Wind is the motion of hot and cold air over the surface of the Earth ( BWEA, 2010 ) . Air is a combination of solid, liquid and gas atoms ( EWEA, 2011 ) . Energy from the Sun radiances on our atmosphere all of the clip, but the surface is heated unevenly. This consequences in some topographic points being warm while others are cool. As the Earth is heated unevenly and because hot air is lighter than cold air and therefore rises, differences in force per unit area are created ( EWEA, 2011 ) . Airflows attempt and equalize these force per unit area differences. Together with the rotary motion of the Earth, the difference in air force per unit area causes an uneven flow of air. i.e. air current ( EWEA, 2011 ) . Due to the rise in nursery gas emanations into the ambiance, from the combustion of fossil fuels such as coal, gas, oil and peat. Wind energy Acts of the Apostless as one of the greatest solution to our jobs, as it is a clean, sustainable, renewable and unlimited solution ( SEAI, 2011 ) . This renewable signifier of energy can be used to bring forth electricity and with increasing environmental consciousness, it acts as a major subscriber to a clean and environmental friendly beginning of energy supply ( EWEA, 2010 ) . Wind energy is for the first clip the taking engineering in Europe ( BWEA, 2010 ) . In relation to put in air current energy capacity, there was over 10 GW installed in Europe in 2009, which produces an addition of 23 % from 2008 ( EWEA, 2010 ) . By the terminal of 2009, a sum of 192,000 workers were employed straight and indirectly in this sector ( EWEA, 2010 ) . By the terminal of 2009, the air current power capacity installed in Europe produced 4.8 % of the electricity demand and the emanation 106 million metric tons of C dioxide was avoided, this would be the equivalent of taking 25 % of autos in the EU off the route ( EWEA, 2010 ) . This sum of electricity would be plenty to power 82 million electric autos that would potentially be more environmentally friendly ( EWEA, 2011 ) . Since the debut of air current turbines, it is salvaging Europe ˆ6 billion per twelvemonth in relation to fuel costs ( EWEA, 2010 ) . With such a immense environmental economy, and besides the universe oil supplies depleting, it is easy to see why renewable energy solutions is a large concern.
1.1 Purposes of the undertaking: The purpose of this undertaking is to compare and contrast an onshore air current farm and an offshore air current farm in footings of feasibleness, besides to detect the advantages and disadvantages associated with both air current farms.
1.2 Technology of a air current farm:
The bulk of air current turbines commercially runing in Ireland today consist of three rotor blades that rotate around a horizontal hub ( SEAI, 2011 ) . The air current passes through the blades which create a lift ; this so causes the rotor to turn which causes the blades to turn ( EWEA, 2011 ) . The rotor is linked to the nacelle which houses the gear box, the low-speed shaft, the high-speed shaft and the generator ( EWEA, 2011 ) . Per minute, the blades rotate the shaft between 30 and 60 times ( EWEA, 2011 ) . The gear box connects the high and low velocity shafts together which increases the rotary motion velocity of the high-speed shaft to about 1,000 to 1,800 bends per minute ( EWEA, 2011 ) . The fast spinning shaft so forces the generator to make energy ( EWEA, 2011 ) . The generator converts mechanical power from the rotor into electrical power. Any electricity produced by the generator travels to a transformer which converts the electricity to the right electromotive force for the distribution system ( EWEA, 2011 ) . The electricity is transported from the air current turbine to the grid along electrical overseas telegrams ( SEAI, 2011 ) . The chief constituents of a air current turbine are shown below:
Figure 1.1: Chief constituents of a air current turbine ( http: //www.alternative-energy-news.info/technology/wind-power/wind-turbines/ , 2011 ) .
