Based on the aggregated intelligence of 180,000-plus investors participating in Motley Fool CAPS, the Fool's free investing community, the PowerShares Cleantech Portfolio (NYSE: PZD) has earned a respected four-star ranking.

With that in mind, let's take a closer look at PowerShares Cleantech and see what CAPS investors are saying about the ETF right now.

PowerShares Cleantech facts

Inception October 2006
Total Assets $109 million
Investment Approach Seeks investment results that correspond to the Cleantech Index, which focuses on leaders in the innovation and commercial deployment of cleantech products across a broad range of industries.
Expense Ratio 0.6%
Dividend Yield 0.2%
1-Year / 3-Year / 5-Year Annual Returns (7.3%) / 7.6% / (0.8%)
Top Holdings with High CAPS Rating (4 or 5 Stars) and Portfolio Weight

Corning (NYSE: GLW) (2.8%)

ABB (NYSE: ABB) (2.7%)

Johnson Controls (NYSE: JCI) (2.7%)
Alternatives

PowerShares Global Clean Energy (NYSE: PBD)

Market Vectors Global Alternative Energy (NYSE: GEX)

Sources: Morningstar and Motley Fool CAPS.

On CAPS, 99% of the 216 members who have rated PowerShares Cleantech believe the ETF will outperform the S&P 500 going forward. These bulls include rcdaddy0609 and All-Star Trimalerus, who is ranked in the top 5% of our community.

Earlier this year, rcdaddy0609 tapped the ETF as an attractive way to go green: "Clean tech is the wave of the present and future. I love the long term growth possibilities for this ETF."

PowerShares Cleantech, in particular, sports an annual turnover ratio of just 24%. That's lower than other clean energy ETFs like PowerShares Global Clean Energy (39%) and Market Vectors Global Alternative Energy (30%).

CAPS All-star Trimalerus elaborates on the bull case:

I think that Alternative Energy will only become more popular as Oil Peak and Global Warming affect our energy supply choices. ETFs are a good way to add diversity while minimizing fees. So I'm snapping up a few Alt Energy focused ETFs with high outperform ratings ... and I'll ride them into our, hopefully much greener future!

What do you think about PowerShares Cleantech, or any other ETF for that matter? If you want to retire rich, you need to put together the best portfolio you can. Owning exceptional ETFs is a surefire way to secure your financial future, and on Motley Fool CAPS, thousands of investors are working every day to find them. CAPS is 100% free, so get started!

Interested in another easy way to track PowerShares Cleantech? Add it to your watchlist.