On Wednesday September 14, 2005 the sophomores from Comfrey visited Chandler Hills Wind Farms in Chandler, MN to learn about wind turbines. Each farm is set up on a 20 year contract and after the 20 years is up the turbines are taken down and either replaced or the land is put back to its original state.
We hopped on a bus in Chandler and went about a mile out of town to the Chandler Hills Wind Farms. On this farm there were nine turbines, three were put up in 1998 and the other six in 2001. When we arrived we learned that one megawatt of electricity powers 300 homes. The turbines that we looked at only produce 660 kilowatts, so they power only 200 homes each.
The turbine itself was 215 feet high. Its cement went 32 feet into the ground. The blades were 77 feet long each and were going 125 mph at the tips on that day. The head on top is big enough to drive a van through and it can turn 720 degrees to find the wind until it shuts down and unwinds itself. If the wind gets over 50 mph the turbines shut down so they don’t get ruined. A 10-mph wind is needed to produce electricity but a 17-mph wind is ideal. They like up drafts so hills are a good spot for them.
The generator is at the top and it sends the electricity down the tower and out to a transformer right outside the tower. Then it goes to the substation through lines under the ground. Winter is the windiest season, so they try to have all the maintenance done by that time.
10th Grade Class Tours Chandler Hills Wind Farm
On Wednesday, September 14, 2005, the sophmore class of Comfrey took a tour of the Chandler Hills Wind Farm in Chandler, Minnesota. The class took the tour to gain a better understanding of how the wind turbines work and how they are important to the future of energy. The tour was put on by Great River Energy, and around 125 people attended.
The nine turbine wind farm generates power and sells it to Great River Energy, the second largest energy distributer in Minnesota. Great River Energy presides over 28 electric co-ops in the state, including the local Brown County Rural Electric Association. The wind farm itself is just a small portion of the thousands of wind turbines on the Buffalo Ridge.
Nine turbines are located on the farm, just south of Chandler. The first three were put up in 1999, the next six were put up in 2001. There are two types of turbines on the farm, depending on how much they are able to produce. The one the class got to go inside was considered a one megawatt turbine. The model is a V74, built by Vesta from overseas. It is 210 feet tall, and contains a generator and the turbine blades at the top. The blades are 77 feet long. They are electronically controlled so they tell which way the wind is blowing from and turn into them. The pitch of the blade can also be adjusted for maximum efficiency. If the wind gets above 50 miles per hour, the turbine automatically shuts down. The other turbine is capable of producing 2-3 megawatts, and that is 80 meters tall.
The spinning blades spin a generator at the top, which produces electricity. The power is sent through wires to the bottom of the turbine and into a control box. Here, workers can shut down the turbine if it needs to be worked on. The control box also displays other information such as power produced, blade rotations per minute, and blade pitch. The power is then sent out to a transformer, which sends the power out to be distributed.
The power is distributed through a project called Wellspring, which sells the energy to customers in 100 kilowatt-hour blocks. An average household, however, uses 800 kilowatt-hours a month. As energy companies look to build more turbines for future power, they will also have to work on replacing old turbines, which last about 20 years.
It was a very interesting trip.
