The following commentary comes from an independent investor or market observer as part of TheStreet's guest contributor program, which is separate from the company's news coverage. NEW YORK ( TheStreet) - Clean Edge and Nasdaq's three benchmark clean-tech stock indices suffered a week of poor performance, with the Nasdaq Clean Edge Green Energy Index ( CELS) down 5.98 percent, the Nasdaq OMX Clean Edge Global Wind Energy Index ( QWND) lower by 0.05 percent, and the Nasdaq OMX Clean Edge Smart Grid Infrastructure Index ( QGRD) down 4.13 percent from the previous week. The overall market moved down as well: the S&P 500 lost 1.28 percent and Nasdaq was down 2.48 percent - while AMEX Oil retreated 3.95 percent from the previous week. CELS - down 5.98 percent for the week and 3.77 percent higher than a year ago - tracks U.S.-listed clean-energy companies and is divided into four categories: advanced materials; energy intelligence; energy storage and conversion; and renewable electricity generation and renewable fuels. Of the 50 total component securities, five had gains and 45 lost ground. CELS' best performer for the week was electronic materials provider Rubicon Technology ( RBCN), gaining 7.92 percent. Rounding out the top five CELS performers were advanced composite material developer Hexcel ( HXL), up 3.44 percent; energy storage technology developer Advanced Battery Technologies ( ABAT), higher by 0.81 percent; LED and solar manufacturing equipment provider Veeco Instruments ( VECO), up 0.17 percent; and ethanol producer Green Plains Renewable Energy ( GPRE), 0.08 percent higher for the week. CELS' worst performer last week was PV product maker Energy Conversion Devices ( ENER), declining 29.55 percent. Other poor performers included solar cell and module maker Canadian Solar ( CSIQ), losing 18.39 percent; solar wafer provider LDK Solar ( LDK), down 15.35 percent; renewable energy project integrator SatCon Technology ( SATC), retreating 14.82 percent; and China-based solar product manufacturer Suntech Power ( STP), 14.74 percent lower for the week. QWND - 0.05 percent lower last week and 25.04 percent lower in the last 12 months - includes companies that are primarily manufacturers, developers, distributors, installers, and users of energy derived from wind sources. Of QWND's 18 pure play components, six saw gains while 12 experienced losses. QWND's best pure play performer for the week was renewable energy project developer Iberdrola Renovables ( IBR), up 13.16 percent. Other top pure play performers included wind turbine gearbox maker Hansen Transmission International ( HSN), gaining 7.75 percent; renewable energy project developer EDP Renovaveis ( EDPR), rising 5.35 percent; wind project developer China WindPower Group (0182), up 4.00 percent; and renewable energy equipment maker and project developer Gamesa Corporacion Tecnologica ( GAM), up 3.33 percent for the week.