For air current turbines to work efficaciously and expeditiously, it is necessary for the rotor to confront straight into the prevailing air current. The stronger the air currents, the more energy can be produced ( EWEA, 2011 ) . Wind turbines produce energy at air current velocities of 4-30 meters per second. The air current turbine control system ensures that if the air current velocity exceeds a velocity of 25m/s, the turbines control system will automatically close down for safety grounds and to forestall any harm to the turbine ( SEAI, 2011 ) . Another variable which helps a turbine green goods more electricity is the blade radius, where the larger the blade radius of the blades, more energy may be created ( EWEA, 2011 ) . Therefore, if the blade radius of a turbine was doubled, four times more power could be produced ( EWEA, 2011 ) . Finally, air denseness besides impacts the sum of electricity produced. The heavier the air the better, this exerts a greater lift on the rotor. Whereas lighter air is a batch less productive ( EWEA, 2011 ) .
1.3 Connection to the Electricity grid:
All wind turbines must be connected to a national grid, which supplies us with electricity. Electricity is distributed to consumers through physical substructure i.e. transmittal and distribution webs ( EWEA, 2011 ) . The transmittal web is made up of overseas telegrams and pylons which transports high electromotive force electrical power across long distances i.e. into metropoliss and big towns ( EWEA, 2011 ) . The transmittal and distribution web are linked at a part called a substation. This is where the high electromotive force is stepped down to medium electromotive force ( EWEA, 2011 ) . The consumers are merely connected to a medium electromotive force degree which is the distribution system. Once the electricity reaches its concluding finish i.e. little towns or single clients, the power is stepped down to a low degree ( EWEA, 2011 ) . Harmonizing to the SEAI, Irelands electricity grid system includes a localised distribution system ( 10, 20 and 38kV web ) and a higher electromotive force transmittal system ( 110, 220 and 400kV web ) ( SEAI, 2011 ) .
Turbines that are traveling to provide electricity demand to be situated on a feasible site. It is of import to find the distance from the site to the nearest connexion point ( SEAI, 2011 ) . The farther off a air current farm is from the national grid, the more costs associated with the transporting the power to the grid, about 15 kilometer is an ideal distance ( SEAI, 2011 ) . The electricity is transported from the site by belowground overseas telegrams and overhead power overseas telegrams ( SEAI, 2011 ) . These carry the electricity to a substation where it can link to a national grid to provide clients with electricity ( SEAI, 2011 ) . However, it is non ever feasible to construct a air current farm near to a grid connexion point due to many grounds such as air currents velocity etc. Costss of linking to the grid can be significant ( SEAI, 2011 ) .
1.4 Targets in Europe
Wind energy is for the first clip the taking engineering in Europe. ˆ13 billion was invested in air current farms in 2009 which was had an addition of 23 % compared to 2008 ( EWEA, 2011 ) . Statisticss released by the EWEA show marks for Europe by 2020 to bring forth 14-17 % of Europe ‘s electricity demand, to avoid the emanation of 333 million metric tons of C dioxide per twelvemonth and to salvage fuel costs by ˆ28 billion and to salvage ˆ8.3 billion in avoided C dioxide costs ( EWEA, 2010 ) . Europe hopes to hold a sum of 230 GW installed air current capacity by 2020. ( EWEA, 2010 ) . However, by 2030, Europe hopes for air current energy to hold even a higher demand with marks of bring forthing 26-35 % of the electricity required by Europe, to avoid 600 million metric tons of C dioxide per twelvemonth and to salvage a monolithic ˆ56 billion per twelvemonth in avoided fuel costs and to salvage a significant ˆ15 billion per twelvemonth in avoided C dioxide costs. ( EWEA, 2010 ) . By 2030, it is expected that Europe will hold 40 GW installed air current capacity ( EWEA, 2010 ) .
1.4.1 Targets in Ireland
Wind energy ‘s part in Ireland continues to increase with extra capacity ( IEA, 2009 ) . Since the first air current farm was set up in Ireland in 1992, 110 air current farms were metered in June 2010 with a sum installed capacity for flying to 1,379 MW. This was adequate electricity to power over 500,000 places across Ireland ( SEAI, 2011 ) . For Ireland to accomplish its national mark of 40 % by 2020, about 5,500-6,000 MW of air current coevals is required ( SEAI, 2011 ) .
