Title: Installments of Wind Turbines on Nose Hill

Purpose:

The purpose of this study is to: determine whether Nose Hill Park is a feasible area to install wind turbines by examining the wind speed of Nose Hill Park and whether or not the wind on Nose Hill Park is suitable for the developing or installing of wind turbines. This purpose will be carried out through qualitative and quantitative based observations regarding Nose Hill Park.

Objectives for this Lab:

To examine and record the wind velocity on Nose Hill Park over a period of time by using an anemometer in order to determine wind suitability on the highest area of Nose Hill Park.

• To determine whether or not the wind on Nose Hill Park is suitable for the development of wind turbines by comparisons to suitable wind velocities for wind turbines to operate in.
• And to evaluate the environment on Nose Hill and environmental factors and concerns both advantages and disadvantages that may arise from wind turbine installments.

Background:

Wind energy has become increasingly popular because it is reliable,

reusable, and environmentally friendly. Wind is defined as a flow of air in relation to the earth’s surface caused by the sun. When the sun is heating the earth, the land warms up, and warm air rises. The air will cool down at a higher elevation, and cold air is denser, therefore it glides down onto land again; this process is what people call wind. Wind patterns are affected by the spin of the planet, weather patterns, and terrain. Wind energy potential increases very rapidly with increasing wind speed. In fact, if wind speed doubles the energy content goes up by a factor of eight.

The direction of wind is determined from the point of the compass from which it blows. To measure wind velocity, an anemometer is used. A typical anemometer is called the cup anemometer. This instrument consists of three or four small hollow hemisphere that catches the wind and causes the instrument to revolve. The revolutions of the cups are recorded to an electrical device and the wind velocity is displayed on a scale. The Beaufort scale is a scale of wind velocity. It has scale ranging from 0 to 12, from calm to hurricane, and is based on the impact of the wind on the environment.

In southern Alberta, the average wind speed is greater than 15 km/h. According to the government of Alberta, in order for a wind energy system to be feasible, the average annual minimum wind speed is at 14-16 km/h.

Table 1. Wind speeds and their Potential in Producing Electricity.

The average electrical energy used by a household in Canada is around 750 KWH per month or about one kilowatt per hour.

Nose Hill is a natural environment park located in Northwest Calgary just 15 minutes from downtown. It is the largest municipal park in Canada because it is 1127 hectares in size. However, only 1/3 of this area is flat enough (upper plateau) and suitable for wind turbines. A single turbine takes up 30 acres of land.

A very important concept that must be understood in order to calculate the energy output is that you cannot simply take the average wind speed and insert it in a formula. We have to take into account the wind distribution and the fact that the wind speed is not linear with power because it is exponential. Wind distribution is not symmetrical. This is because strong winds are rare and moderate fresh winds are common. Thus, instead of a bell curve, the peak is shifted to the left. Another law that needs to be addressed is Betz Law, which basically tells us that wind turbines, only converts 59% of the kinetic energy in the wind to mechanical energy. The Power Coefficient tells us at which wind velocity the turbine converts energy in wind to electricity the most efficiently.

Hypothesis:

If the wind speed and other quantitative and qualitative observations were collected, then the data will support that Nose Hill is an appropriate location to install wind turbines.

Variables:

Controlled: Same anemometer, same location

Responding: temperature, wind speed, and wind direction

Manipulated: different days, different section of area

Materials:

• Anemometer
• Watch
• Flag or cloth
• Compass
• Thermometer
• Measuring Tape

Procedure:

1. Choose two areas that are 10 meters apart on the highest hilltop on Nose Hill Park. It is located near the Edgemont residence up Shagnappi Trail in the northwest region of Calgary, Alberta.
2. Designate each area as area A or B and mark the areas for the continuation of a long-term study on each area’s wind velocities.
3. Choose an area to begin determining the speed of the wind, and set this region as Area A.
4. Record current time down onto an observation data table.
5. Take anemometer to a height of 5 feet 3 inches and record wind speed.
6. Take temperature by using a regular thermometer.
7. Record wind direction with a flag and compass.
8. Record other observations related to the environment such as weather conditions etc.
9. Repeat procedural steps 2-6 with Area B.
10. Repeat procedural steps 2-6 again every five or ten minutes alternating in consistent time intervals for each area for 3-4 trials.
11. It is recommended to repeat this procedure for several days on a daily basis.

Click thumbnails to view larger image.

Observations: Click here

Analysis: Click here

Discussion:

In this experiment, the wind velocity was observed on different days on Nose Hill.  With the data provided in the above tables and graph, it can be determined whether Nose Hill is a feasible area to install wind turbines.

