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U of Delaware get state’s first community wind project

KRemington — Thu, 08 Jul 2010 13:26:50 +0000

A NY state-based community wind company has completed its largest project to date, a 2 MW wind turbine at the University of Delaware’s Hugh R. Sharp Campus in Lewes. The project, assisted by Sustainable Energy Developments Inc (SED), in Ontario, NY, created the first community wind turbine in the state and combines university level research, as part of the university’s College of Earth, Ocean and Environment (CEOE), with the financial, energy and environmental benefits of wind power.

The project completed in early June 2010 following the commissioning and electrical interconnection of a 2-MW Gamesa wind turbine. The culmination of the project was celebrated at a ribbon cutting ceremony.

The university’s CEOE Dean, Nancy Targett, began her pursuit of a wind project in March of 2008 when she hired SED to perform an economic and technical assessment of the Lewes campus. The company helped define the college’s opportunity and convinced university officials to develop the project. SED was then tasked with protecting the interest of the university and guiding the project through the development stages. The company’s assistance included permitting, detailed engineering, turbine procurement negotiations, electrical interconnection, construction, and commissioning. SED also provided assistance in fulfilling the requirements of the National Environmental Protection Act necessary to secure federal funding support for the wind turbine.

Communities to own utililty-sized wind projects

Kathleen Zipp — Wed, 09 Jun 2010 15:55:57 +0000

The first construction phase of Lake Country Wind Energy will be of 20 REpower turbines, each rated for 2.05 MW.

Erin Edholm
National Wind
Minneapolis

One community-based wind project in Minnesota works on another principle of making the landowners the project owners of their community-based wind farm. The arrangement, for example, at Lake Country Wind Energy LLC (lakecountrywindenergy.com) gives ownership interest to those who donate land to the project along with the opportunity to influence its development. Such community involvement fosters camaraderie and growth within the company and the neighborhood. The business model is to form the LLC so that the land owners need not put money into the project. “With a lease agreement and at least 500 acres, they get a unit of stock in the company,” says National Wind spokeswoman Erin Edholm.

This development model, promoted by National Wind, Minneapolis, also works to build larger wind farms than are usually associated with community-wind efforts. “Lake Country, for example, will begin working on the first of a several phases by building 40 MW of wind power and eventually finish with some 340 MW in a footprint that will cover over 25,000 acres,” says Edholm.
Community wind projects often get started when land owners call a development firm looking for opportunities. “Groups that have tried to go it alone often get stuck in the complexity and turn for assistance to other organizations like ours,” says Edholm. “Then we look to partner with 10 to 20 land owners, people we call founders.

On occasion the founders put capitol in to get the operation rolling. A board of advisors, a smaller number, are appointed from the initial founders. These are local people, so they know the local issues. We meet with them on a regular basis to provide updates and listen to their issues. They are our eyes and ears into the project,” she says.

Occasionally, the board requires changes to the lease. “For example, it could be to the provisions for the setback from a road or building, or how they are compensated for the land use, where access roads are built, or to the underground lines that connect to the grid. Occasional concerns are for how the turbines might interfere with crop farming,” she adds.

Payments to landowners vary with their involvement in the project. Some receive leases for their land and others get acreage payments, an operational payment the land owners get for the acres in the project. Edholm says her company has completed two community wind projects and has 11 more in development.

Lake Country Wind Energy has just over 150 participating landowners and eight board members, all people from the community which is mostly of agricultural land. The project started in the summer of 2008 with a site assessment. “We’ve now collected over a year’s worth of wind data from the footprint’s meteorological tower. With that data, our wind assessments team will be able to place turbines at the most productive locations,” says National Wind Field Specialist Jan Donahue.

The first construction phase will put up 20 REpower 2.0 MW turbines. REpower USA Corp., in Denver, has installed or sold more than 400 wind turbines with a total output of over 800 MW in the U.S. since 2007. These were chosen by competitive bids and from wind studies showing that such turbines of the size selected are best for the wind measured on the sites.

