ENERGY FROM THE SUN

IT’S EARLY SEPTEMBER. In the schools around Boston, young people are meeting up with their friends after the long summer vacation and settling into new classes with unfamiliar teachers. Fresh from their summer with me on Cape Cod, Tom and Julie are happy to be attending the same middle school together. As an eighth-grader, Tom is a veteran. For Julie, in grade six, this school is a whole new adventure.

Both kids are excited about Tom’s brainstorm from the end of vacation. They’re eager to get their classmates and teachers to work with them on the challenge of our warming planet, by doing special studies on clean energy—power from the sun, wind, and water.

Tom really wants to find out how solar power works, so about a week after returning to school, he tries out the idea on his Earth science teacher, Mrs. Flannery.

“I like your idea, Tom. You know, our classwork this year focuses a lot on energy.” She tells Tom that he needs to find two classmates to work with him, forming a solar power team. “First, you’ll need come up with a project proposal,” she says. “I’ll review that and discuss it with your team before you start your research.”

Julie tells her sixth-grade teacher that she wants to learn about how energy can come from water. Ms. Rogers is interested but says the class will be too busy for the first few weeks of school to fit in a special project. “Let’s talk about it soon, Julie,” she promises. “Meanwhile, why don’t you think about which other students you might ask to work with you?”

Tom has the go-ahead to start right away, and he has two boys in mind as project teammates. Paul is one of his oldest friends. They met at day care when they were four years old and have gone to school together ever since. Paul is a tall, gangly guy with a tangle of sandy-colored hair and big feet. He’s kind of clumsy and not much of an athlete, but he’s always been interested in science and really knows a lot.

Tom met José two years ago when they joined the same club soccer team. José is a short, wiry kid with a buzz cut and brown eyes that shine with mischief. They are still playing club soccer together—Tom says José is one of the best players on their team.

Soon after speaking with Mrs. Flannery, Tom gathers his team in the lunchroom. “I’ve got this cool idea for a special project in Earth science class,” he says when they’re all seated. “It’s about solar energy and how solar panels work. Mrs. Flannery says I need a couple of other people to work on it with me.”

Paul shakes his carton of chocolate milk. “Solar energy,” he says, opening the carton, “that’s interesting. My dad was talking about maybe putting solar panels on the roof of our house.”

José has already shoveled a forkful of mac and cheese into his mouth. “Sounds cool,” he mumbles while munching. “I’m up for it. Do we get extra credit?”

Tom grins and attacks his helping of pasta. “I’m pretty sure we would.” He wipes his chin with his napkin. “First, we need to come up with a project proposal for her to approve, Mrs. Flannery says.”

“No problem,” Paul responds. He’s brought his own lunch—a chicken salad sandwich on what looks like homemade bread, carrot sticks, and an apple. “That’ll help us figure out what we want to do, anyway. Let’s work on an outline during study hall.”

That evening I get an e-mail from Tom. He tells me that Paul and José have joined up for his solar energy project. They’ve already put together a simple project outline with assignments for each boy. They plan to turn this in to Mrs. Flannery in the morning, and Tom wants me to look at it and give him some feedback first.

This is attached to his e-mail:

Sun, Wind, and Water by Mon Cochran

As Tom explains to me, each team member will research the answers to two of the questions. All three will work together on the hardest question, the one about how solar panels actually capture the sun’s energy and turn it into electricity. They have six weeks to finish the project, then they’ll present it to their class early in November.
 
I CHECK IN WITH TOM a couple weeks after Mrs. Flannery okayed the solar energy project. He reports that the team is meeting three times every week during study hall periods at school. And he says his research on Question 1—why we need to capture the sun’s energy—is coming along well.

A week later, he calls me back. “Gramps, I’m going to send you what I’ve got so far in an e-mail. Can we talk after you look at it?”

The outline Tom sends looks like this:

Sun, Wind, and Water by Mon Cochran

I make a few notes on Tom’s outline, then call him the next night after dinner. I’m sitting in front of my computer so I can look at his work while we talk.

“I can see you’ve been working hard on your project.”

“Hi, Gramps! How do you like my explanation for why we need more solar energy?”

“I like it a lot,” I respond. “The Gas Guy learned quite a bit about the atmosphere last summer, didn’t he?”

Tom laughs. “It’s true,” he agrees. “What I learned about carbon dioxide and how it’s making the atmosphere more dense really helped me with this question. Also, knowing what fossil fuels are and where they came from, millions of years ago—that helped too.”

Tom can’t see me smiling as he talks. “I was thinking of that ‘Threats to Gaia’ list you made at the end of the summer,” I remind him. “Remember? You listed Humans burning fossil fuels as a threat because that sends more carbon dioxide into the air.”

“That’s right,” he confirms. “The main reason we like the idea of solar energy is because it’s clean. With solar power you don’t burn coal or oil, so you don’t put those greenhouse gases like carbon dioxide into the air.”

I’m wondering how Tom’s team will teach their class about the problems caused by burning fossil fuels. “Are there any pictures or videos on the Internet that you could use for your presentation?”

“Sure. I’m going to use some of the things we found last summer—like the picture of Mars, Venus, and Earth side by side, and the one about what happens to the sun’s heat when it shines on the Earth. Also the one showing the carbon cycle. We only have half an hour, so I can’t use too many pictures.”

“How about José and Paul? How’s their research coming along?”

“They’re finding some really good stuff. Today José told me he discovered some great information about how much energy from the sun hits the Earth each day. He’s also figuring out how much energy a typical house uses.”

Slides for Tom’s Presentation

 

The Earth is blue because three-quarters of its surface is covered with oceans.

 

Slides for Tom’s Presentation

 

Earth is one of eight planets that revolve around our sun.

