Zero injection or zero discharge inverter: What is it and what are the advantages?

What would happen if my solar photovoltaic system produced more energy than I need at any given time? What would happen if I did not wish to discharge that energy into the power grid? We will answer these and other questions about the installation of your solar panels and take a closer look at zero injection or the zero discharge inverter.

What is zero injection or a zero discharge inverter?

Both of these terms refer to self-consumption photovoltaic installations, which have an automatic system that prevents the surpluses generated from being discharged into the electricity grid. This system can be found in zero discharge models.

The fact is that, depending on the intensity of the solar radiation and which way the house faces, some photovoltaic installations generate more energy than is actually consumed. The function of zero injection, or a zero discharge inverter, is to modulate the operation of the solar panel so that it does not generate more energy than is required.

In some cases, zero injection involves diverting the surplus energy to charging batteries, so it can always be used when the panels are not working so as to be able to respond to demand at night, for example.

How does zero injection or a zero discharge inverter work?

An inverter is an electronic device that transforms the direct current generated by the solar panel into alternating current, so that it can be used without causing damage to the installation in the home. The characteristics depend on the power with which it will work.

A zero-discharge inverter should also be able to control the performance of the panels. In other words, it needs to have sensitive equipment (an analyser or meter) that monitors both energy consumption in real time and the generation originating from the panels. These two devices make it possible to adapt the performance of the solar panels so they only produce the energy needed to match demand.

However, a new level of complexity is involved if you are looking to store surplus energy in a battery or an accumulator. To do this, an inverter and an analyser enable the optimisation of the charging of the device while at the same time meeting the demand for electricity in the home. When the battery has been charged, the zero injection, or zero discharge inverter, resumes its function of modulating the panel's performance so it does not generate surplus electricity.

Issues to take into account when purchasing a zero injection or zero discharge inverter

It is important to take into account all the information with regard to the inverters so as to be able to establish whether they suit your needs.

We have already spoken about the power of the panels as a determining factor. Zero injection usually requires twice as much to ensure the safe operation of the equipment and avoid overloading or overheating. It will also be very important to know the power of the battery, where this function is present.

Another important issue when choosing an inverter is the input voltage of the equipment. The most common input voltages are 12V, 24V, and 48V, whilst output voltages are usually 220V or 230V.

Selecting the most suitable zero injection or zero discharge inverter for your installation is the key to ensuring that it works properly, so it is advisable to get advice from an expert, who will help you establish the characteristics of the installation and assess you based on this data.

Main advantages of zero injection or a zero discharge inverter

The advantages that solar energy provides in the home are well known, but zero injection or a zero discharge inverter also has many benefits although they are less known.

• Independence from the power grid: In addition to the advantages of savings and efficiency, there is also the possibility of making decisions without having to depend on variations in the price of energy in the markets, as well as avoiding possible power cuts related to the grid. There is also a reduction in repair times for possible breakdowns, as it is easier for technicians to identify the problem simply because the zero injection or zero discharge inverter provides real-time information.
• Promoting sustainability: By maximising the generation of solar energy, you avoid having to depend on the grid because you only use clean energy and you are self-sufficient with regard to demand and consumption.
• Increased efficiency: Consumption habits are aligned with energy generation, optimising the process with regard to efficiency.
• Reduction in bureaucratic procedures: Unlike other off-grid models, zero discharge systems require less paperwork, as they are not considered to be a generating installation so they are easier to approve and install. For example, they do not require a permit to access and connect to the grid, and they do not require the participation of third parties.

But if this option does not exactly match your electricity consumption, you can always choose a model that discharges energy into the electricity grid and you are compensated for your surpluses. Endesa we will always give you the advice you need, as well as suggesting the most suitable offers. We simplify the procedures and help you to enjoy clean energy in your home as soon as possible, without waiting, so you can start saving on your bills from the outset.