Following construction projects in Washington, Oregon, Indiana, Michigan and California, these are the first wind turbines that the U.S. subsidiary of Hamburg-based REpower Systems AG will deliver to Minnesota.

Myths and facts in community wind projects

KRemington — Tue, 08 Jun 2010 15:39:33 +0000

A study by the Lawrence Berkeley National Lab of 7,390 homes surrounded by some 1,300 turbines in several states found that wind farms do not depress land values.

Community-wind developers often encounter some opposition when developing projects. It may surface as misinformed, for example, insisting that the turbines kill birds and wind farms depress land values, among other things. They are not true but the charges deserve more detailed explanations to effectively dispel them. Hence, this column and others to follow will deal with such misinformation and with the goal of a better informed populace. Here’s installment one.

Issue 1: Wind turbine syndrome or WTS, disrupts the lives of some people who live near wind turbines. The expansion of wind farms, therefore, should proceed more slowly.

The facts: The syndrome reached national attention after Nina Pierpoint self-published a non-peer reviewed book on the topic. She reported a variety of symptoms that some say keep them awake at night with a low level thumping and headaches. Others report different symptoms. Her theory is that inaudible low frequencies or infrasound, 1 to 2 Hz, activates the vestibular system and vibrates the chest. Another possibility she theorizes, is that infrasound at 4 to 8 Hz enters the mouth and lungs and disturbs the diaphragm. A definitive cause, however, remains uncertain.

The wind industry wants to address the issue at a serious level, so it hired experts to investigate the allegations and the syndrome. But before that, the industry tried engaging public-health authorities. Their disappointing response was that the affected group was too small and funds insufficient to cover the costs of an investigation. So, the industry funded a study to learn more.

Experts such as Geoff Leventhall and W. David Colby, both medical researchers have separately delved into the subject. Leventhall found the initial research flawed and unsupported by other researchers. He says WTS seems based on uncontrolled and unverified reports of nonspecific symptoms in 38 people interviewed by Pierpont. They apparently had no physical exams or diagnostic testing which might have found other causes for the symptoms. Subjects were selected for the investigation, says Leventhall, using criteria that expose extreme selection bias, leaving Pierpont’s conclusions suspect. Interested readers can hear their comments in a webinar at http://tinyurl.com/wpe-myths.

Leventhall does not dismiss WTS but concludes: “It appears there is no specific WTS but there are stress effects from low-noise levels, either high or low-frequency noise, which affects a small number of people. The audible swoosh-swoosh which, when it occurs, is the cause, not infrasound or low-frequency noise.”

Issue 2: Wind farms decrease land values.

The facts: Not true. An exhaustive scientific study done by the Lawrence Berkeley National Laboratory examined land values over time and found no supporting evidence. The study by Ben Hoen and colleagues at the national lab, examined 7,390 homes surrounded by some 1,300 turbines in several states. Their report, available at http://tinyurl.com/landvalues, concludes that although, “One cannot rule out isolated cases where property values are negatively impacted, any such impacts within our sample are neither widespread nor statistically identifiable.”

Issue 3: Wind turbines kill birds.

The facts: Definitive bird studies or avian issues have cost millions of dollars, and organizations continue to spend on them. The studies often find that wind turbines have only an incidental effect on some birds. It is usually not a concern for populations for a region. In a few instances, projects did not have as much siting control before being built, and so there are a few issues. California’s Altamont pass is one. Tall buildings and cats kill more birds. Still, the issue is taken seriously and tracked, studied, and mitigated, at high cost. (Bats will be addressed in a separate column.)

Interested readers might look to the National Wind Coordinating Collaborative (nationalwind.org) for its many publications regarding wind wildlife studies. Even the Audubon Society and Sierra Club have recognized the studies as valid, accept their conclusions, and acknowledge that the wind industry treats the issue seriously.

