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Fundamentally, winds carry a part of the energy from solar radiations and they blow in every nook and corner on the surface of earth. Uneven heating of earth’s surface and varying pressure differences cause movement of air in the atmosphere that creates the wind as we experience it
Perhaps, the earliest use of wind energy was in the form of sails to steer ships and there is a mention of ambitious plans of mesopotamian ruler Hammurabi to use windmills for irrigation as early as around 1790 BC.
Today, modern wind turbines convert the kinetic energy in the wind to electrical energy and clusters of wind turbines in the form of wind farms generate electricity on a utility scale.
While, undoubtedly, Green House Gas (GHG) reduction is one of the main drivers for investments in wind energy in Europe, ensuring energy access and energy security are equally and sometimes more urgent needs. Today, many parts of the world are known to meet a significant part of electricity requirements from wind. Denmark, parts of Texas, Tamil Nadu in southern India, Spain and Northern Germany have as much as 40% of their energy generated by wind.
It is this question: ‘how much capacity and how much energy from wind is there in the world?’ that is termed as ‘Wind Resource Assessment’ (WRA) or ‘Wind Potential Assessment’ is the most important aspect of wind power development, that this report has tried to address at a worldwide level.
To this end, the Technical Committee of the World Wind Energy Association has published this report which gives a comprehensive overview of currently available wind resources assessment from most world regions, as far as available.
In order to come up with a realistic assessment of worldwide potential for utilization of wind energy, data and information has been accessed from varied sources such as national laboratories, research reports, peer-reviewed scientific publications and industry associations. Interestingly, we find that different methods and information sources have come up with assessment figures that are somewhat similarfor different parts of the world. Be it the wind energy potential for Germany, US, Russia, China or India or the entire world, the order of magnitude appears to be similar and one study corroborates the other. This sort of cross validation of the studies, lends weight to the figures arrived at.
The Wind Resource Assessment (WRA) is the most important aspect of the entire business of harnessing wind energy or wind power development. Apart from providing information on strengths of wind speeds and the energy content in them, it also enables selection of the appropriate type of wind turbine design for deployment at a given location or in a region.
Over the last 50-60 years, electricity generation has grown in most parts of the world, the steepest growth being in developing countries. Therefore, balancing energy access, economic development and environmental sustainability is going to be a major challenge not only for the nations concerned but also for the global community.
Three challenges concerning sustainable development – energy security, climate change and energy access – are important incentives for the development and large-scale utilization of wind energy across the world.
As of June 2014, about 337 GW of wind power generation capacity has been set up in the world (less than 10% of the total installed power capacity of the world). This capacity is more than the total installed electricity generation capacity from all sources in some of the largest countries in the world. With such a large wind power capacity having been installed and widespread geographical deployment in more than 100 countries, wind energy has arrived at the center-stage of the mainstream electricity sector.
The realizable offshore and onshore potential for wind energy utilization with the currently available technologies is sufficient to meet the electricity requirements of the entire world many times over.
Indeed, the total wind potential of the world, as identified by existing studies, is 95 million Megawatt or 95 Terawatt. The relation to the current global energy demand of around 100,000 Terawatt-hours suggests that wind energy alone would be more than sufficient to cover the world’s energy supply several times. According to the IEA, the world’s total energy consumption for all sectors, including industries, heating and cooling as well as transport, in 2011 was 103,000 TWh, which included 19,000 TWh for power consumption.
Table (a) below summarizes the worldwide potential for wind farms according to currently available official estimates, in most cases excluding offshore wind potential.
| US | 11 |
|---|---|
| EU | 37.5 |
| Russia | 36 |
| Rest of the World | 10.3953 |
| Total | 94.8953 |
The world’s wind potential is thus sufficient to cover the whole world’s energy demand - assuming on average 2000 full load hours, the identified wind potential could almost cover it twice. In an assessment by European Environment Agency, the technical potential for onshore and offshore region for the years 2020 and 2030 is assessed to be 70,000 and 75,000 TWh, respectively. Assuming the wind power plant runs at a Capacity Utilization Factor (CUF) of 23%, the potential is assessed to be 35 TW and 37 TW for the year 2020 and 2030 respectively.
