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My guest is John Perlin, author of Let it Shine: The 6,000-year story of Solar Energy. I still have on my shelf an autographed copy of his previous book A Golden Thread: 2500 Years of Solar Architecture and Technology, published in 1980 (now out-of-print). It’s actually one of my favorite books of all time and can’t wait to read the new one. John’s work, to me, is an inspiration for solar energy. John is an international expert on solar energy and has lectured around the world on the subject. We’ll be talking about the history of solar energy and the possibilities of using solar energy as a less toxic energy source now and in the future.





Let it Shine: the History and Possibilities of Solar Energy

Host: Debra Lynn Dadd
Guest: John Perlin

Date of Broadcast: September 26, 2013

DEBRA: Hi, I’m Debra Lynn Dadd. And this is Toxic Free Talk Radio, where we talk about how to thrive in a toxic world. And even though there are many, many toxic chemicals out there, there are also a lot of things that we can do to remove toxic chemicals from our home, remove toxic chemicals from our bodies, remove toxic chemicals from our community. And my personal goal is to have a completely toxic-free world. And that’s possible because all the technology exists. It just is a matter of education and choice.

And that’s why I’m here, to let you know what’s possible so that you can make those choices.

Today, we’re going to talk about solar energy, and I have probably the best person in the world that I can think of to have here as a guest to talk about this subject.

My guest is John Perlin. He’s the author of Let It Shine: The 6000-Year Story of Solar Energy.

Now, the reason why we’re talking about solar energy today is because it’s a less toxic alternative to using fossil fuels which create toxic waste in their mining. I’m not sure if that’s the right word. But when they remove it from the earth, there’s toxic waste. When it gets processed, there’s toxic waste. And when it gets burned for energy, there’s toxic waste.

So, we can eliminate a lot of toxics in the environment by using solar energy.

I actually met John Perlin many years ago—we’ll find out if he remembers—when he had written a book called A Golden Thread: 2500 Years of Solar Architecture and Technology. He was a co-author of that book. And now, his new book, Let It Shine, he talks about the 6000-year story of solar energy.

So, a lot has happened. He’s obviously learned a lot more about solar energy. And when I read A Golden Thread, I couldn’t put it down. I just read it from cover to cover. I was so excited and so inspired because solar energy is a lot more than putting solar panels on your house.

And the thing that I immediately thought of was to use a solar oven. And I now live in Florida. And we have so much sunshine.

We could be using so much solar energy in so many ways, and we aren’t.

And so, this is why it’s important for us to talk about this, so that more people can hear about it.

Hi, John. Thanks for being on the show today.

JOHN PERLIN: Hi! And I do remember you.

DEBRA: Oh, good! I remember you. And when I saw your book I thought, “Oh, yes. Let’s have John on.”

JOHN PERLIN: Well, I hope you find Let It Shine as hard to put down as A Golden Thread.

DEBRA: Well, I actually haven’t started reading it yet. I glanced through it to see where you’re going with it. But I’m taking it with me. I’m going to the Natural Products Expo this afternoon, getting on a plane to Baltimore. And I’m taking it with me so I can read it on the plane, and in between doing other things.

I’m so glad that you have an updated book because your perspective is so unique and empowering. And we’re going to talk about all of these things today.

JOHN PERLIN: First of all, maybe we can do a second show after you read the book.

DEBRA: Well, we could! We absolutely could. And I’ll probably have more questions to ask you. But let’s start out with how did you get so interested in solar energy?

JOHN PERLIN: Well, it’s a long story, but to make it very short, when I was living in Jerusalem, I decided I wanted to be a writer, but I had no idea what I was going to write.

And then, what happened when I came back to America, I got involved in a debate in Santa Barbara, California whether oil, natural gas, was the only way we can fuel the world.

So, I spent—

DEBRA: Let me interrupt you for minute because I’m from California. In fact, I think I met you when I was in Santa Barbara.

So, for those of you who don’t know, Santa Barbara is an extremely beautiful place right on the Pacific Ocean. And off shore, there are oil wells. And there’s a lot of controversy about having those oil wells there. But they’re just unsightly if nothing else.

And they’re probably causing some pollution. And I don’t even know what all the issues are, but there are oil wells off the coast of Santa Barbara. You can just see them in a line.

JOHN PERLIN: Well, the thing was, is they wanted to bring it on shore and build a large refining plant using the argument there was no other choice to fuel America.

So, I went to the library, and explored the literature at the time, and found that solar was viable. And so, what I did was I testified at the supervisors’ meeting. And they liked my talk so much that the leading radio station said if I make a little book on that, they will give me all the air time possible.

