Turnkey Wind Farms
www.TurnkeyWindFarms.com

Wind Power Technologies develops, acquires, owns and operates Wind Farms and Community Wind Farms and provides Carbon Dioxide Credits, Emissions Trading and Carbon Reduction Projects in the U.S. and Canada. We also provide Wind Energy Feasibility Studies and Wind Resource Assessments.

Got Wind Turbines?
www.GotWindTurbines.com

Windpower Technologies, LLC.

Turnkey Wind Farms & Community Wind Farms

For more information on our wind turbines, call (832) 758 - 0027

2 Bladed Wind Turbine or 3 Bladed Wind Turbines?
Why 3-Bladed Wind Turbines are the Optimum Number of Blades on a Wind Turbine

The argument has been settled and the debate is over, 3-bladed wind turbines are better than 2-bladed wind turbines.

While a 2-bladed wind turbine may generate over 90% of the power of a 3-bladed wind turbine of comparable size.  And, while a 2-bladed wind turbine saves the weight of one extra blade when compared with a 3-bladed wind turbine, engineers of the most efficient wind turbines have decided on 3 blades as the optimum efficiency and design for a wind turbine generator in the 600 kW class and above.

The top-3 leading wind turbine manufacturers have standardized on the 3-bladed wind turbine.  They do not manufacture any 2-bladed wind turbines.  Plainly stated, a wind turbine with an even number of blades (2 blades or 4 blades) are NOT of optimum design or efficiency. In fact, this debate was settled years ago when the wind turbine engineers and designers began building wind turbines over 600 kW in power output.

The leading wind turbine manufacturers and their engineers have decided that 3 bladed wind turbines are the optimum number of wind turbine blades due to the stability of the wind turbine as well as the significant wind loads and stresses placed on a 2-bladed wind turbine.  A wind turbine that has an odd number of blades is similar to a disc when calculating the computational fluid dynamics of the wind turbine.  Engineers have learned that wind turbines that have an even number of blades - such as the 2 bladed wind turbines of the past - have stability problems for a machine with a stiff structure. The reason for this problem is simple, engineers recognized that when a 2-bladed wind turbine's top blade bends backwards - when the wind turbine's 2 blades are in the vertical position - since it is now generating the maximum power from the wind - that the lower or bottom blade is now aligned with the tower and the blade is hidden or blocked from the wind - and this generates a huge amount of stress and loads on the wind turbine and its' primary components such as the bearings, shaft, transmission etc.

Because of the extreme wind loads and stresses placed on 2-bladed wind turbines, the remaining 2-bladed wind turbine manufacturers have had to resort to a "teetered hub" that helps remove some of the stress and loads placed on 2-bladed wind turbines. While there are some very fine 2-bladed wind turbines, of smaller power output, the bottom line is, 3 bladed wind turbines are inherently better and more efficient than 2-bladed wind turbines.

Wind Power Technologies develops, acquires, owns and operates Wind Farms and Community Wind Farms in the U.S. and Canada. Wind Power Technologies provides Wind Energy and Wind Power: 

* Consulting
* Capital
* Wind Energy Feasibility Studies and Wind Resource Assessments
* Carbon Credits 
* Emissions Trading 
* Carbon Reduction Projects in the U.S. and Canada

Land And Ranch Owners 
Interested in Wind Turbines 
& Generating a New Income, 
Call Us for More Information

If you are a land owner with at least 100 acres and interested in having one or more wind turbines installed on your property, please provide us with the following information so we can determine whether your property qualifies for an initial, no-cost assessment.

1. Owner's Name __________________________________

    Name of ranch/property ________________________

2. Address _______________________________

    city ______________              

    state ______    

    zip _________ 

3. Phone ____________

Email address __________________

Approximate Acreage __________

Would you be willing to have a small wind speed testing tower on your property for up to 12 months for us to evaluate the wind? 

Have you ever been contacted by wind developer before? If yes, please provide the name of the developer and the date they contacted you.

Additional comments or information

What is a Wind Resource Assessment?

A Wind Resource Assessment is defined as the process of characterizing the wind resource and its energy potential for a specific site or geographical area.

Wind Resource Assessment

All markets for wind turbines require an estimate of how much wind energy is available at potential development sites. Correct estimation of the energy available in the wind can make or break the economics of wind farm development. Wind maps developed in the late '70s and early '80s provided reasonable estimates of areas in which good wind resources could be found. But new tools and new data available from satellites and new sensing devices now allow researchers to create even more accurate and detailed wind maps of the world.

Wind mapping techniques developed by NREL and U.S. companies are being used to produce high-resolution projections of U.S. and foreign regions that are painting a whole new picture of wind potential. These maps are created using highly accurate GPS mapping tools and a vast array of satellite, weather balloon, and meteorological tower data, combined with much-improved numerical computer models. The higher horizontal resolution of these maps (1 km or finer) allows for more accurate siting of wind turbines and has also led to the recognition of higher-class winds in areas where none were thought to exist.

