The same capacity of photovoltaic power plant, some owners will be able to earn more money, some owners earn less money, this is why?
Solar radiation situation
Photovoltaic cell module conversion efficiency of a certain case, the amount of electricity generated by the photovoltaic system is determined by the intensity of solar radiation. Usually the efficiency of photovoltaic system on the use of solar radiation is only about 10%. So it is necessary to take into account the solar radiation intensity, spectral characteristics, and climate conditions.
If the current year's power generation exceeds or does not meet the standard, it is likely that the overall solar radiation for that year is off the average. Of course natural factors are beyond our power to change, but we can purchase electricity generation insurance to protect our income even if the solar radiation is too low for that year.
Tilt angle of photovoltaic modules
The azimuth angle of PV modules is generally chosen to be due south to maximize the power generation per unit capacity of the PV plant.
As long as it is within ±20° due south, it will not have much impact on the power generation, and if conditions allow, it should be as far southwest as possible by 20°.
The tilt angle varies from place to place, and local installers are more familiar with the best tilt angle for the modules. In the case of pitched roofs, many are laid flat on the roof to save brackets, without considering the tilt angle, for aesthetic purposes.
Photovoltaic module efficiency and quality
There are many module types to choose from in the market, polycrystalline silicon, monocrystalline silicon, etc. Different modules have different power generation efficiency, attenuation and quality.
Calculation formula: theoretical power generation = total annual average solar radiation * total cell area * photoelectric conversion efficiency, which has two factors battery area and photoelectric conversion efficiency, conversion efficiency on the power station's power generation is a direct impact.
The most important thing is that when choosing a brand, you must choose products of well-known big brands, and, you must buy them from regular channels, so as to ensure 25 years of stable and reliable power generation.
Component matching loss
Any series connection will cause current loss due to component current difference, and any parallel connection will cause voltage loss due to voltage difference of the components. The loss may reach 8% or more.
To reduce matching loss depletion in order to improve power plant generation, the following aspects should be noted.
1. reduce matching loss by using components in series with the same current as far as possible.
2, the attenuation of components as consistent as possible.
3, isolate the diode.
Temperature (ventilation)
Some data show that a 1°C rise in temperature decreases the output power of crystalline silicon PV modules by 0.04%. So to avoid the effect of temperature on power generation, keep the module in good ventilation conditions.
We see a lot of PV plants sealed behind and on both sides, to leave a door on both sides to facilitate ventilation.
The impact of dust should not be underestimated
The panel of crystalline silicon module is tempered glass, long-term exposure to the air, there will naturally be organic matter and a lot of dust accumulation. The dust on the surface will block the light, which will reduce the output efficiency of the module and directly affect the power output. At the same time, it may also cause the "hot spot" effect of the module, resulting in module damage.
The fall and winter season is here, and the time of dusty time, photovoltaic power plant full of dust seriously affect the power generation efficiency. We must be timely to the photovoltaic power plant cleaning.
Photovoltaic module drainage deslimer is specially designed for low inclination photovoltaic power station, six months back ten times the income, help module edge thorough drainage desliming, solve the big problem of edge frame dust accumulation, increase the power generation, extend the life of the module, become the strongest voice of power station operation and maintenance cost reduction and efficiency.
Shadow, snow blocking
In the process of power plant site selection, be sure to pay attention to the shading of light. Avoid areas that may produce light shading. According to the principle of the circuit, when the components are connected in series, the current is determined by the least piece, so if there is a piece of shading, it will affect the power generation of this way components.
Therefore, the installation of photovoltaic power station, must not be greedy capacity, must be for the roof area, the roof around there is no shading situation to see.
In this regard, it is necessary to find a professional photovoltaic brand installer, they will field survey of the roof situation, and give the optimal installation plan. Rather than just let you install more.
Maximum output power tracking (MPPT)
MPPT efficiency is a key factor in determining the power output of a PV inverter, and is far more important than the efficiency of the PV inverter itself. mppt efficiency is equal to hardware efficiency multiplied by software efficiency. The hardware efficiency is mainly determined by the accuracy of the current sensor, the accuracy of the sampling circuit; the software efficiency is determined by the sampling frequency.
There are many ways to implement MPPT, but no matter which method is used, the first step is to measure the module power change and then respond to the change. The key component in this is the current sensor, whose accuracy and linearity error will directly determine the hard efficiency, while the software sampling frequency is also determined by the accuracy of the hardware.
Reduce line loss
In the photovoltaic system, the cable accounts for very little part, but the impact of the cable on power generation should not be ignored, it is recommended that the system DC, AC circuit line loss is controlled within 5%. The cables in the system should be done well, the insulation performance of the cable, the heat and flame resistance of the cable, the moisture and light resistance of the cable, the type of cable core, the size of the cable specifications.
Therefore, in daily operation and maintenance, we have to check whether the line is damaged and whether there will be leakage and other conditions, especially after each typhoon and hailstorm, it is essential to check whether the line and connectors are loose.
Inverter efficiency
PV inverter is the main component and important part of PV system, in order to ensure the normal operation of the power station, the correct configuration selection of inverter is especially important.
In addition to the configuration of the inverter according to the technical indicators of the entire photovoltaic power generation system and refer to the product sample manual provided by the manufacturer, the following technical indicators should generally be considered: 1. rated output power 2. output voltage adjustment performance 3. overall machine efficiency 4. start-up performance.
There are not many efficiency environments that affect inverters on a daily basis. Pay attention to install the inverter in a cool place and keep ventilation around it to facilitate inverter heat dissipation. Especially in summer and autumn, normal heat dissipation can maintain the power generation efficiency of the inverter.
