Erratic monsoon clouds hydro power generation

Hydro power generation in the state may decline over the next couple of weeks due to erratic and deficient monsoon. This is in contrast to the sharp jump in hydro electricity generation witnessed during the past few weeks.

“Even as the generation has gone up, the reservoir build up (water level) has not been upto the mark this year. If this situation (of erratic monsoon rainfall) continues for next 15 days, then we will have to change our strategy accordingly,” said Miraj Mishra, director, operation, of Odisha Hydro Power Corporation Ltd (OHPC).

Daily generation from seven hydro power plants in the state reached up to 722 MW this week, up from 210 MW in early June. However, as the monsoon rainfall has been below normal so far, power managers feel this could hurt generation in coming days.

“All reservoirs, except Burla, have water levels below or at par with (MDDL) Minimum Draw Down Level. The generations had gone up on expectation of better rainfall, but it has to come down as rainfall has not been satisfactory,” said a senior official of state-run power trader Gridco.

As of Tuesday, Odisha received 18 per cent less rainfall this monsoon. In districts like Kalahandi, Nawrangpur, Angul and Malakanagiri, belonging to western and southern parts of the state, where all hydro power stations are situated, the rainfall deficit ranged between 18 and 21 per cent. Only Sambalpur district in western Odisha received 5 per cent more rainfall between June 1 and July 17.

Koraput district, which houses largest reservoir Machkund and Upper Kolab power station, received only 48 per cent of normal rainfall during current monsoon, data from Regional Meteorological Centre, Bhubaneswar showed.

Even though hydro power generation does not contribute significantly to meet the state’s power demand, cash-strapped Gridco depends on it heavily due to its low cost and easier availability. This summer, thermal units operating in the state had to shut down operations frequently due to technical glitch or coal supply problems, compelling the power trader to look for other sources such as captive power plants.

Gridco is currently drawing about 2,750 MW from all its sources, which is still short by about 50-100 MW from average demand. To meet the deficit, the power trader either resorts to over drawal from eastern grid at astronomical costs or cuts power supply in peak hours.

Odisha has been grappling with power shortages since November 2011. To meet the summer power need of the state, Gridco had finalised agreements with Power Grid Corporation of India Ltd (PGCIL) to draw 200 MW for a month via power banking, which ended on May 1. In return, it had agreed to return the power with 5 per cent interest during August-September, betting on surplus hydro power generation in monsoon months.

“It has been seen that when monsoon gets delayed, we get ample rainfall towards late August or September. We are hoping that reservoir build up will be very good in next month,” said Mishra of OHPC.