The ability to accurately predict when the wind will blow will help remove barriers to wind energy development by allowing wind-power-generating facilities to commit to power purchases in advance. NREL researchers work with federal, state, and private organizations to validate the nation's wind resources and support advances in wind forecasting techniques and dissemination. Wind resource validation is important for both wind resource assessment and the integration of wind farms into an energy grid. Validating new, high-resolution wind resource maps will provide an accurate reading of the wind resource at a particular site. Development of short-term (1 to 4 hours) forecasting tools will help energy producers proceed with new wind farm projects and avoid the penalties they must pay if they do not meet their hourly generation targets. In addition, validating new high-resolution wind resource maps will give people interested in developing wind energy projects greater confidence as to the level of wind resource for a particular site.

Renewable Energy Technologies provides the following power and energy project development services: 

• Project Engineering Feasibility & Economic Analysis Studies  

• Engineering, Procurement and Construction

• Environmental Engineering & Permitting 

• Project Funding & Financing Options; including Equity Investment, Debt Financing, Lease and Municipal Lease

• Shared/Guaranteed Savings Program with No Capital Investment from Qualified Clients 

• Project Commissioning 

• 3rd Party Ownership and Project Development

• Long-term Service Agreements

• Operations & Maintenance

• Carbon Reduction Projects 

• Carbon Emissions & Greenhouse Gas Emissions Credits (Renewable Energy Credit, Carbon Dioxide Credits, Emission Reduction Credits, Certified Emission Reductions, Verified Emission Reductions, Voluntary Emission Reductions) Consulting

We are specialists in Renewable Energy Technologies, Demand Side Management and in developing clean power/energy projects that will generate a Renewable Energy Credit,  Carbon Dioxide Credits and/or Emission Reduction Credits.  Through our strategic partners, we offer "turnkey" power/energy project development products and services that may include; Absorption Chillers, Adsorption Chillers, Automated Demand Response, Biodiesel Refineries, Biofuel Refineries, Biomass Gasification, BioMethane, Canola Biodiesel, Coconut Biodiesel, Cogeneration, Concentrating Solar Power, Demand Response Programs, Demand Side Management, Energy Conservation Measures, Energy Master Planning, Engine Driven Chillers, Solar CHP, Solar Cogeneration, Rapeseed Biodiesel, Solar Electric Heat Pumps, Solar Electric Power Systems, Solar Heating and Cooling, Solar Trigeneration, Soy Biodiesel, and Trigeneration.

Our company raises investment capital for Community Wind Farms and other renewable energy and power projects. For qualified clients, we provide "turnkey" renewable energy project development services, including; EPC (Engineering, Procurement, Construction), Investment/Funding, Permitting, and Emission Reduction Credits under the Kyoto Protocol's Clean Development Mechanism.

^{What are "Renewable Energy Technologies?"}

^{Any technology that exclusively relies on an energy source that is naturally regenerated over a short time and derived directly from the sun, indirectly from the sun, or from moving water or other natural movements and mechanisms of the environment. A renewable energy technology does not rely on energy resources derived from fossil fuels, or waste products from inorganic sources. Renewable energy technologies include; Bioenergy (such as biomethane recovery from , landfills, animal operations and POTW's), Geothermal, Hydrogen, Hydropower, Ocean, Solar, and Wind power generation technologies. More information about these renewable energy technologies follows below beginning with the paragraph on "Bioenergy."}

We provide Renewable Energy Technologies engineering and project development services. We incorporate many energy-saving technologies, products and services into our renewable energy power and energy projects that may include the use of; Absorption Chillers, Adsorption Chillers, Automated Demand Response, BioMethane, Cogeneration, Concentrating Solar Power, Demand Response Programs, Demand Side Management, Energy Master Planning, Energy Performance Contracting, Energy Savings Performance Contracting, Engine Driven Chillers, Geothermal Power Plants, Landfill gas to Energy, Ocean Thermal Energy Conversion, Quadgeneration, Solar CHP, Solar Cogeneration, Solar Trigeneration, Trigeneration and Energy Conservation Measures.  

Our company provides turn-key project solutions that include all or part of the following: 

• Engineering and Economic Feasibility Studies 

• Project Design, Engineering & Permitting

• Project Construction

• Project Funding & Financing Options

• Shared/Guaranteed Savings program with no capital requirements. 

• Project Commissioning 

• Operations & Maintenance 

For more information: call us at:  832-758-0027

^Bioenergy

^{Bioenergy technologies use renewable biomass resources to produce an array of energy related products including electricity, liquid, solid, and gaseous fuels, heat, chemicals, and other materials. Bioenergy ranks second (to hydropower) in renewable U.S. primary energy production and accounts for three percent of the primary energy production in the United States.}

<sup>Biomass (organic matter) can be used to provide heat, make fuels, and generate electricity. This is called bioenergy. Wood, the largest source of bioenergy, has been used to provide heat for thousands of years. But there are many other types of biomass—such as wood, plants, residue from agriculture or forestry, and the organic component of municipal and industrial wastes—that can now be used as an energy source. Today, many bioenergy resources are replenished through the cultivation of energy crops, such as fast-growing trees and grasses, called bioenergy feedstocks. 

Unlike other renewable energy sources, biomass can be converted directly into liquid fuels for our transportation needs. The two most common biofuels are ethanol and biodiesel. Ethanol, an alcohol, is made by fermenting any biomass high in carbohydrates, like corn, through a process similar to brewing beer. It is mostly used as a fuel additive to cut down a vehicle's carbon monoxide and other smog-causing emissions. Biodiesel, an ester, is made using vegetable oils, animal fats, algae, or even recycled cooking greases. It can be used as a diesel additive to reduce vehicle emissions or in its pure form to fuel a vehicle. 

