India has a very large power system with a total installed capacity of 258 GW. The Typical demand on the grid varies throughout the day peaking once in the morning around 125 GW and once in the evening around 135-140 GW. The intra day variation can be seen from the graph below.
This further varies from day to day and season to season. Between themselves, the National Load Disptach Centers and various DISCOMs are responsible to ensure that maximum demand is met. Managing such a large grid with dramatic variations is both a technical as well as an operational challenge.
The situation becomes even more complicated when we introduce grid connected solar power into the equation. Solar power plants generate highly varying amounts of power throughout the day time depending on the amount of sunshine. The output resembles a bell curve which peaks around noon.
Now if we imagine solar power as a negative load on the national power grid, we can essentially calculate plot the net resulting national demand as below:
As per industry measures, national installed solar capacity has ramped up from 2.4 GW in 2014 to 8 GW in 2016 and is expected to cross 18 GW in early 2018. This graph plots the resulting demand on the national grid after adjusting for the supplied solar power.
Note how the required ramp up of demand from the national grid between 2:00 PM and 8:00 PM is becoming progressively steeper each year as we are connecting more solar power to the grid. This is the duck curve and its dilemma.
If you represent a utility or a power generation company, how does this impact your business?