Solar energy
Introduction
Solar energy uses solar radiation to convert it into electrical energy (DC). Inverters are necessary to convert this energy to grid-compatible AC. A mitigation technique used to reduce common-mode currents in this application is to install Blueferrite nanocrystalline cores between the inverter and the grid.
The sun is a constant source of energy. Photovoltaic systems directly convert sunlight into electricity. The sun’s energy comes from the process of nuclear fusion. It radiates about 60 MW/m² of energy on its surface. However, only a small part of this energy reaches the earth, which is about 150 million kilometres away from the sun. Due to this large distance, only 1.3 kW/m² reaches the outer atmosphere of the earth, and after penetrating the atmosphere, approximately 1 kW/m² reaches the surface of the earth. Depending on the time of year and cloud cover, the radiant power that reaches the earth’s surface is roughly between 10 W/m² and 1000 W/m².
Working principle
The invention of the solar cell is more than 100 years old and started off with an efficiency of just about 5%. A big advantage of solar cells is their modular structure, which allows for the scalability of the systems from a few mW to GW. The solar cells mainly use visible, ultraviolet, and infrared radiation and convert it into electrical energy. In the semiconductor material, solar radiation raises electrons from the valence band into the conduction band. The proportion of usable energy is essentially dependent on the wavelength of the light that arrives at the solar cell. The maximum theoretical efficiency of crystalline silicon cells is therefore around 30%. However, due to reflections, recombination, and other such conditions, the actual efficiency of solar cells is lower and might continue to decrease with use.
Damaging effects
Solar cells generate DC voltage. To make this DC voltage usable for the public grid, it must be converted into AC voltage. This requires inverters that use power electronics to convert the DC voltage to AC voltage by alternately switching on and off rapidly. However, these switching processes also cause unwanted high-frequency currents.
The Solution
To prevent these high-frequency currents from travelling through the cables as interference, Blueferrite Nanocrystalline Cores can be installed around the cables. These cores reduce the high-frequency current components to a minimum, so the quality of the network is not endangered, and interference is prevented from being emitted.