gumby je napisal/a: |
Subvencije za proizvedeno elektriko je treba ukinit, pa bo hype hitro minil... |
Citiram: |
Previously published estimates for the energy requirements of present day crystalline silicon modules vary considerably. As noted in Alsema (2000), these differences can partly be explained by different assumptions for process parameters, but they mostly appear to arise from estimates for the silicon purification and the crystallisation process. The majority of silicon solar cells are made from off-spec material rejected by the micro-electronics industry, which introduces the question of whether to include process steps required for micro-electronics wafers in the energy requirements for the PV modules. |
Citiram: |
Many of the studies reviewed, such as Battisti and Corrado (2005) or Raugei et al (2005) utilise accepted standardised methodologies such as Life Cycle Assessments (LCA), Embodied Energy (EE) analyses, Emergy Analyses, and Material Flow Accounting in their analyses. LCA methodology, for example, is governed by ISO (International Organization for Standardization). Some studies, however, use methods that are scientifically incorrect, for example attempting to treat different forms of energy as equal. In any embodied energy calculation, it is important to utilise realistic conversion factors when comparing one form of energy with another. The joule contents of differing forms of energy are not equal and the assumption of 100% conversion efficiency between energy forms is inaccurate. In order to adequately account for this, all energy sources need to be related on some common basis through accepted conversion factors. |
Citiram: |
-Mc-Si, sc-Si and thin film modules are assumed to have efficiencies of 13, 14, and 7 percent respectively. -The systems are assumed to receive an irradiation of 1700 kWh/m2/yr and have a performance ratio of 0.75. -Process steps which are specifically needed for the micro-electronics wafers are disregarded |