Solar energy is the main source of energy in the future and there is a lot of data that tells us so. In 2020, the total installed capacity of photovoltaic systems in Spain increased by 30% and it is becoming increasingly attractive to have solar panels on roofs that produce green energy. As well as being an optimal investment for the environment and for your pocket, solar panels will also increase the value of your home.

Solar panels are made up of solar cells, which are the cells that convert solar radiation into electricity. When solar radiation hits a solar cell, a voltage difference is created between the front of the solar panel, which is negatively charged, and the back of the solar panel, which is positively charged. This voltage difference creates energy in the form of direct current. This energy, passing through the inverter, causes the direct current to be transformed into alternating current, and it is this alternating current that you can consume or send to the grid in the form of surpluses.  If you want to know more about photovoltaic energy, we recommend this article on some of the most popular myths and facts about solar energy.

Solar energy is one of the most environmentally friendly energy options you can choose. The sun is an unlimited resource and as long as the sun shines, we are guaranteed this source of energy that provides 100% renewable electricity. For this reason, photovoltaic is the most cost-effective renewable self-consumption energy on the market.

By installing a photovoltaic system, you are doing the environment a favour by helping to reduce the use of fossil fuels and greenhouse gas emissions. Although some energy is required in the manufacture of solar panels, it only takes approximately 2.5 years, out of the estimated lifetime of a solar panel plant of 25 to 30 years, for the solar panels to produce as much energy as it takes to manufacture them. This is called the energy payback time of the solar panels.

When looking at the cost of installing solar panels, the initial cost may be perceived as a small disadvantage of solar energy. However, the investment is very small in relation to the savings over the lifetime of the photovoltaic system. The payback period for solar panels is typically between 5 and 9 years. By producing your own electricity, you will largely cover the electricity consumption of your entire household, which means you are more independent of other electricity producers, large electricity companies and their prices. In addition, the value of your home increases and increases in value thanks to the installation of solar panels, partly because the operating costs are lower, partly because more and more people are demanding environmentally sustainable housing in the real estate market.

The amount of solar energy produced by solar panels per year is affected by a series of factors. In summer we tend to have a surplus of solar energy, while in winter we need to compensate with other energy sources as the solar peak hours are lower. But it is possible to estimate the expected power output of solar panels based on the efficiency of the solar cells and the amount of energy produced (kWh) per kW installed. Quality solar panels have an efficiency of approximately 20-22%, which means that approximately 20-22% of the solar energy produced by the solar panels is converted into electricity.

When it comes to the measurement of kWh per installed kW, we generally say that one installed kW produces approximately 800-1100 kWh per year. If your Photovoltaic (PV) system has a maximum output of 2.5 kWp, it can produce between 2000 and 2750 kWh of solar energy per year.

In addition to solar hours, efficiency and the amount of kWh per kW installed, there are other factors that affect the amount of electricity produced by solar panels:

• Solar radiation where you live
• Shadows on the solar panels from surrounding objects such as trees, chimneys, buildings, etc.
• Weather lines that your solar panels are aimed at.
• Slope of the solar panels
• Temperature
• The size of the surface where the solar modules will be placed.
• Snow on the solar panels
• Dirt on the solar panels

In other words, the amount your solar panels produce depends on a few particular factors. In our solar calculator, you can see how much electricity the solar panels on your roof can produce.

The three most common types of solar panels on the market are monocrystalline panels, polycrystalline solar panels and amorphous or thin film solar panels. Different types of solar panels are developed for different conditions:

• Monocrystalline solar panels have been on the market for the longest time and are the solar panels that we associate with solar panels for private individuals and that solar cells can produce solar energy with lower solar radiation and thus we can also take advantage of less sunny days.
• Polycrystalline solar panels are the most common solar panels on the market, but they are considered to have a slightly lower efficiency than monocrystalline panels. These panels are often seen in large installations and farms with a lot of space.
• Both the appearance and the manufacturing process of thin-film solar panels are different from crystalline solar panels. In particular, the material can be made flexible, which opens up the possibility of using thin-film solar panels on rounded surfaces. For example, thin-film solar panels can be glued directly to roof tiles.

Solar installations allow you to generate your own green energy in your home and there are two types:

Grid-connected installation: This type of self-consumption solution connected to the grid is the most used and the most recommended by our solar advisors. The main objective of this type of installation is to reduce the electricity bill you have with your electricity company, as you will remain connected to it. You will generate electricity during the day thanks to solar energy, and when this is not possible, you will consume from the electricity grid. As a grid-connected photovoltaic installation, you must be part of one of the two sub-groups:

1. Self-consumption with surplus: This type of system discharges surplus energy to the grid, so you would be giving your surplus energy to the grid. You can request financial compensation for this, but it all depends on a series of conditions that we recommend you consult with your company.
2. Self-consumption without surplus: Requires some kind of storage system such as a battery, to store the surplus energy and use it at another time and so not dump it into the grid.

Isolated installation: This type of solar panel installation is completely disconnected from the grid. Normally this is because the homes or businesses that use this photovoltaic solution are located in places where there is no possibility of connecting to the grid. This type of solution is very similar to grid-connected installations without surplus electricity, as they also have solar batteries.

1. Feasibility study and budget: To find out what is the ideal solar panel budget for your home, it is necessary to request a solar study. In this study, conditions such as your province and its respective solar radiation, orientation and inclination of your roof, available space, and monthly consumption will be evaluated. This study is absolutely necessary to know exactly what you need with your consumption.
2. Acceptance, signature and permits: If you finally decide to accept the quotation, the process of designing the installation on your roof will begin, using structures to achieve the perfect inclination of the solar panels. This way you will be able to make the most of the solar energy that reaches your roof. The provider will also begin the process of applying for permits, legalisations and applying for subsidies if they are available in your community.
3. Installation of solar panels: Once the application process and permits have been completed, the installation of the solar panels will be carried out on your roof, rooftop, roof or available area for the installation of the equipment indicated in the contract. Installations are usually completed within 15 days of signing the contract, but this can always be affected by any setbacks. Installations last between 1 and 2 days.
4. Commissioning and maintenance: When the installation is finished, it will be activated and start generating energy from the sun. In addition, you will receive your own credentials to monitor your solar panels installation from your own mobile phone. The maintenance of the solar panels is minimal, but important.

The value of a photovoltaic installation varies greatly depending on many factors. There are many of these that you can control, but not all of them are the same:

• Whether you want a grid-connected or off-grid installation.
• There are installations with different qualities of components.
• Your budget.
• Your consumption.
• Available space.

A basic installation can cost between €3,000 and €6,000, while a larger installation can cost over €7,000. Keep in mind that this is an investment and not an expense, since with what you are going to save each month, you will end up amortising the installation in a short time and you will start to generate energy while you save each month.