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What are solar panels?

Solar panels, also called photovoltaic panels or solar cells, are technological devices used to convert the sun's energy into electrical energy.

Solar energy is one of the most efficient, economical, and non-polluting renewable energy sources.

In Spain, we have an average of between 2,500 and 3,000 hours of sunshine per year, which makes solar energy an excellent alternative to traditional energy sources. Are you interested in committing to this renewable energy in your home or business? Do you want to know more about solar energy and its benefits? Find out all about the different types of solar panels and what you should take into account when choosing the best one for you. 

Types of solar panels

Solar panels allow us to make the most of an inexhaustible and free resource, sunlight, and transform it into energy through a 100%-clean process, as no carbon dioxide is generated.

There are three main types of solar panels: photovoltaic panels, thermal collectors, and hybrid solar panels. 

Benefits and characteristics of the different types of solar panels

Here are the characteristics, benefits, and disadvantages of each type of solar panel.

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1. Photovoltaic solar panels

  • Monocrystalline: As they are made of a highly pure form of silicon, they offer the highest efficiency rates currently available on the market, between 15% and 20%. Main benefits: generate high power, long useful life, and their size, perfect for homes. 
  • Polycrystalline: These solar panels, easily identifiable due to their blue hue, are made from raw silicon. They are cheaper than monocrystalline panels, but they are less efficient, around 15%, although their power generation is similar. They take up more space and are more sensitive to exposure to high temperatures, so they are not recommended for very hot climates.
  • Amorphous or thin-film solar cells: These types of solar panels use materials such as amorphous silicon, cadmium telluride, or gallium with photovoltaic properties. As such, a flexible and lightweight panel can be made. They are not as efficient as conventional photovoltaic panels, between 7 and 10% less, their useful life is shorter, and they require much more space. However, they are more economical, so they are commonly used in large installations, such as industries or public facilities.
thermal solar panels

2. Thermal solar panels

These have a panel to collect sunlight and a tank or collector where a fluid capable of transferring heat to domestic heating and hot water systems. The panels heat the transfer fluid circuit, which passes to the heat exchanger, located in the storage tank, where the hot water is stored.

Some types of solar thermal panels, such as concentrating solar-thermal panels, transform this heat into steam to power a generator’s turbines, for example.

  • Low-temperature collectors: These solar thermal collectors reach temperatures of up to 50ºC. They are commonly used to supply energy to heating and domestic hot water systems in homes or businesses.
  • Medium-temperature collectors: These types of collectors work in a similar way, although they have a transparent cover to prevent heat losses. As a result, they are capable of reaching temperatures of up to 90ºC.
  • High-temperature collectors: These solar panels have two covers which generate a vacuum, allowing them to operate at temperatures of up to 150ºC. High-temperature collectors are used for electricity generation in thermal power plants.
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3. Hybrid solar panels

Hybrid solar panels are capable of transforming sunlight into electricity and heat, increasing the performance of photovoltaic cells by up to 15%.  Additionally, these systems can also be combined with other renewable energies, such as wind power, to obtain a greater energy contribution.

Innovation and new types of solar panels

In addition to the aforementioned types of solar panels, industry continues to innovate to achieve increasingly efficient energy solutions, such as concentrator photovoltaics, bifacial panels, spherical cells, heterojunction solar cells, among others. 

Aware of the value of this infinite natural resource, at Repsol, we consider solar energy to be one of the main pillars of our energy strategy. Our company's photovoltaic projects include solutions such as Solar360, where together with Movistar, we offer a self-consumption solution for single-family homes, homeowners associations, and companies. Or Repsol Solmatch, a Solar Communities project, which allows those who cannot install solar panels of their own to consume solar energy in their homes, getting connected to the energy generated within a 500-meter radius.

At a corporate level, the Repsol Group also relies on solar panels to reduce its net carbon dioxide emissions, implementing energy self-supply solutions at its service stations, which in many cases are also Solar Communities that share energy with their neighbors. So far, this system has already been successfully installed in many of the group's service stations in Spain, demonstrating the efficiency of these state-of-the-art energy solutions.