As the Manager of Cleantech Index (on which the PowerShares Cleantech Portfolio ETF (ticker: PZD) is based, I must address some inaccuracies in Mr. Lydon's article.

1) PZD currently has a small weighting in CREE (under 2% as I write this). How this gets characterized as a ‘large weighting’ is beyond me.

2) PZD currently has about a 5.5% weighting in First Solar - NOT the 15% Mr. Lydon suggests.

3) Clean energy stocks currently account for about 28% of the Cleantech Index and hence, PZD. The Cleantech Index covers the broad spectrum of clean technology businesses from water, to new materials, sustainable agriculture, transportation, and of course, energy efficiency (including those that improve the efficiency of, and reduce the pollution from, carbon-based fuels which Mr. Lydon contends will remain critical for a long time to come. I agree with his opinion, but I don't like reliance on fossil-fuels or 98% of crop derived fuels either.

4) The PowerShares ETFs Mr. Lydon mentions, PZD and PBW, have very different strategies in terms of composition, weighting & risk management, focus, screening criteria, etc. While there is some portfolio overlap, it tends to be exaggerated prior to quarterly rebalancing - especially when a particular sector common to both is hot (e.g., solar), but the weightings are far different.

Rafael,
Thank you for your detailed response and comments. Yes, the PZD and PBW hold 5% of First Solar and not 15%. First Solar, Suntech and SunPower make up 15% of each of the ETFs. CREE does make up 1.94% of PZD and PBW, which is not necessarily a large weighting. The overall gist of the story was for investors to look into the holdings of ETFs and not to rely just on the name. Sometimes we are not accurate, so please continue to offer your comments and opinions.
Thanks, Tom