The benefits of solar PV systems include the generation of clean and sustainable energy, which can lead to significant cost savings in the long term. However, energy consumption may increase after the installation of a solar system, for example due to the installation of new electrical appliances or an increase in the size of the household. In such cases it may be important to expand the solar system to continue to produce sufficient energy. In this article, we explain how to efficiently expand an existing solar system.
The role of the inverter and possibilities for expansion
The inverter is an essential part of the solar PV system, which converts the energy produced from direct current (DC) into alternating current (AC) energy that we use in our homes. When expanding a solar system, the capacity of the inverter is an important consideration. Ideally, the inverter should have a higher power output from the outset to cater for future expansion needs. The oversizing of the inverter makes it easy to add new solar panels to the existing system without the need for a new inverter.
It is also important to consider the phase number of the inverter, especially if the system power exceeds 2.5 kW. In this case, a 3-phase inverter of up to 50 kW should be used. In optimised systems, expansion is easier, as optimisers ensure that solar panels perform evenly, even if some are shaded or polluted.
Coordinating strings and solar panels
Solar panels are usually connected in strings, which are placed in different parts of the system. The phase number, size and optimisation of the strings affect the expansion possibilities. A string can usually handle 20-22 solar panels, and the utilisation of existing strings determines whether or not additional solar panels can be added.
In the case of optimised solar systems, it is easier to scale up, as optimisers ensure that the solar panels perform evenly. However, in the case of partially optimised systems, the expansion should be carefully planned so as not to compromise the efficiency of existing solar panels.
Compatibility and evolution of solar cells
The type and output of the solar panels is also an important consideration when upgrading. Ideally, solar panels of the same type and output should be added to the existing ones. If older types of solar panels are installed, it is still possible to add newer, modern solar panels, but in this case the use of optimisers may be essential.
Solar cells are constantly evolving, and monocrystalline solar cells are becoming more efficient with new technologies. However, because of the efficiency differences between different types of solar panels, it is important to seek expert advice before upgrading.
Summary
The expansion of a solar PV system involves many technical and design aspects. The right size of inverter, optimisation of strings and compatibility of solar panels are key factors. With expert advice, it is possible to efficiently and effectively expand an existing solar system to continue to produce sustainable and clean energy in the future.