Why You Don’t See Wind Turbines in the City
On-shore wind generation plants are popular across the rural United States, but a rarity in metropolitan areas. Here’s a deep dive as to why.
Size Says It All. Currently, the largest on-shore wind turbine (manufactured by General Electric) has the capacity to generation 4.8MW. That’s equivalent to powering 5,000 homes for a year. This turbine sits at an approximate height of 800 ft. That’s roughly the height of the Golden Gate Bridge. Due to the size and the span of the turbine blades (approximately 420 ft), rural and open areas are the best location.
Powered by Wind. During the site selection process for wind generation plants, infrastructure developers look for areas with constant, strong wind speeds. Metropolitan areas have variable, strong wind speeds that is not ideal to maximize the generation capacity of on-shore wind turbines.
Noise Complaints. On-shore wind turbines have a revolving rotor designed to move the turbines as the direction of the wind shifts to maximize generation capacity. Standing at the base of the turbine, it’s about 100 decibels which is equivalent to standing next to a jack hammer. Thus, clearances (also known as setbacks) from inhabited structures are required by law.
Ice Blades. In cold regions in the United States, it is not uncommon for ice buildup on wind turbines. Required by law, developers need to adhere to setbacks (typically greater than the length of a turbine blade) from inhabited structures. This is infeasible in metropolitan areas. Additionally, technologies are currently available that monitor ice buildup and melt times based on sun exposure to prevent loss of generation capacity during the winter months.
Bats Need Our Love. Rural areas are better locations for wind generation plants; however, our energy infrastructure is a threat to wildlife. Large numbers of migratory bats are killed every year at on-shore wind generation plants. The impact on bat populations across the United States is still unknown (current estimates are at approximately 800,000 bats per year), but research in this space is expanding. On the bright side, researchers continue to put forth policies on preventing or mitigating impacts of energy infrastructure on wildlife.