Every day more and more homes are switching to photovoltaic self-consumption. It is a comfortable and economical form of electricity for the long-term, which is, additionally, environmentally friendly as it is 100% clean energy thus contributing to the fight against climate change. In this article, we will show you all the key points to photovoltaic self-consumption
What is photovoltaic self-consumption?
Energy self-consumption refers to the production of electricity for the consumer’s consumption. The installations for self-consumption can be isolated, that is without a physical connexion to the main grid, but they can also be connected to the electrical grid.
In households, self-consumption is mainly carried out through small photovoltaic solar energy installations which turn solar radiation directly into electricity.
The connexion of self-consumption installations to the grid is completely legal. Any electricity consumer can produce their energy.
This is a very popular option in Spain as in our country we can enjoy approximately 300 sunny days out of 365, which translates into almost continuous energy production throughout the year.
The article “2021 is the year of the pending photovoltaic self-consumption revolution” published by the magazine CincoDías talks about the boom in sales that occurred in 2019, with a record in self-consumption installed capacity of 459MW, according to data from the Spanish Photovoltaic Union (UNEF). This increase happened right after the disappearance of the Sun Tax at the end of 2018, three years after being introduced by Mariano Rajoy’s government. As a result, Spain was again at the top of the photovoltaic energy leadership in Europe and was number six in the world.
Before getting into further detail, it would be interesting to know the different types of solar panels available: solar thermal panels and solar photovoltaic panels.
If you want to know more about the installation of solar panels, types, how, when, and what needs to be considered as well as permits and self-consumption rules and regulations that came into force with the Royal Decree 244/2019, we recommend you read the article “Investing in our future, solar panels and self-consumption” in our blog.
What are solar thermal panels?
Solar thermal panels are panels that are used to obtain thermal energy. These panels use solar radiation to generate thermal energy in the household through the heating of water.
What are solar photovoltaic panels?
Solar photovoltaic panels are solar panels that obtain electricity using solar radiation. In this case, the energy obtained is converted into electricity using the conducting materials from the photovoltaic cells in the panel. The process consists in converting the energy flow into electricity. As we mentioned before, these panels can be isolated, meaning without connection to the electric grid.
Differences between solar and photovoltaic panels
Each of these panels is different, the way they work and their main specific function. However, the following characteristics can be highlighted:
- Function. Solar photovoltaic panels are used to obtain electricity whereas solar thermal panels are used to obtain thermal energy.
- Use. Solar photovoltaic panels are more common than solar thermal ones. The main reason is, that solar photovoltaic panels represent a reduction of the cost of the electricity bill and they can also be used in isolated parts where the main grid does not reach.
- Materials. Solar photovoltaic panels consist of photovoltaic cells which are made out of silicon whereas solar thermal panels consist of a cover made out of tempered transparent glass that has a dark tonality which can capture better heat and work as a greenhouse effect.
- Lifetime. Whereas solar thermal panels usually have a lifetime of approximately 10 years, solar photovoltaic panels have a lifetime of approximately 20 years.
- Installation. On the other hand, the installation of thermal solar panels is easier than solar photovoltaic panels, which are slightly more complex to install.
The installation of a photovoltaic self-consumption system
What is the installation of a photovoltaic self-consumption system like?
The main component in the installation of a photovoltaic self-consumption system is the generating system. If we focus on the production of electricity, the photovoltaic panels are the main visible part of the installation and they are normally located on the roof of the house and are connected to the wiring of the house or building.
The installation needs other components, such as an inverter, cables, parts for protecting, a meter if the installation is collective, and, optionally, batteries. All these components do not take much space; therefore installing self-consumption systems is perfectly viable in both new and old buildings.
A self-consumption installation can supply all of or a part of the electricity consumed by a household, neighborhood association, or a building. Whenever the solar photovoltaic panels don’t produce enough electricity to meet the demand, they can obtain electricity from the main grid without any difference in the functioning of the installation.
However, it is often the case that the electricity produced is greater than what is used. Whenever this happens, it is possible to feed the surplus to the main grid or store it in a battery.
