Article published in the 22st edition of the Magazine Canal Solar. Click here and now for free!
The year 2024 started out very promising for the market hybrid photovoltaic systems. At conventions, congresses and lectures in the sector, there is a significant increase in topics in this regard and we are beginning to notice greater interaction between all agents in the chain (manufacturers, distributors, integrators, energy concessionaires and end consumers) when the subject It is hybrid inverters and batteries.
Although there is still no official data on sales of this type of kit at the time of writing this article, there are already reports among manufacturers, distributors and integrators that there is a significant increase in demand and consequently in sales of this type of system. . There is even talk of a lack of equipment on the market due to the increase in sales.
As applications of hybrid photovoltaic systems with energy storage There are countless and the main ones will be reported in this text. First, let's the concept of hybrid systems, which is nothing more than the combination of different energy sources to compose the power supply for certain systems.
The union of different sources, for example solar and distribution network (which can be a combination of other sources), offers great advantages as it combines the characteristics of on-grid and off-grid systems, that is, connection to the grid and energy storage.
The applications of hybrid systems with batteries are diverse and we can highlight: backup systems, peak time coverage (time of use / time shifting), demand control (peak-shaving), without injection into the network (grid-zero), among others. It is worth highlighting that, in general, when properly designed, it is possible to deliver more than one function in the same project.
Backup systems have the main objective of delivering energy during periods when the public network is out of power, that is, guaranteeing the supply of energy to loads when failures occur in the concessionaire's network.
Some loads are critical for the system, such as CCTV systems, computers and databases, lighting, among others.
Therefore, Many strategies use batteries to ensure supply to these critical loads, ensuring that there will be no interruption in supply, even if there is no energy available on the distributors' network.
Rush hour coverage, or English, time shifting ou time of use, uses storage systems to charge batteries in pre-programmed times or have solar generation (times when energy is cheaper), and then discharge them at convenient times, such as times when grid energy is more expensive (peak hours).
Another strategy is demand control or English peak shaving, where the main function is to supply energy to the system so that the demand of a consumer unit is not exceeded or even to cover the delivery of energy where the network is limited or insufficient.
There is also application in electric mobility, with the rise of electric vehicles and the high volume of current sales, strategies such as demand control using batteries will be increasingly common, especially in condominiums, where it is desired to install electric charging points and The contracted demand is limited and may have a high cost for an increase in demand and will also depend on the availability of the distributor's local network.
Also noteworthy are hybrid systems with storage applied to avoid injection into the grid or control this energy export, known as grid-zero, zero export or zero-grid. Zero-grid systems are a control strategy in a photovoltaic system aimed at non-export or limitation of energy export to the distributor's network.
It is not a classification of a type of photovoltaic system, but rather a way of control implemented within a photovoltaic system, whether on-grid or hybrid.
It is important to mention that you can have a zero-grid with or without storage, but storage allows the use of energy from the photovoltaic system at times when there is a surplus of generation in relation to the load, enhancing financial gains.
Article published in the 22st edition of the Magazine Canal Solar. Click here and now for free!
In the context of sizing hybrid photovoltaic systems with batteries, the simultaneity factor plays a very relevant role. This is because the sizing of the battery bank is directly related to the energy capacity that you want to store, and this amount of energy is directly linked to the customer's consumption profile, that is, the load curve of each consumer.
For context, the simultaneity factor can be seen in another solar channel article: “Law 14.300: What is it and how to calculate the simultaneity factor?”. The simultaneity factor is defined as the ratio between the self-consumed energy and the energy generated during a certain time interval, simply put, it is the quantification of the generation of the solar system that is directed towards instantaneous consumption.
The importance of the factor in sizing hybrid photovoltaic systems with storage can be explained by the simple reason that the energy generated that is not self-consumed can be stored and not exported to the grid.
Therefore, the sizing of the battery bank will be related to the amount of energy that is being generated and not consumed instantly, thus, this sizing will be directly related to the simultaneity factor.
In current situations, since the establishment of Law 14.300 and also the issue of flow reversal in many distributors, storage systems have been used as an alternative to not exporting to the network.
Allied to this is the price of batteries, which has fallen significantly in recent years. The network costs that are paid when exporting or even the impossibility of exporting to the network, has made this solution increasingly sought after by integrators in the photovoltaic solar energy sector.
Knowing this difficulty, the idea of preparing this article is to present an alternative for sizing the battery bank without requiring a measurement campaign to assess the customer's load curve, as this can become costly and impractical for simple preparation. of a hybrid system proposal for a client.