So, I did that. And I had only 10 books that I made. And that sold out really quickly.

So then the librarian at Santa Barbara said he liked the book so much. It was a little book called “Solar Energy Fact Sheet.” I just sent it to a group that reviews such innovative, new literature. It was called a book legger. And they gave it a great review.

And suddenly, I was selling books all over the world.

And then, I got invited to a conference on solar energy and someone said, “If you think you guys are doing something new, back in the turn of the century, we had solar water heaters in Southern California.”
So, I thought, “Wow! What a story. No one knows about this. I’ll write a book on solar water heating in California.”

And then, I talked to an architect that had been around for longer than anyone else. And he said, “If you think this is new, when I was in architectural school, I learned that the Romans heated their baths with solar energy.”

And then, I went to University of California Santa Barbara to the Classics Department to find out where I could find information on this. And suddenly, one of the professors said, “Oh, if you think that’s new, you should explore the excavations at Olympus which talk about the Greeks using solar energy to heat all their houses and building all their cities so every house could use the heat of the sun.”

So, that’s how I began my foray into solar history.

DEBRA: And at the time, nobody else was writing about that. Wasn’t yours one of the first books that really discussed solar energy in the way that you discuss it?

JOHN PERLIN: It was the only book.

DEBRA: It was the only book.

JOHN PERLIN: Actually, that’s one of the interesting things about my work is that it’s primarily original archival research.

DEBRA: Yes. And you and I have a parallel in that about the same time I was starting to write about toxics. My book was the only book. I was in libraries looking up what kind of chemicals were in products in books that nobody ever read—medical books and poison control books and things like that.

And mine was the first book that somebody wrote about toxic chemicals in consumer products.

So, we both started within five years of each other, writing on subjects that nobody had written on before.

JOHN PERLIN: So, in this book, it’s twice as big—twice as long, I should say, twice as many pages of A Golden Thread because, once again, I don’t know, I just had my eyes out in the last 20 years for these historical materials.

For example, there were these Chinese scholars at the university. And their wives, although they have PhDs, they had no work. And I asked them a question and said, “Was solar architecture big in China?”

And they said, “Are you kidding? Today, when a house has a south-facing exposure, it’s 20% or 30% more valuable on the market.”

And so then I asked them do they know any historical antecedents?” And they said, “We all know about the literature.”

And so they went to all these books that were written 3000 years ago that no one in the US has ever seen. They translated them for me.

DEBRA: We need to take a break. And then we’ll be back, and we’ll talk more about this very fascinating subject.

You’re listening to Toxic Free Talk Radio. I’m Debra Lynn Dadd. And I am here with John Perlin, author of Let It Shine: The 6000-Year Story of Solar Energy. We’ll be right back.


DEBRA: You’re listening to Toxic Free Talk Radio. I’m Debra Lynn Dadd. And my guest today is John Perlin, and we’re talking about solar energy. He’s the author of Let It Shine: The 6000-Year Story of Solar Energy.

John, before we go any further, could you tell our listening audience what would be the savings of toxic chemical exposure by using solar energy? What is it replacing that we’re not going to have pollution of?

JOHN PERLIN: Well, first of all, greenhouse gases, all the solar technologies, lessen dramatically the amount of greenhouse gasses in the air. Second of all, in China, the pollution is so terrible. And they see photovoltaics as the only way of stopping the burning of coal, which is terribly, terribly toxic for humans, for everyone.

Also, the dream actually is that photovotaics can produce photovoltaics. In other words, have a breeder type of a plant where you have solar-producing solar.

So basically, I think wires are toxic also. And one of the things that solar does is allow everyone in the world to use their local energy source that’s been on our portfolio for 6000 years—but actually, has been on our portfolio for billions of years—the sun.

And most people believe that its abundancy will last at least another I think 14 billion years.

DEBRA: Yes, I think that’s a good and renewable enough resource. Is it called a renewable resource? Is it renewing itself? Is the sun renewing itself by continuing to burn or is it just a perpetual resource?

JOHN PERLIN: That’s a funny thing that you should mention. In astrophysics, it says it’s not renewable because it’s constantly burning fuel. It’s like a nuclear reaction that’s safely sited 93 million miles away.

So, it is using fuel. It’s not a perpetual motion machine, but the amount of fuel available will last about 16 billion years.

DEBRA: Okay, that’s enough. That is enough.

JOHN PERLIN: So, I guess when you consider coal or oil, the supplies will be only in the hundreds of years, possibly even less. When you look at the sun, it’s renewable in the sense that we don’t have to use any energy except to produce the panels themselves.

