The most important issue that is facing India today if they want to reach 20% wind energy usage by 2020 will be grid compatibility and stability for energy throughout the year. There exist considerable variations in frequency and voltage that the grids generate which creates difficulties in wind farm operations and grid penetration. What is needed are grid codes that specify the wind farm and generator control actions so as to facilitate power production instead of the system that was proposed with the India grid code proposal in 2010 that had an emphasis on wind farms fitting into existing grids (Madsen P. H., and Natarajan, A., 2011).
It is essential for the operation of the wind turbine that the frequency and voltage of the grid be stable. This shows the fact that the wind farm and the grid have a mutual reliance on each other which calls for sustainable wind farm controls and grid codes for high energy penetration into the grid. One of the technologies that has been developed to help support this is known as a low voltage ride though (LVRT) which is when even if the voltage of the grid dips, the turbine will continue normal operation which will supply power back to the grid after the voltage returns back to normal levels. This however cannot be used of there is not grid stability over a long duration of time (in minutes). But in India this LVRT can help in maintaining connection to the grid if long term stability is assured (Madsen P. H., and Natarajan, A., 2011).
In India there also exists the problem that many in rural areas do not have any sort of grid connectivity or uncertain supply of power. This is due partly to the fact that hydroelectric power in India during the summer months becomes greatly reduced so there is then more reliance on thermal power plants which often results in unscheduled power shutdowns that effect rural areas the most. This makes it necessary for different and diverse renewable power sources which can all be interconnected through microgrids or virtual power plants to assist in rural electrification. Virtual power plants are systems that can supply energy to a larger rural grid through this system of connected renewable energies (Madsen P. H., and Natarajan, A., 2011).
This figure above shows an example of how a virtual grid system functions with the various sources of energy all adding to the energy of the grid (Madsen P. H., and Natarajan, A., 2011).
Though we are discussing India, a good way to conclude is through an example of the use of micro-grids for rural electrification and development exists in rural Kenya. The increase in access to electricity though this system resulted in a 100%-200% increase in worker productivity as well as a growth in income levels from 20%-70%. This also enables and improves the delivery of social and business services along with improved agriculture. There also exists the increased income that results from when local electricity users have an ability to charge and enforce tariffs and when the consumption is linked to the production of the energy. This relates to the idea that if micro and virtual grids are present, the rural people can also become workers at the plant that would help raise the income level of their village and community (Kirubi, C. et al, 2009)
Madsen P. H., and Natarajan, A., (2011). Challenges and Prospects for Wind Energy to Attain 20% Grid Penetration by 2020 in India. Current Science, 101(1):35-42.
Kirubi, C. et al., Community-Based Electric Micro-Grids Can Contribute to Rural Development: Evidence from Kenya World Development (2009), doi:10.1016/j.worlddev.2008.11.005
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