"A smart grid makes use of coded signals that travel along power lines, much like DSL broadband messages move through the phone telephone," explains growth stock expert Jim Powell.

In Global Changes & Opportunities Report, he looks at two favorite plays on the development of a smart grid: Esco Technologies (NYSE: ESE) and Quanta Services (NYSE: PWR).

"In a smart grid, the signals allow electric meters to report power consumption automatically to suppliers. At the same time, signals can be sent to customer's appliances such as freezers and refrigerators to prevent them from cycling on and off at the same time.

Wind and solar, two renewable energy sources with a promising future, nevertheless face a bottleneck of sorts in the United States: the electric power grid. The existing grid can not handle the new demands, The New York Times reported Wednesday, forcing renewable wind and solar sites to shut down, even when conditions are right to generate and sell power.

An infrastructure-challenged U.S.

Economist Glen Langan says there's a theme that keeps popping up in the U.S. economy in the early 21st century: inadequate infrastructure. "We're a nation of inadequate infrastructures: the power grid, air travel/air traffic control, railways, highways... pick an infrastructure and you'll see a network that can't handle present demands, let alone an expanded national economy in 2020 or 2030," Langan said.

The power grid bottleneck is particularly frustrating and damaging because both wind and solar power generation systems are mushrooming, and could, with an adequate grid, account for more than 20% of the nation's power needs, Langan said, adding that some economic models put renewable energy's potential contribution even higher, at 25% or more.

"Imagine T. Boone Pickens building his massive, multi-billion dollar wind mill farm and having it sit idle because the grid cannot tolerate and transmit the increased power? Pretty sad," Langan said.

As Congressional Democrats and Bush Administration officials evaluate additional legislative ideas aimed at further stimulating the anemic U.S. economy, one proposal that could gain more traction in the months ahead concerns domestic infrastructure.

The consensus among economists is that the first economic stimulus package will provide only a modest boost (at best) to the U.S. economy, economist David H. Wang told BloggingStocks Tuesday. Further, if many Americans choose to save or invest their $300-$1200 tax rebate, instead of spending it or using it to pay down debt, the stimulus effect will be even less than projected.

That would leave the U.S. economy with a correcting housing sector, record-high oil prices (oil topped $113 per barrel Wednesday), a contracting job sector, an investment banking sector largely seeking to rebuild balance sheets and not lend money, and rising living costs weighing on consumer spending. In other words, Wang said, all of the classic U.S. growth engines, except exports, are likely to serve as contractionary forces through at least the first half of 2008, and most likely for considerably longer.

Readers of this space know that the investment bias is toward large-cap companies with demonstrated business models and who have a competitive advantage in established markets, preferably with a favorable global trend as a support. But every once in while an exception is made for a non-conforming but innovative/promising company, and along this line EnerNOC is worth a review.

EnerNOC, Inc. (Nasdaq: ENOC) develops and provides clean power solutions to commercial, institutional, and industrial customers, as well as to electric power grid operators and utilities.

Analysts really like ENOC's next-generation, technology-based business model. The company uses its network operations center to remotely manage electricity consumption across a network of end-use customer sites and to make electric capacity and energy available on demand to grid operators and utilities.

Every once in a while there's a compelling research report issued in the Concrete Canyon that goes virtually unnoticed. Wall Street, so often caught up in the mood of the market 'right now,' sometimes drifts past data and fails to fully-publicize information that reveals fertile ground and investment opportunities.

That may have been the case with U.S. Global Investors' infrastructure report.

The report, entitled "Infrastructure: A Global Opportunity for Investors" notes that $41 trillion will be needed to modernize urban water, electricity, and transportation systems globally, during the 2005-2030 period, according to an estimate by Booz Allen Hamilton. In the United States, the figure is $1.6 trillion, according to research by the American Society of Civil Engineers. There are two distinct but massive infrastructure tasks: in emerging markets, a massive build-out to support growth; in the United States and the developed world, a focus on repair and replacement, according to U.S. Global Investors.