2.0 Wind Farm Development
Wind energy is a immense industry across Europe with about all European states have or holding prospectus air current turbine installing ( SEAI, 2011 ) . Wind turbine engineering continues to turn and progress. Irelands first air current farm was in 1992 in Co. Mayo ( SEAI, 2011 ) . Wind turbines are big complex industrial equipment and their industry involves the usage of natural stuffs and energy. The stuffs can be recycled at the terminal of their utile being, where the capital from this can be used to restore a air current farm to its original province ( SEAI, 2011 ) .
2.2 Financing air current energy
Like all developments, weave energy undertakings require finance. For any undertaking to be economically feasible, sufficient capital is required ( SEAI, 2011 ) . The development of air current farms is non merely good in bring forthing electricity, it besides creates employment. There are many things a financer will look for earlier come ining a air current farm development.
Planing permission of the selected site is required which would hold a immense clip restraint. An appraisal of the sites wind resource should be carried out on the proposed site to place if the site has a good air current supply ( SEAI, 2011 ) . The undertaking should hold a power purchase understanding and have sufficient cogent evidence of the proposed site rubric and land rights. There should be a development squad with relevant experience in the sector and besides a program for any development costs ( SEAI, 2011 ) . There should be inside informations of any other support of the site and besides have a hard currency flow on a 15 twelvemonth footing ( SEAI, 2011 ) .
During installing of a air current turbine, there are many costs involved. These costs account for 16-32 % of the entire investing ( EWEA, 2009 ) .
Any foundations for building plants and any building costs for route ways. Electricity will be carried by resistance overseas telegrams which will necessitate to be buried ( EWEA, 2009 ) . Transformers must be present to change over low electromotive force to medium electromotive force. Sub-stations are besides required to change over electromotive force from medium to moo ( EWEA, 2009 ) . Any conveyance costs of turbine pieces and usage of heavy machinery. The turbine must be assembled and tested. Besides any administrative, funding or legal costs must besides be paid for ( EWEA, 2009 ) .
Once the turbine has been installed, there are land rental, operation and direction costs staying ; Insurance should be included for any harm, wellness or safety issues ( EWEA, 2009 ) . Regular care to do certain turbine is working expeditiously. Repair of turbine or Spare parts that need to be replaced besides must be taken into history ( EWEA, 2009 ) . Any disposal fees must be paid and besides the land lease from the developer to the land proprietor ( EWEA, 2009 ) .
These costs are low when compared to most other power bring forthing costs ( EWEA, 2009 ) . For air current turbines, there are no fuel costs and the air current is free. The capital costs ( i.e. constructing the power substructure and connecting to the grid ) of a air current energy development is about 75 % of the entire cost ( EWEA, 2011 ) .
Typical undertaking costs in Ireland released by the IEA show that the major cost is the turbine itself accounting for 65 % . This is a capital cost that should be paid instantly. Grid connexion histories for 12 % , onsite electrical ( 8 % ) , civil technology ( 8 % ) , development ( 4 % ) and legal/financial ( 3 % ) ( IEA, 2009 ) . The chart below Figure 1.2 shows the dislocation of typical air current turbine costs in Ireland.
Figure 1.2: Typical fiscal dislocation of a air current turbine undertaking in Ireland
The entire investing for a air current turbine norms ˆ1.6 to ˆ2 million per installed megawatt. So hence, a 5 MW farm would be about ˆ1.6 million ( SEAI, 2007 ) .
This figure will, of class, vary harmonizing to proficient picks made and the peculiar characteristics of the site. A modern air current turbine produces electricity 75-80 % of the clip, but it generates different end products depending on air current velocity ( IWEA, 2011 ) . With most big modern air current turbines holding a life anticipation, with regular care, of between 20-25 old ages, hence air current farms have the possible to be really profitable in the long term ( EWEA, 2011 ) .
2.3 Site choice:
Site choice is important when taking where a air current turbine can be located as some sites can be more suited than others. The most of import demand is the air current velocity. By and large, the most open sites will bring forth the most electricity ( SEAI, 2011 ) . Other considerations must besides be taken into history when choosing a site include ; the size and the status of the site, entree to the site, bing land utilizations and connexion to the electricity grid ( SEAI, 2011 ) .
