Photovoltaic solar energy and aerothermal energy

Aerothermal energy is becoming more and more relevant in the air conditioning market, especially when it comes to newly constructed residential buildings.

This equipment is considered as renewable energy by European regulations and the CTE itself, as long as they have a SCOP greater than 2.5. However, they consume electricity, so if this electricity comes from a renewable and free source, the system will be even more efficient, ecological and sustainable.

Aerothermal energy in the building air conditioning sector

On December 27, 2019, the new Basic Energy Saving Document HE of the Technical Building Code was published. Within this regulation, the aerothermal heat pump is one of the most favored technologies. This is due to the fact that one of the major objectives at European level is to replace air conditioning systems based on combustion by others based on the consumption of electricity.

As we have commented, if an aerothermal heat pump has a SCOP greater than 2.5, it will be considered as a renewable energy system. They are also equipment that can provide air conditioning in homes for both summer and winter, as well as the production of ACS (Sanitary Hot Water).

Integrated systems of aerothermal and photovoltaic solar energy

As we have mentioned, a heat pump consumes energy, although 70% less than other air conditioning and sanitary hot water systems. However, seeking that this energy has a renewable origin, aerothermal has been integrated with photovoltaic solar energy.

From a more technical point of view, it is very easy to connect both installations, since the photovoltaic solar energy installation will be in charge of producing the electrical energy necessary for the heat pump.

How does a heat pump work?

The operation of the heat pump is based on the physical principles of thermodynamics. It manages to transport energy from one environment to another, through the change of state from gas to liquid of a refrigerant fluid, through the ambient temperature and thanks to a compressor.

An aerothermal heat pump is capable of capturing free energy from the air and transforming it into useful energy to produce DHW or air conditioning.

How does the heat pump take advantage of the electrical energy produced by the photovoltaic installation?

The key to making an installation of photovoltaic panels for aerothermal energy profitable is to use at least 80% of the electrical energy produced by the photovoltaic installation. At this point, having a suitable heat pump, capable of obtaining the highest performance from a hybrid system of aerothermal and solar energy, plays a fundamental role.

A heat pump with climate regulation that is integrated with the photovoltaic installation is capable of, if at any time the photovoltaic production is higher than the consumption of the house, use that surplus to produce hot or cold water, accumulating it for when it is needed.

What is done with the energy produced by the photovoltaic installation when the heat pump is not working?

Electric energy can be used to meet the demand of the rest of the electrical appliances in our home.

Why install photovoltaic and non-thermal panels?

In recent years, the cost of photovoltaic panels has fallen by 80%, mainly due to increased efficiency and large-scale manufacturing. This, together with the high price of electricity in our country, makes it more profitable to produce electricity than to consume it from the national grid.

For some years, the installation of thermal solar panels proliferated in Spain, mainly driven by building codes such as RITE and CTE. This type of solar panels took advantage of the heat of solar radiation to produce hot water, either for sanitary use or for heating.

However, nowadays the installation of a photovoltaic solar energy system has more advantages:

• The efficiency of the thermal plates is much lower than the photovoltaic ones since they require a greater amount of solar radiation.
• A solar thermal energy installation requires more space.
• Thanks to the thermal panels we can obtain hot water, either in support of the DHW or, in the best of cases, for low temperature heating. However, thanks to photovoltaic panels we can obtain DHW and air conditioning, both in winter and summer.
• Thanks to photovoltaic solar energy we can achieve self-consumption, that is, generate all the energy that the house needs (since they produce electricity). Thermal solar panels, at most, will produce 30% of the necessary energy.