Due to the high matched profile between solar power generation and load power consumption, industrial and commercial solar projects have the advantages of high proportion of self-consumption, bigger saving on electricity bills, shorter long-term ROI, and thus becoming the popular investment option.

However, not every roof is suitable for the installation of solar power station. First of all, it is necessary to clarify the ownership of the house, the operation status of the enterprise, and the power consumption. Secondly, it is necessary to investigate the roof standards on the project site, including the bearing capacity of the roof, the condition of the roof machinery and equipment, the height of the parapet, whether there are high-rise residential buildings nearby, and the power grid natural environment and supply and distribution of industrial plants electrical system equipment. If the early site inspection is not performed properly and comprehensively, it may lead to huge losses. Therefore there are a few points that need to be focused on when doing site surveys.

1. Property Right Period of the Roof

If the investor is not the owner of the building, he should pay attention to the property right period of the building. If it is a commercial building of a government department, a college, a hospital clinic, or a subway station, etc., the property right period is indefinite and therefore the property is suitable for solar projects. If it is a rented factory, it is necessary to sign a contract with the owner. If there is no reliable real estate certificate, the business risk will be higher.

2. Service Life of the Roof

Solar panels have lifetime of more than 25 years, generally it takes about 8-10 years to get the initial cost paid back. In the development and design of new projects, it is necessary to find out the lifetime of the building. If the building is too old and the left lifetime is too short, it will not be suitable for solar projects.

3. Orientation and Tilting Angle of the Roof

From the perspective of power generation capacity, the best inclination angle and south direction are undoubtedly the best, but most roofs cannot meet this standard. During the inspection, it is necessary to measure the orientation angle of the roof, the inclination angle of the roof and the height width ratio of the surrounding obstructions such as ring beams. The solar power generation simulation software is used to calculate the power generation capacity and profit first, and then decide whether the project investment is or not.

According to the feedbacks from roof inspection, the inverter with different MPPT frame is selected to reduce the product cost and maintenance cost of the solar system and improve the economic benefits. It is proposed to select the single MPPT and unipolar inverter for the roof with consistent installation perspective and direction, which can improve the reliability index and reduce the cost of system software; for the roof with complex landform, multi-faceted and multi housing orientation, and some blocked roofs, the inverter with multi-channel MPPT secondary structure should be selected.

Ningbo Raytech New Energy Materials Co., Ltd. is specialized in “PV Modules Manufacturing and System Integration” and “Smart Panel Materials Manufacturing”. The company has independent product R&D teams, national key laboratory and 1.2GW full-automatic manufacturing line. Raytech Double-glass modules come with 12-year product warranty and 30-year performance warranty (2 years and 5 years longer than industry's standard product / performance warranty respectively).