Heat can be used to chemically convert biomass into a fuel oil, which can be burned like petroleum to generate electricity. Biomass can also be burned directly to produce steam for electricity production or manufacturing processes. In a power plant, a turbine usually captures the steam, and a generator then converts it into electricity. In the lumber and paper industries, wood scraps are sometimes directly fed into boilers to produce steam for their manufacturing processes or to heat their buildings. Some coal-fired power plants use biomass as a supplementary energy source in high-efficiency boilers to significantly reduce emissions. 

Even gas can be produced from biomass for generating electricity. Biomass Gasification systems use high temperatures to convert biomass into a natural gas, or BioMethane. The gas fuels a turbine, which is very much like a jet engine, only it turns an electric generator instead of propelling a jet. The decay of biomass in landfills also produces a BioMethane gas that can be burned in a boiler to produce steam for electricity generation or for industrial processes. 

New technology could lead to using biobased chemicals and materials to make products such as anti-freeze, plastics, and personal care items that are now made from petroleum. In some cases these products may be completely biodegradable. While technology to bring biobased chemicals and materials to market is still under development, the potential benefit of these products is great. 

Biomass Resources</sup>

^Geothermal

^{Geothermal energy technologies use the heat of the earth for direct-use applications, geothermal heat pumps, and electrical power production. Research in all areas of geothermal development is helping to lower costs and expand its use. In the United States, most geothermal resources are concentrated in the West, but geothermal heat pumps can be used nearly anywhere.}

<sup>Geothermal energy is the heat from the Earth. It's clean and sustainable. Resources of geothermal energy range from the shallow ground to hot water and hot rock found a few miles beneath the Earth's surface, and down even deeper to the extremely high temperatures of molten rock called magma. 

Almost everywhere, the shallow ground or upper 10 feet of the Earth's surface maintains a nearly constant temperature between 50° and 60°F (10° and 16°C). Geothermal heat pumps can tap into this resource to heat and cool buildings. A geothermal heat pump system consists of a heat pump, an air delivery system (ductwork), and a heat exchanger—a system of pipes buried in the shallow ground near the building. In the winter, the heat pump removes heat from the heat exchanger and pumps it into the indoor air delivery system. In the summer, the process is reversed, and the heat pump moves heat from the indoor air into the heat exchanger. The heat removed from the indoor air during the summer can also be used to provide a free source of hot water. 

In the United States, most geothermal reservoirs of hot water are located in the western states, Alaska, and Hawaii. Wells can be drilled into underground reservoirs for the generation of electricity. Some geothermal power plants use the steam from a reservoir to power a turbine/generator, while others use the hot water to boil a working fluid that vaporizes and then turns a turbine. Hot water near the surface of Earth can be used directly for heat. Direct-use applications include heating buildings, growing plants in greenhouses, drying crops, heating water at fish farms, and several industrial processes such as pasteurizing milk. 

Hot dry rock resources occur at depths of 3 to 5 miles everywhere beneath the Earth's surface and at lesser depths in certain areas. Access to these resources involves injecting cold water down one well, circulating it through hot fractured rock, and drawing off the heated water from another well. Currently, there are no commercial applications of this technology. Existing technology also does not yet allow recovery of heat directly from magma, the very deep and most powerful resource of geothermal energy.</sup> 

<sup>Exploration

Geological, geochemical, and geophysical techniques are used to locate geothermal resources. 

Drilling

Drilling for geothermal resources has been adapted from the oil industry. Improved drill bits, slimhole drilling, advanced instruments, and other drilling technologies are under development. 

Direct Use

Geothermal hot water near the Earth's surface can be used directly for heating buildings and as a heat supply for a variety of commercial and industrial uses. Geothermal direct use is particularly favored for greenhouses and aquaculture. 

Geothermal Heat Pumps

Geothermal heat pumps, or ground-source heat pumps, use the relatively constant temperature of soil or surface water as a heat source and sink for a heat pump, which provides heating and cooling for buildings. 

Electricity Production

Underground reservoirs of hot water or steam, heated by an upwelling of magma, can be tapped for electrical power production. 

Advanced Technologies

Advanced technologies will help manage geothermal resources for maximum power production, improve plant operating efficiencies, and develop new resources such as hot dry rock, geopressured brines, and magma. 

Environmental

Geothermal technologies release little or no air emissions. Geothermal power production produces much lower air emissions than conventional energy technologies. 

Geothermal Resources

In the United States, geothermal resources are concentrated in the West, although low-temperature resources can also be found in the rest of the country. Geothermal heat pumps can be used nearly anywhere.</sup> 

^Hydrogen

Hydrogen is the third most abundant element on the earth's surface, where it is found primarily in water (H_²O) and organic compounds. It is generally produced from hydrocarbons or water; and when burned as a fuel, or converted to electricity, it joins with oxygen to again form water.

Hydrogen is the simplest element; an atom consists of only one proton and one electron. It is also the most plentiful element in the universe. Despite its simplicity and abundance, hydrogen doesn't occur naturally as a gas on the Earth—it is always combined with other elements. Water, for example, is a combination of hydrogen and oxygen (H²O). Hydrogen is also found in many organic compounds, notably the "hydrocarbons" that make up many of our fuels, such as gasoline, natural gas, methanol, and propane. 

