I recently watched a terrific TED conference video of a presentation by Bill Gates, who is arguably a pretty smart guy. You can watch the 20 minutes of his talk for yourself at www.TED.com, and I won’t mind if you put this column down and go do that right now. I’ve written about the high quality, both visual and intellectual, of TED videos, and this one is no exception. If you haven’t discovered TED.com before, now is a good time.
Back? OK, I suppose there are at least a few of my readers who are skeptical of the whole “global warming due to greenhouse gases” thing. Please let me mention in this context Blaise Pascal and his famous wager regarding the existence of God: Although the existence of God cannot be proven, it’s better to live your life as though he does, since the upside is avoiding eternal damnation, and the downside is nil. Same applies for belief in global warming, particularly if it turns out that Ray “Singularity” Kurzweil (who also has a talk at TED.com) is right, and we’re all going to live forever. And even if you don’t believe in global warming, wouldn’t it be nice for the good ol’ US of A to be energy-independent in a world with increasing global demand for finite oil reserves?
TerraPower
TerraPower, which Gates mentions briefly in his TED talk, is a bold rethinking of nuclear energy, called the Traveling Wave Reactor. Current nuclear reactors rely on large quantities of “enriched” uranium and produce a lot of leftover-but-still-radioactive waste. They must be opened every 18 to 23 months to remove spent fuel, and that waste must be stored somewhere safe. A TerraPower reactor “burns” that leftover waste over a period of decades, using only a small amount of enriched uranium to start the process. The result is a much smaller final amount of radioactive waste.
In both cases, the heat from a conventional (fast burning) reactor or a TerraPower (slow) reactor heats liquid sodium, which then circulates through the reactor’s core. The liquid sodium is cooled by water, which boils to produce steam, which powers a generator. We still live in the Steam Age, the only difference being what we use to heat the water. And of course, the steam is used to generate electricity.
TerraPower reactors are attractive because they don’t need to be refueled, operate for years and use up our existing stockpile of spent fuel that’s potentially large enough to supply U.S. power needs for a century or so. I can see why Gates, himself a shrewd businessman, is a principle investor in TerraPower and its band of rocket scientists.
Of course, this is all theory. As far as I can tell from published reports, the TerraPower reactor exists only as a massive computer simulation based on some pretty solid physics. The biggest hurdle to TerraPower appears to be finding a place where it’ll be permitted to build a test facility, most likely not in the United States. For the moment, TerraPower remains an interesting idea in the realm of carbon-free power generation.
Bloom Energy
On the other hand, Bloom Energy is a “for real” power-generation technology that’s actually in use in California today. The company, again fueled by rocket scientists, has been in “stealth mode” for the past decade and recently announced its first product at a press conference at eBay’s San Jose headquarters.
Why at eBay? Because eBay is one of the first customers for the Bloom Energy Server, a self-contained power generation facility that uses natural gas or biogas (such as cow farts or other naturally produced methane) to produce 100 megawatts of electricity from a device that fits in a single parking space. Other current customers include Coca-Cola, Google and Walmart.
The secret sauce inside the Energy Server is a solid oxide fuel cell (SOFC). Fuel cells, which combine a fuel (like hydrogen) and an oxidant (like oxygen) to generate electricity and water, are not new technology, having been used in the original manned space flight program of the 1960s (watch “Apollo 13” if you need a refresher—the Apollo 13 capsule lost power when its fuel cell exploded, threatening the lives of all aboard). SOFCs were developed for use in NASA’s Mars exploration program and have the advantage of being able to use a variety of fuels besides hydrogen.
Unlike TerraPower’s reactor, SOFCs produce carbon dioxide as a byproduct (the result of using fuels that contain carbon as well as hydrogen), so they don’t help in the reduction of greenhouse gases. When powered by biogas, they’re approximately carbon-neutral, however, which makes them a big improvement over the coal-fired power generation that provides more than half of the electricity in the United States (Google “power generation by fuel type” for more specifics on the fuels we use to produce electricity). Even when using natural gas, they’re reducing our reliance on foreign oil. Moreover, Bloom Energy sees a future in which a smaller version of the Energy Server could be used to power a single residence, much like people have begun to do with solar panels.
If you’re a geek like me, Wikipedia has a great article on fuel cells for you to get more information about this interesting technology.
The future
Regular readers know I’m interested in the question of our energy future. Sebastopol-based Solarworks installed a six-kilowatt PV (photovoltaic) solar array on the roof of my home a year or two ago. Now my electric bill is basically zero (PG&E charges me about $8 a month to keep track of my use), and I’m a very happy camper. I like the idea of solar, because it doesn’t require any fuel at all. Of course, I’m still reliant on carbon-emitting PG&E for my nighttime electric needs, which makes it an incomplete solution. I don’t really want to live “off the grid”—I want a grid that creates fewer carbon emissions.
Gates estimates we have about 40 years to get our act together with respect to carbon emissions: 20 years to develop solutions and 20 more to implement them. I’m not sure I’ll be around to see what happens (I’ll be 95 in 2050), but I’m sure it’s important for all of us.
