The three most important factors affecting the return on rooftop PV

Many friends who have installed home photovoltaic power generation systems have reported that their home installed photovoltaic power stations do not generate electricity well, and the ideal efficiency gap is large, is it because the installation angle of the photovoltaic panels is not at the best angle of inclination? For example, in Shanghai, latitude 31 degrees, and the company installed the photovoltaic panel inclination only 23 degrees, and the theoretical best angle difference of about 10 degrees, this will not cause a significant reduction in power generation efficiency?

The so-called optimal angle of inclination, in a narrow sense, is the angle at which the photovoltaic panel receives the greatest amount of solar radiation, which is a factor affecting the efficiency of photovoltaic power generation, but in practice it is not a mythical existence that determines everything, not to mention that the optimal angle of inclination is originally a dynamic value, single family photovoltaic power generation system installation environment is very different, even if you are all according to the best Even if you install them all at the optimum tilt angle, the returns will be very different.

The tilt angle of home PV power generation has an effect on the efficiency of power generation, but, in general, this effect is negligible and the installation company will take it into account and choose a suitable angle for installation. Take the example of photovoltaic power generation in the Shanghai area, Shanghai 31 degrees north latitude, using simulation software to calculate the efficiency loss of 5 degrees, 15 degrees, 25 degrees, 30 degrees, 40 degrees, respectively, 3.6%, 0.8%, 0, 0.5%, 2.7%, from the data can be seen, Shanghai photovoltaic panels installed inclination angle 15 degrees to 35 degrees are possible. If you waste 50% of the site area for the sake of fighting for 0.5% efficiency, the return will be reduced instead.

For home photovoltaic power generation, since the tilt angle of PV panel installation is not a myth, then what factors have a big impact on the return? Here are three factors that are easily overlooked, but are particularly important.

First: Safety

At all times, the importance of safety is ranked before efficiency, no safety how to talk about efficiency? The home photovoltaic power generation system, some are installed on the roof of 2 or 3 floors, some are installed on the roof of 20 or 30 floors, if the installation is not reasonable, the safety risks are  large.

1, the design is unreasonable, for example, in order to pursue the best tilt angle, take more than 30 degrees angle installation, then 10 meters long photovoltaic array, the height of the bracket will reach 6 meters, which has high requirements for the roof building structure and steel frame structure, roof photovoltaic power station collapse of the incident occurred from time to time.

2, did not consider the later maintenance, many family photovoltaic power generation photovoltaic panels spread throughout the roof, some have to float out some, just like buying a house, as much as possible to take up area. Do not believe what "photovoltaic power generation does not need maintenance cleaning" such nonsense, a weight of bird droppings may destroy the entire power station is not alarmist.

Second: shading

"I have 150 square metres of photovoltaic panel area, it doesn't matter if I shade a little", this is because of the wrong idea of photovoltaic power generation systems do not understand, a small amount of virtual shade shading will not cause a big impact, but close to the real shade shading, even a little, may cause 10% loss, and may even damage the photovoltaic power generation devices, which directly leads to a decline in revenue. This will directly lead to a decrease in revenue.

Third: orientation

Family photovoltaic power generation is generally relying on housing construction to install photovoltaic panels, although most of China's housing is north-south orientation, but east-west orientation is also quite a lot, and, with the diversification of building styles, multi-faceted villa roof is also very common, family photovoltaic power generation if the focus on revenue, not recommended east, west, north installation of photovoltaic panels, south or deviation of about 15 degrees orientation to install photovoltaic panels appropriate.

To sum up: home photovoltaic power generation, safety, site area utilization, environmental impact is the biggest factor affecting the income, according to the actual situation, reasonable design of photovoltaic power generation system, in order to achieve the maximum income.