Science Talk

Here Comes the Sun--A Grand Plan for Solar Energy; and Sci Am's New Body

In this episode, Scientific American editor Mark Fischetti talks about an audacious new plan, featured in the January issue of Scientific American, for turning the US into a solar-powered country. And editor-in-chief John Rennie talks about a new Sci Am health publication, Scientific American Body. Plus we'll test your knowledge of some recent science in the news. Websites mentioned on this podcast include:;;;

Male voice: Today's podcast is brought to you by, the leading provider in spoken word entertainment. Log onto to get a free audio book download today.

Steve: Welcome to Science Talk, the weekly podcast of Scientific American for the seven days starting December 19th, I am Steve Mirsky. This week on the podcast: We'll look at an audacious proposal for solar energy. We'll hear about a new health magazine from Scientific American and we'll test your knowledge about some recent science in the news. The January issue of Scientific American magazine features a multi-author article called, "A Solar Grand Plan." SciAm's Mark Fischetti edited the article, which is also available free on our Web site. Mark and I sat down in the SciAm library to talk about this possible solar solution.

Steve: Hi Mark! How are you?

Fischetti: Hi Steve! Good.

Steve: So, this "A Solar Grand Plan"article in the current Scientific American—very interesting, because I've seen a lot of other write-ups in journals that seem to make the point that it's just kind of theoretically impossible to generate enough power, enough electricity with solar, to really make that much of a difference compared to what we are getting from fossil fuels; this article goes in a whole different direction and says: "No, it is possible, given the will."

Fischetti: Right! I think those articles in the past have sort of taken a look at the country and said, you know, "There is not enough consistent solar radiation across the country" or, you know, "It's only for a few hours a day—what do you do all night long?" So, this grand plan essentially says, put really vast arrays of photovoltaic cells and solar thermal plants in the Southwest covering thousands of square miles, which would clearly generate enough power for the country, then you have to get it to the country; and so what’s also required then is really a new direct-current transmission system from the Southwest that will kind of branch out to the rest of the country to deliver that power.

Steve: How much actual square mileage are we talking about here?

Fischetti: Well, the calculations—you can have the mix of photovoltaics and solar thermal—but essentially we are talking about 46–49,000 square miles.

Steve: 49,000 square miles, most of which would be in Arizona?

Fischetti: Yeah! The desert Southwest; it is a lot of area and it sounds like a huge amount of area, but actually there is a map in the article that shows five or six—if you divide it up just for argument sake—into five or six massive installations, they would fit very nicely in few different parts of the desert Southwest, where of course the solar radiation is highest all year long.

Steve: And there are some people in Arizona who are actually pretty excited about this idea?

Fischetti: Yeah! There are some fairly large demonstration plans up there. And it's also a lot of that land is considered nondevelopable wasteland, if you will; nothing else is going to happen there. There may be some concern about ecological implications, but there is really not much going on there in that respect either, so in a way, you know, if you fly off west [to] California, you go over these areas where you look down [from] the plane [and] there seems to be nothing; well, there really is nothing.

Steve: But there is a lot of sunlight!

Fischetti: A lot of sunlight there. (laughs)

Steve: So, we are talking about a whole lot of square miles and the estimates in the article are [that] by 2050, you could generate 69 percent of all United States electricity and 35 percent of the total energy requirements of the country, strictly with these solar farms out in the Southwest.

Fischetti: Right, and that's making two big assumptions. One is that replacing utility power is one thing, but [a] lot of the total energy in the country goes in transportation, so another big assumption is that you'd largely have to convert the U.S. passenger fleet to hybrid plug-in cars and trucks, all that, so that essentially you are fueling vehicles with electricity as well.

Steve: Yeah! The assumption is there is not a gas-powered car left on the roads.

Fischetti: Not many. (laughs)

Steve: And they also say—your three authors say—that "If you throw in wind biomass and geothermal by 2100, you can generate 100 percent of U.S. electricity and 90 percent of all energy."

