Chennai: The much hyped forecasting of wind power generation seems to have failed to address the problem of grid dropping (non evacuation of energy) of windmills in the state.
To ensure full evacuation of wind energy, the industry has appealed to Tangedco to appoint an officer from its non conventional energy sources department to schedule wind energy to the grid based on the forecast supplied by them.
Despite providing Tangedco with forecast, wind generators have suffered highest ever evacuation loss of over 4,000 million units (MU) due to indiscriminate grid dropping, according to sources in wind sector.
“In 2012, Tangedco evacuated 10,212 MU during the high wind season from April to November. After providing forecast in 2015, the evacuation has touched a new low of 6,108 MU which is 40 per cent less compared to 2012,” sources noted.
From August 2015, the National Institute of Wind Energy (NIWE) was supplying group forecast for all the 7480 MW of wind generators for next eight days in 15 minutes slots to the State load despatch centre of Tangedco, a wind power generator said.
The forecast which is updated every 12 hours has an accuracy of over 85 per cent as mandated by Central Electricity Regulatory Commission.
“We have urged Tangedco to appoint a special officer from NCES department to schedule the wind energy,” the generator said.
Tangedco denies non evacuation charge: A senior Tangedco official denied the charge of indiscriminate backing down of windmills. The backing down of windmills is done due to regulatory constraints to maintain grid security and discipline as per the Indian Electricity Grid Code (IEGC) 2014, the official said.
“The operating range of frequency to be maintained is between 49.90 and 50.05 hertz as per IEGC and to restrict the drawal of power from the grid within the range of plus or minus 150 MW. As the wind generation is highly infirm and its intraday variation itself ranges from 1000 MW to 2000 MW, during the peak wind season, with much difficulties grid regulation of CERC is being maintained,” an official explained.
The official said forecasting alone does not solve the problem of evacuation.
“Wind generators should provide scheduling like conventional power plants and so any deviation in the supply will incur penalties to the generators. Hitherto, Tangedco has been paying penalties for underdrawal or overdrawal from the grid due to interday variation of wind energy generation,” the official said.
S. Gomathinayagam, director general of NIWE, said Tangedco officials could themselves schedule the wind energy with the forecast provided by us.
“We are providing forecast for wind energy at sub-station level across the State.
For the 106 sub stations, we are providing a day ahead forecast with 15 minutes slots. The forecast supplied by us can be used to schedule wind energy,” he said, noting that the institute provides forecast with 95 per cent accuracy as against the Central Electricity Regulatory Commission mandated norms of 85 per cent plus accuracy.
“The NIWE’s forecast for about 7400 MW wind mills in the state is largest such attempt by an agency in a region,” he noted.