2.4 Health and Safety:
As with all industries, wind energy must execute responsibly in relation to any wellness or safety concerns. The chief safety concern with any turbine is blade failure. It can originate from a figure of possible beginnings and consequences in either whole pieces of blades or pieces of blades being thrown from the turbine ( Stankovic et al ) . This is why it is so of import for the turbine to be located at an equal distance from any homes.
Other safety concerns include ; fire, structural failure, conveyance of big and bulky turbine pieces, parachutes crashing into one and development and building workers ( Stankovic et al ) . To day of the month, there has been no coverage of air current turbines holding serious negative wellness effects.
3.0 Wind energy impacts on local Environment:
Wind energy, as do other renewable resources, have their ain environmental impacts. Environmental Impact Assessment ( EIA ) is a procedure which identifies the environmental effects ( both positive and negative ) of air current turbine development proposals. It aims to forestall, cut down and countervail any inauspicious impacts ( EWEA, 2010. ) Impacts that can impact the local environment include ;
Ocular invasion – the coloring material of the turbines tend to be impersonal colorss for the tower and the rotor blades to intermix into the natural skyline. The layout and constellation of the turbines is besides of import, and if they are right positioned on site, they are more aesthetically delighting to the oculus ( SEAI, 2011 ) . The ocular impacts of air current turbines are influenced by: signifier and feature of landscape, design and coloring material of turbines, the layout of the turbine, the bing skyline and the figure and size of turbines ( SEAI, 2011 ) .
Noise – Virtually everything with traveling parts bring forth some grade of sound, and wind turbines are no exclusion ( SEAI, 2011 ) . There are two beginnings of noise produced from the turbine ; mechanical noise from the gear box and generator of the turbine and aerodynamic noise which is produced from the blades go throughing through the air ( SEAI, 2011 ) .When the air current blows the noise degree of the turbine is masked by the sound of the air current itself and when the air current is non blowing, the turbine will non be traveling and hence sit mutely in the landscape ( SEAI, 2011 ) . It is rare to hear a air current turbine traveling at distances of 300 meters or more ( EWEA, 2010 ) .
Wind turbines besides have an impact on bird life. Birds can be affected by two chief ways. The first by hurt or decease due to birds clashing with the turbine, or secondly, by birds being disturbed in their genteelness, nesting or feeding wonts. Research carried out by the European Wind Energy Association ( EWEA ) shows that the hazard of bird deceases through hit with turbines is low ( EWEA, 2010 ) . For illustration, it is estimated that 28,500 birds are killed each twelvemonth by air current turbines. In comparing to this, over 550 million birds are killed each twelvemonth from hits with edifices or Windowss ( EWEA, 2010 ) . To assist minimise the hazard of these jobs towards birds, turbines should non be situated on migration paths or where there are high densenesss of nesting or scrounging or birds ( EWEA, 2010 ) .
Besides, during development phases, impacts on the local environment may include ; transporting of bulky compartments of the turbine with big vehicles which must utilize national roads every bit much as possible, pull off the site i.e. take any waste, addition in traffic flow or an addition in noise degrees i.e. usage of heavy machinery ( SEAI, 2011 ) .
4.0 Wind energy and the current Economic downswing:
Everybody is speaking about the downswing in the economic system of late, and it is non merely a national job, but a planetary job. The building industry has hit a major downswing, and there is a batch of unemployment of late. The key to survival I feel, is farther preparation, and companies diversifying into other countries. For case, the country of renewable energy is acquiring stronger each twelvemonth, the sum of occupations been created in this industry is steadily increasing each twelvemonth. The EU air current energy sector employed 192,000 people straight and indirectly in 2009 ( EWEA, 2010 ) . Whereas in 2007, 150,000 people were employed both straight and indirectly in the EU ( EWEA, 2009 ) . There was a immense addition in employment from 2007 to 2009 and it is predicted that the figure of occupations will more than double to about 446,000 by 2020 if current conditions continue ( EWEA, 2010 ) . There are huge employment chances in this sector.