So far, bird kills have caused serious scientific concern only in the Altamont Pass, one of the first areas in the country to experience significant wind development. Over the past decade, the wind community has learned that wind farms and wildlife can and do successfully coexist. The wind industry’s overall impact on birds is extremely low (<1 of 30,000) compared to other human-related causes, such as traffic and house cats. Birds can fly into wind turbines, as they do with other tall structures. However, some also insist that conventional fuels contribute to air and water pollution that can have greater impact on wildlife and their habitat. WPE

The plus side of large two-blade turbines

Paul Dvorak — Thu, 06 May 2010 14:36:23 +0000

Staffan Engström/Consultant Agir Konsult AB/Nordic Windpower/ Taby, Sweden

A dampened pivot hub, modular drive train, and regulated tip speeds give two-bladed, utility-scale wind turbines a few advantages over three-blade designs.

Nordic Windpower focuses on developing the advantages of two-blade turbines. The company manufactures a 1 MW unit with larger rating in the works. The firm’s earliest units are now 10 years old and have recorded an availability of about 98%.

For a wind turbine to output a particular power, it must have a certain rotor diameter, rotational speed, and a specific aerodynamic area. Although most modern wind turbines use three blades, distributing the necessary surface area over just two turbine blades provides several advantages.

The pros of two
The primary effect is that blade chord (leading edge to trailing edge) must increase. Because a blade profile is characterized by its relative thickness (blade thickness to blade width provides a ratio, normally of 0.15 to 0.20), this also means the blade thickness increases with increased chord. One consequence of a thicker blade is a considerable increase in strength. For a beam, strength is proportional to the third power of its height, or

S ∝ h³

where:
S = strength of the beam and h = airfoil height or thickness.
A thicker blade decreases the need for structural material, which makes the blade lighter and less costly. Because this is in addition to the fewer number of blades needed, the total blade cost drops significantly.
Another significant advantage is that it is easier to erect a two-bladed wind turbine because the blades may be mounted to the nacelle while it is on the ground. A three-bladed rotor must be lifted separately and mounted to the nacelle when it is on the tower. The separate lift is an additional cost.
Under the same general wind conditions, the two-bladed turbine is slightly less efficient than the three-bladed. The difference in the yearly energy production would be about 2 to 3%, but this is easily compensated for with a 1% increase in rotor diameter. Thus, this is no argument against the use of two-bladed turbines.

Nordic Windpower recently shipped the first of 16, 1-MW turbines from its new factory in Pocatello, Idaho. A safety cage surrounds the likely work area on the hub. The oval hatch provides access to pitch mechanisms. The round feature to the right of the hatch is the pivot bearing that allows the rotor about ±2° of movement. The four black discs are cushions or dampers that dissipate pivoting energy.

The reason for the current dominance of the three-bladed turbines is that a two-blade turbine was harder to develop. This is a consequence of its asymmetry, whereas the three-bladed turbine is symmetrical.
Due to complex calculations, access to a comprehensive and easy to use computer simulation is a necessary prerequisite to exploite the advantages of two-blade technology. Nordic Windpower now operates such a program. It was developed in the Swedish wind energy research program in the early l980’s.
Another prerequisite for a successful two-bladed wind turbine is a tilting or teeter hub, which means the hub and blades are hinged to the turbine shaft. Although the pivot range is quite small (± 2°), this motion has a decisive influence on the loads acting on the entire wind turbine.
The lack of accurate computer simulations slowed development of two-blade designs. In many cases this resulted in technical problems and is why most OEMs implemented the less demanding three bladed design. However, the technical advantages for two-bladed wind turbines have long been known to the wind power community, and are why the Swedish National Wind Power Program concentrated its efforts on two-blade technology in the 1970s. For instance, the Swedish program found that the design features needed for a successful two-blade implementation include:
•A pivot hub with damping to dissipates blade forces before they reach the gearbox.
•An integrated drive shaft and gearbox that allows for a more durable bearing configuration
•A single unified, tubular housing for the gearbox, drive shaft, and generator to hold this equipment steady and let forces dissipate away from the gearbox
•Cooling of the gearbox and generator to keep oil temperatures well below critical.

