Another week, another conference. I was recruited last minute (literally over the breakfast buffet) to join an afternoon panel at the cleantech conference sponsored by Cooley Godward Kronish at the Sofitel in Redwood City last week.

Ostensibly, there was a carbon theme to the day, though my panel was entitled "Opportunities for New Technologies in a Carbon-Constrained Environment" (a broad enough brush to cover almost anything in cleantech). Anyway, as occasionally happens at these things, talk turned to the nuclear question -- not just whether new nuclear plants will happen in the U.S. but whether they are desirable from an environmental and carbon standpoint to begin with.

In a nutshell, here is my response whenever this topic comes up:

I think nuclear has to be on the table. I think it is a clean energy source -- whether you call it "renewable" (uranium is a depletable natural resource, after all) or merely "low carbon" (not zero, since there is plenty of embedded carbon footprint in those iconic concrete cooling towers), it stacks up very well against the fossil energy sources that dominate our electric supply. Lest we forget, coal, with the highest carbon footprint of all fossil fuels, still represents 48 percent of the generation mix in the U.S. (and over 70 percent in China). By comparison, renewables (not including conventional hydro) stand at 3 percent of the current portfolio, despite very rapid growth in recent years.

What lights the City of Lights?
I have worked for three different nuclear utilities during my career, including the world's biggest, Electricite de France (80 percent nuclear baseload), and though I have never been involved in the nuclear side of the business directly, I have at least toured plants at each company, including the EDF/Areva plutonium recycling and vitrification facility in Marcoule in the South of France.

To appreciate just how much energy is unlocked by fission, it's worth considering this: At Marcoule, even after re-processing and recapturing a good deal of the energy from spent fuel rods, the residual waste (stored underground as a non-leaching glass solid in large metal cylinders) must be actively cooled with pumped water for 10,000 years. That's right, it's so hot, the leftovers will still be boiling water in the year 12,000!

Now, that obviously underscores the waste storage and safety concerns -- not to mention the proliferation argument against civilian use of nuclear power. And I don't mean to understate those. But it's also apparent how ridiculously powerful a clean energy source nuclear can be when done right.

It wasn't until I spent a year living in Paris that it dawned on me that one of the things that makes it such a beautiful city is that you can actually look almost anywhere on the skyline and not see a single smokestack. Think about that for a moment: Paris, the city of lights, an urban agglomeration of 6 million residents (plus probably a million tourists on any given day), with skyscrapers, metro and RER trains, and the neon lights of the Champs Elysées, all of it powered without a single fossil power plant in sight -- for near zero local air pollution and no direct atmospheric CO2 emissions. This is a stunning and enviable accomplishment that should not be dismissed lightly by anyone who cares about the current climate crisis.

Nuclear's real advantages
Over and above its compelling environmental characteristics, nuclear has at least two cardinal virtues from a grid operational standpoint relative to other clean energy options: namely its baseload operating profile and geographic flexibility. Let's take these two points separately.

In the U.S., there are 105 operating nuclear reactors (interestingly, only 8 of them situated West of the Rockies), with a collective capacity of 100,000 MW producing 806,000,000 MWh in 2008 -- that's a capacity factor of 92 percent. By contrast, wind energy, the most prevalent renewable resource with 25,000 MW installed capacity, averages a capacity factor somewhere in the low-20's, with the best sites clocking in at about 30 percent.

Actually, even this huge disparity in annual figures doesn't tell the whole story -- wind variability is relatively difficult to predict and has grid consequences on a minute to minute, as well as a day-night and seasonal planning basis. By contrast, most of the downtime at operating nuclear plants represents planned maintenance outages scheduled in advance for off-peak times of the year. To put it simply, the grid loves nuclear. It is by far the most firm of all resources in the production mix. Yet while wind deployments rose 50 percent last year (fueled by state-level renewable portfolio standards and the federal production tax credits), no new nuclear plant has been sited, permitted, and built in the U.S. since 1978.

A second, unrelated aspect of nuclear is that plant location is not limited by a natural resource. Those of us who are privileged to live on the sunny West coast -- or close enough to the windier interior parts of the West (like Eastern Washington, West Texas, and the Northern Plains) -- are spoiled. We should spare a thought for the rest of the country, where the available renewable resources are often highly disaggregated (I'm looking at you, woody biomass) and far from urban load centers where people live. Large scale exploitation of these resources will require a costly build-out of transmission to connect remote generation to load and may be technically infeasible in some cases.

We should not assume that there is or will ever be a "one size fits all" solution to our energy challenges. Taken as a region, the U.S. Southeast has generally poor wind resources and is too humid for solar with today's technology (silicon PV prefers direct rather than diffuse sunlight; concentrating solar thermal also works best with very high levels of direct insolation). If a federal energy portfolio standard passes in the range contemplated by current draft legislation (15-20 percent by 2020), Dixie will have a very tough row to hoe. Perhaps it should be no surprise then that more than half of the 21 applications received by the NRC for new reactor licenses in the last two years are located South of the Mason-Dixon line .

Matt Lecar is a veteran energy industry expert with 18 years in utilities, international business development, cleantech venture capital, and consulting. Most recently, he served as Fund Manager for the CalCEF Angel Fund, a first-in-kind seed stage fund focused exclusively on clean energy markets. This article is part of a series called "View from the Poletop" -- broad perspectives on the current state of markets in renewable energy, energy efficiency, and smart grid.

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