An increasing trend is being created to the use of renewable energies and electric self-consumption through facilities such as solar panels or mini-wind.
According to the Royal Decree-law 15/2018, of October 5, of urgent measures for the energy transition and the protection of the consumers, the electric self-consumption is the consumption on the part of one or several consumers of electrical energy coming from production facilities next to those of consumption and associated to them. The energy produced is destined to satisfy to a large extent the habitual consumption of the home.
It is an electricity consumption connected only with a house. It is not connected to the conventional Transport and Distribution electrical network. It is usually found in rural areas with low population, far away since the electricity grid can not reach these homes. Either by having a higher cost as by physical impossibility.
When not being connected to the conventional electrical network, it is essential that they have some batteries, in order to accumulate and store the generated energy.
Self-consumption connected to the network.
It is an electricity consumption that is connected to both the housing and the physical transmission network and conventional distribution.
This type of facilities can have both batteries that store the generated energy, although it is not essential as they have the electric network of transport and distribution supplementary.
Therefore, the electricity company that we hire will provide us with electricity when the solar panel system can not supply us.
Royal Decree-Law 15/2018 establishes two types of electric self-consumption.
1.- Self-consumption without surpluses, that is, destined solely to cover the energy needs of the home.
2.- Self-consumption with surpluses, that is to say, the producer of energy through solar panels can pour this surplus production by injecting it into the transmission and distribution electric network. Self-consumption with surplus is compensated through the net balance with the contracted electricity company. In other words, the excess consumption generated by our solar panels can be discharged into the electricity network. Subsequently, the electricity company will deduct from our monthly consumption the energy that has been discharged. It is not an economic compensation for the energy poured, but the subsequent discount of it.
Normally, the energy consumption is 200 kW per month, consuming 100 kW of the solar panel system and 100 kW invoiced through the contracted electricity company.
If the solar installation produces about 150 kW, the solar panels discharge 50 kW surplus to the electricity grid.
Therefore, the contracted electric company will compensate the customer for the surplus energy in each monthly invoice. In the example shown, only 50 kW difference will be charged in a subsequent billing.
The data entered are indicative, and not real.
One of the biggest doubts about electric self-consumption is about the necessary infrastructure to generate its own energy. Generally having all the necessary infrastructure requires an important investment, although it will be amortized in the medium term.
The most common domestic self-consumption installation types are:
1.- Solar photovoltaic panels. It is a device created in order to convert the light that is reflected in them into electrical current. If you reside in Spain, solar panels will be more recommendable since it is a mostly sunny country. In addition and thanks to the technological evolution is a more affordable system. For the installation of solar panels it will be necessary that you have a surface like a roof, being useful in single-family houses.
2.- Mini wind. Energy is obtained by wind.
3.- Charge regulator. The regulator controls the current that is absorbed by the battery in order to avoid a dangerous overload. In the case of not having batteries, the charge controller would not be necessary.
4.- Investor. The inverter or converter transforms the DC power from the generator into alternating current. The solar panels produce continuous energy, for this reason the inverter transforms it since in most of the houses alternating current is used.
5.- Batteries. The batteries or accumulators store the energy generated by the solar panels during the sun hours in order to use it when more energy can not be generated. The reasons are varied, since it is at night, cloudy or because there is a consumption greater than the power generated.
It is the element with the most economic cost of the installation since the useful life is more limited.
6.- Switch. The switch is a switch that allows switching from one power source to another. An automatic change can occur with the failure of a network.
Before starting with the installation of the infrastructure it will be essential to carry out a preliminary study through a qualified professional.
Factors to consider for the installation of solar energy.
1.- Depending on the geographical area. If we hesitate to install self-consumption we must take into account the geographical area where you reside. Although Spain is extremely sunny, compared to other European countries, it should be mentioned that while the southern half of the peninsula enjoys more hours of sun, the north of it can not take advantage of solar energy in the same way.
2.- Depending on the type of housing. It is essential to have a roof of your own in your home for the installation of solar panels.
3.- Depending on whether it is an isolated self-consumption or self-consumption connected to the Network, one procedure or another will take place.
Once you have informed, through a qualified professional, you have two options to perform the installation.
- 1. Through a company specialized in the installation of solar energy collection, storage and distribution equipment.
- 2. Perform the installation on your own.
In both cases the economic investment will be high depending on the size of it. It is a cost that implies the cost of the necessary materials, as well as the placement of the panels and the materials themselves.
The electric self-consumption can be considered profitable, amortizable in the long run. However, we must bear in mind that it will not be immediately.
The sun tax is a levy applied on the bills of energy producers for self-consumption through solar panels which was an impediment for consumers who wanted to access an alternative energy system. This tax made the electricity bill even more expensive.
That is why, with the approval of Royal Decree-Law 15/2018, of October 5, on urgent measures for the energy transition and the protection of consumers, the sun tax was abolished, thus promoting electric self-consumption in Spain.
Therefore, consumers of solar energy will no longer have to pay that tax facilitating access to this type of electricity consumption to Spanish households.