Hydrogen can be made by separating it from hydrocarbons by applying heat, a process known as "reforming" hydrogen. Currently, most hydrogen is made this way from natural gas. An electrical current can also be used to separate water into its components of oxygen and hydrogen. Some algae and bacteria, using sunlight as their energy source, even give off hydrogen under certain conditions. 

Hydrogen is high in energy, yet an engine that burns pure hydrogen produces almost no pollution. NASA has used liquid hydrogen since the 1970s to propel the space shuttle and other rockets into orbit. Hydrogen fuel cells power the shuttle's electrical systems, producing a clean byproduct—pure water, which the crew drinks. You can think of a fuel cell as a battery that is constantly replenished by adding fuel to it—it never loses its charge. 

Fuel cells are a promising technology for use as a source of heat and electricity for buildings, and as an electrical power source for electric vehicles. Although these applications would ideally run off pure hydrogen, in the near term they are likely to be fueled with natural gas, methanol, or even gasoline. Reforming these fuels to create hydrogen will allow the use of much of our current energy infrastructure—gas stations, natural gas pipelines, etc.—while fuel cells are phased in. 

In the future, hydrogen could also join electricity as an important energy carrier. An energy carrier stores, moves, and delivers energy in a usable form to consumers. Renewable energy sources, like the sun, can't produce energy all the time. The sun doesn't always shine. But hydrogen can store this energy until it is needed and can be transported to where it is needed. 

Some experts think that hydrogen will form the basic energy infrastructure that will power future societies, replacing today's natural gas, oil, coal, and electricity infrastructures. They see a new hydrogen economy to replace our current energy economies, although that vision probably won't happen until far in the future.

Production

Hydrogen is produced from sources such as natural gas, coal, gasoline, methanol, or biomass through the application of heat; from bacteria or algae through photosynthesis; or by using electricity or sunlight to split water into hydrogen and oxygen. 

Transport and Storage

The use of hydrogen as a fuel and energy carrier will require an infrastructure for safe and cost-effective hydrogen transport and storage. 

Fuel Cells

Hydrogen's potential use in fuel and energy applications includes powering vehicles, running turbines or fuel cells to produce electricity, and generating heat and electricity for buildings. The current focus is on hydrogen's use in fuel cells. 

Safety

Hydrogen has an excellent safety record, and is as safe for transport, storage and use as many other fuels. Nevertheless, safety remains a top priority in all aspects of hydrogen energy. The hydrogen community addresses safety through stringent design and testing of storage and transport concepts, and by developing codes and standards for all types of hydrogen-related equipment. 

The Hydrogen Economy

The vision of building an energy infrastructure that uses hydrogen as an energy carrier — a concept called the "hydrogen economy" — is considered the most likely path toward a full commercial application of hydrogen energy technologies. 

^Hydropower

Hydropower (also called hydroelectric power) facilities in the United States can generate enough power to supply 28 million households with electricity, the equivalent of nearly 500 million barrels of oil. The total U.S. hydropower capacity—including pumped storage facilities—is about 95,000 megawatts. Researchers are working on advanced turbine technologies that will not only help maximize the use of hydropower but also minimize adverse environmental effects.

Flowing water creates energy that can be captured and turned into electricity. This is called hydropower. Hydropower is currently the largest source of renewable power, generating nearly 10% of the electricity used in the United States. 

The most common type of hydropower plant uses a dam on a river to store water in a reservoir. Water released from the reservoir flows through a turbine, spinning it, which, in turn, activates a generator to produce electricity. But hydropower doesn't necessarily require a large dam. Some hydropower plants just use a small canal to channel the river water through a turbine. 

Another type of hydropower plant—called a pumped storage plant—can even store power. The power is sent from a power grid into the electric generators. The generators then spin the turbines backward, which causes the turbines to pump water from a river or lower reservoir to an upper reservoir, where the power is stored. To use the power, the water is released from the upper reservoir back down into the river or lower reservoir. This spins the turbines forward, activating the generators to produce electricity. 

Types of Hydropower

Impoundment
An impoundment facility, typically a large hydropower system, uses a dam to store river water in a reservoir. The water may be released either to meet changing electricity needs or to maintain a constant reservoir level. 

Diversion
A diversion, sometimes called run-of-river, facility channels a portion of a river through a canal or penstock. It may not require the use of a dam. 

Pumped Storage
When the demand for electricity is low, a pumped storage facility stores energy by pumping water from a lower reservoir to an upper reservoir. During periods of high electrical demand, the water is released back to the lower reservoir to generate electricity. 

Sizes of Hydropower Plants
Facilities range in size from large power plants that supply many consumers with electricity to small and micro plants that individuals operate for their own energy needs or to sell power to utilities. 

Large Hydropower
Although definitions vary, DOE defines large hydropower as facilities that have a capacity of more than 30 megawatts. 

Small Hydropower
Although definitions vary, DOE defines small hydropower as facilities that have a capacity of 0.1 to 30 megawatts. 

Micro Hydropower
A micro hydropower plant has a capacity of up to 100 kilowatts (0.1 megawatts). 

Turbine Technologies
There are many types of turbines used for hydropower, and they are chosen based on their particular application and the height of standing water—referred to as "head"—available to drive them. The turning part of the turbine is called the runner. The most common turbines are as follows: 

Pelton Turbine
A Pelton turbine has one or more jets of water impinging on the buckets of a runner that looks like a water wheel. The Pelton turbines are used for high-head sites (50 feet to 6,000 feet) and can be as large as 200 megawatts. 

