Mining is the second most dangerous occupation in the U.S., averaging roughly 27 deaths for every 100,000 workers per year. That's nearly nine times higher than the overall fatality rate for U.S. industry as a whole, according to data from the U.S. Census Bureau (pdf).

So it stands to reason that energy derived from renewable resources such as the sun and wind might cause fewer workplace deaths than energy industries—coal, oil and natural gas—that rely on mining, drilling and otherwise extracting fossil fuels. And that's exactly what doctors from Medical College of Wisconsin and Duke University Medical Center found in an analysis published in JAMA The Journal of the American Medical Association on August 19.

If solar power is ever going to take off—and the world needs it to—photovoltaic cells will have to become a whole lot cheaper to produce.

Making solar cells from silicon, the most common approach, can be expensive and relatively inefficient at turning sunlight into electricity. As semiconductor manufacturer Applied Materials chief technology officer Mark Pinto told me last year: "With solar, it's all about cost."

But there are signs of improvement, writes Richard Swanson of SunPower Corp. in this week's Science. Last year, manufacturers made 5 gigawatts of photovoltaic panels. And some of these panels required just under six grams of silicon per watt of power—down from 15 grams at the turn of the century. And that watt of power now costs around $1.40 to produce compared with $2 or more in the 1990s.

Duke Energy wants to put a power plant on your house.

Over the next year, the utility plans to spend $50 million to plop a variety of photovoltaic panels on commercial buildings, the roofs of private homes, and other property in North Carolina.

Once installed, the 10 megawatts worth of solar panels are expected to produce enough alternating-current electricity to power 1,300 homes. But the utility’s main goals for the demonstration project are to gain experience with distributed generation—putting the power plant closer to the customer—and with integrating intermittent, renewable resources like sunshine into the grid.

Pres. Obama in a televised address to a joint session of Congress last night told lawmakers—and the nation—that his three top priorities are energy, health care and education. First and foremost on his list: seeking renewable power sources and reducing U.S. dependence on foreign oil.

"We have known for decades that our survival depends on finding new sources of energy.  Yet we import more oil today than ever before," he said, harking back to a time when former Pres. Carter wore sweaters in the White House to promote conservation only to be followed by former Pres. Reagan, who had solar photovoltaic panels taken off the rooftop of the White House and eliminated most research and development funding into alternative energy sources.

In its waning days, the Bush administration's Environmental Protection Agency (EPA)  has essentially halted all new construction of coal-fired power plants until the government can figure out what to do about climate-change-causing carbon dioxide (CO₂) emissions. In a ruling yesterday (pdf) on a petition to build a new 110-megawatt coal-fired power plant in Bonanza, Utah, the EPA decided that it could no longer grant permits for such new construction until it determines what is needed to limit CO2 emissions.

The decision refers back to a 2007 U.S. Supreme Court  ruling that found that the EPA, much to its own chagrin, has the authority to regulate emissions of CO₂, the most ubiquitous greenhouse gas. In essence, permits cannot be granted until the agency figures out whether or not to force power plants to install technology to control such emissions.

Munich-based Phoenix Solar AG, a German photovoltaic system installer, has committed $615 million (450 million Euros) to purchasing Solyndra's cylindrical solar cells as a core part of its future rooftop installation business. Why? "We see significant cost-savings," says chief technology officer Manfred Bächler. "We simply do not need any supporting structures or ballasts or roof penetrations," because, unlike traditional flat solar panels, the new round kind don't need any help to keep grounded when the wind blows.

In addition, the ability of the solar cylinders to collect direct, diffuse and sunlight reflected from the rooftop—as well as the ability to lay panels of them horizontal to the roof itself means more electricity can be made from a given rooftop. Further, the solar cylinders keep cooler overall, which enhances the performance of the system, Bächler says.

The amount of solar photovoltaics harnessing electricity from sunshine in the U.S. will more than double by 2013, thanks to plans to build 800 megawatts (MW) worth in California. The two vast solar farms—covering more than 12 square miles—will be among the largest ever built in the world and dwarf the current U.S. record holder: Nellis Air Force Base in Nevada with 14 MW. In fact, the total amount of solar photovoltaics connected to the grid in the entire U.S. is just 473 MW at present.

"These landmark agreements signal the arrival of utility-scale PV solar power that may be cost-competitive with solar thermal and wind energy," said Jack Keenan, chief operating officer and senior vice president for utility PG&E, which made the deal, in an announcement yesterday.