Agriculturalists from Great Falls and the Surrounding Area Have Been Hearing a Great Deal

TEAM PROBLEM – CONTESTANT SCENARIO

Situation

Montanans have been hearing a great deal about wind energy resources within the state, and are interested in learning more. The Governor has organized a committee to investigate the feasibility of wind power development in Montana. Your team represents this committee, and includes representatives from Montana Alternative Power, Basics Inc., and the Montana Department of Natural Resources. Basics Inc. is one of the largest wind energy equipment dealers in the United States. You have been asked to look into this innovative technology and find out if it is practical for Montanans to consider.

You are to submit a preliminary report of your findings to two members of the Governor’s staff this afternoon. You should include the following in your report:

1.)  Should Montana utilize wind power as an energy source?

2.)  Where would the best place(s) be to establish a wind farm? Why?

a.  Include costs, benefits, incentives, potential difficulties that may be encountered with the specific location(s), and the resources necessary to set up and maintain the wind farm.

General Info

WIND POWER

·  Wind is caused by the sun’s uneven heating of the Earth’s surface.

·  Wind patterns are affected by weather patterns, terrain, and the Earth’s spin.

·  As wind speed increases, wind energy potential increases rapidly.

o  (Wind speed doubles=energy content increased by factor of 8)

·  California lead the United States in wind development, even though it has little wind resource.

·  Texas and Minnesota are quickly increasing wind power investments.

·  Europe is leaving the United States way behind in wind power development.

HOW WIND ENERGY WORKS

Turbines are placed on high towers and blades that are modeled after airplane wings rotate when the wind blows. The wind causes a pressure differential on the turbine blades as it moves over their surfaces. The blades then cause a rotor to turn which drives an electrical generator. The whole system works to convert kinetic energy into electrical energy.

A FEW SPECIFICS

Turbine blades are always oriented to face the wind either by computer control or naturally by the wind. Turbines are designed to operate at either a constant speed or at variable speeds. Although the variable speed design is more complex, it is more efficient at converting wind power into electricity. Most wind turbines are made to utilize wind blowing anywhere from 9 mph to 65 mph. Turbine sizes range from 500 kW to 750 kW.

BENEFITS

Wind energy systems provide a cushion against the increasing prices of electric power. They also help decrease the dependence of the Unites States on foreign countries for fossil fuels. For people living in remote locations, wind energy systems can help avoid high costs of bringing utility lines to the site. These systems are quite competitive with other energy sources over a lifetime of use through reduced and possibly avoided utility costs.

Unlike fossil fuels, wind power does not create any emissions that lead to greenhouse gases, particulates, or acid rain precursors. Wind power can have a negative effect on the environment, however, if not sited or managed correctly.

It is projected that wind energy projects provide three times as many jobs as the same amount of spending on fossil fuels. Also estimated is that a 240 MW natural gas plant pulls $28-55 million from the regional economy for annual fuel imports. By using wind energy systems, more money can be reserved in local companies and the possibility of extra income going to property owners in the form of power sales or royalty payments is much greater.

DISADVANTAGES

Wind systems are associated with a high initial investment. Payback periods, the time before the savings equal the cost of the system, depend on the chosen system, wind resources, area electricity costs, and management of the system.

DECIDING IF A SITE IS RIGHT

Although Department of Energy (DOE) maps showing the average wind speeds and resources are available, each site in question will vary depending on a variety of factors. It is important to understand the wind resource at the location in question. If you don’t have site specific data, it is a good idea to measure the wind speeds at your site for a year to acquire a more accurate and predictable idea of the wind resource available. (The costs of doing this are not really worth it when looking to install a wind turbine in a small residential area. For that situation, the DOE maps are generally sufficient.) One way to do this is through the use of a recoding anemometer. The best height for recordings is at the elevation at the top of the tower, where the wind turbine would be positioned, which is also called “hub height”. The Department of Energy uses a standard of 33 feet (10 meters) to obtain data. The anemometer has to be placed high enough to not be affected by trees, buildings, or other obstructions that may change the data. The cost of a recording anemometer can range from $500 to $1500.

