There are many people who want to disconnect from the electricity grid, bet on renewable energy and use self-consumption. Produce the electricity that you consume in your home without depending on the electricity grid and its high prices.
It is a very good idea to want to have your own consumption, but it is important to take into account some guidelines to follow from self-consumption law. Do you want to know all the most important aspects that you must have to enjoy your own consumption?
What do you need to have renewable energy?
Solar panels or small windmills
To have self-consumption, the priority is have the necessary infrastructures to generate energy by yourself. That is, being able to install renewable energy on your land so that it is clean and the investment can be amortized in the medium term. It is important that you separate what you have to have to achieve total independence from the electrical network. That is, being totally electrically isolated and self-sufficient.
For this you need solar panels or small windmills. The most powerful energy for self-consumption today are solar panels. Its investment cost is getting lower and lower and the amount of energy produced leads to greater competitiveness in the markets.
In addition, Spain is a country where, thanks to the climate, the hours of sunshine are quite abundant. One of the great advantages of solar panels is that their installation is very simple and does not take up too much land, since they can be placed on the roof.
Mini-wind energy does require a bit more land and needs a somewhat more complex installation, but if you live in an area where the wind blows constantly and with a medium-high intensity, you can opt for this energy.
Controller for charging, inverter and batteries
To control the current drawn through the battery you need a charge regulator. This is essential if we want to prevent it from overheating and causing some kind of accident. If we don't have batteries to store energy, we won't need a regulator.
The inverter is the one that transforms direct current into alternating current.
It is important to have batteries that store the energy generated by the solar panels to use it when it is not being produced or its production is lower (cloudy days, at night, consumption is greater than the energy generated ...).
It should be mentioned that batteries are the most expensive elements of the entire installation, given that compared to the 25-year useful life of the solar panels and the wind turbine, batteries only have a 15-year shelf life.
Relying on renewables
The important thing in this is that if we want to disconnect from the electricity grid, we have to know that we will be dependent on renewables and their negative aspects. That is, we can have energy as long as there is sun or wind. However, at night, on rainy days or when there is no wind, our energy could be intermittent.
The more autonomy we want to have, the more money we must invest in batteries. Depending on the area of Spain in which we live, we can have storms of almost a week that would cause the solar energy to stop. On the other hand, wind turbines stop working below winds of 20m / s. Therefore, it is necessary to be proactive and invest additionally in batteries that help in the storage of energy for this type of situation.
Energy storage is the biggest problem for renewables and self-consumption.
Self-consumption law and Sol tax
When talking about self-consumption, the Sun tax always comes out. However, all facilities that have a power less than 10kW should not pay anything. If we have self-consumption completely isolated from the electricity grid, we will not have to pay anything. On the other hand, if we are having self-consumption, but we are connected to the network, we will have to pay the same as any network client, but with a tax on the sun, as long as your consumption exceeds the contracted power that we have.
Next I am going to show you the most important things you should know about the self-consumption law:
You will not have to pay anything if you are not on the network, that is, if you have a totally isolated self-consumption.
On the contrary, if you have self-consumption but are on the electricity grid, the following will happen:
- If you exceed the electricity consumption according to your contracted power, you will have to pay a charge for the extra energy discharged.
- You will not pay anything if your installation has a power lower than 10 kW, if you are from the Canary Islands, Ceuta and Melilla, your installation is for cogeneration and train braking (this ends in 2020) and you will have a lower tax if you are from Menorca or Mallorca.
If your consumption is higher than the power you have contracted you will have to pay 0,5 euros / MWh and 7% of the production tax. In addition, there are charges for ancillary services, in relation to the energy consumed.
These taxes apply only to photovoltaic solar panels (hence the so-called sun tax). However, as an alternative to photovoltaic solar panels we can have thermal solar panels. They take advantage of the sun's energy to heat water and do not have any tax on them.
Mini-wind power too it is tax exempt.
Profitability of self-consumption
The profitability of a self-consumption installation requires several things. The most profitable option is to have a net balance of one year, but in Spain this is not yet possible. However, we can save a lot on the electricity bill.
For example, if our home consumes 5000 kW per year and we have an installation of solar panels with 2,5kWp batteries, we can save the variable part of the electricity bill.
Depending on the area of Spain where we install renewable energy, it will be more or less profitable. A solar panel on a roof in Córdoba is not the same as in one in Oviedo, for example. What can be assured is that in a matter of 8-10 years the installation will be fully amortized. If we take into account that the installation will last us more than 20, it will be profitable for us to bet on self-consumption in the medium and long term, generating our own 100% renewable energy.
Electric self-consumption
There are many people who are betting on electricity self-consumption given that the prices of electricity in Spain are increasingly higher. After Portugal, we have the highest electricity prices in all of Europe. For this reason, with the help of renewable energies we can have an electrical self-consumption to have an independence from the electrical network.
With electricity self-consumption we can meet our needs for heating, hot water, electrical devices and household appliances as a result of renewable energies. For higher performance, it is important to have good energy storage, since renewables are intermittent (especially mini-wind). Depending on the area of Spain in which we live, you can have electricity self-consumption totally independent of the electricity grid or not. This depends entirely on variables such as the strength of the wind, the frequency with which it blows, the hours of sunshine, the cloudiness, etc.
As you can see, self-consumption has its advantages and limitations and you have to know your potential well before installing it at home.