An alternative to using solar energy as on-grid or off-grid is to use it with self-consumption systems. In self-consumption systems, while continuing to receive electricity from the grid, an additional source of energy is created thanks to solar panels and energy needs during the day are met from this source. The difference with grid-based systems is that in this system, since there is no two-way electricity meter, excess energy is not transferred to the grid. Instead, the excess energy is adjusted with the device called smart meter and brought up to the level of the system’s current need, preventing excess energy for the system. In short, since the excess energy produced in the self-consumption system cannot be transferred to the grid, it is absorbed by the smart meter.
It is important to give preference to the system of self-consumption in cases where the electricity generated by solar panels cannot meet consumption due to lack of space. For example, if an enterprise with a small roof area has a piece of equipment or machinery that consumes a lot of electrical energy and this enterprise prefers to work between 8 a.m. and 7 p.m., it can have solar energy installed on its roof to reduce electrical energy from the grid. In this way, the company will immediately use the energy produced by solar energy and reduce the electricity it receives from the grid and the bill it pays.
In addition, batteries can be added to the system by using a hybrid inverter in the self-consumption system. In this way, excess energy generated by solar panels that cannot be transferred to the grid can be stored in batteries for use. However, using both a hybrid inverter and batteries increases the initial investment cost of the self-consumption system. The self-consumption system basically consists of 5 components;
Solar panels, which are the most basic component of solar systems, convert the sunlight (photon) falling on them into equivalent electrical energy by means of solar cells made of semiconducting silicon material. Solar panels are calculated on the basis of daily energy consumption and the size of the area of application. Based on the calculation result, suitable Arçelik monocrystalline panels with high strength and efficiency are selected.
On-Grid Inverter / Hybrid Inverter;
Inverters, in the simplest definition, are electronic devices that convert DC (linear current) electrical energy into AC (alternating current) electrical energy thanks to the circuits inside. inverters convert DC electricity into single-phase or three-phase AC electrical energy, depending on the area of application. These inverters work together with power from the sun and power from the grid.
If a hybrid inverter is preferred for the system, these inverters have battery outputs. Thus, they first send the excess energy produced to the battery for storage. After the batteries are full, they detect the excess energy produced by the smart meter and send as much energy to the system as needed. In the evening hours or in case of a grid failure, the energy stored in the batteries is used in the system thanks to hybrid inverters. Since these inverters are more comprehensive devices, they are more expensive than other inverters.
At the points of contact between the solar system and the grid, protection of the system is provided by the fuse, ground fault circuit interrupter and surge protector in the panel. In this way, the protection and control of electricity and thus the life safety of consumers is ensured.
This device is installed at the point where the meter is located between the grid and the energy consumption point and measures the direction and power of energy. It records information such as electricity consumption, voltage level, current and power factor and sends the information to the inverter through the communication protocol provided on it. When the energy consumption approaches zero, it starts limiting production. Thus, it works in parallel with the grid and sends zero energy to the grid. It can also limit the power to be sent to the system.
Battery (gel battery or lithium batteries) – Optional
These are devices for storing the sun’s energy. Batteries meet energy needs by releasing the energy they store to the system during periods when there is no or insufficient sunlight. It is imperative that the batteries to be used in the system are long lasting, can withstand high temperatures, have a high cycle efficiency and leak as little gas as possible. The choice of battery should take into account the operating voltage of the inverter and the daily energy consumption.