What’s interesting about that too is you can look at a solar electrical panel as basically a little mini electrical generator. And in about a year, it produces enough electricity to pay for all the electricity that went into making it.

DEBRA: And then how long does a photovoltaic last?

JOHN PERLIN: If built properly with proper back sheet, proper packaging, they should last 50 or 60 years at least. I mean, there are solar cells that were built in 1980 that are still producing as much electricity as they did 30, 40 years ago, which is amazing when you consider that it’s the only electronic material that’s exposed to night and day, snow and rain, and hot sun.

DEBRA: So, what kind of materials are solar cells made from?

JOHN PERLIN: Solar cells are made of—well, the primary solar cell used today is the silicon solar cell. And it’s made up of silicon which is one of the most abundant materials on the earth.

DEBRA: Is there anything toxic about it?

JOHN PERLIN: There are a few toxic elements. But if they are recycled, it is a very clean technology.

But I’d like to get into what the book covers. The book covers all the solar technologies. People don’t realize that there are various ways of using the sun. One is using the heat of the sun.

DEBRA: Actually, this is what I want to talk about the most because I think that people know that photovoltaic exists. But I want everybody to see that there are so many other ways. So just go ahead because that was what excited me the most.

JOHN PERLIN: First of all, just siting a building can really change the way a structure uses energy. For example, if you site your house just like the Chinese did 4000 years ago or 6000 years ago, or how the Greeks did, in the same fashion, or as the Romans did, or as in succeeding chapters, how the Europeans did in the 19th century, you can cover—depending on the climate you’re in—at least 60% of your energy needs.

And using glass, which was invented by the Romans, you can trap solar heat, so you can even get more heat inside the house.

What people don’t realize is one of the beauties of solar—they say, “Well, solar is too [diffuse].” Well, that’s the beauty of it because it fits the temperature that you want in your room, in your house, in your interior.

So, that’s one way. An interesting example is the proofreader was reading my book, and she said, “Now, I know why my house is so uncomfortable because it’s sited east west.” And east west, you get tremendous amounts of sun heat into the house during the summer time and almost no solar energy in the winter time.

While if you face your house south—I was in Turkey. They still build like they did 2500 years ago in Ancient Turkey. And even in 96 degree weather, in the hottest time of the day, if you go in the house, it’s comfortable.

DEBRA: Yes, I totally, totally agree with this. We need to take another break. We’ll be right back. And we’ll talk more about this.

You’re listening to Toxic Free Talk Radio. I’m Debra Lynn Dadd. And my guest today is John Perlin, author of Let It Shine: The 6000-Year Story of Solar Energy. And we’ll be right back with more about the history of how solar energy has been used.


DEBRA: You’re listening to Toxic Free Talk Radio. I’m Debra Lynn Dadd. And my guest today is John Perlin, author of the book Let It Shine: The 6000-Year Story of Solar Energy.

John, what proof do you have that solar power has been used for 6000 years?

JOHN PERLIN: Well, we have the archeological evidence from [unintelligible 18:30], which is a Neolithic community. Every house had a thatched roof. It was like wearing a hat. So it kept the high summer sun off the house and allow the low summer sun to go into the windows that were all faced south. And so, we have archeological proof.

And then 4000 years ago, we have, again, archeological proof that the big, big city called Erlitou not only had its buildings with, once again, a big hat, and on the north side of a south-facing courtyard where all the sun could come in during the winter months when it’s low. And the hat, you might say, of the building, kept the high summer sun off.

You might say it’s almost like God’s plan because, by having a building that’s stationary, we can design it so it could keep the hot summer sun off and allow the winter sun to enter.

I would like to get back to the different technologies that we have so people can know.

The next technology we have is called mirrors or concentrators. They’re called burning mirrors. And one of the real great science of the new book was that, 3000 years ago, the Chinese were using what they called solar igniters or thick mirrors that would focus the rays of the sun to a point, and they would ignite combustibles.

You have to understand. It was really difficult back in the old days to light a fire because you had to use friction. There were no matches. So, about 3000 years ago, the Chinese started using the sun to alleviate that problem. And they found molds for those mirrors—actually 30,000 molds to make. And they also found [caches] of the mirrors themselves.

And a very bright archeologist, he restored one of the mirrors, and then he shined it up. He had a fire going in maybe 15 or 16 seconds.

So there are solar mirrors that have also been with us for 3000 years that can provide power. And it also provide cooking.

Your stove that you talked about is a combination, I think, of glass that traps solar heat and also in the interior is like a mirror which then focuses more solar heat onto what you’re cooking. Isn’t that what it is?

