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 indexes experienced a week of mixed performance, with the Nasdaq Clean Edge Green Energy Index ( CELS) down 3.08 percent, the Nasdaq OMX Clean Edge Global Wind Energy Index ( QWND) lower by 0.26 percent, and the Nasdaq OMX Clean Edge Smart Grid Infrastructure Index ( QGRD) up 0.42 percent from the previous week. The overall market moved slightly higher. The S&P 500 gained 0.10 percent and Nasdaq was up 0.13 percent. The AMEX Oil rose 1.06 percent from the previous week. CELS, down 3.08 percent for the week and 13.85 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 49 total component securities, 15 experienced gains and 34 lost ground. CELS' best performer for the week was demand management firm EnerNOC ( ENOC), gaining 13.62 percent. Rounding out the top five CELS performers were power management device maker IXYS ( IXYS), up 9.79 percent; demand energy management service provider Comverge ( COMV), higher by 7.14 percent; ethanol producer Green Plains Renewable Energy ( GPRE), up 5.85 percent; and electric car maker Tesla Motors ( TSLA), 5.68 percent higher for the week. CELS' worst performer last week was Chinese solar wafer manufacturer ReneSola ( SOL), declining 19.76 percent. Other poor performers included energy storage technology developer A123 Systems (AONE), losing 12.58 percent; PV product maker Energy Conversion Devices ( ENER), down 12.44 percent; solar cell and module maker Canadian Solar ( CSIQ), retreating 12.08 percent; and wind energy product and service provider Broadwind Energy ( BWEN), 11.25 percent lower for the week. QWND -- 0.26 percent lower last week and 23.61 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, nine saw gains, eight experienced losses, and one remained unchanged. QWND's best pure play performer for the week was wind turbine gear transmission provider China High Speed Transmission Equipment Group (0658), up 5.90 percent. Other top pure play performers included wind turbine maker REpower Systems ( RPW), gaining 5.71 percent; advanced composite materials developer Gurit Holding ( GUR), rising 3.69 percent; France-based wind farm developer Theolia ( TEO), up 3.45 percent; and wind project developer China WindPower Group (0182), up 2.74 percent for the week.