Picture of Sun on screen
David Emer: The Sun, reaching temperatures of 11,000°F, releases 5 million tons of matter into pure energy every second. For centuries civilizations have realized the awesome power of the Sun and some like the Incas have worshipped it. But along with worshiping it, the Ancient Egyptians used its energy to keep their homes warm. In recent times, people have found other ways to heat their homes like using natural gases and coal but these resources are limited and can cause irreversible damage to the environment. But today, with a new sense of responsibility people are starting to change their ways and are beginning to once again use the power of Sun for solar heating.
Music. Zooming in on news desk.
David Emer: Welcome To New Frontiers. I’m David Emer. In this special edition of New Frontiers we’ll take a look at ways to use solar energy for heat, the problems with using natural gases and coal for heat, and then finally we will talk to two designers who are building solar homes. Rebecca Nourse Van Meter, who is a professor of solar energy at Yale, now joins me. She has designed a solar heating system using water storage and transfer. Thank you for joining us today, professor.
Becky Nourse Van Meter: Thank you, it is my pleasure.
David Emer: Professor, Could you tell us about solar energy?
Becky Nourse Van Meter: Solar energy is created by the Sun through a process known as nuclear fusion. Nuclear fusion is a complicated process. In simple terms, it occurs when four hydrogen nuclei are converted into one helium nucleus in the Sun. In this process, every second, an incredible 5 million tons of matter are converted into pure energy and are released through this process. Not all of the energy goes to the Earth and some of it is scattered, absorbed or reflected by the atmosphere. But there still is enough energy to create a vast array of living things on Earth.
David Emer: Is there a way to harness this energy?
Becky Nourse Van Meter: Yes, one early form is actually wind mills because the Sun causes winds, which then allows people to either create electricity or in early days to grind wheat. Energy from the Sun can also be used for solar cells, which converts solar energy into electricity using semiconductors. When the semi-conductor absorbs light, electrons are freed, which create an electric current. Another use of solar energy is for heating.
David Emer: You have studied the use of solar energy for heating right?
Becky Nourse Van Meter: Yes, I have designed a passive solar heating system using water.
David Emer: What does passive heating signify?
Becky Nourse Van Meter: True passive solar heating would occur when heat is simply being soaked up by the house but my water system can still be called passive because the heat is only be stored and not being transferred into electricity like in a solar cell.
David Emer: So, how does your system work?
Becky Nourse Van Meter: It’s quite simple actually. During the day, the oversized glass windows that face the south let in the sun, which heats the house. While the windows are at work heating the house, my solar collector transfers the heat gathered by the sun in to a tube filled with water. The water in the tube gets circulated around the house by a pump located in a water tank beside the house. Then, the heated water releases the heat as it goes around the house, thus, heating the house. Once the house is heated you may turn off the pump to stop the circulation of the water.
David Emer: Thank you Professor Nourse Van Meter. Now we will take a short break and then we will talk to professor of Petroleum, Oliver Hong about the problems of using natural gases and coal for heating. Now joining us is Dr. Oliver Hong from the Mass. Institute of Tech. He has studied the uses of petroleum for the last 2 decades.
David Emer: How are most homes heated, today?
Oliver Hong: Most homes are heated through a system invented in the 1800s known as central heating. In a home or building, there is a device known as a furnace where heat is produced by burning oil, natural gas or coal. Then, water, steam or air is used to transfer the heat throughout the house.
David Emer: Is there a limit to how long these methods of heating can be used?
Oliver Hong: Yes, most definitely. Petroleum and natural gas are in the most danger of running out. Many experts have predicted that oil will no longer be a common commercial material by the mid-21st century. Petroleum and natural gas are formed from the deposition of marine organisms. It takes millions of years for remains of marine organisms to transform into usable oil and natural gas. We are using up the natural gases and oil at a faster rate than they are being reproduced.
David Emer: What about coal?
Oliver Hong: Coal is much less in danger of running out but it has very significant environmental hazards. It releases many dangerous chemicals into the air and is a known cause of global warming. Global warming occurs from a process known as the greenhouse effect.
David Emer: What is the greenhouse effect?
Oliver Hong: It has to do with carbon dioxide. Naturally, the Carbon Dioxide produced by plants allows the Earth to absorb heat and stay habitable for all the living organisms of this Earth. However, with new technologies including the burning of coal, too much Carbon Dioxide is getting trapped in the atmosphere and too much heat is retained causing the Earth to get too warm.
David Emer: Are there any other problems with coal?
Oliver Hong: Coal is also dangerous to mine because explosions are common and prolonged exposure to coal can cause damage to the lung tissue of the miners.
David Emer: Are there hazards related to the use of fossil fuels?
