grid-connected
|
How do
grid-connected solar systems work? Solar panels convert the sun's energy directly into direct current (DC). The produced DC is converted in 230 V- alternating current (AC) or in 400 V- three-phase current by the inverter. Application areas: - rooftops and garages, car-ports - roofs of factory buildings - roofs of agricultural buildings - field installations
1. Solar cells are the heart of a solar installation. These cells produce electricity when sun light impacts upon. It has to be distinguished into three different cell types: monocristalline, polycrystalline and amorphous. (Also called thin film modules) Crystalline cells are made of Silicon. In contrast, thin film modules consist of a thin layer made of Gallium arsenide, Cadmium telluride or copper-Indium-Diselenide. The solar cells are interconnected in the solar modules and they are weatherproof. 2. The DC is transported via a special solar cable to the inverter. Depending on the size of the application, the strings are collected in a string-box to reduce their amount. A DC switch is necessary to ensure all safety standards. By means of the switch it is possible to separate the DC-site of the modules from the voltage if required. 3. The inverter converts the DC in AC. Thereby, the inverter is configured so that the solar panels reach an optimal operating point and yield maximally. The electronics of the inverter controls the application and points out dysfunctions, like disconnections of a power failure which can then be processed. 4. The export meter reproduces how much solar electricity was fed into the grid. It works independently from the ordinary meter and counts each fed in Kwh. 5. The fed in solar electricity is reimbursed by the network operator according to EEG in Germany
|
