You've probably noticed lately that there are more and more rooftops covered in glowing solar panels. And it's no wonder, because the idea of ​​becoming less dependent on the power grid and starting to generate your own electricity is appealing to everyone. Energy self-sufficiency isn't magic; it's simply the ability for an individual or business to produce the electricity they need using renewable sources, which translates into savings for their wallet and a huge benefit for the planet.
While photovoltaic panels are the most common, this system is much more versatile than it seems. You can incorporate small wind turbines, biomass, or even small hydroelectric plants , depending on where you live and what resources are available. Essentially, it involves setting up your own power generation system connected to the grid, so you're never left in the dark and can manage your energy as efficiently as possible.
How exactly does the self-consumption system work?
To make all this work, you need a few basic components. The heart of the system is the generators, such as solar panels, which capture energy from the environment. Since the current they generate is direct current (DC), an inverter is needed to transform it into alternating current (AC) , which is what household appliances use. In addition, you'll need wiring, electrical protection devices, and a meter.
The process is simple: as long as there's sun or wind, you consume the energy you produce at that moment. If you have excess energy, you have two options. You can store it in batteries for use at night or on cloudy days, or you can feed it back into the electrical grid. In this second case, that energy is used by other consumers, and you receive financial compensation reflected as a discount on your bill.
When your own production isn't enough, the system automatically switches to the main electricity grid. This ensures you have a 24-hour power supply, always prioritizing the consumption of free energy generated on your own roof before buying energy from the distributor.
Installation methods and types of self-consumption
Not all installations are the same, as each one has different needs. We can talk about self-consumption without surplus , where an anti-islanding device is installed to prevent any energy from flowing back into the grid; here, batteries are almost essential to avoid wasting any energy. On the other hand, self-consumption with surplus allows excess energy to be fed into the transmission grid.
Within systems with surpluses, there are two paths: simplified compensation , where the supplier deducts the value of the kWh injected into the monthly bill (being limited to total consumption), and the total sale of energy, which involves registering as a producer and managing more complex tax procedures, since it is considered a professional economic activity.
There are also off-grid systems, which are those without a physical connection to the main power grid. In these cases, battery storage is vital to ensure a continuous power supply throughout the day. A very cost-effective example of this model is solar pumping, ideal for extracting water in rural areas without electricity.
Shared and collective self-consumption
Many people think that if they live in an apartment they can't do anything about it, but shared self-consumption has come to change the game. This allows a community of neighbors or an industrial park to benefit from a single installation. For this to work, a sharing agreement is necessary to define how the energy is distributed among the participants.
For this model to be viable, 75% of the owners must agree, and the equipment must be located within the same cadastral reference. A key factor is distance: thanks to recent regulations, shared self-consumption is now permitted up to 2 kilometers from the generation point, greatly facilitating the creation of energy communities on industrial land or shared rooftops.
Steps to set up your own installation
If you've decided to take the plunge, the first thing is to have the right space, preferably south-facing to maximize performance , although other options will also work. Don't jump in blindly; find a specialized company to conduct a preliminary study with production estimates and prices. It's highly recommended to request several quotes to compare the quality of materials and technical solutions.
Next comes the bureaucratic part. For installations under 100 kW, the preliminary administrative procedures are usually minimal. However, it will always be necessary to obtain a building permit from the town hall , which is often resolved with a self-declaration and payment of the ICIO (Construction, Installations and Works Tax). If you live in a building with shared ownership, you will need to obtain approval from the Owners' Association.
Once the panels and inverter are installed, the installer must legalize everything by submitting the Electrical Installation Certificate (CIE) to the regional government. From there, the distribution and energy supply companies should update your supply contract within approximately 15 days so you can start seeing real savings.
Economic, fiscal and environmental advantages
The main reason to switch to self-consumption is undoubtedly the savings. You can reduce your electricity bill by between 50% and 70% once the investment is recouped. The payback period is usually between 6 and 8 years , while the panels have a lifespan of around 25 to 30 years, meaning you'll have almost free energy for decades.
From a tax perspective, there are some very attractive incentives. Although some direct aid programs have changed, there are still income tax deductions for energy efficiency renovations that improve a building's energy rating. Furthermore, many municipalities offer property tax (IBI) or construction tax (ICIO) reductions for those who install clean energy systems, thus lowering the initial cost of the project.
From a business perspective, industrial self-consumption not only lowers fixed costs but also improves brand image by demonstrating a genuine commitment to sustainability. For a household, this translates into an increase in property value and reduced vulnerability to sudden electricity price hikes.
Setting up your own energy generation system is a smart decision that combines energy independence with environmental responsibility. By reducing your carbon footprint and optimizing the use of natural resources, you achieve a fairer and more sustainable consumption model that protects the environment while easing the financial burden of your monthly bills.
