In my mind, that's one of the most important numbers in the debate over whether to expand nuclear power in the U.S. The country currently has 104 commercial nuclear plants and these plants provide approximately 20 percent of the electricity for the nation. (The navy also has 103 nuclear reactors).

That's a plant-to-power ratio that's tough to beat. By contrast, the U.S. gets around 49 percent of its electricity from around 614 coal plants, and these coal plants belch carbon dioxide and particulate matter into the atmosphere. Coal mining and burning can also be linked to thousands of deaths annually around the world and shortened life spans.

And, despite all of the rooftops covered in solar panels you see today, solar right now only accounts for around 0.03 percent of power in the U.S. (That's three hundredths of a percent if you don't feel like counting the zeros.

Although pro nuke factoids might sound a little weird coming from someone who works at a research firm dedicated to green technologies, it is difficult to look at America's energy needs for a long time without warming to nuclear. Simply put, nuclear remains one of the most feasible ways right now to produce large amounts power consistently without generating carbon emissions. Constructing nuclear plants generates emissions, but once erected, the plants produce carbon-free power for decades.

And more power will be needed, make no mistake. Despite the huge opportunity for reducing power consumption, electricity demand will continue to spiral upwards. Data centers will replace shopping centers and regional offices as hubs of commerce, but that will mean producing more electricity for all of those computers and storage systems. Electric cars? Great idea for reducing petroleum consumption, but if you fill them up on coal-fired electricity, you get about the same amount of emissions.

The U.S. will need 25 to 30 nuclear plants by 2030 just to stay at the 20 percent figure, according to Christine Todd Whitman, the former governor of New Jersey who is now part of the Case Energy Coalition, a nuclear advocacy group.

To meet the current goals for greenhouse gas emissions, the U.S. would have to build 187 new nuclear plants by 2050, she adds. Despite a ban on new nuclear plants in California , French engineering firm Areva is seeking approval to build two nuclear plants near Fresno. The Electric Power Research Institute expects nuclear to provide 29 percent of U.S. power by 2030. To expand nuclear, Case and others are lobbying Congress to allow "clean" energy rather than just "renewable" energy to qualify for federal loan guarantees under the energy bills.

But what about wind? Wind provides more power than solar panels, but it's even more sporadic and unpredictable. Wind turbines only produce power 20 to 30 percent of the time and often produce power at night when it's not needed. Nuclear plants generate power more than 91 percent of the time, one of the highest uptimes of any source of power, according to my colleague Eric Wesoff who recently wrote a nuclear report.

Energy storage technologies-large battery banks, compressed air, man-made reservoirs-can help solve wind's sporadic nature, but storage is in its infancy.

But don't geothermal and solar thermal power plants-those big mirrors in the desert that turn heat into power-- produce consistent amount of power? Yes. The solar power plants in California's Mojave Desert have produce power consistently for two decades, according to consultant Fred Morse, one of the world's experts on solar thermal. When Mt. Pinatubo blew its top in 1989, the output of power from the sun dimmed a bit, but that's been about the extent of the problems. (link to morse http://www.greentechmedia.com/articles/read/solar-thermal-which-technology-is-best-6091/)

But there's a problem of geography. Solar thermal plants need dry, warm heat. Good luck getting one to work in Maine. Geothermal is most promising in the west.

Don't get me wrong. I'm a big advocate of solar thermal, wind and PV panels, as well as efficient use of natural gas and clean coal. But to really reduce carbon emissions quickly, nuclear remains one of the few known knowns. It probably has to be part of the answer. Think of it what goes through your mind when interviewing prospective employees. Sure, Leonardo Da Vinci might be the next person through the door, but it might be more realistic to take one of the five people you've already spoken too.

Nuclear could also generate jobs. Building a reactor can employ 1,200 to 4,000 people, she said and operating a reactor will employ 400 to 700. The total economic output to a community from a single reactor can be as high as $430 million a year, according to Whitman.

Potentially it could even bring back high-end, high-tech jobs. Note that a French company wants to build the plant in California. France's 16 reactors provide 78 percent of its power and the government hopes to make know-how more exportable. Forty four plants are under construction worldwide, Wesoff tells me. In Asia-Pacific, approximately 100 are under construction or planned. The U.S. once led in nuclear technology: retirement has changed that.

There are, of course, major problems, like what to do about nuclear waste. The U.S. could reprocess nuclear waste into fuel, but it would require a change in policy.

A knowledge problem also exists. Expanding nuclear power means educating more engineers and technicians on how to build and operate plants. In turn, that means more people that could be susceptible to bribes and blackmail from less democracy friendly nations. This can't be dismissed lightly. If the Physical Dynamics Research Laboratory in the Netherlands hadn't hired and trained a newly minted PhD named A.Q. Khan back in 1972, Pakistan and North Korea may not have missiles today.

On the same day that Areva announced its Fresno plans, an intelligence report from the International Atomic Energy Agency stated that Iran cut a secret deal to obtain uranium from Kazakhstan.

And on a more prosaic level there is cost. The nuclear industry has a history of drastic cost overruns. The high costs in the past came from the custom nature of plants. Of the 104 plants in the U.S., 95 are based on distinct designs, admits Whitman.

As Amory Lovins of the Rocky Mountain Institute likes to point out, nuclear companies are like defense contractors. Once a project is approved, the cost concerns go out the window. The nuclear industry will hoover in a disproportionate share of any energy bill goodies. If there's a no nukes concert this time, accountants might be in the front rows.

But in the end it will be public sentiment that will decide. So what do you think?