What is wind power?
We feel a wind blowing when warm patches of air rise and denser, cooler air rushes in beneath it creating an air current. Wind power is the conversion of wind energy into a useful form of energy, such as wind mills for mechanical power, wind pumps for water drainage, wind sails to direct ships, or wind turbines to make electricity. A windmill uses wind power for directing machinery, such as for pumping water, grinding stones or cutting lumber. A wind turbine has propellers (aerodynamic blades) that extract energy from the wind and turns a rotor that converts it into electricity. Most wind turbines produce electricity when the wind is blowing at 10-30mph.The blades of the propellers can be angled in a certain way to cope with varying wind speeds and can be turned to face the wind. Propellers are built high where the wind is stronger allowing the land beneath to be used for farming [1]. A wind farm is many wind turbines built together that create much electricity and they can be onshore or offshore. The first wind farm was built in Delabole in 1991. Offshore wind farms cost more to build but produce more electricity because they are usually positioned in isolated windy spots. The more wind turbines there are, the more wind there is, and the larger the propellers on the turbines, the more electricity is generated. Wind farms are built in places that have strong, steady winds such as coastal areas, on top of rounded hills or open plains. There needs to be an average wind speed of about 25km/h for wind farms to be worthwhile.
Wind represents a vast source of energy that humans have harnessed as an energy source for centuries. Sail boats have been around since the ancient Egyptians, then the Chinese and the Babylonians used wind energy to pump water for irrigating crops and Europeans used wind to grind corn in windmills in the Middle Ages. Wind power is currently one of the most developed and cost effective renewable energy technologies and is growing rapidly due to huge technical advances. The modern wind turbine is quiet, simple to run and available in many sizes. Moreover, there are several countries (Denmark, Spain and Portugal) that have reached relatively high levels of wind power generation, however worldwide, wind power only equates to approximately 2% of total electricity usage [2]. A major reason for this is the mass opposition to onshore wind farm projects. It is difficult to get planning permission for wind farms because opposition to them is becoming more entrenched and better organised. There are now 151 anti-wind farm action groups in the UK. Nevertheless, the government has announced plans for thousands of new offshore wind turbines which could power every home in Britain by 2020 [3].
Britain has some of the best wind resources in Europe and there is enough wind to power the country several times over. There are currently 186 operational wind farm projects in the UK and most of the wind farms are in Wales or Cornwall. Large scale wind farms are connected to the electric power transmission network, while smaller, domestic turbines provide electricity to isolated locations, for example farms. It is now common for utility companies to buy surplus electricity produced by these domestic turbines.
Advantages and disadvantages of wind energy
Advantages:
- Wind energy is a renewable resource (winds will keep blowing) that is clean and produces no greenhouse gas or radioactive emissions during operation [2]. Wind turbines have the capacity to prevent 3,682,563 tonnes of carbon dioxide per annum and therefore helps prevent climate change.
- It is free and can be captured effectively with modern technology. This means that once initial installation costs have been paid, your electricity costs will be significantly reduced. It is not like fossil fuels that rise in price and it is not governed by market forces.
- Land beneath can still be used for agricultural purposes.
- Wind farms can be tourist attractions as many people find them an interesting feature of the landscape.
- It can be widely distributed, therefore supplying energy to remote areas.
- Wind power is powerful and plentiful. It has been suggested that there is enough wind to generate one-third of the world’s electricity.
- The UK is one of the most suitable locations for using renewable energy and it has the most offshore wind capacity than any other country.
- The UK government (among others) have introduced initiatives and proposals to ensure more of our energy comes from renewable sources in order to help decarbonise the economy. The UK government’s renewable energy strategy states that 15% of all the UK’s energy comes from renewables by 2020. This will create over 100,000 green collar jobs [4].
- There is no damage to the environment or residues left behind if turbines need to be taken down.
- Wind turbines have an important role to play in both the developed and developing world.
- Wind turbines are available in a range of sizes which means a vast range of people and businesses can use them.
- You can store excess electricity in batteries and use it when there is no wind.
- Wind has been the world’s fastest growing renewable energy source for the last seven years, and this trend is expecting to continue with falling costs of wind energy and energy security threats.
- Any business or individual wishing to generate electricity through wind power is eligible for a government grant called the Renewable Obligation Certificate and can be obtained from Ofgem. Thus, it is a perfect time to invest in wind power.
Disadvantages:
- Wind farms can be portrayed as having a negative visual impact on the landscape.
- The wind is intermittent and not always predictable (it is not windy every day). Thus, wind turbines do not produce the same amount of electricity all the time.
- Suitable areas for wind farms are often expensive, such as near the coast.
- Can kill migratory birds. However, this is not likely as wind farms are not built on migratory routes [5].
- Can affect television reception in nearby homes.
- Initial costs expensive, however these are dropping considerably as the industry grows.
- Wind farms can be costly to maintain.
- Current offshore farms can encroach on shipping lanes, affect sea bird sanctuaries and disturb marine life. This limits the number of suitable sites.
Get more information and even a quote for a wind turbine project at your home or business with ESW