Francis Turbine
A Francis turbine has a runner with fixed vanes, usually nine or more. The water enters the turbine in a radial direction with respect to the shaft, and is discharged in an axial direction. Francis turbines will operate from 10 feet to 2,000 feet of head and can be as large as 800 megawatts. 

Propeller Turbine
A propeller has a runner with three to six fixed blades, like a boat propeller. The water passes through the runner and drives the blades. Propeller turbines can operate from 10 feet to 300 feet of head and can be as large as 100 megawatts. A Kaplan turbine is a type of propeller turbine in which the pitch of the blades can be changed to improve performance. Kaplan turbines can be as large as 400 megawatts. 

Environmental Issues and Mitigation
Current hydropower technology, while essentially emission-free, can have undesirable environmental effects, such as fish injury and mortality from passage through turbines, as well as detrimental effects on the quality of downstream water. A variety of mitigation techniques are in use now, and environmentally friendly turbines are under development. 

Legal and Institutional Issues
Legal and institutional issues include federal licensing as well as state and local permits, laws for historic and cultural preservation, and recreational requirements. 

^Ocean

Ocean energy draws on the energy of ocean waves, tides, or on the thermal energy (heat) stored in the ocean.

The ocean contains two types of energy: thermal energy from the sun's heat, and mechanical energy from the tides and waves. 

Oceans cover more than 70% of Earth's surface, making them the world's largest solar collectors. The sun warms the surface water a lot more than the deep ocean water, and this temperature difference stores thermal energy. Thermal energy is used for many applications, including electricity generation. There are three types of electricity conversion systems: closed-cycle, open-cycle, and hybrid. Closed-cycle systems use the ocean's warm surface water to vaporize a working fluid, which has a low-boiling point, such as ammonia. The vapor expands and turns a turbine. The turbine then activates a generator to produce electricity. Open-cycle systems actually boil the seawater by operating at low pressures. This produces steam that passes through a turbine/generator. And hybrid systems combine both closed-cycle and open-cycle systems. 

Ocean mechanical energy is quite different from ocean thermal energy. Even though the sun affects all ocean activity, tides are driven primarily by the gravitational pull of the moon, and waves are driven primarily by the winds. A barrage (dam) is typically used to convert tidal energy into electricity by forcing the water through turbines, activating a generator. For wave energy conversion, there are three basic systems: channel systems that funnel the waves into reservoirs, float systems that drive hydraulic pumps, and oscillating water column systems that use the waves to compress air within a container. The mechanical power created from these systems either directly activates a generator or transfers to a working fluid, water, or air, which then drives a turbine/generator. 

Wave Energy
The total power of waves breaking on the world's coastlines is estimated at 2 to 3 million megawatts. In favorable locations, wave energy density can average 65 megawatts per mile of coastline. 

Tidal Energy
Tidal energy traditionally involves erecting a dam across the opening to a tidal basin. The dam includes a sluice that is opened to allow the tide to flow into the basin; the sluice is then closed, and as the sea level drops, traditional hydropower technologies can be used to generate electricity from the elevated water in the basin. Some researchers are also trying to extract energy directly from tidal flow streams. 

Ocean Thermal Energy Conversion (OTEC) Systems
A great amount of thermal energy (heat) is stored in the world's oceans. Each day, the oceans absorb enough heat from the sun to equal the thermal energy contained in 250 billion barrels of oil. OTEC systems convert this thermal energy into electricity — often while producing desalinated water. 

^Solar

Solar technologies use the sun's energy and light to provide heat, light, hot water, electricity, and even cooling, for homes, businesses, and industry. 

Sunlight—solar energy—can be used to generate electricity, provide hot water, and to heat, cool, and light buildings. 

Photovoltaic (solar cell) systems convert sunlight directly into electricity. A solar or PV cell consists of semiconducting material that absorbs the sunlight. The solar energy knocks electrons loose from their atoms, allowing the electrons to flow through the material to produce electricity. PV cells are typically combined into modules that hold about 40 cells. About 10 of these modules are mounted in PV arrays. PV arrays can be used to generate electricity for a single building or, in large numbers, for a power plant. A power plant can also use a concentrating solar power system, which uses the sun's heat to generate electricity. The sunlight is collected and focused with mirrors to create a high-intensity heat source. This heat source produces steam or mechanical power to run a generator that creates electricity. 

Solar water heating systems for buildings have two main parts: a solar collector and a storage tank. Typically, a flat-plate collector—a thin, flat, rectangular box with a transparent cover—is mounted on the roof, facing the sun. The sun heats an absorber plate in the collector, which, in turn, heats the fluid running through tubes within the collector. To move the heated fluid between the collector and the storage tank, a system either uses a pump or gravity, as water has a tendency to naturally circulate as it is heated. Systems that use fluids other than water in the collector's tubes usually heat the water by passing it through a coil of tubing in the tank. 

Many large commercial buildings can use solar collectors to provide more than just hot water. Solar process heating systems can be used to heat these buildings. A solar ventilation system can be used in cold climates to preheat air as it enters a building. And the heat from a solar collector can even be used to provide energy for cooling a building. 

