Wide Scale Distributed wind power |
A study funded by the Carbon Trust in the UK noted the untapped potential of roof mounted wind turbines. The study revealed a 180% velocity gain associated with wind tumbling over rooftops known as the ‘rooftop effect’. Since the power of the wind is proportional to the cube of the velocity doubling the wind speed will produce eight times more power. Producing power at the point of consumption, known as distributed power has other advantages as well. According to AWEA “…the construction of a wind farm necessitates the use of heavy industrial equipment. Developers will need to invest in roads capable of accommodating significant weight. To do so will require the cooperation of landowners and, in some cases, the local community.” A newly permitted 848MW wind farm near Arlington, Oregon known as the Shepherd’s Flat Wind Farm will require 90 miles (140 km) of new high voltage transmission lines and 85 miles (137 km) of roads on the 30-square-mile (78 km2) wind farm. Utilizing existing rooftops to site wind power conversion units eliminates the enormous environmental footprint required of centralized wind farms while maximizing the already existing urban footprint of buildings. This also reduces cost because the wind turbine tower is already built and is a sunk cost. Rogue River Wind, Ltd (RRW) has developed a vortex assisted low profile ducted fan (V-LIM) to capitalize on windy rooftop real estate. The V-LIM further combines the above rooftop effect with an additional 20% gain by inducing a pressure drop or Bernoulli Effect behind the fan. The V-LIM properly situated on a rooftop or steep hillside extracts approximately 6 times the power per swept surface area of an equivalent size turbine not unlike a jet turbine. The 3 meter diameter V-LIM is self-indexing, silent, vibration free, operates comfortably in winds as high as 100 mph and easily manages gusting, turbulent airflow making it suitable for rooftop mounting and extensive use in urban settings. The V-LIM fan tips are terminated by an outer ring or annulus that can be screened to protect birds. The V-LIM implements patentable aerodynamic features and a high-bandwidth direct drive DC generator that operates at variable wind speeds. The generator is built into the outer annulus making the turbine a self-contained generator. (USPTO Application #12/617,531) Factors relating to grid reliability, the high costs of transmission and even national security have led to a movement away from centralized power and toward wide scale distributed energy . Wind is presently the fastest growing renewable energy source with average annual growth rates of 29% worldwide for the last decade. While distributed energy is expected to contribute 11% of the US expected increase of 450,000MW by 2025 only 3% is from renewable sources owing in part to the issues surrounding wind generation in congested urban locations. Renewable distributed wind energy, or small wind , received, in 2008 long term federal incentives for the first time since 1985. “The US market for small wind turbines grew 78% in 2008 with an additional 17.3MW of installed capacity. This growth is largely attributable to increased private equity investment that allowed manufacturing volumes to increase, particularly for the commercial segment of the market (systems 21-100kW). The still-largest segment of the market, residential (1-10kW), was likewise driven by investment and manufacturing economies of scale, but also by rising residential electricity prices and a heightened public awareness of the technology and its attributes. “The industry projects 30-fold growth within as little as five years, despite a global recession, for a cumulative US installed capacity of 1,700 MW by the end of 2013. Much of this estimated growth will be spurred by the new eight-year 30% federal Investment Tax Credit passed by Congress in October 2008 and augmented in February 2009.” These figures are reflective of small wind in use in rural, commercial and industrial locations only. Safety, height, noise and other environmental issues have prohibited wind turbine technology in urban locations. In 2008 according to AWEA, approximately 200 units, primarily vertical axis, were sold in the US for urban or rooftop applications and, at least “10 US companies manufacture or plan to manufacture building-mounted models.” Despite consistent high growth in the small wind arena spurred by a new 30% federal small wind investment tax credit (ITC) and cumulative big wind installations of more than 10,000MW in 2009, an industry record, traditional centralized wind power in the US faces a significant hurdle, transmission. The US DOE identifies inadequate transmission capacity as the largest hurdle to meeting 20% of America’s electricity requirements by 2030. It is estimated that at least 19,000 miles of 765KV transmission lines, dubbed green power superhighways are required to deliver the more than 300,000 MW of current wind power projects from remotely sited areas to areas with heavy energy demands. Deploying new high voltage transmission lines faces many policy and regulatory hurdles that are further complicated as they cross state lines where one state can withhold permitting if it perceives an inequity in the share of benefit. The enormous environmental footprint associated with miles of transmission lines also runs afoul of wildlife and land use protections and regulations. Decentralized energy, producing power at the point of consumption offers a viable alternative to the traditional centralized model of power generation and delivery. According to the World Alliance for Decentralized Energy “…based on the WADE economic model concluded that the UK could save 15% of its delivered electricity costs relative to central generation (CG). Capital costs could be reduced by even more- 27% relative to CG.” WADE estimates the capital cost savings in the US to be as much as 44% resulting in a 15% savings to the consumer. A study by The New Rules Project highlights the importance of distributed power generation on local economies and notes “…Achieving energy independence with homegrown renewable energy resources is well within the technical and financial capability of most states… …Local economic benefits will total over $1.6 billion a year during the wind farms operations. And widely dispersed energy production can be the basis for a resilient energy system where a branch falling on an electric line in Ohio does not result in a 12-state blackout as happened in the U.S. in 2003.” The report goes on to state that high energy consuming states “…should look to distribute energy production facilities as widely as possible, with a potential to increase economic benefits even further.” |