Blade chord and profile height are for two and three-bladed wind turbines of equal power.

Other advantages
When these features are combined in a single design, two-blade turbines show several advantages over three-blade units. For example, onshore wind turbines are usually limited in their power production by their noise output which is determined by the blade-tip speed and hence rotational speed. Siting wind turbines offshore avoids this problem. Two-bladed turbines benefit more from this location change than three-bladed turbines. The 50% larger chord and greater structural blade strength allows increasing tip speed to substantially larger values than those that are possible with three-bladed turbines. This is of great importance, because the cost of the gear box or direct-drive generator is inversely proportional to the rotational speed, or:

C-gearbox ∝ 1/ω-rotor

where:
C-gearbox = cost of the gearbox, and ω-rotor = rotor speed.

This leads to further cost reductions. The need for large turbines and the easier handling of two-bladed designs are more reasons these turbines are likely to find wider use offshore than on.

Equal noise or less

The yearly energy production comes from optimized two and three-bladed wind turbine systems.

Noise restrictions determine an acceptable blade tip speed for onshore wind turbines in populated areas. Two-blade wind turbines are designed for the same tip speeds as three-blade designs. Fewer blades have fewer noise producing surfaces. This will even result in slightly less noise, about 1 dB lower than corresponding three-bladed turbines.

Shadows
Flicker or shadows from a turbine blade hitting a building’s window results in an annoying variation of lighting conditions inside the room. An investigation by the Swedish government (Vindkraftsutredningen, SOU 1999:75, p. 101) concluded that an annual cumulative shadow time of 10 hours is acceptable to inhabitants. This factor may become increasingly important because the generally less noisy wind turbines are placed closer to buildings which will make shadow conditions important in determining acceptable distances to nearby habitation. A two-bladed turbine has a shadow frequency of 2/3 that of a corresponding three-bladed turbine.

A thicker cross section provides a stronger blade and hence, fewer blade problems on two-blade turbines.

Improved visual appearance
This topic is, of course, quite subjective. The experience of the general public with two-bladed wind turbines is mostly with small units. These have a high rotational speed, regardless of their blade number because any wind turbine is designed for a certain blade-tip speed, which makes the rotational speed inversely proportional to the turbine diameter. The high rotational speed on a small two-bladed turbine has the drawback of making the rotation appear irregular, which disturbs some people. However, the impression disappears by increasing turbine size and decreasing rotational speed.
The visual experience of rotational-speed differences is primarily connected to the frequency of blades passing the tower or horizon. At the same rotational speed, the blade passage frequency of a two-bladed turbine is just 2/3 of the value of a three-bladed turbine. This may be why large, two-blade turbines, some say, appear calmer. WPE

Communities to own utililty-sized wind projects

Paul Dvorak — Wed, 05 May 2010 23:18:22 +0000

The first construction phase of Lake Country Wind Energy will be of 20 REpower turbines, each rated for 2.05 MW.

