How to survey photovoltaic power plants with tile and concrete roofs?

The building roof is mainly a tile roof and concrete roof. For the installation of domestic photovoltaic power plants, the following points should be paid attention to in the early site survey.
The site the survey needs to prepare a tape measure of more than 20 meters, a laser rangefinder (available online and inexpensive), a compass or mobile phone compass APP, paper and pen, etc. If you need to tilt the roof, it is recommended to wear non-slip laces and safety ropes.

Architectural survey points

● Tile roof
1. Ask about the year of completion of the building and the ownership of the property.
2. Roof orientation and azimuth. On-site compass measurement plus google satellite map query.
3. Roof tilt angle. Calculate the roof inclination angle by measuring the width of the roof and the width of the house. The roof in the south is generally larger than the roof in the north, and the roof in Shanghai is about 30 °.
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 beams and purlins. The hook of the bracket system of the tile roof is fixed on the purlin.

● Concrete roof
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 available installation area.
3. Check the waterproofing of the roof, taking the principle of not destroying the waterproof structure of the roof, and 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 bearing the 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 installation method is preferred.

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 incoming main 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 inverters and grid cabinets. The installation position of the inverter and grid-connected the cabinet also takes into consideration the issues of heat dissipation, ventilation, and waterproof and sun protection.