Clean Edge and Nasdaq's three benchmark clean-tech stock indices ended last week with little movement. The Nasdaq Clean Edge Green Energy Index (CELS) was up 0.78%, the Nasdaq OMX Clean Edge Global Wind Energy Index (QWND) fell 1.69%, and the Nasdaq OMX Clean Edge Smart Grid Infrastructure Index (QGRD) was 0.10% lower from the previous week.

The overall market was slightly lower -- the S&P 500 lost 0.66%, Nasdaq fell 1.20%, and AMEX Oil was 0.43% lower from the previous week.

CELS -- up 0.78% for the week and 4.16% lower 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 53 total component securities, 26 experienced gains and 27 experienced losses.

CELS' best performer for the week was biofuel producer Green Plains Renewable Energy ( GPRE), gaining 11.54%. Rounding out the top five CELS performers were energy management firm EnerNOC ( ENOC), up 11.48%; Chinese solar power product maker Trina Solar ( TSL), higher by 10.82%; semiconductor manufacturer IXYS Corporation ( IXYS), up 7.83%; and geothermal project developer Ormat Technologies ( ORA), higher by 6.66% for the week.

CELS' worst performer last week was energy storage technology developer Maxwell Technologies ( MXWL), declining 7.76%. Other worst performers included wind energy product and service provider Broadwind Energy ( BWEN), losing 6.94%; electric motoer maker UQM Technologies ( UQM), down 6.10%; power management device manufacturer O2Micro International ( OIIM), retreating 5.34%; and biomaterial developer Metabolix ( MBLX), 4.92% lower.

QWND -- down 1.69% last week and 37.15% 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 21 pure play components, 5 experienced gains and 16 lost ground.

QWND's best pure play performer for the week was wind power project developer and operator Japan Wind Development Co. (2766), up 3.71%. Other top pure play performers included energy delivery technology developer American Superconductor (AMSC), gaining 2.72%; Germany-based wind turbine manufacturer REpower Systems (RPW), rising 2.16%; wind turbine gearbox maker Hansen Transmissions International (HSN), growing 1.85%; and wind turbine manufacturer Nordex (NDX1), 1.28% higher.

QWND's worst pure play performers were wind farm developer Infigen Energy (IFN), losing 11.11%; Greece-based renewable energy project developer (TENERGY), down 8.60%; Broadwind Energy (BWEN), losing 6.94%; wind turbine manufacturer Clipper Windpower (CWP), declining 5.30%; and advanced composite material maker Gurit Holding (GUR), falling 4.86% from the previous week.

QGRD -- 0.10% lower from the previous week - is composed of companies that are primarily involved in the electric grid; electric meters, devices, and networks; energy storage and management; and enabling software used by the smart grid and electric infrastructure sector. Of QGRD's 21 pure play components, 10 experienced positive movement, 10 saw losses, and one ended the week unchanged.