Let’s see how and by what technologies we convert heat and sunlight into energy:

– Thermal solar energy:

Technical principle: the sun’s energy reaches a solar panel, which heats the fluid that circulates inside it. In this way, we have energy in the form of hot water.

Uses: the main use is like Sanitary Hot Water (or ACS: that we use in the bathroom or the kitchen of our houses). It can also be used for heating, for pool heating, and even for cooling.

Regulations: the Technical Building Code requires the coverage of a percentage of the demand for domestic hot water by means of solar thermal energy in newly built homes. Therefore, it is increasingly common to find solar panels on the roofs of new buildings.

or Appearance: thermal solar panels (also called “collector” or “getters”) are usually dark, flat, and circulates inside a coil. The fact that they are inclined is due to the search for the greatest use of solar incidence. Sometimes the accumulator tank is in sight, although in blocks of houses it is usually hidden.

or contribution to the environment: a detached house with 2m2 of sensors can be avoided annually 1.5 t of CO₂ per year (replacing electricity consumption).

– Photovoltaic energy:

or Technical principle: sunlight striking a semiconductor material (such as silicon) generates an electric current in part, can be exploited.

Uses: the only use of photovoltaic energy is the generation of electricity. This can be used in two ways:

– Isolated installation: the photovoltaic installation generates electricity for its own consumption at the same point. It is used for isolated homes without access to the electricity network, and also for SOS poles, telecommunications repeaters, etc.

– Installation connected to the network: the electricity produced is dumped into the electricity network. It can be generated in a small installation on the roof of our house or in a large installation on the ground (the so-called “solar farms”).

Regulations: the energy produced by photovoltaic installations connected to the grid is subject to the Special Regime, like other renewable sources. This regime seeks to promote the development of non-polluting alternative energies.

Appearance: photovoltaic modules are composed of cells that contain semiconductor materials. By looking at them, we can see some “threads” that intersect on their surface.

Contribution to the environment: A single-family house with an installed power on its roof of 5 kW can avoid 1.9 tons of CO₂ per year.