太阳能光伏报告外文翻译.docVIP

外文翻译 原文 Solar Photovoltaic Report Material Source: ABS Energy Research 2009 Author: Anonymous Author PV Industry Value Chain The PV industry has three essential components, which constitute the value chain, each dependent on each other. Some companies concentrate on individual segments of the value chain others address all segments as integrated solar PV companies. These components are: ? Feedstock ? Solar PV cells and modules ? Balance of system Raw silicon is by far the most prevalent feedstock for solar cells, although reduced to 87% from 94% in the last few years. Bulk silicon is separated into multiple categories according to crystallinity and crystal size in the resulting ingot, ribbon or wafer. ? Monocrystalline silicon (c-Si) is often made using the Czochralski process. Single-crystal wafer cells are expensive because they are cut from cylindrical ingots ? Poly- or multi-crystalline silicon (poly-Si or mc-Si) is made from cast square ingots. They are cheaper because they are less expensive to produce than single crystal cells but they are less efficient ? Ribbon silicon is formed by drawing flat thin films from molten silicon and they have a multi-crystalline structure. These cells have lower efficiencies than poly-Si, but save on production costs due to a great reduction in silicon waste because this approach does not require sawing from ingots. ? New Structures: These new compounds are special arrangements of silicon, such as organically modified silica, a-Si, and nanotechnological combinations that can dramatically improve efficiency. Thin film alternatives to thick crystal accounted for 13% of cells produced in 2007 according to Prometheus Institute. The various thin-film technologies currently being developed reduce the amount of light-absorbing material required in creating a solar cell. Such coatings have about one percent of thick crystal’s depth. Polysilicon There are two sources of solar grade (SoG): silicon feedstoc