Engineer Harvey Williams’ presentation on renewable energy blew away an excited group of Scotia-Glenville seventh graders recently.
Williams, who is head of project operations for GE Wind Energy, explained the basics of collecting wind power with massive turbines to students in a class taught by science teacher Sheri Matthews and special education teacher Kevin Warren.
Warren knows Williams and persuaded him to come to the school last week to discuss alternative energy as the class has been working on a project to design ways to save money and energy at the school. The students have studied a hydrogen cell and examined ways to increase gasoline mileage in cars.
Williams explained that much like an airplane’s wing is designed to help provide lift, a turbine’s blades are shaped in similarly — shorter on the bottom than on top. Because the air has to travel farther, the air is less dense on top.
“The pressure underneath is greater than the pressure up above and the wing rises,” he said.
An anemometer measures the wind speed and sends a signal to a computer on the ground to change the direction and pitch of the turbine blades to match the direction and speed of the wind. The goal is to have the turbine spin at a constant rate of speed.
One of these turbines can generate 1.5 megawatts of electricity — 1.5 million watts. That is enough electricity to power 500 houses, 1,200 hair dryers, 25,000 light bulbs and 652,000 GameBoys, according to Williams.
Although some wind turbines are located in the more mountainous areas of the Northeast and on the Pacific coast, Williams said they are primarily placed in the Midwest.
“The wind blows all the time because the land is flat,” he said.
The huge structures rise 262 feet above the ground and are 126 feet long. They can operate in winds as little as 7 miles per hour and up to 62 miles per hour. The blades rotate about 10 to 20 times per minute.
Farms are becoming popular locations for the turbines as farmers can collect royalty payments for allowing the structures to be placed on their property. Even better, there is little farming area lost as the turbines do not take up much ground space.
“The cows will walk right up around them. It doesn’t bother them,” he said.
During the last few years, GE has installed more than 17,000 of these wind turbines around the world, according to Williams.
Students peppered Williams with questions including asking about what it would take for the turbine to break.
He could only recall two or three turbines breaking in the last 10 years because they couldn’t be adjusted when the wind was spinning them too quickly.
One student excitedly asked how much one of these turbines would cost.
“If you wanted to buy one, get your dad to write a check for $2 million and we’ll bring one to your house,” Williams quipped.
Williams offered an example of wind powering a community. The 5,000 residents of Kodiak Island in Alaska get 60 percent of their electricity from three GE-installed wind turbines. They replaced very expensive diesel power.
Williams also gave tips to students designing their own renewable energy projects including analyzing the cost to produce the energy.
“You have to think about how much it is going to cost to put the project together and how much electricity are you going to get out of it,” he said.
Ava Soule, 12, said she enjoyed learning about wind turbines. “They’re really big. It would be cool to see one in person,” she said.
Student Nick Thomas, 12, of Glenville said his grandfather used to take him to see windmills.
His team’s project is about saving paper.
“We’re trying to see how many pieces of paper come from a tree. We’re trying to reduce the paper use at school — maybe taking online quizzes instead of paper quizzes,” he said.