Solar energy system losses directly impact the overall solar panel’s performance, efficiency, and output power. Various factors affect the power production of a solar PV system. The solar module characteristics as well as solar system design, orientation, and configuration all ensure the output of a solar energy system. Any issue with these factors becomes the reason for solar energy system losses. However, the best solar design and installation services reduce the risk of system loss issues in a solar panel system.
To help homeowners, in this article, we will highlight the 10 solar energy system losses that might occur in a solar PV system. We will describe some of the reasons for energy loss in the solar energy system. Also, we will come up with some solutions for increasing the performance of your system.
10 Common Solar Energy System Losses
Some of the common energy losses include:
1- Shading Effects on Solar Panel System
Shading impacts directly on solar energy panels’ performance. The shade will decrease the efficiency of the PV system because this interrupts sunlight from directly hitting the panels. This issue can be more severe sometimes depending upon the shading condition. If half of the energy panels are under shade, it will then affect the production. Therefore this system loss issue is important.
But, on the other hand, A good solar design can solve this issue and decrease the degradation rate. Routine maintenance practice is also the solution to avoid this system loss. This solar panel system maintenance activity will help you to ensure that your panels are not over shaded.
Another type of shading is “Soft Shading”. This type refers to the shadow made by the clouds. This issue may occur in some geographical locations where there are clouds. Soft shading generates diffuse light. But, this is not as serious an issue as the shading of the object.
Solutions for Solar Shading Issue
Adding By-Pass Diodes: Nowadays, by-pass diodes are fitted with energy systems. This helps the current to flow around those solar panels cells which may not work due to under shading. This is the cheapest solution to deal with the solar panel shading problem. But also, the diodes are not lifelong solutions because of failure issues.
According to a recent study, the operating conditions for most PV systems are much harsher than those we use in laboratory testing. It accounts for 47% of failure rates. However, there are better methods for both increasing output and minimizing output losses from the shade. And also safeguarding solar panels from overheating damage by back-feeds and unbalanced loads.
Built-in Micro Inverters in Solar Energy System: Solar inverter install with PV system to convert DC power into AC. Now if one solar panel is under shading, due to the series connection, the output will not reduce as much as in the case of shading it can.
Also, a micro-inverter that converts to AC and sends the energy to a central box for further distribution can be installed on each panel as one solution. This prevents the output of one solar panel from affecting the performance of the others.
Addition of Solar Optimizers: Every PV panel has a DC optimizer, which uses the MPPT function (Maximum Power Point Tracking) to work. They transmit the voltage to a typical string inverter instead of converting DC to AC. The panel voltage converts to current to make up the shortfall when the optimizer notices a reduced current caused by shading effects.
2- Dust Effects on Solar Performance
Dust particles also impact the performance of the solar photovoltaic system. While making a solar design and calculations, the energy experts should consider this energy system loss also.
The dust effect factor mainly depends upon the geographical location of your home. Like, if the house is in such an area where it is all-year-round, the dust loss will be less. However, if the home location is in dusty weather areas, the PV system loss in such areas cannot be ignored because of the higher ratio.
The solution to deal with the dust factor is Solar Panel Cleaning. The solar professionals recommend cleaning solar panel arrays once every six months. This not only increases energy output by 3 to 5% on average but also improves efficiency up to 25% in really dusty places.
3-Solar Cell Array Optical Losses
Light photons interact with the P-N junctions in the solar cell’s crystalline structure to produce energy in solar cells. Optical losses happen when light bounces off the panel’s surface rather than being absorbed into it to interact with the electrons.
This is a feature of the panel design, and it is the focus of continuing research into increasing panel effectiveness. The difficult part is increasing light absorption while minimizing surface reflectance.
This type of solar energy system loss can be overcome by adding another type of light-trapping mechanism or “roughing up” the surface with granular paint additives.
4- Solar Cells Spectral Responses
This system loss is about the output of different types of wavelengths that solar cells receive. Solar energy cells do not use all sun’s wavelengths. There are different frequencies, but the most common ones are 4 percent UV, 54% infrared, and 43% visible light. To enhance electrical output, manufacturers work to design panels so that they offer a generic, broad response.
5- Solar Energy System Loss Due To Irradiance Level
System loss due to irradiance level shows the reduction in solar efficiency when the irradiance level decreases from the STC rating (Standard test Conditions) of 1000W/m2 to a low irradiance of 200W/m2. It is average out for practical reasons at 1.5 percent.
Energy production is not linear. As efficiency decreases, a value needs to account for energy loss both during the design process and over the PV system’s lifetime.
6- Solar Panel Cells Thermal Loss
A solar cell loses 0.5 percent of its output for every 1 degree C above the STC-rated temperature of 25 degrees C. That is why this is the most important loss in the energy system. This loss is due to an intrinsic feature of the solar cell structure.
However, there are some innovative suggestions for minimizing thermal loss. Many involve creating natural airflow channels by drilling holes or wide slits through the aluminum framework.
Among other recommendations, one of the solutions is the hybrid PV-thermal solar panel. This cools the face of the solar cells with water and recovers the heat for use in the building.
7- Solar PV Modules Mismatch Loss
When two or more solar panels in an array produce differing amounts of energy, there is a mismatch between the solar modules. Two factors may contribute to this. On is the partial shade. Another is variations in the electrical properties of the solar cells.
From a car part to a solar cell, everything has a tolerance level. In the case of solar panel cells, this ranges from +/-1.5 to +/-5 percent. In essence, this means that solar modules made from these cells won’t generate the same amount of electrical energy.
Anyhow, using panels with integrated micro-inverters or adding panel-level electronics like DC optimizers is the best option.
8-Solar Panels DC Wiring Losses
It is not possible to eliminate DC cable losses. This is because whenever current flows, it will lose energy. The only thing which we do is to minimize the loss as much as possible.
Although, 2 percent is acceptable. Designers strive to keep DC cable losses to less than 1% of the peak power output of the entire solar panel system.
Moreover, when current flows through the cables, their electrical resistance causes a voltage drop as well as power loss in the form of heating. The heating effect is a factor across connections and gets worse the higher the current.
The two basic strategies for reducing DC cable loss are proper design and routine electrical maintenance.
9- Losses in Solar Power Inverters
The efficiency of the most popular type of inverter, the string inverter, is 97 percent. It means that for every 100kWh, 3kWh will lose.
Temperature and load are two of the key variables impacting solar inverter efficiency. If the unit is positioned outdoors or inside, make sure it is well-ventilated and sheltered from the sun’s glare.
The efficiency curve of inverters is similar to that of most devices with maximum efficiency occurring around the maximum working load. This is typically not a problem until the inverter load goes below 25 to 30 percent, but below this point, it drops down sharply.
10-Energy Systems AC Cable Losses
In both DC and AC cable lines, regulations permit voltage drops of up to 3%, but designers aim for 1%. In actuality, the only ways we can reduce AC losses are by selecting the appropriate parts and building cable runs with the optimum cross-section area and a minimum length.
Best Strategy for Solar Energy System Losses Reduction
Concludingly, the majority of solar PV losses are related to design flaws or component characteristics. In order to maximize output, the installation might choose the right cabling and pay particular attention to both nearby and far-off shading.
Also, Installing the most recent DC optimizers or micro-inverters can significantly reduce mismatch loss or other impacts by partial shade.
Moreover, Regular cleaning and maintenance guarantee that the maximum amount of solar energy reaches the panel’s surfaces and prevents shade caused by plant growth.
For premium solar installation services, contact Solar SME at 214–556–8288 or request a FREE quote for estimation.
