Amorphous silicon thin-film cells work better than crystalline silicon cells under weak light conditions. In practical applications, it is rare for photovoltaic modules to work under the standard light intensity of 1000W/M2. It is lower than this intensity, and if the crystalline silicon battery wants to achieve the ideal working state, it requires vertical irradiation of strong light. Amorphous silicon thin-film batteries have much smaller restrictions on light intensity and sunlight angle, so for a period of time before the sun sets, crystalline silicon batteries may not be able to continue to generate electricity, but thin-film batteries can continue to work. Another point is that the amorphous silicon thin film battery has a milder I-V curve, so it can reach the best working output power faster.
Since the output power of solar cell components depends on the intensity of sunlight, the distribution of solar spectrum, and the temperature, shadow, and crystal structure of solar cells. Therefore, the measurement of solar cell components is carried out under standard conditions (STC), and the measurement conditions are defined by the European Commission as Standard No. 101. The conditions are: the spectral irradiance is 1000W/
m2; spectrum AMl.5; battery temperature 25 ℃.
Under this condition, the maximum power output by the solar cell module is called peak power, and its unit is expressed as peak watts (Wp). In many cases, the peak power of a module is usually measured with a solar simulator and compared with standardized solar cells from international certification bodies.
It is difficult to measure the peak power of solar cell modules outdoors, because the actual spectrum of sunlight received by solar cell modules depends on atmospheric conditions and the position of the sun; Strong (light intensity) is also constantly changing. Errors in outdoor measurements can easily be 10% or more.