While wind turbines are known to generate electricity in distributed manner often for consumption at local load centres, in the long term for wind to emerge as a mainstream source of energy, more than what it is today, one may have to explore large scale generation in high potential areas and transmission of electricity over hundreds of kilometers on high voltage AC or high voltage DC.
Technical and scientific studies, and technological developments in wind turbines, smart grid concepts, power system reliability, grid integration and energy storage systems consistently point to the fact that in spite of winds being variable in nature, wind farms on a large utility scale can meet a very significant part of electricity and load in the power system without any adverse impacts on its reliability. It is possible to meet all electricity requirements with technologies and options that are a combination of wind, solar, hydro and biomass and storage technologies and devices. Technically, it is thus possible to phase out nuclear and fossil fuel based generating stations.
Of course, the actual deployment of a very large wind capacity will depend on smart integration into energy supply structures, combination with other renewable technologies, storage options, demand-side management etc.
For a highly developed and industrialized region of the world, also subject to very cold conditions in winters, the prospect of energy shortage can be a serious concern. In recent times, Europe has faced some of these uncertainties in gas supplies from Russia. Even traditionally, fuel supplies from middle-east, in some manner, are a source uncertainties in terms of price and supply.
Those regions of the world that face such energy resources constraints to meet their electricity demand are also the regions where wind energy has been utilized to the largest extent. Electricity access is going to be one of the main drivers of wind power development in those countries that have enough wind resources. In those countries with less than 50% electricity access, wind power generation, in combination with solar energy, biomass and hydro, can be a low carbon solution.
Europe, India, China & US together account for 93% of the total wind power installed capacity. In Europe, between 2000 and 2013, more than 100 GW of capacity was added. In the United States, while more than 80% of energy consumed comes currently from oil, natural gas or coal, by the end of 2013 more than 61.1 GW of wind power capacity had been installed.
In India, heavy and growing dependence on imported fossil fuels, apart from adding to energy insecurity, creates serious monetary problems for the country. India has achieved nearly 21 GW of cumulative installed capacity of wind power by 2014. China, where energy security is of immense importance because of massive industrialization has emerged in just about eight years, as the leading country with more than 91 GW of wind farmed capacity. Despite high wind potential, the installed capacity in Africa was only 1.1 GW in 2011.
According to the Intergovernmental Panel on Climate Change (IPCC) wind energy offers significant potential for near-term (2020) and long-term (2050) greenhouse gas (GHG) emissions reductions. The need to reduce GHG emissions is yet another major driver and a compelling reason for countries to set up wind power plants. The countries and regions that face energy security issues also face the challenge of environmental sustainability in planning their future energy mix.
At any given location or in a region, any stakeholders - investors, financiers, utility managers or policy makers – interested or investing in wind energy would like to know how much electricity can be generated from a project so that the economic rationale of such an investment can be examined. The question of wind energy potential is thus important from different perspectives:
At project level, the answers to this “Wind Resource (or potential) Assessment (WRA) will enable developers and investors to take a “go”/ “no go” decision and at a national or regional level, and will enable the concerned agencies or the governments to figure out if there is enough potential to utilize wind energy and whether certain policy and regulatory frameworks are required in order to harness such potential on a large scale.
The techniques of undertaking WRA at project level differ from the techniques and approaches to assess the resource on a regional or a meso-scale.
Project level WRA involves design of an optimized deployment of wind turbines of a certain make or type in a given patch of land and assessment of the annual energy output.
In regional or meso-study, the area in question can be thousands of square kilometers. Some studies have covered the entire globe based on global data sets including satellite data.
This approach uses various models such as the Weather Research and Forecasting (WRF) model, which is a Numerical Weather Prediction (NWP) and atmospheric simulation system. It uses a wide range of meteorological applications across scales ranging from meters to thousands of kilometers that include meteorological investigations, idealized atmospheric simulations or data assimilation studies and development to generate map, elevation and land information for the WRF model.
New atmospheric analyses using together historical data and analyses of the current atmospheric state contain the information of climate variables with different time setups available in daily averages and monthly averages and at various spatial resolutions at various spatial resolutions from 1948 till present.
At international level, there are now many agencies involved in developing wind maps for different parts of the World. For example, the Energy Sector Management and Assistance Program (ESMAP) of the World Bank is currently involved in developing these maps for different regions, a major focus being Africa. Similarly other international organizations and foundations are also involved in supporting such regional assessment.
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