Tip1: Which type of solar panel roof mounting brackets to choose
Installation methods of photovoltaic modules are different for different roof type, common installation methods include attached type, ballast type and pile foundation type.
Attached type is the best choose for Caigang tiles roof. Laying the modules on the roof directly has the best windproof effect and more safety.
In addition, the tile roof also has a certain inclination. Although it may not be the best inclination corresponding to photovoltaic power generation, but the transformation cost caused by increasing the inclination also needs to be considered comprehensively.
For cement roofs, the common installation methods are ballast type and concrete foundation pile type. In many cases, building owners are not allowed to drill holes on the concrete flat roof. On the one hand, they are worried about the strength of the old building, on the other hand, they don’t want to change the waterproof performance of the roof. This is the reason for choosing ballast type or concrete foundation installation.
Since the ballast type is not anchored to the roof, a windshield can be considered to be added on the side. The main purpose of the concrete foundation is to ensure that the flat roof solar racking remains intact even during stormy seasons. It ensures a good installation without causing roof leaks, and can also improve the efficiency of solar cell modules
Tip2: Flat roof does not mean tile installation
It seems the most ideal way to install photovoltaic modules on a flat roof is using tiled methods. This method not only maximizes the installation area, but also allows the photovoltaic panel to be used as a roof top to increase the space area.
But in fact, installing photovoltaics on a flat roof does not mean that you should set its inclination to 0 degrees. We need to consider many factors and should avoid tile installation. These factors include:
1. Tiled components are easy to accumulate dust, which may cause 10% or even 30% of power generation loss;
2. It is inconvenient to clean, and the ponding is not easy to flow out;
3. Compared with inclined installation, the power generation will be reduced;
4. The payback period of investment will be longer;
5. It may not be possible to remove dust accumulation by rainfall;
Tip3: Flat roof solar mount must consider wind speed
In the design phase of the solar mounting system, the maximum wind speed that may occur in the local area must be considered, especially in areas where the wind speed exceeds 180 kilometers per hour.
Ordinary flat-roof solar power generation systems can withstand wind speeds of 160 km/h. But if wind protection is not considered between the arrays, the instantaneous wind speed caused by the airflow in a local area will far exceed the actual wind speed. Therefore, the selection of solar mounting brackets, structural design, ballast or concrete foundation strength design must rely on the recommendations of professional organizations. At this time, Corigy's professional engineer team can help you solve this problem.
Tip4: Water leakage risk of flat roof pv mounting systems
As the roof drainage slows down, any cracks and holes on the roof will become places for ponding. At this time, the flat roof with the photovoltaic system installed, due to the damage of the waterproof layer that may be caused by the installation of the bracket or the concrete pile foundation, becomes the biggest water leakage risk of the flat roof.
If it is a Caigang tile roof, it is better to install with a clamp than to make holes in the roof. If holes must be punched, you need to make sure that all holes are properly sealed for waterproofing.
Tip5: Need to consider mechanical device units on flat roofs
One of the challenges of designing and installing photovoltaics on cement flat roofs is the various mechanical devices on the roof of existing buildings, such as outdoor air conditioning units, drain pipes, exhaust fans, ventilation facilities, water tanks, railings, roof structures, and HVAC systems, etc.
These existing equipment not only affect the layout of the roof photovoltaic, the spacing and arrangement of the system brackets, but also may cause shadows on the photovoltaic array, or affect future operation and maintenance.
Some designers will consider installing PV above these facilities to protect the facilities from wind and rain, but another problem is the high design requirements and wind protection requirements, as well as the difficulty of operation and maintenance.
Roof facilities can only be designed according to local conditions, but this is an unavoidable problem that roof photovoltaic must pay attention to.