A solar collector is not always needed when using sunlight to heat a building. Some buildings can be designed for passive solar heating. These buildings usually have large, south-facing windows. Materials that absorb and store the sun's heat can be built into the sunlit floors and walls. The floors and walls will then heat up during the day and slowly release heat at night—a process called direct gain. Many of the passive solar heating design features also provide daylighting. Daylighting is simply the use of natural sunlight to brighten up a building's interior.

Solar Technologies

Photovoltaics (PV)
Photovoltaic solar cells, which directly convert sunlight into electricity, are made of semiconducting materials. The simplest cells power watches and calculators and the like, while more complex systems can light houses and provide power to the electric grid. 

Passive Solar Heating, Cooling and Daylighting
Buildings designed for passive solar and daylighting incorporate design features such as large south-facing windows and building materials that absorb and slowly release the sun's heat. No mechanical means are employed in passive solar heating. Incorporating passive solar designs can reduce heating bills as much as 50 percent. Passive solar designs can also include natural ventilation for cooling. 

Concentrating Solar Power
Concentrating solar power technologies use reflective materials such as mirrors to concentrate the sun's energy. This concentrated heat energy is then converted into electricity. 

Solar Hot Water and Space Heating and Cooling
Solar hot water heaters use the sun to heat either water or a heat-transfer fluid in collectors. A typical system will reduce the need for conventional water heating by about two-thirds. High-temperature solar water heaters can provide energy-efficient hot water and hot water heat for large commercial and industrial facilities. 

Issues

Solar Resources
Solar resource information provides data on how much solar energy is available to a collector and how it might vary from month to month, year to year, and location to location. Collecting this information requires a national network of solar radiation monitoring sites. 

Solar Access
The availability or access to unobstructed sunlight for use both in passive solar designs and active systems is protected by zoning laws and ordinances in many communities. 

Green Power
Consumer demand for clean renewable energy and the deregulation of the utilities industry have spurred growth in green power—solar, wind, geothermal steam, biomass, and small-scale hydroelectric sources of power. Small commercial solar power plants have begun serving some energy markets. 

^Wind 

Wind energy uses the energy in the wind for practical purposes like generating electricity, charging batteries, pumping water, or grinding grain. Large, modern wind turbines operate together in wind farms to produce electricity for utilities. Small turbines are used by homeowners and remote villages to help meet energy needs.

Wind turbines capture the wind's energy with two or three propeller-like blades, which are mounted on a rotor, to generate electricity. The turbines sit high atop towers, taking advantage of the stronger and less turbulent wind at 100 feet (30 meters) or more aboveground. 

A blade acts much like an airplane wing. When the wind blows, a pocket of low-pressure air forms on the downwind side of the blade. The low-pressure air pocket then pulls the blade toward it, causing the rotor to turn. This is called lift. The force of the lift is actually much stronger than the wind's force against the front side of the blade, which is called drag. The combination of lift and drag causes the rotor to spin like a propeller, and the turning shaft spins a generator to make electricity. 

Wind turbines can be used as stand-alone applications, or they can be connected to a utility power grid or even combined with a photovoltaic (solar cell) system. Stand-alone turbines are typically used for water pumping or communications. However, homeowners and farmers in windy areas can also use turbines to generate electricity. For utility-scale sources of wind energy, a large number of turbines are usually built close together to form a wind farm. Several electricity providers today use wind farms to supply power to their customers.

Wind Energy Technologies
Modern wind turbines are divided into two major categories: horizontal axis turbines and vertical axis turbines. Old-fashioned windmills are still seen in many rural areas. 

Wind Turbine Use
Wind turbines are used around the world for many applications. Wind turbine use ranges from homeowners with single turbines to large wind farms with hundreds of turbines providing electricity to the power grid. 

Research
Research advances have helped drop the cost of energy from the wind dramatically during the last 20 years. Research is carried out by research labs, universities, and utility organizations. 

Wind Resource
The wind is the fuel source for wind energy. The United States has many areas with abundant winds, particularly in the Midwest and Great Plains. Understanding the wind resource is a crucial step in planning a wind energy project. Detailed knowledge of the wind at a site is needed to estimate the performance of a wind energy project. 

Environment
Wind energy is considered a green power technology because it has only minor impacts on the environment. Wind energy plants produce no air pollutants or greenhouse gases. However, any means of energy production impacts the environment in some way, and wind energy is no different. 

Economics
The cost of energy from the wind has dropped by 85% during the last 20 years. Incentives like the federal production tax credit and net metering provisions available in some areas improve the economics of wind energy.

Forces Behind Wind Power

Introduction

In the past several years, a number of new wind farms have begun commercial operation. Industry sources have estimated that more than 900 megawatts (MW) of wind capacity was under construction in 1999. A major portion of this capacity was constructed outside of California, the birth place of the wind power industry in the United States.⁽¹⁾ While the economics of wind turbine technology is improving, it is generally not yet competitive with fossil fuels.⁽²⁾ Just as the outlook for wind improves, it can also improve for other energy sources. Thus, despite the encouraging portrayal of wind turbines, they face uncertainty in the future. This paper looks at the forces behind recent wind energy development.