It’s important to consider the terrain when choosing an installation site. Considering both current and future obstacles, including buildings and trees, is wise. Also important to realize is that the available power increases exponentially as wind speed increases. A site with 12.6 mph average wind speed would produce twice as much energy as a site with an average wind speed of 10 mph.

Before spending much time or money, it’s a good idea to check into the potential environmental and legal obstacles to installing a wind system. There are some jurisdictions that limit the height of structures permitted in residentially zoned areas. It’s usually easy to get a variance, however, thought the neighbors might not appreciate an obstacle in their view or might be worried about noise. When interested in connecting the wind energy generation system to the local utility company’s grid, find out its requirements for interconnection. Obtaining costs and performance data from manufacturers is also very beneficial along with understanding the basics of a wind system.

PRICING A SYSTEM

To better define what size of turbine is needed, an energy budget should be formed. Keep in mind that energy production is often more expensive than energy efficiency, meaning that it’s wise to make a house (or anything else) more energy efficient and therefore requiring less energy. Have your financial advisor conduct a thorough analysis before deciding on a wind energy system.

After deciding that a wind energy system can be used legally and without any major problems, start pricing various systems. Make sure to research whether the manufacturer is recognized as a wind energy business and that parts and services will be available when needed. Check out the warranty: it’s time frame and what is included. Another good idea is to ask for the names of customers with similar wind energy systems to the one you are considering. Those people can give you a better idea about the performance, reliability, maintenance and repair, and if the system is satisfactory.

LARGE WIND TURBINES

·  They are huge machines and used mostly in wind farms.

·  They require large amounts of wind because they must compete with conventional energy generation, such as coal, natural gas, oil, and nuclear.

·  They are not often used for “off-grid” applications.

·  They can produce electricity less expensively than power from coal or nuclear plants.

·  There are many subsides available for them.

SMALL WIND SYSTEMS

·  They are used principally for individual homes, businesses, or facilities.

·  They can be used “on-grid” or “off-grid”.

·  “On-grid”, also called grid-connected systems, are used along with an electricity transmission and distribution system. If there isn’t enough wind and the turbine can’t deliver the energy required, the utility provides the difference.

·  “Off-grid”, also called stand-alone systems, are used alone.

·  They generally cost more than large turbines.

·  They can be used in areas with less wind resources and can compete at the retail level.

·  Not many subsides are currently available.

SITUATION FOR A STAND-ALONE / OFF-GRID SYSTEM

·  Area with annual wind speeds of 9 mph or greater

·  No available grid connection or only made with an expensive extension

·  High cost of running power lines ($15,000-$50,000 per mile depending on terrain)

·  Interest in gaining independence from the utility

·  Concern about environmental impact of electricity production

·  Understand the intermittent characteristic of wind power and have a plan to deal with the irregular power resource available to meet needs

SITUATION FOR A GRID-CONNECTED / ON-GRID SYSTEM

·  Area with annual wind speeds of at least 10 mph

·  Expensive utility-supplied power in the area (10-15 cents per kilowatt hr)

·  Economical requirements for connecting wind system to the local utility’s grid

·  Building codes & land covenants allow legal installations of a wind turbine

·  Feel at ease with long-term investments

·  Available net metering

RESIDENTIAL WIND TURBINES

For a typical residential purpose, a home is served by both the local utility and the wind turbine (on-grid/grid-connected systems). The cut-out wind speed, under which no output is received from the turbine, is generally 7-10mph. If a system produces more power than the house needs, the extra electricity is usually sold to the utility.

In a residential application, a wind turbine will typically lower an electricity bill by 50%-90%. Of course this depends on many factors, including the location of the residence and the cost of electricity in that area. The amount of money saved in the long run by installing a wind energy system depends on those same factors as well as the system’s cost, the average wind speed at the particular site, and many other aspects.

