The wind is one of the Earth's most sustainable natural resources when it comes to generating electrical power. To harness it, all you need to do is construct a wind power turbine that converts the movement of the air into kinetic energy. To do that on a large scale, however, you'll need a wind farm—a collection of specially designed wind turbines positioned across the landscape or ocean, where the winds are steady and strong. Wind turbines have multiple blades, which are set high on towers, that spin in the breeze and harvest power.
Industry experts say the United States has enough wind resources to effectively double its current wind generation capacity, and that doing so comes with a slew of environmental benefits. In America alone, wind power prevents the release of about 62 million tons of greenhouse gases, and it conserves 20 billion gallons of water annually.
Potential obstacles to building wind farms include the public controversy over the placement of the wind turbines, permitting challenges, financial concerns, and technical issues, such as the need for infrastructure to transmit the power to the electrical grid that serves customers. However, if you wish to construct your own wind farm, it isn't too hard to do.
Getting Started: Planning Your Wind Farm
Building a wind farm is a big project that requires teams of specialists to handle the many aspects of the project—from conception and planning to implementation. Planning is especially crucial for this type of energy generator. The proper location must be assessed for any risks to wildlife, permits must be acquired, and the turbines themselves need to be tested.
First, make sure to choose a location that has enough wind resources. The best sites for commercial wind farms have wind speeds of 13 miles per hour (6 meters per second) or more, according to the American Wind Energy Association. While it may seem like the more wind the better, too much wind can strain equipment and make the project more expensive.
Special wind speed maps can help you identify a region with suitable wind resources. For example, the U.S. Department of Energy offers a handy wind map. You can also take wind energy measurements yourself, using a tool called an anemometer, at the site you're considering. Some states even offer anemometer loan programs. Your engineer may use specialized services and software to optimize the location, such as Windnavigator and GH WindFarmer, which analyze topography, weather conditions, and aerodynamics.
Furthermore, you’ll need to consider special concerns of the target location, such as road access, potential noise impacts, flickering shadows from the blades, and cultural issues.
Assessing Wildlife Risks
The spinning blades on wind turbines can kill endangered birds, bats, raptors, and waterfowl, so it’s best to position turbines away from busy wildlife corridors and annual migratory paths. The U.S. Fish and Wildlife Service’s Wind Turbine Guidelines Advisory Committee recommends a tiered approach that includes a preliminary assessment, site characterization, and field studies to predict and assess the species and habitats harmed by the wind farm.
As the site developer, you’ll need to work closely with the appropriate government agency (or permitting authority) to reduce and mitigate the deaths of animals due to the wind farm. In some cases, you may be allowed to build the wind farm in sensitive areas if you alter its operation to be more wildlife-friendly. For example, you could be required to temporarily stop turbines during migration seasons or during periods of low wind, when bats are most active and power yield is minimal.
Wind Farm Costs and Financing
Think about how much energy you want to produce—or how much the site can produce—and how much money you can spend. Purchasing wind turbines alone can set you back an average of $1.37 million per megawatt of capacity.
Generally, it’s cheaper for utilities to develop wind power facilities than it is for private investors because utilities can tap into favorable financing structures that reduce costs by about 30%, or about 1.4 cents per kilowatt-hour, according to a report funded by the U.S. Department of Energy.
Government stimulus programs also make it easier to develop a wind farm. The production tax credit (PTC) now provides a 2.3-cent-per-kilowatt-hour tax credit during the first decade of operation.
To project the levelized cost of financing your wind project, plug your specific details into the interactive BITES tools (buildings, industry, transportation, and electricity scenarios) provided by the National Renewable Energy Laboratory. You may also want to browse the database of state and federal incentives for renewable energy.
Ensure Your Farm Meet Legal Requirements
Electricity producers are governed by federal laws such as the Public Utility Regulatory Policies Act of 1978 (PURPA), the Energy Policy Act of 2005 (EPACT 2005), and the Energy Independence and Security Act of 2007 (EISA 2007). Individual states also have different interpretations of how these federal laws apply, and they have varying mandates to promote renewable energy through Renewable Portfolio Standards (RPS) legislation.
A lawyer or consultant who specializes in renewable energy development can help you navigate the laws governing your proposed project. These people can also help you acquire the various building and environmental permits you will need from government agencies.
If your wind farm will sit on government property or has a federal agency partner, permitting can be contingent on a formal environmental impact assessment process. For example, wind farms placed on property managed by the U.S. Bureau of Land Management are governed by certain guidelines intended to protect federally protected species and other natural resources.
Identify Equipment and Wind Farm Design
Modern wind turbines are sleeker and bigger than old-fashioned windmills, with enormous blades and towers as tall as high-rise buildings. The precise placement of these turbines on a wind farm affects its overall energy production.
As a general rule, the larger the wind turbine, the greater its generation capacity. The most commonly installed wind turbine has a capacity rating of 1.5 megawatts and can power up to 500 homes, but newer models run even bigger. General Electric’s website lists sizes of up to 3.4 megawatts for onshore use and up to six megawatts for offshore use. Other leading wind turbine manufacturers include Vestas, Goldwind, Enercon, Siemens, Sulzon, Gamesa, United Power, Ming Yang, and Nordex.
Large and heavy wind turbines require bigger foundations, and they cost more to install. Offshore wind turbines must be designed for ocean conditions. Wind turbines rarely run at full capacity since their energy generation is weather-dependent.
In addition to wind turbines, a wind farm requires an electrical power collection system, transformers, a communications network, and substations. What's more, a supervisory control and data acquisition (SCADA) information system is used to monitor performance. An engineer can recommend suitable equipment and turbine placement based on your site, finances, and energy goals.
Secure Transmission Capacity
If you’re planning a commercial-scale wind farm, you need a way to deliver energy to wholesale or retail customers. Typically this requires transmission lines linking the output of your wind farm to the electric power transmission network—the energy grid—in your region. Commercial wind farms in remote locations can find it challenging to secure transmission capacity and interconnectivity with the grid.
Alternatively, smaller wind farms can be used as a dedicated source of electricity for a community or business. In these cases, the wind farm may not require a link to the regular electric grid. However, to sell excess power, you still need a way to deliver that power to the electric utility.
For more information, check with the National Renewable Energy Laboratory (NREL), which works with wind developers to secure transmission capacity and interconnectivity. The Utility Wind Integration Group also provides resources for connecting a wind farm into the electric system.
Install, Test, and Run the Equipment
Wind farm construction can be completed within a few months. However, you may first need to build roads into the site for hauling in the wind turbines and other equipment.
For each wind turbine, you’ll need to excavate a hole and fill it with reinforced concrete to serve as a stabilizing foundation. This process is more demanding in rocky conditions or on offshore wind farms. Once the foundation is prepared, you'll need to erect the turbines with specialized hoists.
Next, you'll put the electrical wiring and systems in place and run tests to ensure that all the elements are operating properly. It often takes six months before the kinks are ironed out and the wind farm achieves full commercial production capacity.
Each wind turbine needs about a week’s worth of routine maintenance per year. The American Wind Energy Association says it takes one wind technician to service every 10 megawatts of installed generating capacity.