the companies that are dedicated to offering self-consumption contributed to an increase in the percentage of installations by 65%. Self-consumption of energy takes off in Spain although much later than in other European countries like Holland or Germany, with much fewer hours of sunshine. The main problem is regulation, since in these countries and in others in the EU this is much more favorable than in Spain , where it was not until 2019 that the changes in the legality necessary to make the initial investment in the entire kit of solar panels profitable.

Royal Decree 244/2019, of April 5, was established to ensure the necessary conditions at all levels to make the option of self-consumption profitable. The first step was taken in 2018 with the elimination of the Sun tax, which was a strong impediment, since it raised the price considerably. With this, the intention was to start the energy transition towards a more sustainable future.

The process of converting solar energy into electrical power for contractors of the self-consumption service is very simple. Photovoltaic panels are plates that receive sunlight and transform it into electricity thanks to the photovoltaic cells that make up the materials of which they are composed, mainly silicon, both monocrystalline and polycrystalline, although there are also those manufactured from arsenium gallium, another semiconductor material.

These cells come together and create the modules, and solar panels can be made as desired. The option of self-consumption with Lumisa incorporates a solar panel with 144 cells, which are interconnected through conductive metallic materials. Cells mix with other materials to create negative charge and positive charge. With the Sun, the negative photons pass to the positive part and electrons are generated, which is what ends up generating electricity. The part of the negative electrons with which they have not been converted into electricity is reoccupied and the process begins again. For this reason we speak of renewable energy, since the direct current generated has no limit and can be used incessantly.

The most efficient panels are the monocrystalline ones and have the longest useful life, while the polycrystalline ones are cheaper.

However, to achieve self-consumption, solar panels are a small part of the photovoltaic installation, since an inverter is needed that allows us to convert this direct current of electricity into alternating current so that it can be used in homes. There are two different types of photovoltaic inverters:

  • Connected to the electricity grid, among which we find the string type, which take advantage of the energy generated online from the solar panel; the microinverters, smaller but connected to the entire solar panel; and power optimizers, which allow the adjustment of solar production, instead of just collecting the energy that is produced.
  • With batteries, among which, those of isolated photovoltaic installations, which assimilate the energy collected to what is used in homes; inverter charger, which incorporate chargers for days without sun; and the hybrid inverter.

Although it is not mandatory, there is the option of acquiring solar batteries to store all the excess energy that is not used to do so at times when solar production is more complicated or not feasible, such as at night and the regulator, which avoids overloads. to batteries. After the inverter, the electrical panel is the element that allows this alternating current to be used by all the connected devices. With some more security elements, this is the process that leads the sun's rays to convert into electricity to illuminate your living room, turn on your television or keep your food fresh in the fridge, nothing more than 4 simple steps.

Lumisa will compensate you for the emission of energy surpluses to the electricity grid thanks to Royal Decree 244/2019. To do this, you must be subscribed to the supply mode with self-consumption with surpluses not receiving compensation. Check our FAQ section to learn more about this modality and thus make the most of your installation. You can also benefit from tax deductions...

The price of solar panels, is it profitable?

One of the main pitfalls of people who did not want to bet on solar energy in the past was the high cost of installing all the necessary infrastructure to have self-consumption at home. However, at present this statement is in doubt, since the reduction in investment is substantial and it is not so illogical to think about the possibility of obtaining supplies thanks to self-production.

As can be seen in the following image provided by the intergovernmental agency IRENA, the evolution of the average price of solar panels has greatly reduced the curve anywhere in the world.

 Evolución del precio del panel solar fotovoltaico ($/kW)


The reality is that there is no formula to indicate a priori how many solar panels you will need to supply you and cover your needs, as this figure will depend on the watts (W) of power you need, on the electricity generation capacity of the solar panel selected and how many hours of sunshine you have in your locality. The option that includes self-consumption with Lumisa is a photovoltaic panel with the capacity to generate 450W of power, a figure that exceeds the average of panels that are usually found in other offers. The best thing is that you consult the Lumisa simulator to find out what you need and calculate an approximate budget based on the possibility, in square meters, that you have in your house. Even if you do not intend to install the infrastructure right now, it is always good to know all the options to save on the electricity bill, right?

Grid parity was achieved in Spain in 2013 and implies that solar energy production is equivalent to energy production with traditional sources.

What we can assure, based on known data, is that the price of facilities for domestic self-consumption has been greatly reduced. In this sense, with regard to large photovoltaic plants, the estimate speaks of a price of between 0.04 and 0.07 euros per kWh, which implies the assimilation of the cost of producing solar energy to other traditional energy sources, like gas or coal. This fact is called network parity and we achieved it in our country in 2013, along with Italy, Denmark and Germany.

With the initial investment, it must be taken into account that the price includes not only the kit of the solar panels, but also the procedures and legalization of these, in addition to the advice to know if you have the option of taking advantage of subsidies or bonuses in your locality . It also includes the installation of the photovoltaic panels and their maintenance. You see that with Lumisa you don't need to worry about anything other than taking the final step to consume YOUR energy green and sustainable.

What can be absolutely assured is that opting for self-consumption and solar panels is profitable for several reasons:

  • The useful life of the installation is long, around 25 years.
  • The amortization of the investment is calculated in about 7 - 8 years, although each case is particular. To learn more about each case, the Internal Rate of Return can be calculated Internal Rate of Return (IRR), with which we can see the percentage of return on the total investment and know the years it will take.
  • Savings in 10 years of self-consumption use is double the initial investment, a figure that is exponential with each passing year. The average annual amortization is between 630 and 1270 euros with Lumisa, depending on the selected rate.
  • The compensation of surpluses to the network allows to lighten the bill and, therefore, the price paid for electricity at the end of the year is lower.
  • There are subsidies and grants to encourage their use.

Solar windows, the latest trend

As we have seen, technology has evolved over the years and its ability to improve efficiency and reduce cost has made solar panels a real option to obtain energy today and the trend indicates that in the future there will be many households that bet on it.

The very evolution of the issue leads us to question what will be the next thing we will see in the market in relation to solar energy and self-sufficiency. The highlight currently being developed are solar or photovoltaic windows. This idea emerged in 2017 and was published in the journal Nature from his creator, Richard Lunt, and his research team from Michigan State University.

Actually these windows are nothing more than solar panels much thinner and more flexible than usual, so they allow their installation in places such as windows, something very interesting because it leads us to think of buildings covered with this type of windows that are capable of self-sufficiency. In addition, this technology incorporates filters that allow better insulation and, therefore, be much more efficient and save on air conditioning and heating.

Other trends that are expected to shape the future of solar technology applied to homes are:

  • Printed organic solar cells. It seeks to be an alternative to silicon plates and, although they are not as efficient, they are much cheaper.
  • Solar tiles. They follow the same principle as windows, but the conductive material is ceramic. Tesla includes them in its solar roofs.
  • Liquid coating. A material that can be applied to any surface and that absorbs the Sun's energy to store it, or for direct use in a device.

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