WIND WHAT IS wind WINDenergy? ENERGY? What is Wind is air on the move. Each air molecule has Wind energy generated harnessing kinetic energyisbecause it is by moving. The energy of the the combined kinetic the wind andwind is theisworld’s fastest growing energy of all of the molecules. The wind is a energy source. It’s becoming more important free and renewable sourcetoofuse energy, it is for electricity companies wind and energy the world’s fastest-growing as it’s a renewable and free electricity resource. resource. How is electricity generated from wind? HOW IS ELECTRICITY GENERATED FROM Electricity companies harness wind energy WIND? with wind turbines. When the wind flows Electricity companies catch the energy of the past using the turbine’s rotor blades, thefarm’ blades wind wind turbines. A ‘wind will turn and convert the wind energy into kinetic often contain many identical turbines. When energy. energy spins rotor inside the windThis flows through theablades of a a generator where the kinetic energy turbine, they rotate and spin, poweringisa rotor converted into electrical energy. electricity. inside a generator and producing Each turbine works independently. The Once the wind energy is converted into electricity flows through cables in the turbine, electricity, flows and through cables flows downthe theelectricity turbine tower combines in the theother turbine tower to with theturbine, energy down from the wind turbines with thebefore outputentering from thethe other wind inconnect the wind farm local turbines innetwork the wind before entering local electricity orfarm the national grid, which electricity networks. The greater the wind provides power to New Zealand. speed, the more electrical energy generated. WHAT’S INSIDE A WIND TURBINE? You’llwind usually see more than wind Each turbine has four keyone parts. turbine working to generate electricity – this is called a wind farm. All the wind turbines in Foundation The foundation holds the turbine in place in a wind farm work independently. The output the ground. A wind turbine has to have a of each turbine is combined before it enters strong foundation to handle strong winds and a local electricity network or the National Grid support the overall height and the length of What’s inside a wind turbine? the blades. Each wind turbine has four key parts: Foundation: The foundation holds the turbine in place in the ground. A wind turbine has to Tower Generation equipment is kept in the tower. have a strong foundation to and withstand strong The tower raises the blades generation winds and support the overall heightinto andthe the equipment high above the ground smoother, stronger wind currents. Access to length of the rotor blades. the nacelle and rotor is through the tower. Tower: Generation equipment is kept in the tower. The tower raises the blades and Nacelle generation above the ground The nacelleequipment is the hearthigh of the turbine, where into the smoother, stronger wind are currents. the generator, gearbox and rotor held. Access to the nacelle andnacelle rotor isisthrough The generator inside the used to convert the wind energy into electrical the tower. energy. Nacelle: The nacelle is the heart of the turbine, Blades where the generator, gearbox and drive train are held.that Mostturbine wind turbines haveparts three blades The generatortoinside the nacelle is used are attached the rotor. The longer theto convert the the wind energy blades and faster theinto windkinetic speed,energy the and then electrical energy. higher theinto possible output power. The blades are tested thoroughly to ensure that they will Rotor: wind severe turbines have three blades handleMost the most weather conditions that are attached to the rotor. Blades in wind expected at the wind farm. turbines are tested thoroughly to ensure that they will stand up to the most severe weather conditions. Are wind turbines safe to use? Each wind turbine has an internal computer system that monitors the direction and speed of the wind, and allows it to automatically set itself to operate at a safe level. If there is any damage to the turbine due to overcapacity (wind speed and strength), the turbines shut down automatically. RENEWABLE ENERGY AT HAU NUI WIND FARM, WAIRARAPA SOURCE: GENESIS ENERGY What are the advantages of wind energy? The greatest benefit of using wind energy is This work is copyright. The copying, adapting or issuing of this work to the public on a non-profit basis is welcome. No other use of this work is permitted without the prior consent of the copyright holder. From ElectroCity www.electrocity.co.nz © Genesis Energy 2010. ARE WIND