Based on the aggregated intelligence of 150,000-plus investors participating in Motley Fool CAPS, the Fool's free investing community, ethanol producer Green Plains Renewable Energy (Nasdaq: GPRE) has received the dreaded one-star ranking.

With that in mind, let's take a closer look at Green Plains' business and see what CAPS investors are saying about the stock right now.

Green Plains facts

Headquarters (Founded)

Omaha, Neb. (2006)

Market Cap

$417.8 million

Industry

Oil and gas refining and marketing

Trailing-12-Month Revenue

$1.3 billion

Management

CEO Todd Becker (since 2009)

CFO Jerry Peters (since 2007)

Trailing-12-Month Return on Capital

3.6%

Price-to-Earnings (GPRE and Industry)

21.2 and 14.8

1-Year Return

1,096%

Competitors

Archer Daniels Midland (NYSE: ADM)

Pacific Ethanol (Nasdaq: PEIX)

Other Ethanol Stocks

The Andersons (Nasdaq: ANDE)

MGP Ingredients (Nasdaq: MGPI)

Highly Rated Green Energy Alternatives

Cosan (NYSE: CZZ)

Suntech Power (NYSE: STP)

Sources: Capital IQ (a division of Standard & Poor's) and Motley Fool CAPS.

On CAPS, 56.6% of the 122 members who have rated Green Plains believe the stock will underperform the S&P 500 going forward. These bears include DarthMaul09 and jed71.

Late last year, DarthMaul09 warned our community about being corny:

I thought that ethanol for fuel went out with the Bush administration. Now it's electric and dual fuel cars. ... The added benefit of ethanol was to the growers and crop prices. I suspect that political support for ethanol supplements will fade if this impairs domestic auto sales or causes other unforeseen problems.

In a pitch from two days later, jed71 also advised Fools to find another alternative. Here's an excerpt:

I was looking at their quarterly statements and, although revenue is growing by leaps and bounds, operating profits are incredibly thin. They also do not have positive operating cash flows yet on normal operations (stripping out acquisitions), and are sitting on a pile of debt. ....

They have got to get their expenses under control, show a profit for a few quarters and spend a little time shoring up their balance sheet rather than continuing to acquire bankrupt biofuel firms. Smart growth, not growth at any cost. ...

My gut instinct tells me the tide will turn against Ethanol in the next few years and trend toward cheaper energy sources that don't impact America's food source, such as Natural Gas.

What do you think about Green Plains, or any other stock for that matter? If you want to retire rich, you need to protect your portfolio from any undue risk. Staying away from dangerous stocks is crucial to securing your financial future, and on Motley Fool CAPS, thousands of investors are working every day to flag them. CAPS is 100% free, so get started!

Fool contributor Brian Pacampara owns no position in any of the companies mentioned. Suntech is a Motley Fool Rule Breakers pick. The Fool's disclosure policy always gets a perfect score.