Fischetti: Right! There is always going to be some local need for fossil-based fuels, you know, in industrial processing or some things you just can't do with electricity, but by and large, right, if you wanted to try to replace those sorts of applications with biofuels and things like that, then you could be off oil altogether. One of the interesting points is that, in the 2050 scenario, if 69 percent of the electricity is being produced by solar power, you essentially eliminate any need for any foreign oil imports, which has enormous implications for policy, international relations, trade deficits. So there is a lot more in that than just energy that we are talking about; but I guess the point is that the United States wouldn't be relying on Middle Eastern oil, which changes[has], you know, massive foreign policy implications for the country.

Steve: Yeah! Absolutely! So one interesting factoid in the article is that although that huge land mass that we are talking about seems just, you know, mind boggling, according to the article, it's actually less land [than] that's[what's] required to run 300 equivalent energy output coal plants.

Fischetti: Yeah! The estimate again is for 2050. What in effect, we would be doing is displacing 300 oil-fired power plants and another 300 coal-fired power plants; so the land required for 600 fossil fuel power plants—if you are going to think that way, if you consider the whole system, which includes mining coal, which includes drilling for oil, the refining of all that, it's not just the power plant—that the land tradeoff actually gets to be fairly close, you know, the solar power plant is the footprint of the solar power and that's it. There is no mining, there is no processing, there is no fuel that you have to purchase that need[s] to be transported there, so yes, it's very interesting when you think about really the whole system [being] involved.

Steve: Yeah! Because it's so energy intensive just to bring fossil fuels to the consumption stage.

Fischetti: Right, that alone, right!

Steve: I just want to clarify one thing—I think you said 300 coal and 300 oil. I think the article says 300 coal and 300 natural gas plants, right?

Fischetti: Right!

Steve: Okay, I just wanted to get that on record for anybody who is out there preparing their investments and/or their local power plants.

Fischetti: Right!

Steve: The article talks about a secondary energy-storage medium, that's really pretty interesting because when we think of solar, we always think of solar panels—or most of us do—I assume that you know, photovoltaics that turn the solar energy into electric current, but we also have this hot salt business that's really got very interesting where you are turning the solar energy into heat.

Fischetti: Right, if you think about a long trough that reflects sunlight, it concentrates the sunlight along a pipe that runs parallel to the long trough and concentrate[s] the sunlight like a magnifying glass, [which] heats the fluid inside this pipe really hot, so the hot fluid circulates out to a somewhat traditional power plant where it's allowed to expand into high pressure gas that turns a turbine which generates electricity. The problem with that, as well as the photovoltaics, is when the sun goes down, you don't have the power source anymore. So what you need if you're really going to have a full energy system, you need a way to store energy—excess energy that's generated during its daylight hours, so that you've got a reserve for evening or at night time; and that has been an impediment for a long time. In the solar thermal case, the troughs, what you'd do is have big tanks of molten salt where those are heated up during the daytime, and they stay hot, they retain heat overnight, and you're essentially drawing heat out of there to run the turbines.

Steve: There is this other technology of compressed gas that takes advantage of—or it doesn't take advantage, it's a way to deal with the fact that solar isn't getting anywhere at night. So during the day you compress gas, and then at night, you release the gas and the gas turns the turbines and you produce electricity.

Fischetti: Right! Here you've got underground caverns essentially, so if you think about a photovoltaic farm producing electricity, it basically goes to a compressor that compresses air and pumps it into these caverns that are underground which are kind of everywhere. Fill the cavern with high-pressure gas and then at night release it again to get a high-pressure gas that turns the turbine that creates energy—electricity.

Steve: So, one big issue that needs to be dealt with, and it isn't discussed in the article, but we need to make sure that our compressed-air systems are really airtight because the amount of energy that's wasted in leaks of compressed air could be really significant if this whole system were ever actually put in place.

