A new report by the electricity industry suggests that the construction of a new nationwide grid to support alternative energy could cost up to $100 billion, throwing another roadblock in the path of investors seeking profits from the Obama mandate.

The study pits hard economics against White House politics and feel-good special-interest groups. The new evidence begins to show that even the most starry-eyed optimists of the green movement may not be the best friends of individual investors looking for speculative returns in alternative energy.

Articles in the Wall Street Journal and elsewhere have recently begun to call attention to the elephant in the room: that today’s state of economics simply don’t make sense for a major renewable-energy push in America. Low oil prices, tight credit and the highest unemployment in decades have conspired to make renewable energy a losing proposition.

Investors who believe otherwise may soon find themselves in the red.

Massive blackouts in the East Cost over the past decade certainly provide evidence for a grid overhaul. But to do it in the name of a greener America presents investors with a misleading business case for the investment.

The study was sponsored by the most powerful players in the electricity industry, including the Tennessee Valley Authority, PJM Interconnection LLC, Midwest Independent System Operator, Mid-Continent Area Power Pool, the SERC Reliability Region and the Southwest Power Pool. It was funded to probe the financial challenges of weaning America off fossil-fuel power plants.

The results are especially pertinent as the Obama administration sets a mandate of sourcing 20% of the country’s electricity through renew energy by 2024. In 2007, the U.S. drew about 7% of its electricity from renewables, according to the Energy Information Administration.

As a result of Washington’s green-mania, headlines have been luring investors into alternative energy. The new report underscores the importance of due diligence in making forays into this type of investments where profits are driven more by hype than by real returns.

The report concludes that the revamped national grid would cost up to $100 billion. On top of that, an additional $720 billion would be required for wind turbines to meet the guidelines of the Obama administration. The overhaul could take at least 15 years, doing little if anything at all to fulfill the mission rebuilding the current wrecked economy.

The Wall Street Journal article reported that the $100 billion would fire the opening shot of a political and legal battle that could stall the massive project indefinitely. “Getting the high-voltage power lines build across the country would require the assent of local authorities and landowners, and might require federal intervention.”

In short, it would constitute a full-employment act for lawyers at almost every level. Since most wind and solar installations are in remote locations, the installation of high-voltage, intelligent transmission lines into the closest grid would fire up landowners and environmentalists look to protect their land and the endangered species affected by the construction.

Once again, investors should be cautious about get-rich-quick schemes in alternative energy. To reiterate our position, renewable energy could one day turn ordinary investors into millionaires. We’re just not sure we’ll live long enough to see it.