The Cleantech Index (CTIUS) adds smart grid, desalinization and solar leaders

GT Solar, and Energy Recovery and Canada’s RuggedCom join elite Index

New York, April 1, 2009 – The Cleantech Group™ LLC, in conjunction with the American Stock Exchange (AMEX), today announced the quarterly rebalance of its Cleantech Index™ (AMEX: CTIUS), effective March 31, 2009.

As part of the rebalance, RuggedCom (TMX: RCM.TO), GT Solar (NASDAQ: SOLR) and Energy Recovery (NASDAQ: ERII) will join The Cleantech Index. They will replace LDK Solar and Echelon.

The changes will also be reflected in the exchange-traded funds (ETFs) based upon CTIUS: the PowerShares Cleantech Portfolio ETF (AMEX: PZD) and the KSM Cleantech ETF in Israel (Ticker: KSCUS.15).

“We chose both companies for their profitable growth, industry leadership, impact, and focus areas,” said Rafael Coven, Managing Director of Cleantech Indices for the Cleantech Group, LLC, and Index Advisor.

California-based Energy Recovery, Inc. (ERI) is a leading manufacturer of energy recovery devices that help make desalination affordable by significantly reducing energy consumption. ERI has R&D and manufacturing facilities in the San Francisco technology corridor sales offices and technical support centers in key desalination hubs worldwide.

GT Solar International of New Hampshire is a leading global provider of specialized manufacturing equipment and services essential for the production of photovoltaic wafers, cells and modules and polysilicon utilized in the solar power industry.

RuggedCom is a leading provider of communications networking solutions designed for mission-critical applications in harsh environments such as those found in electrical power substations and “Smart Grids,” intelligent transportation systems, industrial process control and military applications.

The Cleantech Group’s Cleantech Index is the first, and only, equity index to offer investors and index licensees an easy, liquid, and cost effective way to track and invest in the broad cleantech category. Unlike indices that specifically track narrow sectors such renewable energy or water, the Cleantech Index includes leading companies from a broad range of sectors such as advanced materials, agriculture, transportation, manufacturing, in addition to energy efficiency, renewables and water. For more information visit: www.cleantechindex.com.

Contact: indexinfo@cleantech.com

About the Cleantech Group, LLC
The Cleantech Group pioneered the clean technology investment category in 2002. Today, it accelerates the development and market adoption of clean technologies globally. The company’s worldwide network of investors, entrepreneurs, enterprises, service providers and others—representing trillions of dollars in assets—receives access to capital, investment deal flow, networking, market leading research and data, sales leads and promotional opportunities. The Cleantech Group also provides advisory services for large corporations and governments, publishes leading cleantech sector industry news coverage and produces the premier Cleantech Forum® events worldwide. Details are available at http://www.cleantech.com.

“Cleantech” Defined
Cleantech products, services and processes provide superior performance at lower costs while greatly reducing or eliminating negative ecological impact, at the same time as improving the productive and responsible use of natural resources.