DEBRA: Yes. I actually don’t have one. I was looking at building one. And I think it was lined with aluminum foil, so the foil acted as a reflector. And then you would put the food in a pot or a glass baking dish. And then it would create and it would bake.

I’m still very interested in doing that. I just need to do it.

I think that the first step is to be inspired and get the information to know what the different technologies are, and have the inspiration to do it. But then there’s also—I looked into putting solar panels on my roof, and it was some tens of thousands of dollars. And so that didn’t happen.

But I really want to see—especially here in Florida, I’d like to see a lot more solar just right here in my community, and in the State of Florida, because we have such a huge resource. And I’m looking at what’s an entry level thing that people could do and afford to do. And I think that solar ovens might be it.

JOHN PERLIN: Well, let me tell you what Florida did in the past. I actually was in Coral Gables.

DEBRA: I love Coral Gables!

JOHN PERLIN: And Coral Gables, if you look, they have these false chimneys that are made out of—I believe, it’s aluminum.

And what they are are storage tanks that either connect or used to connect to solar water heaters that were built during the ‘30s and the ‘20s and the ‘40s. And I had the luck to climb up to an apartment building roof, and see a solar water heater that was built in 1923 in Coral Gables that was still producing such heat that I could only keep my finger on the output pipe for a second.

So, that’s the amazing thing about the technology. That’s 90 years ago and still working.

DEBRA: Well, why do you think, since we had all these technologies—our modern method of heating and electricity and all of that is very industrial and only about 200 years old. Why do you think that all these old technologies are not in use? And do you think that we’re going to be able to bring them back?

JOHN PERLIN: Actually, first of all, it’s not true that they’re not in use. I was, for example, in Western Turkey, and every building, every house, had a solar water heater. In China, they have 60 million solar water heaters.

DEBRA: Well, I meant in America.

JOHN PERLIN: America is a special case. And that’s what my book does—it thinks internationally. And so the solar water heater which was developed in America has traveled or migrated throughout the world in places like Cyprus, places like Israel, places like China, places like Barbados. They’re producing the majority of the hot water for those countries.

Now, what it’s based on is glass as a solar heat trap, which the Romans discovered, and then in the 1700s, they tried to see how much glass could trap solar heat. And actually, you can build a very good oven that way—and they did—by just using insulation in a box, that has two or three glass covers.

DEBRA: I really, really want to do that. But we need to take another break. You’re listening to Toxic Free Talk Radio. I’m Debra Lynn Dadd, and my guest is John Perlin, author of Let It Shine: The 6000-Year Story of Solar Energy.

And if you want to go to his website, it’s John-Perlin, P-E-R-L-I-N, dot com. And we’ll be right back.


DEBRA: You’re listening to Toxic Free Talk Radio. I’m Debra Lynn Dadd. And my guest today is John Perlin, author of Let It Shine: The 6000-Year Story of Solar Energy. And if you’re interested in getting a copy of his book, you can go to, and click on the title or click on the book cover that’s there, and it will take you right to a place where you can order it.

John, I wanted to just also mention we’ve been talking about using the sun, but I want to also say that, here in Florida, instead of needing heat, what we need is to not have sun because it’s too hot here. And so, I know that one of the challenges I’m facing on my property is how can I keep my house cooler and be shielding my house from the sun instead of bringing the sun in?

And so I think that, in considering the sun, we can be considering how we can use the sun, but then also, how we can block the sun when it’s necessary in order to control temperature.

JOHN PERLIN: Actually, that’s what all the ancient cultures did. As I’ve said, they built a house—first of all, you have to face your house correctly.

DEBRA: Yes. I was thinking about that while you were thinking. I was thinking, “Well, let me just pick up my house and turn it around.”

JOHN PERLIN: Is your house facing east west?

DEBRA: The windows are all on the east and west side.

JOHN PERLIN: So, what you want to do is possibly look at the new windows that have thermal control in the glass. Secondly, what you want to do is insulate. And third of all, what you want to do is possibly build eaves, very long eaves, that will keep out the summer sun because you’re not going to get any winter sun anyway.

DEBRA: No, we don’t have much winter sun. But in the summer sun—I mean, my desk actually, where I’m sitting right now, faces east. And I have 17 feet of windows that look out into the garden. It’s very nice. But every morning, the sun shines right in, and I have to put a shade down or I can’t sit here.

And a friend of mine who’s an architect and is familiar with all these natural flows, she actually suggested that I put up some lattice, so that I can build a blind on it.

JOHN PERLIN: Exactly! I was just going to say that. What you can do is plant diurnal plants that have leaves during the summer time and shed those leaves during the winter time.