From Table 2, information is provided on the wind speed, temperature, and wind direction.  There is a noticeable relationship between the wind velocity and temperature.  On the days that had low temperatures and snowy weather, the wind speed was slow.  According to research the lower the temperature, the higher wind speed.  However on our observation data, the higher temperatures obtained a higher wind speed. It is also evident from this table that the average wind direction is North.  Thus, if down wind turbines were to be installed on Nose Hill, they would have to be facing North.  From this table, it also supports the fact that the wind speed fluctuates constantly.  For example, on December 18^th, 2004, the wind speed was around 10 km/h, although on the next day on December 19^th, 2004, there happened to be wind speeds that were in the 40 km/h range.

            Figure 1 also supports the fact that wind speed fluctuates throughout the month.  In this figure, the bars represent the velocity of the wind speed, and all bars are very different. 

            In the sample calculations, the average wind speed for both areas is 4.0 m/s, which is approximately 15 km/h.  According to the government of Alberta, the average annual minimal wind speed is at 14 to 16 km/h.  This proves that the potential energy production in Nose Hill provides enough wind speed to produce potential electricity.  However, Table 1 analyzes Nose Hill as an area of poor suitability as a result of this wind speed.  In another component of the sample calculations, the number of turbines was also determined.  As mentioned in the background, only a third of Nose Hill is suitable for wind turbine distribution, because the rest of the area is too steep.  The total energy produced by these 31 turbines was also calculated to 9 865 750 kilowatts per year, this power is enough to provide electricity for 1096 households.  31 turbines require 375 hectares, and therefore the other two-thirds of Nose Hill will be left untouched for the wildlife.  Although this will only power 0.33% of Calgary’s households it is enough to power smaller communities within Calgary like North Haven.  This community is located beside Nose Hill and has 945 houses.

            Figure 2 shows the relationship between power and wind speed.  It supports that the maximum power will be produced at 13 to 17 m/s.  Therefore in order for the wind turbines on Nose Hill to achieve maximum power efficiency, they would have to be in this range.  Any wind speed above 27 m/s or lower than 5 m/s will produce the least or even no energy at all. 

Mechanical Sources of Error

1. The anemometer that was used for the lab was inoperative in that one of the wings would not stay on the anemometer.  Although tape was used to secure its place, it could have affected the all results since the damaged wing could have thrown the balance off of the anemometer.  This major area was systematic through the whole experiment because the same anemometer was used.  
2. The anemometer that was used in the experiment was very common and easy to use.  However, the anemometer had increments that were too far apart and the scale was too small.  As a result of large increments, the wind velocity had to be estimated in wide range, which can affect the all data systematically.  This minor error could be avoided by using a more advanced and accurate anemometer for next time.  Also, on December 19, 2004, the wind velocity was greater than 45km/h, which is the maximum speed.  The wind velocity might have been greater than 45 km/h, thus the minor error only affected this set of data.

Procedural Sources of Error

1.      Wind turbines have heights of 80-120 ft.  During the experiment it was impossible for the observer to take wind velocities at such great heights.  Thus, a constant height of 5ft 3” to measure the wind velocity was decided upon.  This major error greatly affected all of the data systematically.  The higher the altitude, the faster the wind speed.  Scientists who also study wind speeds place their anemometer on top of an electricity pole and attach a digital scale near the bottom.  If this lab were to be redone again, this could be a possible path to take.

2.      During the lab, an error that was made was the time intervals.  The data was not collected in daily constant time intervals.  Longer time intervals may provide more data but the wind velocity may change during the time.  Short time intervals provide information on quick changes on wind speed but do not allow sufficient data for overall wind speed of the day.  This error affects all data randomly because some data were taken at 10 minutes and 5 minutes intervals.  Researchers who study the wind speed study the wind at 10-minute intervals.  

3.      The data may not be accurate because it is based observations gathered in a short period of time.  Observations were taken from November 20^th, 2004 to December 20, 2004 several times a week.  It is known that wind speeds are greater in the winter than in the summer because of the air pressure system.  Thus, the data gathered from a winter month is not adequate to conclude for other months like in the summer.  Also, these wind velocities were also taken at different times of the day.  It can be noted that the days of observation shows drastic changes in speed and it cannot be concluded that it is related to time of day since the times weren’t consistent.  This is a major error because it affects all data systematically.  The procedure would be much improved if it were done in a year with a consistent time frame.

4.      Two areas were chosen in the procedure to receive more accurate data.  Thus, the areas that were chosen were relatively close to each together since they were meant to represent a large area.  However, this is an error because by choosing areas that are too close will not allow for comparison.  This is a major and systematic error that could be avoided easily by choosing different areas.  However, Nose Hill is 1127 hectares and it is very hard to travel from place to place.  Also, even if next time the areas are further apart, they still won’t allow for an accurate comparison because Nose Hill is so big.

5.      Wind observations were taken mainly during the day.  However, according to research, wind speeds are slower at night.  This minor error may alter the average wind speeds but since no observations were taken during late at night, it is assumed that the wind speed during those times is the same as daytime.  There was no data to prove the fact that wind speeds are slower during nighttime.  To avoid this error, it is important to get variety times to increase accuracy.

Conclusion: Click here