Traditional wind plant developers often say their work benefits landowners by providing them with royalty or lease payments. While such an arrangement does provide some benefit to the community, the business model makes little provision for ownership or local participation.
One community-based wind project in Minnesota works on another principle of making the landowners the project owners of their community-based wind farm. The arrangement, for example, Lake Country Wind Energy LLC gives ownership interest to those who donate land to the project along with the opportunity to influence its development. Such community involvement fosters camaraderie and growth within the company and the neighborhood. The business model is to form the LLC so that the land owners need not put money into the project. “With a lease agreement and at least 500 acres, they get a unit of stock in the company,” says National Wind spokeswoman Erin Edholm.
This development model, promoted by National Wind, Minneapolis, also works to build larger wind farms than are usually associated with community-wind efforts. “Lake Country, for example, will begin working on the first of a several phases by building 40 MW of wind power and eventually finish with some 340 MW in a footprint that will cover over 25,000 acres,” says Edholm.
Community wind projects often get started when land owners call a development firm looking for opportunities. “Groups that have tried to go it alone often get stuck in the complexity and turn for assistance to other organizations like ours,” says Edholm. “Then we look to partner with 10 to 20 land owners, people we call founders.
On occasion the founders put capitol in to get the operation rolling. A board of advisors, a smaller number, are appointed from the initial founders. These are local people, so they know the local issues. We meet with them on a regular basis to provide updates and listen to their issues. They are our eyes and ears into the project,” she says.
Occasionally, the board requires changes to the lease. “For example, it could be to the provisions for the setback from a road or building, or how they are compensated for the land use, where access roads are built, or to the underground lines that connect to the grid. Occasional concerns are for how the turbines might interfere with crop farming,” she adds.
Payments to landowners vary with their involvement in the project. Some receive leases for their land and others get acreage payments, an operational payment the land owners get for the acres in the project. Edholm says her company has completed two community wind projects and has 11 more in development.
Lake Country Wind Energy has just over 150 participating landowners and eight board members, all people from the community which is mostly of agricultural land. The project started in the summer of 2008 with a site assessment. “We’ve now collected over a year’s worth of wind data from the footprint’s meteorological tower. With that data, our wind assessments team will be able to place turbines at the most productive locations,” says National Wind Field Specialist Jan Donahue.
The first construction phase will put up 20 REpower 2.0 MW turbines. REpower USA Corp., in Denver, has installed or sold more than 400 wind turbines with a total output of over 800 MW in the U.S. since 2007. These were chosen by competitive bids and from wind studies showing that such turbines of the size selected are best for the wind measured on the sites.
Following construction projects in Washington, Oregon, Indiana, Michigan and California, these are the first wind turbines that the U.S. subsidiary of Hamburg-based REpower Systems AG will deliver to Minnesota. WPE

Communities to own utility-sized wind projects

Erin Edholm — Sat, 03 Apr 2010 15:37:52 +0000

One community-based wind project in Minnesota works on another principle of making the landowners the project owners of their community-based wind farm. The arrangement, for example, at Lake Country Wind Energy LLC gives ownership interest to those who donate land to the project along with the opportunity to influence its development. Such community involvement fosters camaraderie and growth within the company and the neighborhood. The business model is to form the LLC so that the land owners need not put money into the project. “With a lease agreement and at least 500 acres, they get a unit of stock in the company,” says National Wind spokeswoman Erin Edholm.

The first construction phase of Lake Country Wind Energy will be of 20 REpower turbines, each rated for 2.05 MW

Community wind projects often get started when land owners call a development firm looking for opportunities. “Groups that have tried to go it alone often get stuck in the complexity and turn for assistance to other organizations like ours,” says Edholm. “Then we look to partner with 10 to 20 land owners, people we call founders.

NREL and Great Lakes Wind target midsized turbine designers and manufacturers

Paul Dvorak — Tue, 16 Mar 2010 00:25:22 +0000

The DOE and NREL have launched the Midsize Wind Turbine Development Project to help close a technology gap and facilitate development and commercialization of midsize wind turbines. The Laboratory is sponsoring workshops in Ohio and Oklahoma, facilitated by Cleveland-based Great Lakes Wind Network, to build awareness of the DOE-NREL Midsize Wind Turbine Development Project and encourage collaboration to assist U.S. manufacturers and wind turbine designers in producing near-term commercial value-engineered midsize turbine prototypes.

NREL worked with Northern Power Systems to redesign its 100-kW wind turbine.

