Wind Power
Summary:
Wind power need not be backed up by an equal amount of reserve power, according to new research. The production of wind power varies and is harder to forecast than the fluctuations in electricity demand. Adding large quantities of wind power to power systems is therefore challenging. The power system impacts of wind power were studied in depth. The results indicate that the frequently stated claim of wind power requiring an equal amount of reserve power for back-up is not correct.
The production of wind power varies and is harder to forecast than the fluctuations in electricity demand. Adding large quantities of wind power to power systems is therefore challenging. The power system impacts of wind power were studied in international collaboration coordinated by VTT Technical Research Centre of Finland. The results indicate that the frequently stated claim of wind power requiring an equal amount of reserve power for back-up is not correct. A substantial adjustment tolerance is already built in to our power network, and the impacts of wind power fluctuations can be further balanced through a variety of measures.
The collaboration within the International Energy Agency (IEA) Implementing Agreement for Wind Energy, coordinated by VTT, has resulted in the publication of the first state-of-the-art report assessing the international experience gained on the system impacts of wind power.
The impact of a large share of wind power can be controlled by appropriate grid connection requirements, extension and enforcement of transmission networks as well as integration of wind power production and production forecasts into system and market operation. The state-of-the-art report presents the assessments of the impact of wind power on the reliability and costs of the power system conducted in different countries.
The assessments performed in different countries are often based on substantially different assumptions. Comparison of the studies showed that in particular the assumptions concerning the use of international transmission connections and the time scale of updating wind power forecasts had a major impact on the results.
The aggregation benefits of a power system covering a large area help in reducing wind power fluctuations and improve predictability. A large power system also has a larger amount of generation reserves available, and the increased regulation effort can be implemented cost-effectively. The transmission capacity between areas is crucial for the utilisation of the benefits arising from large production areas. An electricity market in which production forecasts can be updated a few hours ahead also helps in keeping down the forecast errors and thereby the costs of balance power.
The report contains a summary of the wind power impact assessments performed in 11 countries. The assessments are divided into three categories:
1. Additional costs arising from the balancing of wind power fluctuations
2. Grid reinforcement needs due to wind power
3. Capacity of wind power to replace other power plant capacity
With wind power penetrations amounting to 10–20% of the gross electricity demand, the additional costs (per MWh of wind power) arising from the balancing of wind power fluctuations are estimated to range between1–4 €/MWh. This is less than 10% of the long-term market value of electricity.
Current wind power technology makes it possible for wind power plants to support the grid in the event of faults such as significant voltage drops and to participate in voltage regulation. Wind power plants are also able to limit their production fluctuations. The grid reinforcement needs due to wind power vary in different countries depending on how far from the consumption centres the wind power plants are constructed and how strong the existing national grid is.
Even though wind power is mainly an energy resource that replaces fossil power generation, it can also be used for replacing existing power plant capacity. In areas where wind power production is high during peak demand, wind power can replace other capacity by up to 40% of the installed wind power capacity. However, when a larger share, more than 30%, of electricity is produced by wind power and in areas where the wind power production is low during peak demand, wind power can only replace other capacity by 5–10% of the wind power capacity.
Publication: Design and operation of power systems with large amounts of wind power. Available from link below.
ADVANTAGES OF WIND POWER:
1. The wind is free and with modern technology it can be captured efficiently.
2. Once the wind turbine is built the energy it produces does not cause green house gases or other pollutants.
3. Although wind turbines can be very tall each takes up only a small plot of land. This means that the land below can still be used. This is especially the case in agricultural areas as farming can still continue.
4. Many people find wind farms an interesting feature of the landscape.
5. Remote areas that are not connected to the electricity power grid can use wind turbines to produce their own supply.
6. Wind turbines have a role to play in both the developed and third world.
7. Wind turbines are available in a range of sizes which means a vast range of people and businesses can use them. Single households to small towns and villages can make good use of range of wind turbines available today.
DISADVANTAGES OF WIND POWER:
1. The strength of the wind is not constant and it varies from zero to storm force. This means that wind turbines do not produce the same amount of electricity all the time. There will be times when they produce no electricity at all.
2. Many people feel that the countryside should be left untouched, without these large structures being built. The landscape should left in its natural form for everyone to enjoy.
3. Wind turbines are noisy. Each one can generate the same level of noise as a family car travelling at 70 mph.
4. Many people see large wind turbines as unsightly structures and not pleasant or interesting to look at. They disfigure the countryside and are generally ugly.
5. When wind turbines are being manufactured some pollution is produced. Therefore wind power does produce some pollution.
6. Large wind farms are needed to provide entire communities with enough electricity. For example, the largest single turbine available today can only provide enough electricity for 475 homes, when running at full capacity. How many would be needed for a town of 100 000 people?
Wind Energy Facts
There are many different wind energy facts relating to the use of this renewable energy source.
Wind energy is fast becoming a more popular choice for many large scale renewable energy designs and construction.
A well known wind energy fact lies within the opposition usually met from a proposed wind farm development and this is down to the “NIMBY” factor (not in my backyard).
Most people would like the idea of a wind farm proposal to provide clean, cheap electricity from wind energy, yet how many of these people would like a wind farm close to their home?
The “NIMBY” factor is something we are going to have to get used to and be prepared to live with in future decades.
In 2007 it was estimated that only 1 – 2% of the worlds energy supply comes from a renewable wind energy source.
In some smaller countries (such as Denmark) the fact that they are able to provide between 20 and 40% (2007 figures) of the countries energy demand through the use of renewable wind energy, shows the potential of wind energy and that this just becomes a way of life.
Another fact of wind energy is shown through the effectiveness of one well placed turbine.
Some households across the U.K are taking advantage of the average wind energy and have attached a varied amount of small wind turbines to some homes in order to cut electricity bills.
Larger scale wind energy developments have a well known fact of been able to provide electricity to large villages or small towns.
A lesser known fact concerning wind energy is the placement of wind turbines and how this can greatly affect the long term efficiency of a small or large scale, wind energy project.
If you would like to learn more energy facts relating to other renewable energy sources, we feature an article explaining some geothermal energy facts which you may be interested in.