voltage, current, power tolerance, system voltage, etc. that we should pay attention to when choosing a solar panel. we explain what the technical details mean. solar panel review, one of the most important parts of solar energy.
Solar Panel Selection (datasheet details)
Although the choice of solar panel is an issue that needs to be decided by evaluating many details, unfortunately, we see that it is very simplified. I would like to talk about what should be considered when choosing these generators where very long guarantees are given. Datasheet (product information summary) to read, will allow you to make the right comparison.The following details will be useful in solar panel selection.
solar panel standard and linear guarantee graphI would like to talk about the performance guarantee section first, this section can also be considered as a section that shows the quality of the panel. The following point often escapes attention or does not want to be taken into account; PV panels start their production life with 2%-3% loss shortly after commissioning. We know that photovoltaic panels experience 0.7-0.8% output power losses every year due to their structure. In this case, we should look at this curve very carefully.
Our focus is on how much the production % starts from and how many % levels it goes down at the end of 25 years. How high it starts and how high it is at the end of 25 years will be a situation that is to your advantage. In addition, when making feasibility, the calculation of 99% in the second year and 98% in the next year will be misleading.
Another important issue; cell type
Datasheets will no longer be sufficient only mono crystalline, poly crystalline or thin film panels. Poly crystal, mono crystal, thin film solar panels are divided into varieties within themselves and each of these varieties has its own characteristics. You can read my previous article on this subject from this link: www.keremcilli.com/solar-hucre...
How many bypass diodes should there be?
In a standard 60-cell panel, there are usually 3 bypass diodes. Its purpose is to ensure that other sections that are not connected to it can operate without being affected by the shadow in any shading. The high number of bypass diodes means that the losses in the shadow are less. It is possible to find products designed with 4 bypass diodes and 6 bypass diodes.
Temperature coefficient (Pmax) panel temperature coefficient value
Another important point to look at when you buy a photovoltaic panel is the temperature coefficient value. It is generally written as "-0,40% / ° C", "-0,280% / ° C". The closer these values are to zero, the less your losses due to temperature. In summary, let me say this; air temperature and panel temperature are not the same, for example, in a place with an air temperature of 30 ° C, the temperature in the cell is likely to be 50-55 ° C. (may vary according to installation conditions, figures are given to explain this difference)
What is a busbar?
I will discuss this issue in another article, let me briefly state, the busbar is the lines through which the energy generated on the panel is transmitted. More or no lines (back/rear contact cells) means more efficient panels. Currently, non-busbar or 3, 4, 5, 6 or even 12 busbar solar panels can be easily found.
It is necessary to pay attention to power tolerance
Another point that we should pay attention to on the labels of solar panels is the power tolerance line. Zero and + directional products should be preferred. (for example 0~ +5%) This detail, which is generally not paid much attention, may cause an increase in our production loss when using a series inverter. Having numbers such as ±3%-5% on it also reveals the possibility that the solar panel may go down from the label value, and the production values will decrease due to the structure of the solar panels over the years. Therefore, it is important not to choose solar panels with negative tolerance values.
PID effect is very important
Especially many of the panels installed in our country so far may not have this feature. PID can occur for various reasons; for example, the use of poor quality cells, designs made at high voltage levels, weather conditions, etc. This effect is a condition that reduces the life of solar cells, ages them while they can produce more and causes them to work more inefficiently. The worst part of the job is not a visible error. While you think your solar power plant is healthy, perhaps your solar panels may have started to work inefficiently. Preferring PID free products, inverter preference with transformer or N type cell solar panel may be the solution. I recommend that you have your field x-rayed every year about PID.
16 май 2019
