These are usually the main environmental concerns that arise in association with the set up of a wind turbine.
Visual Impact
Wind turbines are highly visible structures often opposed by homeowners or real estate developers owning land near a proposed site. Several studies have shown that opposition often diminishes after the turbines are in place as homeowners find the structures aesthetically pleasing and realize their environmental benefits. Thus, opposition related to visual impact can be reduced through careful arrangement of the wind turbines, rendering them impressive against a landscape and through the education of the benefits of wind energy. Less opposition arises in rural settings where farmers are often paid rent or fees by the owners of the turbines.
Magenn Power has an added benefit in that our MARS units may be deployed much higher above surrounding terrain than conventional systems, thus capturing more wind. Conventional systems are positioned in areas where winds are higher such as coastal areas and high terrain. These locations are typically at greater distances to customers. MARS, due to it ability to reach greater winds at higher altitudes can be placed closer to demand centers, reducing transmission line costs and transmission losses.
Avian Mortality
Birds and bats occasionally collide with wind turbines, as they do with other tall structures such as buildings. However, collisions with Magenn's Air Rotors should be significantly less.
Birds and bats tend not to fly into objects directly in front of them. Birds can see these objects and bats can sense them. Current terrestrial wind turbines are large fast-moving blades slicing through the air, hitting birds and bats from the side without the animals sensing the presence of blades. In contrast Magenn wind turbines are three-dimensional, softer objects. Birds and bats will more easily be aware of the turbine's presence.
A large number of studies have addressed this issue. The findings indicate that overall, bird deaths due to wind turbines are low, especially when compared to other manmade structures. An extensive literature review was conducted and a comparison of annual avian mortality in the United States was presented. The table outlines the results.
ÂCollisions with wind turbines account for about one-tenth of a percent of all "unnatural" bird deaths in the United States each year. And of all bird deaths, 30 percent are due to natural causes, like baby birds falling from nests [source: AWEA].
Birds Deaths from http://www.on.ec.gc.ca/pollution/fpd/technologies/t-1000-e.html
| Man-made structure/technology | Associated bird deaths per year (U.S.) |
| Feral and domestic cats | Hundreds of millions |
| Power lines | 130 million -- 174 million |
| Windows (residential and commercial) | 100 million -- 1 billion [source: TreeHugger] |
| Pesticides | 70 million |
| Automobiles | 60 million -- 80 million |
| Lighted communication towers | 40 million -- 50 million |
| Wind turbines | 10,000 -- 40,000 [source: ABC] |
Source The American Wind Energy Association: http://www.awea.org/faq/sagrillo/swbirds.html
Noise
There are two types of noise generated by a wind turbine: mechanical noise from the gearbox and generator; and aerodynamic noise created by the rotors passing through the air. Progress through technological improvements has practically eliminated mechanical noise. Aerodynamic noise has also improved through better rotor design although it will tend to increase with increasing wind speeds. This is not of great concern since background noise will also increase with increasing wind.
