A critical review of global wind power generation

American Journal of Applied Sciences, Feb, 2009 by T Ahilan, K.P Mohammed, S. Arumugham

INTRODUCTION

Wind turbine is a non-polluting means of generating electricity. Large-scale modern wind turbines are presently able to produce electricity in the United States at economically competitive rates in a significant portion of the country, depending upon the average wind speed of the location of the turbine. The production cost at a given location depends predominantly upon the wind speed and to a lesser extent the type, size and configuration of the turbines. The placement of wind turbines in offshore locations is a relatively recent occurrence and it is an offshoot of commercial wind turbine development. The necessary conditions where offshore wind farms make sense are the combination of a strong wind resource, large areas of shallow waters located near land in an area where a demand for the electricity exists. Since installation in water is more expensive than land installation, the wind resource must be sufficient to cover the added cost.

The wind energy boom includes more and more countries. Wind turbine technology has reached a

mature status during the past 15 years as a result of international commercial competition, mass production and continuing technical success in R and D. The earlier concerns that wind turbines were expensive and unreliable have largely been allayed. Wind energy project costs have declined and wind turbine technical availability is now consistently above 97%. Wind energy project plant capacity factors have also improved from 15% to over 30% today, for sites with a good wind regime (1). With nearly 74,000 Mega Watts (MW) installed all over the world by the end of 2006. In 2005-06, the annual capacity additions worldwide nearly 14,900 MW. After 14,900 MW additional capacity, the global rate of growth increased to 31.66% in the year 2006. With this growth rate continuing, one expects 1,60,000 MW to be installed worldwide by the year 2010 (2). Over the last three years or so India has added more than 4,500 MW of wind power generation capacity accounting for more than 60% of the total installed capacity of 7,280 MW. Due to this growth, India is ranked fourth in the world, has more wind power generation capacity than Denmark and has almost more than double the capacity on nuclear power in the country itself. The Clean Development Mechanism (CDM) of the Kyoto Protocol provides industrialized countries with an incentive to invest in emission reduction projects in developing countries to achieve a reduction in C[O.sub.2] emissions at lowest cost that also promotes sustainable development in the host country. Wind power projects could be of interest under the CDM because they directly displace greenhouse gas emissions while contributing to sustainable rural development, if developed correctly.

Many of these countries can use wind energy in standalone or hybrid mode to meet the rural electrification needs. On the other end of the spectrum are countries like the UK Ireland, Canada, New Zeland, Scandinavian countries and Russia perhaps in the northern latitudes. There are excellent wind resources, but these countries have not been as forthcoming in wind power development as Germany, which has the largest wind farm installations in the world but not the best wind resources (3).

IMPORTANCE OF WIND ENERGY

With more and more evidence coming to light about the adverse effects of concentrated amounts of [CO.sub.2] in the atmosphere we would know that we need to change the way in which we produce the majority of our energy, i.e. burning of fossil fuels. This need for change led to introduction of the Kyoto accord; a legally binding agreement dedicated to reduction of [CO.sub.2] emissions. With respect to the geographic location, for instance there doesn't seem to be many places where hydro dams and reservoirs can be installed in Denmark or the Netherlands, the same goes for solar where the northern European climate will limit its impact. As for wave power; well it hasn't proved itself yet despite the fact that it has been around for some time now. That leaves wind; wind has been seen as the fastest way to make an impact on increasing a country's share of renewable energy and reducing emissions, making wind the renewable energy of choice. Solving many of the environmental and energy problems in industrialized countries, the growth of wind energy has been fuelled by this increased awareness of both public and private parties in environmentally friendly energy technology. Nationally, there have been increasing efforts to promote renewable energy as a response to the awareness of the limited supply of fossil fuels and also to meet the growing energy demand. State and local governments as well as the federal government have realized that not only can renewable energy be a way to meet future energy demands but also could promote economic growth in rural communities, some of the hardest hit areas with job losses and declining population in recent years.

Carbon emission reduction from electric generation to the level required to stabilize atmospheric carbon concentration, most effectively achieved through a combination of natural gas, energy efficiency and renewable energy is tabulated in Table 1. Wind energy is a clean source that provides electricity with virtually no CO2 emissions. Wind along with displacement of carbon dioxide, also displaces other harmful emissions contributing to smog, acid rain and airborne particulates. Though the combustion of natural gas produces no sulphur oxide emissions, it does produce significant amounts of nitrogen oxides and particulates as well as about 40% of carbon emissions produced by coal. Wind technology provides an outstanding opportunity to cut carbon dioxide output at reasonable cost. In addition to helping the various countries to meet its greenhouse reduction goals, setting up of wind turbines will result in healthier air and water for millions of people and in the conception of new jobs.