The wind industry is growing fast in North America but the use of midsize wind turbines in the U.S. is hampered by a lack of options and market availability. This growth market provides a chance for designers, manufacturers, and component suppliers to join forces, close the technology gap, and at the same time build our nation’s midsize wind turbine supply chain.

Workshops will feature networking, panel presentations by turbine designers and manufacturers, information on NREL’s National Wind Technology Center, and existing and future manufacturing opportunities.

Cost for each full day event is $95. For sponsorship details contact Mari-Elen Sammon at (216) 588-1440 ext. 121. For more information, contact Ed Weston (GLWN) (216) 588-1440 ext. 125 or EWeston@glwn.org or Karin Sinclair (NREL) (303) 384-6946 Karin.Sinclair@nrel.gov .

Where and when:

In Ohio, Wednesday, March 24, 2010

Doors Open at 7:30 am

8:00 am to 5:00 pm – Networking Reception to Follow

University of Cincinnati – College of Applied Science

2220 Victory Parkway, Cincinnati, OH 45206

In Oklahoma, Thursday, April 8, 2010

Doors Open at 7:30 am

8:00 am to 5:00 pm – Networking Reception to Follow

Northeastern State University – Building A – Banquet Room

3100 East New Orleans, Broken Arrow, OK 74014

Community wind shapes a growing trend

WindPower Engineering — Fri, 26 Feb 2010 21:42:08 +0000

An emerging group of wind-farm developers are focusing on midsized project farms and in places utility companies are overlooking. These community-wind projects, ranging from five to 80 MW, are cropping up in part due to recent financial incentives and guidance from firms such as OwnEnergy Inc, Brooklyn, NY (ownenergy.net). “Several converging factors make community wind projects viable,” says OwnEnergy Founder and CEO Jacob Susman. “First is a transmission capacity. This is an opportunity for smaller projects to tap into the transmission infrastructure, avoiding the need for costly new upgrades. Also, as the industry matures, people in local communities are looking for more involvement, control, and a financial stake in a project, more than just the land leases they may be offered by an “absentee” developer. Finally, banks are more interested in making relatively small loans, as little as $20 million loans for a community wind project. The inudstry is now saying that ‘small is the new big’”.

Susman says his company’s role is to identify a local partner or entrepreneur, someone who lives in the community or has ties there, and preferably a significant land owner in the project footprint. “Then we form a joint venture with the local partner. For example, partners in Kay County Oklahoma, a father and son team with property in the footprint, can count several generations in the area. Their land will be used in the project along with neighbors’ land. That arrangement brings a sensitivity to projects. Our role is to make the project work for everyone in the community.”

An island community off Maine, Fox Islands Wind LLC, provides another example of community wind. “Instead of importing power from the mainland on a cable, they generate it themselves. They decided to install three wind generators, and then structured the power, financing, procurement contracts as a community with an entrepreneurial person at the lead. A development company such as ours is in the lead so all members have an ownership stake,” says Susman.

Wind projects develop in several stages. An early stage involves feasibility and gathering land for the project, getting a wind assessment of the property, and steps such as getting in the transmission queue. ”A lot of the early effort is local, a good amount of that is done by the local partner. We provide the documentation he would take around to the community. We would do the feasibility work, site assessment to figure out the farm size, make sure we are not in areas of endangered habitat, on whose property the turbines would be placed, and how it would connect to the grid,” he says.

A middle development phase is outsourced. It includes studies around transmission and permitting, and continuing the wind resource work by a third party, while OwnEnergy typically manages the third parties with input from the local partner. That person might be working with the community dealing with the land owners, and getting county tax abatement for the locals. If anyone in the community is not comfortable with the project, the third party works with that person. A final stage signs up contractors and gets the project ready for financing by wind energy lenders and tax-equity firms.

A powerful idea: Wind turbines in the city

WindPower Engineering — Wed, 24 Feb 2010 21:34:45 +0000

The large and small generator (green and belt driven) are just visible. Red calipers for the disc brake are in the foreground.

