A decade and a half before it blew apart in a hydrogen blast that punctuated the worst nuclear accident since Chernobyl, the No. 3 reactor at the Fukushima nuclear power plant was the scene of an earlier safety crisis.

Then, as now, a small army of transient workers was put to work to try to stem the damage at the oldest nuclear reactor run by Japan's largest utility.

by Harumi Ozawa

Thousands of people rallied in Japan Saturday to demand a shift away from nuclear power after an earthquake and tsunami sparked the world's worst atomic crisis since Chernobyl a quarter-century ago.

Winds are set to blow low-level radiation from Japan's quake-crippled nuclear power plant out over the Pacific Ocean in coming hours, easing health worries after drifting toward Tokyo early on Tuesday, experts said.

To shift the global economy from fossil fuels to renewable energy will require the construction of wind, solar, nuclear, and other installations on a vast scale, significantly altering the face of the planet. Can these new forms of energy approach the scale needed to meet the world’s energy demands?

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.

This is hardly unique to China. In the U.S., electricity produced from the breeze has increased 13-fold in the past decade, yet still only provides 2.3 percent of the country’s electricity — compared to just under 50 percent provided by burning coal. Even Denmark, which has done more than any other country to boost wind power, struggles to integrate an intermittent generating resource into a grid whose customers expect the lights or the television to come on whenever they flick the switch.

As the world attempts to wean itself from fossil fuels — a result of the converging desires to combat climate change, improve energy security, and