Current Status and Recent Events

In 1997, wind power generation capacity of 1,579 MW produced 3,254,117 megawatthours (MWh) of electricity.⁽³⁾ More than 99 percent of generation was by independent power producers, and nearly all of it was located in California. During 1998 and 1999, wind farm activity expanded into other States, motivated in part by financial and regulatory incentives and, in the case of Iowa and Minnesota, State mandates. Iowa, Minnesota, and Texas each had capacity additions exceeding 100 MW that came on line in 1999 (Table 1). During 1999, wind farm capacity that came on line consisted of state-of-the-art wind turbines manufactured primarily by Zond, a subsidiary of Enron Wind Corporation (392 MW); NEG Micon (325 MW); and Vestas (159 MW).⁽⁴⁾ Less than 32 percent of new wind power construction was located in California in 1999.

Table 1. United States Wind Energy Capacity by State, 1998, and New Construction, 1999 and 2000 (Megawatts)
State	Existinga 1998	New Construction
		1999	2000
Alaska	*	.58	.10
California	1,487	b290.33	b208.50
Colorado	0	16.00	0
Hawaii	20	0	39.75
Iowa	*	237.45	0.60
Kansas	0	1.50	0
Maine	0	0	6.10
Massachusetts	*	0	7.50
Michigan	1	0	0
Minnesota	129	139.56	32.00
Nebraska	0	1.32	0
New Mexico	0	0.66	0
New York	0	0	18.15
Oregon	25	0	0
Pennsylvania	0	0	26.17
South Dakota	0	0	0.75
Tennessee	0	0	1.98
Texas	34	145.82	25.10
Utah	0	0	.23
Vermont	1	0	5.00
Wisconsin	0	21.78	0
Wyoming	1	71.25	28.12
Total	1,698	926.24	395.05
a Defined as net summer capability.    b Includes a substantial portion of repowered capacity.    * = Less than 0.5 megawatts capacity.    Sources: 1998 Capacity: Energy Information Administration, Renewable Energy Annual 1999 With Data for 1998, DOE/EIA-0603(99) (Washington, DC, March 2000) and New Construction: Based on data in American Wind Energy Association (AWEA), "Wind Energy Projects Throughout the United States," http://www.awea.org/projects/index.html (July 7, 2000).

A number of recent events have triggered an interest in wind energy. Significant interest has arisen in the ability of renewable energy to survive as a viable energy source, compared with less expensive fossil fuels, as the electric power industry moves from a regulated to a competitive environment. Because renewable energy sources are generally perceived to be more environmentally benign than other energy sources, much recently enacted and/or proposed Federal and State legislation on electric competition contains provisions encouraging consumption of renewable energy. Hence, in those instances, electric restructuring may actually promote renewable energy use rather than restrain it. Wind energy, which is more economically competitive than most other renewable energy options, should benefit most from this effort.

Another event that increased interest in wind energy was the expiration of the federal production tax credit for any projects beginning operation after June 30, 1999. This tax credit was established by the Energy Policy Act of 1992 and provided a 1.5 cent per kilowatthour tax credit for the first 10 years of the project's life. Since all projects in operation by June 30, 1999, would be eligible for the tax credit, most of the capacity that came on line in 1999 came on by that date. Although the credit actually expired, it was reinstated in December 1999, it is retroactive to July 1999, and extends until the end of 2001. The current schedule for new capacity is less ambitious than 1999, but substantial (Table 1). A total of nearly 400 MW of new wind power construction (including a significant share of repowered capacity in California) was expected for 2000.

Additionally, in June of 1999, the Secretary of Energy announced the start of a new initiative, "Wind Powering America." The stated goal of this program is to have 80,000 MW of wind power generation capacity in place by 2020 and have wind power provide 5 percent of the Nation's electricity generation.⁽⁵⁾ Year-end 1998 wind power capacity was about 1,698 MW,⁽⁶⁾ so this goal represents an enormous increase in capacity additions. The initiative is mentioned here because of its potential importance and the attention it is drawing to wind energy. However, the full impact of the program on wind energy will be over the long-term future and is a concern more so for the Energy Information Administration's (EIA) Annual Energy Outlook, and less so for this paper, which covers the recent past and near-term future.⁽⁷⁾

Another long-term impact on renewable energy sources is concern over global warming and formulating a policy to reduce greenhouse gases in accordance with the Kyoto Protocol. A United Nations conference with representatives from more than 160 countries met in Kyoto, Japan, in 1997 to negotiate binding limits for greenhouse gas emissions for developed nations. Carbon dioxide is the major greenhouse gas. The target for the United States is to reduce carbon dioxide to 7 percent below 1990 levels in the 2008-2012 time frame. Adopting a carbon tax to accomplish this goal would increase the price of fossil fuels (particularly coal) but have little impact on the cost of renewables, which have zero or net zero carbon dioxide emissions. Assuming a carbon tax is imposed, analysis indicates that an increase in the consumption of renewable energy, led by wind, would make a significant contribution to achieving the targeted level of reduced emissions.⁽⁸⁾ The next United Nations Conference of Parties (COP) meeting to develop strategies to achieve the goals of the Kyoto Protocol was held in November 2000 in the Hague, Netherlands.⁽⁹⁾ No significant agreement was reached at that time, but future meetings are expected.

