And photovoltaic antivert system It is the mechanism that some self-consumption solar installations have through which excess energy is controlled so that it is zero and does not flow into the power grid. Thus prevents electrical discharge to the distribution network when the consumption of the installation is lower than the production of the photovoltaic plant. These anti-dumping photovoltaic systems are within the so-called \»zero injection\» installations.
Lost zero injection or anti-spill systems it measures the solar production and electricity consumption of an installation in real time, monitoring that if the solar production exceeds the consumption, the anti-discharge system automatically decreases the solar production to avoid the generation of surplus Kw that would be poured into the electrical network.
When the Council of Ministers approved, at the proposal of the Ministry of Ecological Transition, Royal Decree 244/2019 of April 5a new definition of self-consumption methods was established, reducing them to two: self-consumption with or without surplus, depending on the fact that the installations can or cannot discharge energy into the distribution and transmission networks.
For installations in \»no surplus\» mode, RD exempted them from the need to obtain an access and connection permit, which simplifies procedures and normally shortens execution times. But for a self-consumption facility to qualify for this modality, it is it is necessary to have an anti-spill mechanism which prevents the injection of excess energy into the transmission or distribution network.
In addition, the question can be asked if self-consumption with surplus or without surplus is better, guaranteeing a zero injection. There is no better or worse option, everything will depend on our electrical installation, consumption, photovoltaic production and the conditions of connection to the electrical grid. The only advantage is that in a zero-surplus installation, guaranteeing zero discharge to the grid, we save paperwork with the electricity supplier, generation fees and grid access fee for surplus energy.
Operation of a photovoltaic anti-dumping system
He operation of a photovoltaic anti-dumping system is established in Annex I \»Systems for the prevention of energy spillage in the network\» to Royal Decree 244/2019 which regulates self-consumption.
The aforementioned annex states that An anti-spill system can work through two main mechanisms:
- Current interruption or limitation mechanism. This option makes it possible to use generation systems without power regulation capability.
- Energy exchange regulation mechanism between the system that produces electricity (solar panels) and the one that consumes it (the household electrical network and the appliances and electrical appliances connected to it). This can be achieved through load control, energy generation or storage. This second antivertization method is the most interesting and the most common.
If we opt for the photovoltaic self-consumption option with a regulation mechanism, in our anti-spill installation there will be a device that controls the consumption we make in our house. This device will inform the caller dynamic power controller, which works together with the installation\’s inverter.
This way, if we don\’t consume all the energy that our solar panels generate, the dynamic controller will act on the inverter and reduce the energy drawn from the sun.
That\’s what the most common anti-spill system deals with it balances production all the time in such a way as to adapt to consumption. Thus, no excess energy is generated.
However, this mechanism is not exclusively used in domestic installations for self-consumption. Actually, The largest photovoltaic anti-spill system in Europe is located in Spain, in the province of Badajozwith an installed power of 8 MWp.
In this high-generation power plant, the same anti-spill system is used, which reduces its output power in sync with the customer\’s consumption.
Antivert systems for home use
With the current legislation on self-consumption, For installations smaller than 100 kW/h, a compensation mechanism is established in the electricity bill if we transfer the surplus energy produced to the network. This trade-off helps us to make the investment profitable sooner, which meant that PV antiversion doesn\’t make much sense for people starting out in the field. household self-consumption.
But In some cases, PV antiversion makes sense. For example, at the household level, if we have a off-grid solar installation an anti-spill system will be required as well as the use of batteries. In this way, the excess can be redirected to the batteries, and when they are full, the anti-spill system will regulate the production in the usual way.
Another situation where using an anti-spill device makes a lot of sense is in case some installations with a power greater than 100 kW/h. If the respective installation has an anti-dumping photovoltaic system, it is exempted from the access authorizations and connection to the network. This means fewer procedures and more agility in the execution of the project, which can reach large dimensions.
Anti-spill systems in industrial installations
As I mentioned before, P.O.W was a pioneer in the making the largest photovoltaic self-consumption installation without surplus in Spain. An 8MWp installation on an industrial roof in Badajoz consisting of nearly 22,000 370Wp monocrystalline PERC technology modules and 44 185 kW/h inverters connected to 3 800/15,000V transformers. These generation transformers are ring-connected with others that are exclusively for consumption, and all are connected to a 15/66kV substation, which is the Border Point with the Distribution Network and where the Anti-Divergence Device is to be located.
Together with our partners, WATTKRAFT and SUMSOL, we designed and installed control and regulation equipment (CPU MASTER) which, measuring in the substation, transmits the commands to the 3 CPUs via optical fiber, which in turn act on investors connected to each transformer. Transmission speed is essential, as the response time and power adaptation of the inverters must be less than 2 seconds from the moment the leak is detected. Optical fiber was chosen because of its greater immunity to noise in industrial environments and because of the long distance between equipment.
For the legalization of the installation, all tests were successfully carried out and a report was issued by CERE, an accredited testing laboratory according to UNE-EN ISO/IEC 17025, as provided by RD 244/2019 for passing the Evaluation. Conformity.
This installation of the anti-spill system It has been running at full capacity for several years without incident, which proves it the robustness of the adopted solutionso the commitment on the part P.O.W perform photovoltaic installations of the highest level for industrial consumers.