Oliver Hong: Yes, fossil fuels also cause global warming because they give off carbon dioxide when they are burned in large quantities. There are restrictions on the amount of sulfur dioxide that can be released into the air but regulations still allow some of the dangerous substance to be released into the air. Oil spills have been a hard issue to deal with and are an environmental threat. Most recently, many of us can remember the Exxon Valdez spill off the coast of Alaska. Oh and one more thing. Politically, it is very bad for the United States to use fossil fuels because it gives the Arab countries a potential weapon against us with oil. This year, Iraq put an oil embargo on us and there was a much larger one in the ‘70s.
David Emer: So, what is you suggestion?
Oliver Hong: I truly believe in the clean, efficient method of using solar energy. Solar energy is clean, efficient and should last us for the next 5 billion years. Thank you Dr. Hong. We will now take a short commercial break and then be joined by the designers of a solar home.
In the Other Section
David Emer: Welcome back. Haoshu Yang and Ning Qin of Hingkorp Industries who have designed a solar home using Dr. Nourse Van Meter’s water heat transfer system now join me. Good evening to both of you.
Haoshu Yang: Good evening
Ning Qin: Good evening
David Emer: So, this is the model of what your solar homes will look like, right? When will you begin selling them to the public?
Haoshu Yang: We will begin selling them in 2003.
David Emer: Can you explain how the heating system works?
Ning Qin: Well, during the day, the glass helps absorb heat and keep the heat in the house, similar to the way a greenhouse works, which also absorbs heat and traps it inside. Notice that the glass is facing the south, this is because that is where the sun at noon time shines most directly in the northern hemisphere.
David Emer: How does the house use Dr. Nourse Van Meter’s water transfer system?
Haoshu Yang: The water is needed to absorb heat and store it at night. The glass absorbs and holds the heat of the Sun into the water during the day. Then a pump is used to carry the water around the house and heat up the house.
David Emer: What stops the people from getting too hot during the summer with huge glass windows in front?
Ning Qin: Well, as you can see right now the glass of the windows is pointed 60 degrees so that the winter Sun shines directly on the glass. In order to point towards the winter Sun, the windows must be pointed perpendicularly to the direction which the rays hit the ground. During the winter, the rays hit the northern hemisphere at 30 to 40 degrees. Then, during the summer the huge windows will be pulled back to point at 70 degrees so that the windows don’t point at the summer Sun, which hits the northern hemisphere at 70 degrees. The angle of the roof can be changed between seasons and the window angles can also be changed depending on where in the world the home is located. Two people can easily pick up the glass to readjust the angle of the windows when needed. If you need help you can call a representative at Hingkorp Industries.
David Emer: Are there any others ways to block the Sun when needed?
Haoshu Yang: We will also be planting trees or building around existing trees. (Pointing at front) This allows heat to stop entering the house during the summer when there are leaves blocking the Sun and during the winter when the leaves fall, the Sun is let in.
David Emer: Is there any form of ventilation system?
Haoshu Yang: Yes, as you can see there is a fan in the top corner of the ceiling that pushes out the warm air in the house and circulates fresh air from the outside.
David Emer: I’ve read that overhangs can also be used to block out the summer sun but let in the winter sun due to the angle of the Sun’s rays. Do you have one?
Haoshu Yang: Yes, it serves a vital purpose too. It blocks out the Sun during the summer when the rays of the Sun hit the northern hemisphere at a higher angle and lets the Sun in during the winter when the rays hit at a lower angle.
David Emer: I notice that the model is made out of a very nice foam board but I don’t think it will hold up to the New England winters. What will the real houses be made of?
Ning Qin: They will be made of brick on the inside and outside because brick is good at absorbing heat and then holding heat. Brick actually has about the same thermal conductivity rate as glass. As you can see, glass makes up the other parts of the house.
David Emer: Do the tiles help the efficiency of your design?
Haoshu Yang: Yes, most definitely. The tiles are also good at absorbing heat because they are ceramic and are black.
David Emer: Ok, thank you very much for talking to us.
Haoshu Yang: It’s our pleasure.
David Emer: Now, we will take another short commercial break before wrapping up.
David Emer: Welcome back. If you would like more information about solar energy log onto our web site at New Frontiers: Solar Energy
Be sure to join us next week where we discuss the grave dangers of soil erosion with another panel of expert scientists. That will be all for now. We will end to the tune of Smashmouth’s, “Walkin’ On the Sun.” Good night everyone.
Disclaimer: Oliver Hong and Rebecca Nourse Van Meter are not professors as MIT and Yale, respectively. Hingkorp Industries also does not exist. The video was really made at Acton Boxborough Regional High School and a model solar home was built. At the time, Ning and Haoshu have little interest in starting a real company though. So, we think.