DEBRA: That would be great. Yes, I like that idea a lot.

JOHN PERLIN: So just getting back into the books so people know what it contains, one of the really massive uses of solar energy that remains today and no one thinks of it is making salt. What you do is you take very shallow [troughs] or you just allow the sea water to come into channels, and then you allow the sun to evaporate the water. And you have salt. That’s probably the biggest use of solar energy over the millennia.

And still, in San Francisco Bay, you see this pink area, and it’s producing solar salt.

DEBRA: Yes, especially when you fly into the airport. Everybody can see that when you fly into San Francisco.

JOHN PERLIN: That’s actually a solar salt plant. And the opposite or the inverse is producing fresh water. Instead of evaporating—when you evaporate the water, you collect it on the surface, and allow it to trickle down, and allow the salt to collect in the middle of your solar still. That saved thousands of air men in World War II and is still a standard fair for everyone in the air force. So, there you have solar saving, saving lots of lives.

And to get to solar cells, the first solar cells were actually discovered in the 1870s.

DEBRA: I didn’t know that.

JOHN PERLIN: Actually, in the book, there’s a picture of the first solar module. The problem was, because they didn’t have the science, they didn’t realize that their solar cells were very inefficient.

And then in the ‘50s, with silicon, they discovered how to make very efficient solar cells and they became the power house of the satellites. And what people don’t realize is that all modern light is run by satellites, and all satellites are run by solar cells.

DEBRA: Wow! So we’re using it in many, many more ways than I think that the average person even realizes.

JOHN PERLIN: For example, when you do a bank transaction, or when you pump gas, all that is run by satellite. If you look at the top at the roof of the building, there’s a little microwave fixture. And the microwave repeater sends the transaction to a satellite. The satellite sends it to a hub or its central company. And then the transaction is done in milliseconds.

And also, cell phones, for example, would have never existed without satellites, of course—GPS, I could go on and on, CNN.

All those that we take for granted are products of satellites run by solar cells.

DEBRA: Well, so it really is in our culture even though we don’t know it. How can people who are not using solar in their homes get started?

JOHN PERLIN: Well, first of all, your house, try to make the house as best a solar collector during the winter time and as a solar avoider during the summer. You’d save lots of money. You probably could coat your glass, for example, with a tint, a material that would keep a lot of the sunlight out for example.

DEBRA: That’s something people do here actually.

JOHN PERLIN: And now, like I said, they’re developing smart glass which can actually not only keep the heat in during winter time, the heat out during the summer time, but also can produce electricity. So, by replacing glass, that’s another way.

Also, they can do what they did in Florida in the 1920s and 1930s, if they can do it then, they certainly can do it today, is have a solar water heater.

I don’t know when you were quoted […]?

DEBRA: It was several years ago. Are the prices coming down?

JOHN PERLIN: That’s the big secret that no one knows. The price of solar cells has dropped below a dollar a watt—and so, by a factor of four. And that’s why photovoltaics where every house can become its own producer is actually seen now by many utilities as a threat to their existence because, rather than being powered from a distant central generating plant, your rooftop can become a power source.

And the beauty of that is transmission losses are about 30% and all of that is avoided because you’re using the electricity that’s produced on your roof in your home.

DEBRA: I could really see that every house could have solar cells on them. So are there programs that help people finance them and things like that?

JOHN PERLIN: There are several companies like Solar City that actually lease photovoltaics. And what happens is they charge you less than your utility bill, and then they get all the subsidies and benefits that are available. And so that’s how they make money.

I don’t know how it is in Florida, but in California, solar actually is the least expensive way of producing electricity at this moment.

DEBRA: I’m going to look into that. I wish we could talk about it more, but we’ve only got about one minute left in the show. So I want to give you the opportunity to say whatever you’d like to say in closing that we haven’t yet covered.

JOHN PERLIN: I think the book provides the background story behind today’s worldwide solar revolution which is really, really happening. Everywhere, we have gone from maybe 360 kilowatts in 1977 to 100 gigawatts today in photovoltaics.

But also, in solar water heating, we have gone from about 60 or 70 gigawatts equivalent to about 300 today.

So now, the essentials are covered by solar energy like I said on the satellites. But also, solar energy is the fastest growing energy source in the world. And this is what Amory Lovins says. “Let It Shine show how today’s renewable revolution builds on the tenacious efforts of countless generations of innovators whose vision we may finally be privileged enough to bring into full flower.”

DEBRA: And I have to interrupt you because we’re at the end and the music is going to come on. Thank you so much, John Perlin.

You’re listening to Toxic Free Talk Radio. I’m Debra Lynn Dadd.


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