How to choose the photovoltaic system: what you need to know before buying and installing a photovoltaic system
Practical guide to photovoltaic systems: the mounting location, the resistant roof, the avoidance of shade and the adaptation of the network for efficient production. Advice on orientation and consumption calculation, essential before investing in solar energy
Content
The place of assembly
First of all, there must be an assembly place whose orientation is not towards the North.
The best surface in terms of orientation is the facing South, you can also opt for the East-West option.
If the mounting place is the roof of the house or an annex, and the orientation of the slope (water) is only on the East or only on the West, you must take into account the fact that half of the day the production will be minimal.
The East-West orientation is chosen when it is possible to mount the panels both on the west side and on the east side, so the system will produce energy from the panels on the east (sunrise) in the morning and from the panels on the west (sunset) at noon and in the evening.
Also in the chapter on the place of installation, it should also be specified that the angle of inclination of the roof or the structure on which the photovoltaic panels are mounted will be directly proportional to the production of the system.
In Romania, the suitable mounting angle for photovoltaic panels is between 25-35 degrees.
The roof
Second, but equally, you must ensure that the roof or structure on which the panels will be mounted has Mechanical resistence for a weight of approximately 10 kg/m2 where snow loads or the influence of wind are also taken into account.
The Shadow
Third, you need to make sure that the place where you want to mount the panels it is not shaded. Shading a single PV panel will drastically decrease the output of the entire system. Certain inverters, such as those from Huawei, can reduce the effects of shading by installing de Optimum on each panel. These optimizers also have the role of protecting the photovoltaic system, through the "rapid shut-down" function, which, upon detection of rapid heating, such as an electric arc, disconnects the entire assembly of panels in a maximum of 3 seconds.
Mains type and voltage
Regarding the network type, you should know that for a single phase system expenses are lower than for a three-phase system.
Regarding the network voltage, it should be known that the average value of the voltage in the national energy system is 230V line voltage and 400V phase voltage. If you notice flickering of the bulbs or increases in the luminous intensity of the bulbs, you should first measure the voltage in your home. If it is observed that the voltage drops below 200V or increases to 250V, you will have problems with frequent restarts of the inverter, or in certain cases, the power of the photovoltaic system must be limited. These restarts last 10 minutes, and during this time the system will not be able to produce energy.
Earth socket
If you know that you don't have grounding done at home, or it's not done properly, you have to consider an outlet separate land, or improved the existing one. The standard value of the resistance of the earth socket at the national level is 4 Ohms.
Your current consumption
Which type of system to choose depending on your current consumption.
One of the most important aspects in choosing your photovoltaic system is the current consumption of your home. Depending on this own consumption and the available mounting surface, you can choose the technical-economical system that suits you.
Below, it was calculated with the software PVWatts Calculator, the energy production of selected photovoltaic systems of 3kW, 5kW and 6kW:
If you do not fit these values and want calculations for larger systems, do not hesitate to contact us.
We hope this article helps you and convinces you to invest in photovoltaic energy.
Now that you have found out how to choose the photovoltaic system, we recommend that you also find out what you need to do to become a prosumer:
Sunny days!