5.0 Advantages and Disadvantages of air current energy from air current turbines
Based on this literature reappraisal, the undermentioned advantages and disadvantages associated with air current energy being produced from air current turbines have been noted:
Saves fuel costs, reduces dependance on fuel and importing fuel ( EWEA, 2010 ) .
Avoids emanation of nursery gases ( GHG ) and air pollutants ( EWEA, 2010 ) .
Creates employment during the development and keeping phases ( EWEA, 2010 ) .
Low-cost electricity produced ( EWEA, 2010 ) .
Clean and environmental friendly energy beginning ( SEAI, 2011 ) .
Local country receives an income from leasing out land ( EWEA, 2010 ) .
Reduce electricity cost as it has a lower fringy cost ( EWEA, 2010 ) .
Wind energy is free ( BWEA, 2010 ) .
Europe ‘s taking renewable energy resource ( BWEA, 2010 ) .
Land beneath the turbine can still be used i.e. in agribusiness ( EWEA, 2009 ) .
Turbines are available in different sizes ( EWEA, 2009 ) .
Turbines can be a tourer attractive force ( EWEA, 2009 ) .
Have negative effects on bird and chiropteran life ( EWEA, 2010 ) .
Not all countries have a great air current resource ( EWEA, 2009 ) .
Wind dependent, hence if there is no air current on a given twenty-four hours, production of electricity can be hapless ( EWEA, 2009 ) .
Some people find wind turbines noisy and an unsightly construction barricading a countryside position ( SEAI, 2011 ) .
Feasibility of Survey:
The purpose of this survey is to look into and compare onshore and offshore wind farms. – Onshore farms were foremost developed in the UK in 1991 ( BWEA, 2010 ) . Since so onshore air current energy has become more cleaner and a more mature engineering ( BWEA, 2010 ) . Onshore air current farms are located widely across Europe, with Ireland, Denmark, France, Norway and the UK holding the best coastal locations with the UK holding the windiest sites ( BWEA, 2010 ) . Medium wind velocity sites include the inlands of southern and cardinal Europe including ; France, Germany, Spain, Italy and Holland ( EWEA, 2009 ) . The air current velocity on site has a major influence over the profitableness of the turbine ( EWEA, 2009 ) .
-Offshore wind farms now have a cumulative capacity of 2,063 MW across Europe with a sum of 39 air current farms. Offshore air current turbine farms are a new and prima engineering in Europe that provides a cleaner and more low-cost signifier of electricity ( EWEA, 2010 ) . In Europe from 2008 to 2009, there was a 56 % addition in entire installed capacity, with Europe holding 374 MW in 2008 and a value of 582 MW twelvemonth stoping 2009 ( EWEA, 2010 ) .
– Offshore air current power is more expensive than onshore, with a dramatic monetary value addition of 50 % ( EWEA, 2009 ) . This immense monetary value difference is due to the larger air current constructions and complex logistics of the installing of the air current turbine ( EWEA, 2009 ) . However, with offshore turbines holding greater air current velocities than onshore turbines, these have a higher electricity production ( EWEA, 2009 ) . Depending on locations, typically an onshore installing normally reaches 2,000-2,500 full burden hours per hebdomad whereas ; an offshore installing is about doubled with 4,000 full burden hours per hebdomad ( EWEA, 2009 ) .
– Depending on site considerations, normally offshore wind turbines provides greater air current velocities and has a lower ocular impact of the larger turbines ( EWEA, 2009 ) .
– There are differences in cost between the onshore and offshore farm with the foundations being more expensive on the offshore turbine. However cost will change depending on the type of foundation being built and besides the deepness of the sea ( EWEA, 2009 ) . Besides connexion to the electricity web will change between sites. Connection costs from the turbine to the transformer station must besides be taken into history ( EWEA, 2009 ) . The farther off from the connexion point, the more expensive the undertaking will be.