Not all wind farms have to be located far from power purchasers. A recent ribbon-cutting for a 120 kW turbine was right in Cleveland, Ohio, where the turbine is visible to thousands driving by on I-480 and Pearl Rd. Electrical Design Consultants President David Graneto, Pepper Pike, Ohio, says power from the turbine is sufficient for lights and equipment in three buildings of the automobile recycling yard at which the turbine is sited.

During a visit, the remanufactured Vestas V-20 (20-m rotor diameter) that sits atop a 140-ft tower, was churning out about 78 kW in a modest 5.3 m/s breeze. When originally manufactured the turbine was rated for 100 kW but the updated design can pump out 120 kW in wind of at least 10 m/s.

The turbine now sports two induction generators producing three phase 480V. The smaller generator is for low wind speeds up to 4.5 m/s and the large generator for higher winds. It cuts in at 4.5 m/s. A flat panel display inside one build shows running stats. For instance, after 351 hr of operation the unit had generated nearly 5,000 kWh of power in an urban location not known for its wind.

Costs for the turbine before incentives was about $375,000. Graneto, an electrical engineer and turbine erector working with PearlWind, calculates a payback in 8 to 9 years and sooner if power rates head up. He says a taller tower would capture faster winds which makes one wonder that with sufficiently tall towers and public acceptance, wind farms and cities could be one and the same.

Wind-turbine manufacturer adds solar interest, changes name

Paul Dvorak — Thu, 21 Jan 2010 15:47:14 +0000

The Earth Turbine 2500 can generate 2.5 kW in a 11 m/s wind.

Earth Turbines Inc, Williston, Vermont, the state’s only manufacturer of small scale grid-connected wind and solar tracking systems, announces a corporate name change to AllEarth Renewables Inc. “Our company is dedicated to developing new wind and solar technologies,” says David Blittersdorf, CEO and president of AllEarth Renewables. ”We want to be sure that our corporate name reflects this larger focus for the future.” Since founding Earth Turbines in 2005, Blittersdorf has lead a team of engineers dedicated to designing rugged and reliable grid-connected renewable energy systems that help homeowners and businesses realize the dream of generating electricity with local, renewable energy. Much of what was learned while testing and refining the Earch Turbine 2500 influenced development of the AllSun Tracker dual-axis solar system, which was introduced in May of 2009.

The company provides turnkey site assessment, permitting, and installation for both the Earth Turbine 2500 and the AllSun Tracker dual-axis solar system. The company adds that with a 30% federal tax credit and available Vermont tax credits or rebates, each renewable energy system can fit the budget of a wide array of consumers seeking to reduce their dependence on nuclear and fossil fuels, support renewable energy and assure a fixed-cost, reliable power source for their home or business.

The Earth Turbine 2500 uses a patented direct drive, induction generator with no inverter or gearbox. The innovative design was chosen for its reliability and relative simplicity. The system is mounted on a 112-ft guyed tilt-up tower, placing the turbine at best height to capture wind. The company says the 2500 weighs a hefty 450 lb, providing unprecedented durability for a small wind system. The turbine uses a wireless monitoring interface and is easily installed and connected directly to the grid through homes or businesses. After a five-year testing period, sales of the Earth Turbine 2500 are scheduled to begin in the summer of 2010.

More than 80 AllSun Tracker solar systems have already been installed, including 36 at the Green Acres Tracker Farm in Hinesburg, Vermont, the largest solar installation to date in the state. The electricity produced by the Green Acres Tracker Farm (estimated at 200,000 kWh per year) is divided between the corporate headquarters of AllEarth Renewables and NRG Systems of Hinesburg through a process called group net-metering. This allows sharing the electric output of a system among multiple entities located within the same utility service area. The company estimates that with the electricity generated by the Green Acres Tracker Farm, both NRG and AllEarth Renewables will meet 100% of their electricity needs.