TURBINES SAFE? that generates electricity withoutcomputer emitting Eachitwind turbine has an internal greenhouse Wind hasand little system that gases. monitors theenergy direction effect this automatically is because: speedon of the the environment, wind. The system sets itself to operate at a safe level. If the • wind energy is a renewa ble res ource, wind speed exceeds a safe level or if there is sodamage it can never run out the computer will any to the turbine, •shut thethe re aturbine re no em is s ion s when generusually a ting down automatically, from windinto the wind so they byelectricity twisting the blades don’t turn the turbine. Wind farms lessen the need for us to use fossil fuels to generate electricity, which helps WHAT ARE THE ADVANTAGES OF WIND to reduce greenhouse gas emissions. ENERGY What areenergy the disadvantages of wind energy? Wind is a renewable resource, so it will never runenergy out. is a great Although wind Wind energy has little direct effect on the environmentally friendly option to generate environment, as there are no greenhouse electricity, a lot of turbines are needed in one gas or heat emissions or other pollutants. place in order to generate power forof up to Modern turbines with capacities communities use.wind Somefarms people think they 1 MW meantothat of between 100 have a negative visual impactThese on theare and 150 MW are practical. landscape and are comparable withnoisy. many existing hydro and geothermal power stations in New Zealand. How is windcan energy used in and Newrepaired Zealand? Turbines be serviced individually without the need close down Wind energy plays a useful role intoenergy an entire wind farm. generation for New Zealand. There are Once a wind farm has been constructed, the currently seven wind farms in operation in land can still be used for other purposes, New Zealand. Combined, these wind farms such as farming or agriculture. have a capacity of 170MW, which will produce enough energy for aboutOF 75,000 WHAT ARE THE DISADVANTAGES WIND average New Zealand households. ENERGY? Wind farms tend to be highly visible and cover large areas, usually on ridges or hilltops. Some people dislike seeing large numbers of turbines on the horizon and some complain that they are noisy. HOW IS WIND ENERGY USED IN NEW ZEALAND? Wind energy plays a significant, growing role in energy generation for New Zealand. By the end of 2009, there were seven main wind farms in operation in New Zealand. Combined, these wind farms have a capacity of nearly 500 MW. In addition, there are several smaller wind farms and individual turbines, and more wind farms are under construction. ACTIVITIES ACTIVITY ONE Divide the class into groups. Assign each group one of the seven main wind farms in operation in New Zealand. Hau Nui Horseshoe Bend Tararua Te Āpiti Te Rere Hau West Wind White Hill The teacher displays a large map of New Zealand on the wall and labels the wind farms. Groups research their assigned wind farm, find out why the site was chosen and present this information back to the class. For example: Hau Nui wind farm, south-east of Martinborough in the Wairarapa, is ideally located to capture the wind currents that are funnelled and accelerated through the nearby Cook Strait and over the Rimutaka Ranges. The wind farm has 15 turbines and a capacity of 8.65 MW, which provides enough energy for around 4,200 homes in the Martinborough area and, depending on demands and output, as far north as Greytown. ACTIVITY TWO WIND ENERGY QUIZ Students answer the following questions. How long have wind turbines been available as an energy source? Before wind turbines were invented, how did people use wind to generate electricity? Why is wind energy a good choice for environmental management? What is kinetic energy? ACTIVITY THREE BUILD A MODEL WIND TURBINE Here are some websites and publications showing how to build devices that use the energy of the wind. Make an Anemometer (Energy Quest – California Energy Commission). An activity that shows students how to make an anemometer, which is a device that tells you how fast the wind is blowing. http://www.energyquest.ca.gov/projects/ anemometer.html Make Your Own Wind Winch (Solar Schools) http://www.solarschools.net/resources/p df/make%20your%20own%20wind%20w inch.pdf Ministry of Education. 2004. ‘Windmills and Waterwheels’. Building Science Concepts (Book 54). Wellington: Learning Media. SUPPORTING RESOURCES - New Zealand Wind Energy Association: www.windenergy.org.nz Ministry of Economic Development: www.med.govt.nz Energy Efficiency and Conservation Authority: www.eeca.govt.nz Genesis Energy: www.genesisenergy.co.nz