The amount of time that it takes for a wind turbine to pay for itself, which is also called the return on investment (ROI), varies widely. Depending on the size and location, the ROI can be as little as five months, or as long as 10-15 years. Most turbines pay off the cost of their installation within three years.
The Concept of Net Energy
Determining how long it takes for turbines to produce more energy than was required to build them involves looking at the concept of net energy. Net energy includes all the energy used to build wind turbines compared to the energy they produce in return. A two-megawatt turbine, for instance, requires about 170 tons of coal and 300 additional tons of other minerals such iron ore, for its construction. The elements used to build turbines must be sourced through mining and then transported to their final destination.
Location is another critical factor when evaluating a turbine’s energy payback period. Turbines placed on a good site, which is one with favorable wind speeds and environmental conditions, will generally pay for themselves over the course of about three years. Turbines that are sited in less than optimal locations are much less efficient, which means they can take five to 10 years or even longer to break even or begin producing more energy than what was used to make them.
A turbine’s life cycle is also a consideration when trying to figure out when it will produce as much energy and ultimately more energy than it required for construction. Most turbines have a lifespan of about 20 years. In studies, wind turbines evaluated from 50 different sites in the United States between 1977 and 2007 had an average energy payback period of less than one year. Wind farms were particularly productive, with a total energy that averaged 20-25 percent more than the energy required to build them. Turbines were evaluated for their energy production over the course of 20 years.
Types of Turbines
There are two basic types of turbines:
- Horizontal-Axis Turbines
- Vertical-Axis Turbines
Horizontal-axis turbines are the most common design. They’re often used in a range of applications from small residential to commercial-scale projects. They are generally sited “upwind” with their blades facing into the wind to maximize energy production.
Vertical-axis turbines are manufactured in multiple varieties. They do not need to face the wind’s prevailing direction to generate wind power.
The type of turbine used, combined with its geographic location, determines the machine’s overall level of effectiveness, and in turn its power output.
Categorised in: Latest Wind Power Industry News - Kurz Wind Division
This post was written by Matt Passannante