Photovoltaic (PV) Technologies- Overview
Overview:
Product Description:
Background:
The photovoltaic effect is not a new phenomenon; in 1839 the French physicist Antoine-Cesar Becquerel observed that by shining a light on an electrode submerged in a conductive solution, an electric current was produced.
The first silicon solar cell wasn’t produced until 1941, but the high price of manufacturing silicon wafers kept them out of common applications until the late 20th century.
As PV technologies continue to improve and large carbon emitters are being held increasingly accountable for their emissions, photovoltaics are becoming increasingly cost competitive with traditional energy sources.
Purpose:
This report attempts to demystify solar panel technologies and some technical jargon used in the PV industry. Although this report does its best to cover all major PV technologies and some interesting and innovative PV applications, some emerging technologies may not be covered.
Terms:
When comparing the differences between PV materials in this report or on a manufacturer’s website, it is important to understand the intricacies of a few descriptions:
- Energy Payback Period: This term is used to quantify the amount of energy that is consumed in the production of a PV module (embodied energy) and the amount of time before the module has produced enough energy to offset its production. This subject is a major source of contention and is difficult to get a definitive energy payback timeframe by consensus. The figures given in this report reflect Ecospecifier’s best estimates based on reliable scientific reports.
- Efficiency: Cell efficiency is the ratio of power produced by the cell to solar energy hitting the cell. Cell efficiency is generally tested under standards testing conditions (STC) in the lab using a very small photovoltaic cell. Unlike a PV module, where gaps between cells and frames increase the area but not the efficiency of the module, 100% of the area in a cell is producing power. Module efficiency is usually significantly smaller than cell efficiency because these gaps and the frame must also be included in the area that is receiving energy from the sun. Thus, the ratio of energy hitting the module versus power being produced by the module is much smaller.
Types of Photovoltaics:
There are two main categories of PV modules: crystalline silicon and thin-film. Both types have their advantages, but with the terms outlined above and some additional type-specific information below, determining the most suitable PV technology for a particular application will be much more simple.
PV Technologies References:
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