A recent report titled ‘Wind and solar energy for meeting Karnataka’s future electricity demand’, by the National Institute of Advanced Studies (NIAS) and Power System Operation Corporation Ltd. (POSOCO) analyses trends in consumption in Karntaka to predict the expected demand for power in the State in 2017 and 2022, as well as also accounts for the increase in generation from other sources. The most striking point the report drives is the need for ‘Pumped Storage Technology’ if Karnataka achieves its target of 5GW of wind +solar power by 2017.
What is pumped storage?
In a typical hydroelectric power plant the water from a dam or reservoir at a high level is let to run down through pipes and generator thereby converting gravitational potential energy into Kinetic energy.
On the contrary pumped storage involves the reverse process where the water from a lower level reservoir is raised to the higher reservoir using alternate energy (wind or solar) when they are in excess. The water then is let to run down the generator when there is a drop in wind and solar generation but a spike in power demand thereby maintaining the power supply-demand equation.
Why Karnataka needs pumped storage systems?
Karnataka today has a deficit of 3GW and has ambitious targets to raise the penetration of solar and wind power generation from the current state of 16% to nearly 27% of total power generation by 2017. If that goes as per plan we would have nearly 3.1GW of Wind and 1.3GW of solar power by 2017. This number is phenomenal considering we would have overturned the projected 10% deficit in 2017 by generating nearly 2% of excess energy.
The report goes on to predict that if all goes as per plan Karnataka would have solar, wind penetration of 31% by 2022 which could mean we would nearly export one fifth of our power production. However increasing wind and solar in the grid means we are raising our stakes on unpredictable energy but can be successful if we utilize the vast hydro potential of Karnataka.
In a recent report nearly 2000 tmcft of water was being considered to be wasted in Karnataka by rivers. A notable point was the failure of the Mekedatu pumped water storage project to take off.
(In the end there will be a few skeptics who point to the declining pumped storage systems in the developed nations; that debate is for another day.)