Laying solar panels on the roof for power generation and storage is a point that the photovoltaic industry has been paying attention to so far. It is also the first impression many people have of the term "photovoltaic" when they do not understand the photovoltaic industry. It can be seen that the proportion of rooftop photovoltaic power stations in the photovoltaic industry is absolutely critical. The editor has compiled five main matters that need attention in the site selection and exploration of rooftop photovoltaic power plants, which can be used as a preliminary reference when constructing rooftop photovoltaic power plants.
1. Classification of roof main structure
Mainly tile roof, concrete roof and color steel tile structure
2. Tools needed for early site survey
Tape measure over 20 meters, laser rangefinder, spirit level, compass or mobile phone compass APP and paper pen, etc. If you need to tilt the roof, it is recommended to wear non-slip laces and safety ropes.
3.Survey points of tile roof and color steel tile structure roof
(1) Ask about the year of completion of the building and the ownership of the property.
(2) The orientation and azimuth of the roof. On-site compass measurement plus google satellite map query.
(3) The roof is tilted. Calculate the roof inclination angle by measuring the width of the roof and the width of the house. The south roof is generally more inclined than the north roof.
(4) Tile type and tile size. Common tile types for civil buildings include Roman tiles, hollow tiles, double groove tiles, asphalt tiles, flat tiles, fish scale tiles, Spanish tiles and slate tiles. If the tile size is not easy to measure on site, you can also check the size online after determining the tile type. Because the size of the tile, especially the thickness, determines the selection of parts such as the hanger system hook.
(5) Consider the occlusion of the roof. Accurately measure the size of the obstructions around the roof, and later use the shadow analysis software to make a sketch of the available area of the roof. Shadow occlusion on solar panels can greatly affect the amount of electricity generated.
(6) Open some tiles to check the roof structure, and note the size and spacing of the main beam and purlin. The hook of the bracket system of the tile roof is fixed on the purlin.
(7) Obtain the house structure drawing from the project owner for easy calculation of roof load.
(8) Ask the owner if there is a high-rise construction plan on the south side of the roof of the photovoltaic system.
4. Points for surveying concrete roofs
(1) Year of construction completion, ownership of property rights; roof orientation and azimuth.
(2) Measure the height of the daughter's wall, and conduct shadow analysis in the later stage to determine the area that can be installed and used.
(3) Check the waterproofing of the roof. Based on the principle of not damaging the waterproof structure of the roof, consider whether the installation of the bracket is self-loading or fixed with expansion bolts. The bearing capacity of a standard civil concrete roof needs to be greater than 3.6KN / m2. In the case of short-term wind and snow loads, the load of the support system is also less than the bearing capacity of the concrete roof. In order to avoid any damage to the waterproof structure of the building after the installation of the photovoltaic system, the self-supporting bracket mounting method is preferred.
(4) Obtain the house structure drawing from the project owner to facilitate the calculation of the roof load.
(5) Ask the owner if there is a high-rise construction plan on the south side of the roof of the photovoltaic system to be installed.
5. Electrical survey points
(1) Check whether the household power supply is single-phase or three-phase. Civil villas are generally three-phase power. The single-phase output photovoltaic power generation system should be connected to the three-phase dual-phase incoming line switch which consumes more power. Conditions allow the best use of three-phase inverters or three single-phase inverters.
(2) Ask about the average monthly electricity consumption or electricity cost and the main electricity time period. As a reference for photovoltaic system installation capacity.
(3) Check the capacity of the owner's main incoming switch. Considering the revenue problem, the output current of the photovoltaic power generation system should not be greater than the capacity of the household switch. Under the current subsidy policy, the benefits of spontaneous full self-use are still the largest.
(4) Based on the principle of convenient and economical wiring, consider the installation position of the inverter and grid-connected cabinet. The installation position of the inverter and grid-connected cabinet also takes into consideration the issues of heat dissipation, ventilation, and waterproof and sun protection.