Advantages of using photovoltaic energy
What are the advantages of using photovoltaic energy?
- The reduction of emissions compared to more conventional systems of producing energy. This contributes to the energy transition, the fight against climate change and it helps improve the air quality.
- It cuts down the consumption of fossil fuels and the energy dependence on imports.
- It means a significant financial saving as the electricity bill will drop
- You can manage your renewable energy, so it is a step forward towards energy democracy.
- It contributes to the creation of a model of distributed energy which will reduce the loss of energy in the grid associated with the transport and distribution of electricity.
- It stimulates economic activity by creating jobs that are not at risk of relocation and the appearance of new business models.
Now that we know what self-consumption is, the types of existing panels and we understand the advantages of this model, let’s have a look at the different types of installations and self-consumption.
Types of installations. Individual or collective
Self-consumption installations can be individual or collective. In Individuals installations, the power produced is associated with a single household, for instance, the photovoltaic installation on the roof of a house which supplies the energy for the most common consumption of a household such as light, the washing machine, or the computer.
The legislation also allows that more than one household be associated with the same installation. In the case of a neighborhood association, the photovoltaic installation is usually located on the roof of the building and it could also supply energy to common areas such as the lift of the staircase lighting.
What types of photovoltaic self-consumption are there?
Leaving aside the installations not connected to the main grid (rural areas), there are two types of photovoltaic self-consumption.
- Self-consumption without surplus. These are installations that stop the leftover energy from going into the main grid. Batteries can be added to store this energy that can be used at night or on cloudy days, for example.
- Self-consumption with a surplus. These are installations that allow that the leftover energy to be exported to the grid. Consumers can sell the energy or compensate for future electricity bills.
How will it be shown on my electricity bill?
The following video (audio in Spanish) explains in 5 minutes what photovoltaic self-consumption is with examples of bills.
To summarize, the concepts that appear would be the following:
- Fixed contracted power. A fixed monthly amount to the electricity company is independent of the energy consumed. It is the maximum amount of power that we can use, so the amount of kW can be consumed at once.
- Consumption. A variable monthly amount for the electricity used during the period appears on the bill and accordingly to the pricing.
- Electricity tax.
- Meter rental. Monthly rental unless you own the meter.
- Valued Added Tax (21% VAT) on the total of the above-mentioned concepts.
Self-consumption legislation and regulations
Recently, governments from all over the world are legislating to improve the procedures concerning self-consumption and are offering financial benefits to consumers.
As we have already mentioned, in Spain the abolition of the so-called Sun Tax in 2018 and the appearance of the Royal Decree 244/2019 have meant the start of a new era for photovoltaic self-consumption in the sunniest country in Europe.
Some of the advantages of the new Decree are the boost given to the collective self-consumption– neighborhood associations or the launch of the so-called business parks amongst others- the reduction of bureaucracy or the launch of the so-called simplified compensation for surplus, a concept similar to the zero-cost.
Consult the legislation in different countries here.
Renewable energies and passive houses
Like in other articles, whenever renewable energies or self-consumption are mentioned, the idea of passive houses or the “Passivhaus” comes to our heads. In our article “A passive house and the certification “Passivhaus” we talk about it and about how we want to achieve with this type of buildings to increase energy efficiency to avoid unnecessary waste of energy and the exploitation of resources for the functioning of household systems with a minimum impact in the environment.
The best way to achieve this goal is the use of renewable energies as they are endless natural sources. One of the main advantages of these types of energies are the benefits for the environment as they are clean and they hardly emit any greenhouse gases and therefore, they have a minimum impact on the environment…
Another concept to take into consideration is aerothermal as a renewable energy source as it uses the stored energy in the form of hot air and it can be used for heating, refrigeration, and sanitary hot water in the household.
The advantages of a passive house are obvious. Energy savings, thermal and acoustic comfort, clean air inside, the reduction of co2 and volatile compounds, and, most importantly, the improvement of the occupants’ health.
In Grupo Pagès BCN we remain at your disposal for any further information or clarification.
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