Fischetti: Yeah! There is another interesting parallel, too, which is again if you sort of think of this in your mind geologically or geographically, I should say—so you've got these big farms in the Southwest; if you got these high-voltage, direct-current, sort of trunk line feeding other parts of the country with the power, what do you do with it there? Well, so you have these caverns kind of spread all over the place, where you are compressing air and then you are tapping into that locally to supply power for any given region. That may sound little grandiose too, except that the natural gas industry, which is obviously a huge industry nationwide, that's how they work, too. There is a network of pipelines, but the natural gas is stored underground in caverns all across the country, so it actually makes a lot of sense to think about it that way.

Steve: So, here is the big question. You know, whose going to pay for all this?

Fischetti: Right! Well, the plan basically is set up like this. From, 2010 to 2020 roughly, the federal government would have to supply about 420 billion dollars in subsidies to get these massive scale[s] of production for, you know, all the mix of photovoltaic systems, solar power systems, the compressed air systems, the direct current system. So 420 billion dollars in subsidies; after 2020, essentially, you've got like a 30-year subsidy–payback kind of plan, so that by 2050, all the components of this new industry would be on their own. It's a lot of money, and yet when you compare it to other national infrastructure expenditures over time, it's not unreasonable at all. It's actually less money than what is [was] spent to create the whole federal interstate highway system, which completely remade the system of commerce in the country. It's the high-speed communications network that's nationwide, everybody has got high-speed Internet—how do you actually get high-speed Internet? Well, there is a physical system that's been built, satellites, terrestrial, and that's estimated to have cost about a trillion dollars. So, on those scales at least 420 billion is still a lot, but it is not [an] unheard of amount of money.

Steve: And for those of you Grover Norquist fans out there who don't want the federal government investing in anything, you are listening to this presumably because you have an Internet connection that the federal government invested in it first and then the whole technology was privatized. You know, that's the way cancer research works in this country too, where the federal government sponsors the initial research and then the pharmaceutical companies take advantage of what's been learned through drug screenings and they go and develop the drugs for profit. So, it's really the standard business model.

Fischetti: Yeah! It's how lots of things, you know, the telephone systems, there is a lot of systems, infrastructure-type systems—that's how essentially the government is putting in the seed money, if you want to think of it that way; and now it's a lot of seed money. Nonetheless, you know, farming systems—there are farm subsidy programs that are equally large, in the hundreds of billions of dollars; so yeah, it is how things can get done.

Steve: And here's a question that should almost always be asked and very seldom [is]—if you think this is expensive, what's the cost of not doing it?

Fischetti: Right! Actually if you calculate, you think about those 600 fossil fuel power plants, and if you calculate how much money is spent to purchase the fuel, that's the big thing that people don't really think about. The solar fuel is free. Fossil fuels cost a lot of money and [have] a lot of climate impact; that's something we haven't covered either, but this plan will also reduce carbon dioxide emissions to about a third of what they are now [by] 2050, assuming some level of growth as well.

Steve: It's a really interesting proposal, and it's one of those rare opportunities where we'll actually be able to track whether or not anything happens, and if it does, how well this actually works over the coming decades.

Fischetti: Yes, right, right.

Steve: Thanks a lot, Mark.

Fischetti: Okay, thank you.

Steve: Again the article, "A Solar Grand Plan",is in the January issue of Scientific American and is available free at our Web site, And you can take part in a discussion of the solar plan. Just go to the article at the Web site and leave a comment. Two of the article's authors, Ken Zweibel and James Mason, are posting detailed responses to readers.

We have Scientific American magazine, Scientific American Mind magazine, so there was an obvious place to go next. That's right: Scientific American Body, which looks at the science of health. It hit the newsstands last week. editor in chief, John Rennie and I talked at his office.

Steve: Hey John! How's it going?

Rennie: Just fine Steve, how're you?

Steve: Tell us about Scientific American Body.

