It is very unfortunate that after 65 years of independence approximately 8 crore households do not have power connections, which means that population of 40 crore is still deprived of electricity in India. It is pertinent too note that approximately 19000 villages are still un electrified across the country and in order to achieve government’s target of “Power to All” by 2019, it is very important to electrify these villages. In order to do so Decentralized Distributed Generation or off grid power solution from renewable sources of power generation might be helpful.
Repowering of Wind Farms: Evaluating Potential in India
India has a vast wind energy potential and for close to 2 decades the wind sector has witnessed number of challenges, opportunities and changes. Over this course of time, the industry has made path breaking improvements in wind turbine technology, due to which we are now in a state to provide more efficient and reliable turbines with high output ratings even in low wind zones. The advancement in technology has now opened gates for another remunerative approach termed as Repowering.
Repowering is “the process of replacing older power stations with newer ones that either have a greater nameplate capacity or more efficiency which results in a net increase of power generated”. Repowering can be done in following ways:
- 1-to-1 up-scaling of solitary wind turbines
- 2-to-1 replacement, i.e. replacement of two smaller wind turbines by one large wind turbine
- Clustering of wind turbines in a farm, e.g. replacement of 20 solitary wind turbines by clustering 6-10 wind turbines at one location
- 1-to-1 replacement of wind turbines with similar rates but with newer machines
- 1-to-1 up-scaling of wind farms
The typical WTGs that can be repowered are the ones that have completed at least 12-14 years of their service life. The major cause of concern is that these turbines are located at most premium locations which have great wind potential and due to their smaller capacity the actual potential of these sites cannot be tapped effectively. Thus, with modern technology, the installed capacity can be increased tremendously , with net generation of energy going up several times. Hence the concept of repowering comes into play.
From Exhibit 01 and Exhibit 02 it is evident that more than 10% of wind turbines have capacities less than 500kW which are installed till 31st March, 2014, whereas nearly all turbines have same capacities installed before 31st March, 2000 . Further, more than 45% of the wind turbines installed till 2014 have capacities less than 1MW. Hence, from the above discussion we can conclude that rest of the turbines with capacities more than 1MW have all come up after 2014. This gives us the clear picture of immense opportunities which lie in the repowering market as more than nearly half of the presently installed wind turbines have potential to go beyond 1MW. Obviously there are multiple factors like feasibility, financing issues, force closure of PPAs with DISCOMs etc., which are to be addressed before going for repowering, but if this framework is implemented then PLFs will go up several times and net generated output power will also increase and thereby clearly pointing out a fact that the generation from wind energy in India is likely to go up several times in the near future.It can be observed from above Exhibits the major Indian wind resource rich states which should go for repowering at very beginning are Gujarat, Maharashtra and Tamil Nadu as these are some of the states where wind energy development programme started way back in 1990s and most potential sites here are under utilized.
The framework will also help in promoting off grid use of wind power same as it is being done for solar. The framework includes the concept of net metering to encourage people to go off grid. The mechanism involves generation of power through repowered wind plants till the time grid supply reaches to that place, once grid supply is there, the off grid generator can supply power to the grid through net metering. The basic concept of doing so is to make the consumers with no grid connectivity self reliable in terms of catering to their energy needs till the time grid supply reaches there, after connection with the grid, government will purchase power from the independent generators at the tariff decided by the respective state electricity regulatory authority.
Net Metering: Evolving new business case for Repowered Capacities
Exhibit 03 depicts two models of power sale. Model I is the simplest, off shore consumers directly procure power from the developer at mutually agreed price. Model II involves sale of power either to the grid or to the off grid consumers, further by introduction of net metering the off grid consumers will now be able to sell excess power to the grid, hence enabling them to generate more revenue. Hence if net metering mechanism is introduced, off grid generation of power through wind will get a launch pad and will be the key driver of wind sector.
Powering India through Wind: Biggest bottleneck being addressed
The mode of sale of electricity has been the biggest bottleneck in implementation of repowering framework in the country, but the introduction of net metering will pave way for the development of this framework as well as off grid connectivity will be seen as the better alternative as the developer will have the freedom to choose the mode of PPA (Power Purchase Agreement).The need of the hour is repowering the old WTGs, and non performing windfarms. Although socio economic, financial, geo political, techno commercial and regulatory issues are quite complicated for repowering wind farms , but for long term sustainability repowering should be backed up by the large energy mix of renewable power in India’s energy mix. Off grid sources will play a very vital role in achieving government’s target of “Power to All” by 2019 and repowering will help to achieve the ambitious target having 60GWs of installed capacity through wind by 2022.For a more detailed examination of the developments on Repowering Framework in India get in touch with the author and read more related articles here.