Noise Levels from http://www.gcaudio.com/resources/howtos/loudness.html
| Weakest sound heard | 0dB |
| Whisper Quiet Library | 30dB |
| Normal conversation (3-5') | 60-70dB |
| Telephone dial tone | 80dB |
| City Traffic (inside car) | 85dB |
| Train whistle at 500', Truck Traffic | 90dB |
| Subway train at 200' | 95dB |
| Level at which sustained exposure may result in hearing loss |
90 - 95dB |
| Power mower at 3' | 107dB |
| Snowmobile, Motorcycle | 100dB |
| Power saw at 3' | 110dB |
| Sandblasting, Loud Rock Concert | 115dB |
| Pain begins | 125dB |
| Pneumatic riveter at 4' | 125dB |
| Even short term exposure can cause permanent damage - Loudest recommended exposure WITH hearing protection |
140dB |
| Jet engine at 100', Gun Blast | 140dB |
| Death of hearing tissue | 180dB |
| Loudest sound possible | 194dB |
| Hours per day | Sound level |
| 8 | 90dB |
| 6 | 92dB |
| 4 | 95dB |
| 3 | 97dB |
| 2 | 100dB |
| 1.5 | 102dB |
| 1 | 105dB |
| .5 | 110dB |
| .25 or less | 115dB |
| Imperceptible Change | 1dB |
| Barely Perceptible Change | 3dB |
| Clearly Noticeable Change | 5dB |
| About Twice as Loud | 10dB |
| About Four Times as Loud | 20dB |
| Normal piano practice | 60 -70dB |
| Fortissimo Singer, 3' | 70dB |
| Chamber music, small auditorium | 75 - 85dB |
| Piano Fortissimo | 84 - 103dB |
| Violin | 82 - 92dB |
| Cello | 85 -111dB |
| Oboe | 95-112dB |
| Flute | 92 -103dB |
| Piccolo | 90 -106dB |
| Clarinet | 85 - 114dB |
| French horn | 90 - 106dB |
| Trombone | 85 - 114dB |
| Tympani & bass drum | 106dB |
| Walkman on 5/10 | 94dB |
| Symphonic music peak | 120 - 137dB |
| Amplifier rock, 4-6' | 120dB |
| Rock music peak | 150dB |
NOTES:
- One-third of the total power of a 75-piece orchestra comes from the bass drum.
- High frequency sounds of 2-4,000 Hz are the most damaging. The uppermost octave of the piccolo is 2,048-4,096 Hz.
- Aging causes gradual hearing loss, mostly in the high frequencies.
- Speech reception is not seriously impaired until there is about 30 dB loss; by that time severe damage may have occurred.
- Hypertension and various psychological difficulties can be related to noise exposure.
- The incidence of hearing loss in classical musicians has been estimated at 4-43%, in rock musicians 13-30%.
Statistics for the Decibel (Loudness) Comparison Chart were taken from a study by Marshall Chasin , M.Sc., Aud(C), FAAA, Centre for Human Performance & Health, Ontario, Canada. There were some conflicting readings and, in many cases, authors did not specify at what distance the readings were taken or what the musician was actually playing. In general, when there were several readings, the higher one was chosen.
Height Restrictions
Magenn has carefully studied deployment of its MARS units. Of particular focus are altitude guidelines as directed by FAA regulations. The five points, below represent a summary of Magenn planning to satisfy these guidelines. Magenn has established a rapport with cognizant FAA and Transport Canada officials.
See: http://www.chem.hawaii.edu/uham/part101.html
- MARS units may not operate in controlled airspace or within five miles of the boundary of any airport.
- MARS units that are deployed on a permanent basis will require a NOTAM, which stands for: Notices to Airmen. A NOTAM is issued by the FAA or its equivalent to inform pilots of new or changed aeronautical facilities, services, procedures, or hazards, temporary or permanent. NOTAMS are not difficult to obtain, but will be necessary in most deployment cases around the world.
- MARS units will have a lighting system including individual lights that are placed at intervals according to FAA guidelines. The lights will flash once per second.
- MARS units will have a Rapid Deflation Device installed that will automatically and rapidly deflate the balloon if it escapes from its moorings. MARS device will be equipped with at least two deflate systems that will bring the units slowly and safely to the ground. If the MARS unit "cut down" system does not function properly, it will immediately notify the nearest ATC facility of the location and time of the escaped and the estimated flight path of the balloon.
- MARS units balloon envelope is equipped with a radar reflective material that will present an echo to surface radar operating in the 200 MHz to 2700 MHz frequency range.
Magenn Power Envelope and Tether System
The MARS envelope and tether system will be made of a Vectran material which is stronger and lighter than steel, abrasion resistant, minimal moisture absorption and UV resistant.
See NASA report on Vectran material.
All MARS units will have an internal bladder system called a ballonet to maintain pressure.
Magenn believes that it has solved the problems associated with the 1000 foot tether system that is to be used in our design. The Defense Department of the United States uses unmanned, tethered airships, called aerostats, for drug and border surveillance from the Caribbean to the California border1. These tethered airships operate at heights up to 15,000 feet. Magenn Power will use the consulting expertise of MAPC who helped develop the surveillance airships for the US Government.
1 http://www.airshipman.com/NewsArticles/news13nov02.htm