Rennie: Yes. Scientific American has been trying to expand the offerings it has in the health area for awhile, most of which are available through our Web site,, and we thought that certainly in conjunction with that, a great thing to do would be to bundle together a lot of this great new content we have and try to present that as a special issue, which is hitting newsstands now as Scientific American Body.

Steve: We have Scientific American, Scientific American Mind, and now Scientific American Body.

Rennie: Yes. We are hitting it from all sides now.

Steve: Right. You can't avoid us.

Rennie: (laughs)

Steve: And what are some of the highlights of Scientific American Body?

Rennie: Well, let's see. I think we have, the centerpiece of the issue is a special report we are doing about diabetes and the management of diabetes these days. Because of the advances in science surrounding the disease, you have a lot more options these days both in how you want to manage that and potentially maybe even cure that some day.

Steve: And of course, that's such a huge problem because it's connected to the obesity epidemic.

Rennie: Right! Diabetes is one of the fastest rising health problems all over the world. It's a strange thing in some ways that many of us think of diabetes as what they used to call a disease of affluence, that it was a disease you'd find a lot in the richer, in [the] developed world. But in fact some of the fastest rising areas afflicted with diabetes now are places like India, and so you can imagine that's going to be a tremendous problem and it's something that's going to be very important to get all the right kinds of information out to people there.

Steve: That's really amazing that that's the case. I know that in our September issue of Scientific American, Barry Popkin pointed out that there are now more people on the planet suffering from obesity than from malnutrition.

Rennie: Right! It'sWhich is a dizzying thing for those of us who have been alive for just a few decades and have seen how much concerns about overpopulation and starvation used to color a lot of these discussions.

Steve: So, back to Body: What else do we have that would be of interest to the Scientific American–interested audience?

Rennie: Well, we have a story about the state of the artificial heart. For decades researchers have been trying to develop a really good permanent implantable artificial heart. In some ways you would think that would not be that hard a problem. I mean, the heart is basically just a mechanical pump; surely if there is any kind of organ we should be able to replace, that would be it. But the science writer Wray Herbert goes into [not only] why it is that developing a good artificial heart is indeed such a tough problem to crack, but how close we are to it right now.

Steve: So, by 2050, do you think that artificial hearts will have a real strong place in the medical armamentarium?

Rennie: Well, I would say probably a lot sooner than that, yes. In a sense, your need for an artificial heart always is a way to counterbalance the shortage of transplantable hearts. So it's the fact that we don't have enough other hearts that are being donated or available for donation that determines the need that we have for artificial hearts. Now, with new kinds of technologies that are coming up, new types of tissue engineering and, you know, some of the hopes that people have for stem cells and [the] like, it may be interesting to see if there are other ways, alternatives to dealing with really badly damaged hearts that would involve growing a new heart or replacing or repairing the damaged to a badly damaged heart that might make artificial hearts less important in the somewhat more distant future. But I wouldn't expect really probably within just another few years, artificial hearts or this permanent implantable heart may really be something that we can rely on.

Steve: Do we avoid some rejection issues with artificial hearts?

Rennie: Well, that's one way of dealing again with, you know, with the transplant issue overall. The more you want to relax your considerations about how close a match you need with donors, you know, you open up the field of organs that are available for any particular patient, but you risk, of course, obviously very, very serious indeed lethal reactions in most of those cases. And we only do have something on the order of about 2,200 hearts that are available for donation and transplantation every year, whereas the need is much, much higher than that.

Steve: So, back to Scientific American Body. In some ways it resembles the classic Scientific American magazine. We have the feature well with a few long featured articles and then we have some departments—what are people going to be interested in terms of just wandering around in the magazine?

