Household solar photovoltaic power station is a small distributed photovoltaic system, also known as household photovoltaic power station. Generally, what we see are installed on the roof, but not all roofs are suitable for installation. In the design of photovoltaic installation, the actual situation should be fully considered, and the principle of economical application should be followed.
Remember the following knowledge points about the installation of household photovoltaic systems!
Installation site selection
The location of home photovoltaics can generally be selected on their own roofs or open spaces. The conditions that need to be considered are the usable area, house structure and load-bearing requirements, ground foundation conditions, and meteorological and hydrological conditions. If you choose to install it on your own roof, the roof bearing capacity must be greater than 20kg/㎡.
If the house beam is a wooden structure, don't consider it. The photovoltaic system has a service life of up to 25 years, and the wooden beam is perishable. It is recommended not to install it.
Herringbone structure roof
If a solar photovoltaic power station is built on the roof of the herringbone structure, the optimal inclination angle cannot be designed like a ground power station, and the front and rear shading distances should be considered. In order to facilitate the combination of photovoltaic modules and roofs, brackets are generally directly tiled on the south-facing roof. The bracket is connected to the roof by a clamp, and the battery pack is installed on the bracket. This approach is not only beautiful, but also maximizes the use of roof area.
Flat roof structure
To build a solar photovoltaic power station on the roof of a flat roof structure, it is necessary to erect photovoltaic brackets and design the optimal inclination angle and the distance between the front and rear of the components.
own open space
If you choose to install it on your own open space, you can use anchor piles and concrete strip foundations as the support foundation. The specific choice needs to be comprehensively considered from the geological conditions and cost. In addition, the design of the foundation strength of the support should be based on the local meteorological conditions.
It should be noted that considering the thermal expansion and contraction effect of the components, the interval between the upper, lower, left and right components should be about 3cm during installation.
Grid-connected inverter selection
Grid-connected inverters are mainly divided into three categories: high frequency transformer type, low frequency transformer type and transformerless type. According to the designed system and the specific requirements of the owner, the transformer type is mainly considered from two aspects of safety and efficiency.
The household distributed photovoltaic system is a small system and does not require high technical indicators. When the inverter does not have an isolation transformer, the energy conversion efficiency is higher. Combined with factors such as cost, it is more reasonable to choose a transformerless type.
Lightning protection design
In order to ensure the safety and reliability of the photovoltaic grid-connected power generation system and prevent the damage of system components caused by external factors such as lightning strikes and surges, the lightning protection grounding device of the system is essential. The solar photovoltaic power station is a three-level lightning protection building, and lightning protection and grounding involve the following two aspects:
1. Try to avoid the projection of the lightning rod falling on the photovoltaic module
2. The ground wire is the key to lightning protection and lightning protection.
Prevent lightning induction: The metal sheath including equipment, racks, metal pipes, and cables must be reliably grounded. Each metal item must be connected to the grounding trunk separately, and it is not allowed to connect to the grounding trunk in series.
Choose reliable after-sales service
The continuous power generation of photovoltaic panels installed on the roof will not be less than 25 years. Whether it is an industrial and commercial rooftop distributed power generation system as large as several MW or a residential distributed power generation system as small as several KW, a reliable and complete after-sales service system is particularly important.