Clean Edge and Nasdaq's three benchmark clean-tech stock indexes experienced solid gains last week with the Nasdaq Clean Edge Green Energy Index ( CELS) up 6.58 percent, the Nasdaq OMX Clean Edge Global Wind Energy Index ( QWND) up 3.49 percent, and the Nasdaq OMX Clean Edge Smart Grid Infrastructure Index ( QGRD) 3.81 percent higher from the previous week.

The overall market also ended the week with gains - the S&P 500 gained 2.37 percent, Nasdaq rose 2.95 percent, and AMEX Oil was 3.49 percent higher from the previous week.

CELS -- up 6.58 percent for the week and 5.57 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 53 total component securities, 48 experienced gains, four lost ground, and one remained unchanged from the previous week's close.

CELS' best performer for the week was LED equipment provider Veeco Instruments ( VECO - Get Report), gaining 19.23 percent.

Rounding out the top five CELS performers were lithium-ion battery system maker Ener1 ( HEV), up 17 percent; electronic materials provider Rubicon Technology ( RBCN - Get Report), higher by 16.91 percent; thin-film solar module maker First Solar ( FSLR - Get Report), rising 15.30 percent; and demand energy management service provider EnerNOC ( ENOC), up 15.10 percent.

CELS' worst performer last week was microturbine maker Capstone Turbine ( CPST), declining 9.09 percent. Other worst performers included network infrastructure product maker Echelon ( ELON), falling 6.11 percent; stationary fuel cell developer FuelCell Energy ( FCEL), losing 0.58 percent; organic LED technology developer Universal Display ( PANL), down 0.37 percent; and energy storage technology developer Advanced Battery Technologies ( ABAT), unchanged from the previous week.

QWND -- up 3.49 percent last week but 26.24 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, 16 experienced gains and five saw losses.

QWND's best pure play performer for the week was wind energy product and service provider Broadwind Energy ( BWEN - Get Report), up 14.53 percent.

Other top pure play performers included wind turbine part provider China High Speed Tranmission Equipment Group (0658), gaining 9.09 percent; Spain-based renewable energy developer EDP Renovaveis ( EDPR), rising 8.08 percent; renewable energy project developer and operator Gamesa Corporacion Tecnologica ( GAM), growing 7.88 percent; and carbon fiber composite material developer Zoltek Companies ( ZOLT), up 7.11 percent for the week.

QWND's worst pure play performers were wind power project developer and operator Japan Wind Development (2766), losing an astonishing 62.34 percent; wind turbine manufacturer Clipper Windpower ( CWP), down 12 percent; gearbox and drive train manufacturer Hansen Transmissions International ( HSN), losing 7.70 percent; advanced composite material maker Gurit Holding ( GUR), declining 1.69 percent; and German wind turbine maker REpower Systems ( RPW), down 1.39 percent from the previous week.

QGRD -- up 3.81 percent 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. Last week, 13 of the 21 pure play QGRD components saw gains while eight lost ground.

QGRD's best pure play performer was EnerNOC ( ENOC), gaining 15.10 percent.

Rounding out the top five pure play performers were demand energy management firm Comverge ( COMV), up 7.79 percent; large-scale power conversion technology developer Satcon Technology ( SATC), up 7.03 percent; power generation and delivery equipment provider AZZ ( AZZ), 6.17 percent higher; and wire and cable provider General Cable ( BGC), gaining 5.68 percent.

QGRD's worst performers included Echelon ( ELON), losing 6.11 percent; communication equipment maker RuggedCom ( RCM), down 5.52 percent; Italian energy infrastructure equipment provider Prysmian ( PRY), retreating 4.33 percent; energy storage technology developer NGK Insulators (53330), down 3.66 percent; electric infrastructure specialty contractor MYR Group ( MYRG), lower by 2.52 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. For more on Clean Edge's stock indexes - including methodology, components, historical performance, financial products and licensing information, please visit www.cleanedge.com/ceindex.

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.