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 ( Clean Edge) -- Clean Edge and Nasdaq's three benchmark clean-tech stock indices all rose last week, with the Nasdaq Clean Edge Green Energy Index (CELS) up 0.74% , the Nasdaq OMX Clean Edge Global Wind Energy Index (QWND) higher by 8.63% , and the Nasdaq OMX Clean Edge Smart Grid Infrastructure Index (QGRD) down 0.83% higher from the previous week. The overall market moved down - the S&P 500 lost 1.92% and Nasdaq was down 2.65% -- while AMEX Oil retreated 0.33% from the previous week. CELS -- up 0.74% for the week and 4.73% 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, 24 experienced gains and 26 lost ground. CELS' best performer for the week was wind energy product and service provider Broadwind Energy ( BWEN), gaining 16.94%. Rounding out the top five CELS performers were LED technology developer Universal Display ( PANL), up 15.64%; power conversion device maker Power-One ( PWER), higher by 14.86%; solar module encapsulant maker STR Holdings ( STRI), up 10.09%; and PV product maker Yingli Green Energy ( YGE), 9.81% higher for the week. CELS' worst performer last week was lithium-ion battery system maker Ener1 ( HEV), declining 13.99% . Other worst performers included PV product maker Energy Conversion Devices ( ENER), losing 11.29% ; demand response service provider Comverge ( COMV), down 7.22% ; advanced composite material developer Hexcel ( HXL), retreating 6.07%; and power management device maker ON Semiconductor ( ONNN), 6.03% lower for the week. QWND -- 8.63% higher last week and 17.72% 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, 16 saw gains, one declined, and one ended the week unchanged. QWND's best pure play performer for the week was wind turbine maker Nordex (NDX1), up 22.84% . Other top pure play performers included wind turbine gear transmission provider China High Speed Transmission Equipment Group (0658), gaining 16.45% ; wind turbine manufacturer Vestas Wind Systems (VWS), rising 16.20% ; wind turbine gearbox maker Hansen Transmission International (HSN), up 16.01% ; and wind farm owner and operator Japan Wind Development (2766), up 15.35% for the week.