Rennie: Well, we think that certainly there is a new section called,The Pulse, which covers a lot of new breaking sorts of developments, we have a column called, Alternatives, in this, that is designed to help people take a look at some sorts of alternative therapies that are sometimes disputed, kind of alternatives to conventional western medicines. In this issue, we put together, we look at the treatment called EMDR, which is sometimes used as a way of treating people who have certain sorts of posttraumatic syndrome. It's a question that's seemingly, this type of strategy of just having people think about what happen[ed] to them and moving their eyes is supposed to be able to help them get over the trauma associated with that. That's, the researchers writing about the state of what's actually known about it say, "Actually it's not really clear that this works any better than any number of other cognitive therapies that have been developed."

Steve: So, in our Alternatives look, we'll be taking a pretty hard-headed [look] at these kinds of alternative therapies?

Rennie: That's right. I mean I think what the point of that is we are trying to be open-minded enough to look at these and be open to see where maybe some of these kinds of therapies really do work. For example, acupuncture is something that seems to bring at least as much relief to people who suffer some kinds of back pain as a lot of other surgical or other conventional techniques do; but we also want to try to warn people away from the sorts of remedies that are being prescribed that maybe or[are] not really backed up by much science at all.

Steve: So, Scientific American Body, it hits the newsstands …

Rennie: Some newsstands may want to try to put it over in their health section as well, but look for it in your Scientific American.

Steve: The word Scientific American [is] very small [on] the cover, the word Body is big, and you see what looks like a guy swimming through a double helix.

Rennie: Yes, yes, that's right; with a big glowing heart.

Steve: Some of the articles in SciAm Body are free on the Web site, such as the special report on managing diabetes and the feature article that asks the controversial question, "Is there really an autism epidemic?" Check them out at

Now it is time to play TOTALL……. Y BOGUS. Here are four science stories; only three are true. See if you know which story is TOTALL……. Y BOGUS.

Story number 1: Human beings register incredibly faint odors coming off each other which [that] we don't realize we are smelling but affect whether or not we like the people. .

Story number 2: Mud can form in moving water.

Story number 3: Australian researchers are trying to isolate bacteria that kangaroo stomachs have, so they can give them to sheep and cattle because the bacteria keep the roos from contributing greenhouse gases via flatulence.

And story number 4: George Smoot, winner of the 2006 Nobel Prize in Physics, took a half a million dollars of his winnings and bet on red to come up at a roulette wheel at Caesar’s Palace in Las Vegas. He won, doubled his money and walked away.

Time is up.

Story number 1 is true. We apparently do smell these really faint smells coming off other people and it affects how we feel about them. That's according to a study in the December issue of the journal Psychological Science. And you thought you didn't like your brother-in-law because he keeps borrowing money.

Story number 2 is true. Mud can still form in moving water according to research published in the journal Science. For more, crystal-clear mud news, check out the December 18th edition of the daily Scientific American podcast, 60-Second Science.

And story number 3 is true. Bacteria in kangaroo stomachs apparently keep their flatulence from including methane. The wire service AFP reports that researchers are trying to find the microbes and add them to livestock digestive systems to see if that can cut their output of greenhouse gas. Some wags suggest a simpler solution: stop eating cattle and sheep and switch to kangaroos.

All of which means that story number 4 about Nobel laureate George Smoot doubling his money at a roulette wheel in Vegas is TOTALL……. Y BOGUS. Because Smoot actually took $500,000 of his $700,000 share of the Nobel Prize and used it to help start the New Berkley Center for Cosmological Physics. For an explanation of why the unit of measurement called the "smoot" is not named for George Smoot, just go to the SciAm Web site and search for Smoot; the column that comes up will explain all.

Well that's it for this edition of the weekly SciAm podcast. You can write to us at and check out numerous features at the new Web site, including "The Clash;" you know those shows where people with different view points snipe at each other? Imagine if really smart people are doing it about science; that's "TheClash." You can find it in the sections menu at For Science Talk, the weekly podcast of Scientific American, I'm Steve Mirsky. Happy Holidays! And thanks for clicking on us.

Share this Article:


You must sign in or register as a member to submit a comment.

Starting Thanksgiving

Enter code: HOLIDAY 2015
at checkout

Get 20% off now! >


Email this Article