This is a pretty balanced report report from Environment 360 on the hurdles in front of a green-energy future. Some key excerpts . . .

First up, for those in the “China is kicking our butt” camp:

From the dust-blown steppes of Inner Mongolia to the waters off Shanghai, China installed more wind turbines in the first half of 2010 than any other country — 7,800 megawatts of potential power production, or more than the United States, the European Union, and India combined. In fact, in northeast China alone, autumn and winter winds now produce some 17 billion kilowatt-hours of electricity, roughly 5.5 percent of the total power generation in the region. That’s up from 534 million kilowatt hours just five years ago.But despite this rapid progress, wind energy still only generates a tiny fraction of China’s electricity. Indeed, even with aggressive government backing and green energy mandates, such “new energy” — including wind, solar, nuclear power plants, and biomass — accounts for less than 3 percent of China’s electricity production, compared to more than 70 percent provided by coal, which produces roughly 3 metric tons of carbon dioxide for every metric ton of the dirty, black rock burned. And as China’s economy continues to expand at a dizzying rate for the foreseeable future, wind and other renewable sources of energy will not even be able to keep pace with new demand, meaning fossil fuel burning will continue unabated.

And are you ready for some NIMBY here in the U.S.?

Assuming the U.S. will require roughly 4 terrawatts of power by 2050 (a conservative estimate, given that we already use more than three), replacing all that fossil fuel would require at least 4 million wind turbines — necessitating building 12, three-megawatt wind turbines every hour for the next 30 years, according to Griffiths. The numbers are similar for solar — 160 billion square meters of photovoltaic cells or concentrating mirrors. “We need to be making a square yard of solar cells or mirrors every second for the next 40 years to install that much in North America,” Griffiths calculates.It’s not just a matter of making the necessary equipment, it’s also a question of finding the space for it. A coal-fired power plant produces 100 to 1,000 watts per square meter, depending on the type of coal it burns and how that coal is mined. A typical photovoltaic system for turning sunlight into electricity produces just 9 watts per square meter, and wind provides only 1.5 watts per square meter.

Is nuclear the answer? If so, we better start building:

Just to supply one-quarter of its current energy mix from a resource that emits far fewer greenhouse gases — nuclear power — the U.S. would need to build 1,000 one-gigawatt nuclear reactors by 2050. Yet construction has begun on only two nuclear reactors in the U.S. since 1974. And just to power an electric car and truck fleet to replace the U.S.’s current gas and ethanol-fueled one would require 500 new nuclear power plants. There are currently 442 reactors in the entire world, of which the U.S. has 104 — the most of any nation.

This reminds me of an op-ed I read in the WSJ a few months before the tech-bubble burst. The op-ed basically argued that if you tally up all of the projections from the tech sector and take them even at a discounted value, there was not enough electricity in the U.S. to meet  the demand for the projected sales. Either power plants needed to be built, or the numbers from the tech sector would prove bogus. And since no construction of the scale needed to meet the tech industry projections was underway, said projections would fail. And pop went the bubble.

Anybody see 12 wind turbines getting built per hour? Yeah, me neither. Which means all of the construction and money we’re spending won’t dent what the policymakers say is the problem of carbon emissions.