This paper is divided into two main sections followed by an appendix. The first section includes a technical discussion of expectations for wind turbine performance and efforts to improve it. The second section provides an overview of the world in which the wind power industry is developing. This discussion includes a broad view of the impact of electric power industry restructuring, as well as Federal and State incentives. These two main sections are supplemented by an Appendix of State Wind Profiles that takes a snapshot of the status of electricity restructuring in each State, the type of incentives or green power programs available to wind, and status of wind energy development through 2000. References are included so more current information can be obtained as needed.⁽¹⁰⁾

Wind Turbine Performance

The following sections provide an overview of the turbine technology being installed in today's wind farms. These turbines have generation capacities at or above 225 kilowatts (kW).⁽¹¹⁾ The discussion examines (1) wind resource issues and related siting considerations, (2) factors affecting wind turbine performance, (3) physical and operational characteristics of wind farm turbines and (4) operation and maintenance (O&M) considerations. The discussion focuses on wind farm turbines manufactured by NEG Micon, Vestas, and Zond, as they represent most of new installed capacity in the United States. The discussion indicates that each of their designs is equally adaptable to a variety of wind farm sites. The discussion shows how O&M considerations can be managed to ensure that the cost of O&M for a wind farm can be controlled and minimized.

A major caveat in evaluating information presented in this section is the availability of data. Performance data on operating wind turbines are frequently proprietary and extremely closely guarded. Thus, although some historical data are available, the data used in this chapter are often based upon engineering sources and not actual commercial operational performance data.

Factors Affecting Wind Turbine Performance
Wind Resources and Wind Turbine Machine Basics ⁽¹²⁾

Winds are created by atmospheric temperature and pressure variations caused by the sun heating air during the day, so general wind patterns coincide well with electricity demand during the daytime. During nighttime, temperature variations are lessened; therefore, winds are less severe. Although geostrophic winds (or global winds) winds determine the prevailing direction and magnitude in an area, the surface winds (up to an altitude of 100 meters) such as sea breezes and mountain winds are key factors in calculating the usable energy content of the wind at a particular site. Wind direction is influenced by the sum of global and local effects; when larger scale winds are light, local winds may dominate the wind patterns.

The wind resource is seldom a steady, consistent flow. It varies with the time of day, season, height above ground, and type of terrain. An area's surface roughness and obstacles are also important determinants in wind resource. High surface roughness and larger obstacles in the path of the wind result in slowing the wind by creating turbulence. Wind speed generally increases with height above ground.

A wind turbine converts the force of the wind into a torque (turning force) that turns the turbine blades, which are connected to the shaft of an electric generator. The amount of energy that the wind transfers to the blades depends on the density of the air, the blade area, and the wind speed. Wind speed determines how much energy is available for conversion to electricity. For wind farm applications, developers seek sites with an annual average wind speed of at least 7.0 meters per second (15.7 miles per hour), measured at a wind turbine hub height above ground of 50 meters (164 feet).

Wind power density, measured in watts per square meter of blade surface, is used to evaluate the wind resource available at a potential site. The wind power density indicates how much energy is available for conversion by a wind turbine. The power available at a given wind speed varies with the cube (the third power) of the average wind speed.⁽¹³⁾ Wind power developers think in terms of ranges of wind power density, termed wind power classes. Sites with a wind power class rating of 4 or higher are preferred for large-scale wind plants (see Table 2), which have installed capacity of at least 10 MW.⁽¹⁴⁾ For any given wind power class, the wind power density range and wind speed range increases with hub height; a hub height of 50 meters is the approximate hub height for utility-scale turbines. For instance, NEG Micon turbine hub heights range from 40-55 meters for 600 kW and 750 kW turbines, to 49-80 meters for their 900 kW to 1.5 MW turbines.⁽¹⁵⁾ Depending on rotor diameter, Vestas turbine hub heights range from 35-65 meters for their 600 kW and 660 kW models, to 60-100 meters for their 1.5 MW and 1.65 MW models.⁽¹⁶⁾ The Zond turbine hub height is 53 meters for their 750 kW turbines, with an optional 65 meter height for the 48 meter and 50 meter rotor diameter versions of the 750 kW turbine.⁽¹⁷⁾

The goal of wind turbine design is to convert as much of the power in wind, illustrated by the wind power classes in Table 2, into turbine generator power output. The power curve for a wind turbine shows this relationship of wind speed to turbine power output by plotting turbine power output (e.g., kilowatts) as a function of wind speed (e.g., meters per second). Power curve values vary among turbines because turbine design approaches differ. The impact of design on power curve values is illustrated by comparing the wind speeds at which various turbines achieve rated power. For instance, the Zond Z-48 turbine achieves 750 kW rated power output at a lower wind speed (11.6 meters/second) than does the NEG Micon Multi-power 48 (16 meters/second) (Table 3). The shape of the power curve also varies with turbine design. For instance, the NEG Micon Multi-power 48, which uses a generator that operates at constant speed, produces less than 750 kW output at wind speeds less than or greater than 16 meters/second (Table 3), the speed at which it achieves rated power. In contrast, the variable speed generator used in the Zond Z-48 design enables the turbine to maintain rated output of 750 kW over the range of wind speeds listed in Table 3, starting with 11.6 meters per second (the speed at which it first achieves 750 kW output), because the generator speed varies with wind speed to maintain rated output. Power output per unit of rotor swept area offers a way to compare performance among wind turbines. Restated, the goal of wind turbine design is to obtain the highest value of power output per unit of rotor swept area (Table 3) for the lowest capital cost.