Clean Edge and Nasdaq's three benchmark clean-tech stock indexes experienced rough movement last week with the Nasdaq Clean Edge Green Energy Index ( CELS) down 8.69 percent, the Nasdaq OMX Clean Edge Global Wind Energy Index ( QWND) falling 5.18 percent, and the Nasdaq OMX Clean Edge Smart Grid Infrastructure Index ( QGRD) 7.07 percent lower from the previous week.

The overall market was also lower: the S&P 500 lost 3.78 percent, Nasdq fell 5.02 percent, and AMEX Oil was 4.19 percent lower from the previous week.

CELS -- down 8.69 percent for the week and 6.96 percent 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, three experienced gains, 48 experienced losses, and two ended the week unchanged.

CELS' best performer for the week was wafer manufacturer MEMC Electronic Materials ( WFR), gaining 4.91 percent.

Rounding out the top five CELS performers were OLED developer Universal Display ( PANL - Get Report), up 1.34 percent; fuel cell maker Ballard Power Systems ( BLDP - Get Report), higher by 0.59 percent; energy storage technology developer Advanced Battery Technologies ( ABAT), unchanged; and semiconductor manufacturer IXYS Corporation ( IXYS), also unchanged for the week.

CELS' worst performer last week was energy storage technology developer A123 Systems ( AONE), declining 28.56 percent.

Other poor performers included microturbine maker Capstone Turbine ( CPST), losing 27.84 percent; wind energy product and service provider Broadwind Energy ( BWEN - Get Report), down 27.72 percent; solar and LED manufacturing equipment provider Veeco Instruments ( VECO), retreating 21.60 percent; and LED technology developer Cree ( CREE), 19.63 percent lower.

QWND -- down 5.18 percent last week and 32.28 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 21 pure play components, 5 experienced gains and 16 lost ground.

QWND's best pure play performer for the week was wind turbine manufacturer Clipper Windpower ( CWP), up 23.76 percent.

Other top pure play performers included wind farm developer China Longyuan Power Group, gaining 3.82 percent; wind turbine manufacturer Vestas Wind Systems ( VWS), rising 3.25percent; Greece-based renewable energy project developer TENERGY, growing 1.66 percent; and wind energy project developer China Windpower Group Limited, 1.30 percent higher.

QWND's worst pure play performers were Broadwind Energy ( BWEN - Get Report), losing 27.72 percent; renewable energy project developer Gamesa Corporacion Tecnologica ( GAM), down 12.21 percent; advanced material developer Zoltek Companies ( ZOLT), losing 11.19 percent; Denmark-based renewable energy developer Greentech Energy Systems ( GES), declining 9.82 percent; and wind power project developer and operator Japan Wind Development Co. falling 9.51 percent from the previous week.

QGRD -- 7.07 percent 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, oneexperienced positive movement, 19 saw losses, and one ended the week unchanged.

QGRD's best pure play performer was communication equipment maker RuggedCom ( RCM), up 2.04 percent for the week.

Rounding out the top five pure play performers were Italy-based energy delivery equipment provider Prysmian ( PRY), unchanged from the previous Friday's close; electric transmission grid owner and operator ITC Holdings ( ITC), falling 0.64 percent; substation equipment manufacturer Jinpan International ( JST) , 1.65 percent lower; and utility contractor Quanta Services ( PWR), falling 2.63 percent.

QGRD's worst performers included power management and conversion device maker Power-One ( PWER), losing 15.06 percent; demand energy management company Comverge ( COMV), down 12.80 percent; network infrastructure product manufacturer Echelon Corporation, down 9.96 percent; electrical infrastructure contractor MYR Group ( MYRG), lower by 8.95 percent; and energy delivery technology developer American Superconductor ( AMSC), falling 8.88 percent.

This information is not intended to be used as a guide to investing, and the authors make no guarantees that any investments based on the information contained herein will benefit you in specific applications, owing to the risk that is involved in investing of almost any kind.

Clean Edge, Inc., founded in 2000, is the world's first research and publishing firm devoted to the clean-tech sector. The company, via its publications, events, and online services, helps companies, investors, and governments understand and profit from clean technologies. Clean Edge, with offices in the San Francisco Bay Area and Portland Oregon, offers insight and intelligence on emerging clean-tech trends, opportunities, and challenges. The company publishes a range of reports including the annual Clean Energy Trends and Clean Tech Job Trends report series; hosts the annual Clean-Tech Investor Summit (along with IBF); maintains a number of benchmark clean-tech stock indices with NASDAQ OMX including CELS, QGRD, and QWND; and produces Clean Edge Jobs, a leading online jobs board for clean-tech job seekers, employers, and recruiters. To keep abreast of the latest clean-tech news; access industry reports; learn more about our services; or sign up for our free e-newsletters; visit CleanEdge.com.