 

Slides for Tom’s Presentation

 

Venus is too hot for life because its atmosphere is very dense. Mars is too cold for life because it has very little atmosphere. On Earth, the atmosphere is just right to support life.

 

Slides for Tom’s Presentation

 

This view from space shows the different layers of Earth’s atmosphere.

 

Slides for Tom’s Presentation

 

More and more of the sun’s energy that reaches Earth is being trapped by our atmosphere, causing our climate to warm up.

 

Slides for Tom’s Presentation

 

The leaves on plants take carbon dioxide gas out of the atmosphere, in a process called photosynthesis. This helps keep our atmosphere just right for life.

 

Slides for Tom’s Presentation

 

In the natural carbon cycle (green arrows), the same amount of carbon dioxide that enters the atmosphere is taken out again by plants. The black arrows show how burning fossil fuels overloads the atmosphere with carbon dioxide.

 

Carbon dioxide is making the atmosphere denser.

I tell Tom I’d be interested in hearing about José’s part of the project, and Tom promises to let him know. I don’t hear any more for a while, then suddenly an e-mail from José pops up in my inbox.

Tom has a really organized mind, so he’s good at putting things in an outline. José is more of a storyteller, so he wrote out his report like this:

Sun, Wind, and Water by Mon Cochran

I want to meet José, too. I e-mail back to thank him for sharing his research, and I’m happy when Tom invites me to their next team meeting.

“You can hear what Paul’s been learning about different ways to capture energy from the sun, Gramps,” he says. “And maybe help us figure out how a solar panel works.”
 
LATE ON THE NEXT TUESDAY MORNING, I pull up in front of Roslindale Middle School. Tom got excused from study hall to meet me. He shows me where to park my car, then leads me on a winding route through the corridors until we arrive at his science classroom. They’ve been spending their study hall time there to meet about the project, with the teacher on hand to help out now and then.

“Welcome, Gramps!” Mrs. Flannery grins as she greets me. She’s not as young as my grandchildren, but she looks pretty young to me. Tom says she’s really smart. She nods toward a table in one corner, where José and Paul are sitting. When Tom and I join them, they both push back their chairs to stand and say hi.

I’ve watched José playing soccer with Tom on their club team, but this is the first time we’ve actually met. He’s wearing a soccer jersey and gives me a big smile. Paul and I have met several times—years ago at the day care center he and Tom both went to, and more recently at birthday parties. Today I see a serious-looking young man with wire-rimmed glasses and a long-sleeved shirt with a collar. He shakes my hand quite formally.

“Okay, Gramps,” Tom says after we all sit down again. “We want to get you caught up on our research about solar energy, and then talk about solar panels.

“You already know why we think solar energy is important, and how much energy the sun shines on Earth each day, and how much energy a typical home uses. Now Paul’s going to tell you about some of the
different ways we can capture the sun’s energy.”

Paul looks up at me a little nervously. “First,” he says, “let me tell you what we’re not going to talk about. We know that nature has a special way of capturing energy from the sun, called photosynthesis. Tom said you learned about that last summer. And Mrs. Flannery taught our class how plants use photosynthesis to turn sunlight into oxygen and energy for growing plants.

“But that’s different, and only plants can do it. Our team is interested how humans can use energy from the sun in other ways.”

“Sounds good,” I reply. I want Paul to relax and to know that I’m very interested in what he has learned. “What other ways are we talking about?”

“The two main ways we can capture the sun’s energy are called passive and active,” Paul explains. “Passive means that you just let the sun shine into a space and heat it up. Then you hold the heat inside so the air will stay warm for as long as possible.”

“If I want to build a house that’s heated with passive solar energy, what should I do?” I ask.

Paul smiles because he knows the answer. “First, you should face the long side of the house toward the sun,” he begins. “That means facing south. Then you want to make sure there’s lots of glass on that side of the house—like windows and glass doors.”

He turns to the laptop set up on the table. “Here’s a picture of a passive solar home. Notice how much glass there is on the sunny side.”

Sun, Wind, and Water by Mon Cochran
A Passive Solar Home
This house is designed to let in as much solar energy as possible through windows and glass doors.

 
Tom glances at me with a question in his eyes. “Your house on the Cape … doesn’t it use passive solar heat?”

“It does,” I say, nodding. “We were careful to design it with the long side facing south, into the sun, like Paul says. And we put lots of windows and glass doors on that side. So even when it’s below freezing outside in the winter, as long as the sun is shining, most of the rooms inside are toasty warm. We don’t need to use the furnace much at all.”

Paul clicks the computer mouse, and another picture comes up on the screen. To my surprise it shows the front of our house on the Cape, with glass doors and windows on both floors.

“That’s a picture I took last summer,” Tom explains. “I remember how we’d open all the doors and windows to let in the cool breezes.”

“Right,” I agree. “So in the summer it uses passive cooling instead of air conditioning. But in the winter the sun pours in through all the glass and warms the air, kind of like a greenhouse.”

Sun, Wind, and Water by Mon Cochran
The House that Gramps Built
This house faces south, toward the sun, and contains lots of glass so the sun can warm it up in the winter.

 
Mrs. Flannery comes over to see how we’re doing.

“I’m impressed by how much these guys are learning about energy from the sun and how to make use of it,” I tell her, gesturing toward the team.

“I am, too,” she agrees. “Their project is coming along.” She turns her attention to the boys. “Remember, there’s only two more weeks until your presentation. Didn’t you say that figuring out how solar panels produce power was the most complicated part? Have you made any progress on that?”

The three of them make eye contact, looking a little uneasy. It’s José who speaks up. “Yeah … but a lot of things go into it. We have to decide how to tell the story.”

I stand up and stretch.

“Well, let’s take a quick break—then we can see how far you’ve gotten.

Continue to Chapter 2: Solar Panels and Where to Put Them