Homes use 9,400 kilowatt-hours (kWh) of electricity per year on average, which calculates out as about 780kWh per month. A wind turbine rated in the area of 5 to 15 kilowatts would be needed to make a significant impact on the demand of the residence, once again depending on average area wind speeds.

If economics are a concern, use this rule of thumb: a small wind turbine owner should have at least a 10mph average wind speed and should be paying at least 10 cents/kWh for electricity to make the system worthwhile. Many times a wind system will recover its investment through utility savings within six to 15 years. After that time, electricity produced from the wind-energy system is in effect free. A residential wind-energy system investment is like any other improvement and increases property value, assuming it’s well-sited. Currently in the United States, people purchasing residential wind-energy systems are often doing so in preparation for retirement. They don’t want to be subjected to the ever-changing utility rates and see this as an economical avenue to guard against that.

ESTIMATED SYSTEM COSTS

These are some general estimates of system costs, including installation. Price variances are due to actual size, application, service agreement, warranty details, shipping, and grid hook-up costs.

Small wind turbine system

$6,000-$22,000

Mid-sized wind turbine system

$13,000-$42,000

Large wind turbine system

$28,000-$68,000

Industrial wind-turbine systems

$45,000-$95,000

FINANCIAL INCENTIVES

Many states provide financial incentives for the installation of wind energy systems. There are also federal incentives. In Montana, a personal tax credit is offered for residential, industrial, and commercial users. A 35% tax credit for an individual, partnership, or corporation is permitted for those investing $5,000 or more in a wind electricity generation system, or facilities used to manufacture wind energy equipment. Property eligible for tax deductions include those containing wind energy equipment, transmission lines, and equipment used to manufacture wind energy devices.

WHAT ABOUT MONTANA?

When considering Montana, Washington, Oregon, and Idaho, Montana has the greatest potential wind energy by far. Washington comes in with the least at 3,700aMW and Oregon follows not far ahead with 4,900aMW. Idaho has a slightly greater potential with 8,300aMW. But Montana outdoes them all with a potential wind energy rating of 116,000aMW. Montana has the potential to provide enough wind energy for 15 percent of the US electricity demand; Oregon and Idaho could supply all of their power requirements through wind energy; Washington could supply power for approximately 3 million homes by tapping their wind energy resources.

The great wind energy resources in Montana are a result of being located in the zone of prevailing westerlies. Winds blowing from the poleward side of the subtropical high pressure belts are repelled toward the east as the transition into higher latitudes. These winds, extending from 35-60 degrees (north and south) latitude, are labeled prevailing westerlies.

There are many factors that play a role in determining the circulation of air, including insolation, gravitation, condensation, and rotation. The interaction of these forces produces more specific forces which establish the motion of air in a particular area. These more specific factors include:

Pressure gradient force-- the force that drives air from areas of high pressure to those of low pressure

Coriolis force—deflects air to the right in the northern hemisphere due to the earth’s rotation.

Centripetal force—comes into play when air is moving in a curved instead of straight path along the earth’s surface

Frictional forces—includes friction between earth’s surface and the atmosphere as well as atmospheric internal friction

When determining the wind aspects at a certain location, frictional forces are the most important. Mountain passes, high-elevation plateaus, long valleys coming down from mountain ranges, mountain rides and summits, and the leeward slopes of mountain ranges perpendicular to the prevailing wind are all surface features linked with high wind speeds. Features associated with low wind speeds are sheltered basins, valleys perpendicular to prevailing winds, and areas of high surface roughness. In Montana, four different wind areas are recognized: western valley floors, eastern slopes, east and northeast plains, and exposed mountain crests.

WESTERN VALLEY FLOORS

The western third of Montana is quite mountainous. This region has many parallel mountain ranges containing deep valleys, usually running north-south or northwest-southeast, between them. Since these valleys are parallel to the prevailing wind direction and because of their depth and narrowness, average winds speeds are low. Periods of stagnation (no wind movement) are common, although some specific areas occasionally see high winds because of airflow through mountain gaps.