On June 14, 2013, the premier of the State Council presided over the executive meeting of the State Council, at which ten air pollution prevention and control measures were deployed, six national measures were issued to rescue photovoltaic enterprises,
and the concept of "better and stronger" was put forward especially for photovoltaic enterprises. On June 16, 2013, in the work meeting on distributed photovoltaic power generation demonstration area held in Beijing, the office of the National Energy
Administration issued the work plan for distributed photovoltaic power generation demonstration area.
Color steel plate
2. Significance of developing distributed photovoltaic roof demonstration area for power generation
The distributed photovoltaic roof demonstration area uses the color steel plate roof to generate solar photovoltaic power through the installation of solar panels, all of which are self used. Solar power generation is conducive to accelerating the pace of energy structure adjustment, increasing the supply of clean energy, and making up for the shortage of primary energy in Baoding.
In th demonstration area project, solar energy is used to generate electricity. Every 10000 kilowatt hours of electricity can replace about 4 tons of standard coal and reduce the emission of pollutants generated by thermal power generation. In 25 years, the distributed photovoltaic power generation project in this demonstration area has saved 598600 tons of coal, 1556400 tons of CO2, 13000 tons of SO2 and 5900 tons of nitrides.
The construction of the demonstration area involves public places such as industrial and commercial enterprises, schools and supermarkets, and residential users. It has a wide coverage and a large audience. Mobilizing the enthusiasm of all parties to participate in the construction of distributed photovoltaic power stations is conducive to popularizing "saving, green consumption patterns and living habits" to the public and mobilizing the whole people to participate in environmental protection and supervision.
3. Influencing factors on photovoltaic power generation of color steel roof
The following factors need to be considered in the photovoltaic power generation design of color steel sheet roof:
(1) impact analysis of meteorological conditions
The working temperature range of inverter selected for distributed photovoltaic power generation demonstration project is - 25 ℃ - 60 ℃, and the working range of solar cell module selected is - 40 ℃ - 85 ℃. Under normal conditions, the working temperature of the solar cell panel is about 30 ℃ higher than the ambient temperature.
Generally, it needs to be checked according to the data of minimum and maximum temperature in the area where the demonstration project is located, and the operating temperature of solar cell module and inverter can be controlled within the allowable range.
(2) wind speed impact analysis
When the air around the solar cell module is in the flowing state, it can enhance the forced convection and heat dissipation of the module, reduce the working temperature of the solar cell module panel, so as to improve the power generation to a certain extent. However, due to the large windward area of solar cell module, when the wind speed is too high, the influence of wind load must be considered in the design of bracket. The basic principle is that the wind resistance of solar cell module support and foundation is not damaged under the wind speed of 21m / s.
(3) impact of thunderstorm
According to the area and operation requirements of solar cell module layout, the lightning protection and grounding system is designed reasonably.
(4) impact of snowfall
In snowy weather, the solar radiation will also be correspondingly reduced, which will directly affect the work of solar modules. After snowing, the solar radiation accepted by solar modules will also be reduced due to the snow cover, which has a certain impact on the power generation of photovoltaic system. Measures for snow removal of battery components need to be considered.
4. Design principle of solar cell module support scheme
The solar cell module bracket is installed on the color steel roof of steel structure. The solar cell module support is considered as the most unfavorable combination of wind load and snow load. Each part of the support is calculated and selected according to the components. The design of the support is safe, reliable, economic and reasonable.
For the roof of light steel structure workshop, in order to make full use of the roof area and increase the installed capacity of photovoltaic, photovoltaic modules are connected with roof profiled steel plate through fasteners. The weight of accessories such as 250wp polycrystalline silicon common battery module and aluminum alloy keel is 17.0kg/m2, and the installation mode of module square array is interval installation, which can reduce part of the average load, so it meets the requirements of photovoltaic module laying. See the following figure for the structure: