Starting January 1, 2012, wind power generators will have to forecast output 24 hours ahead of delivery, in 15-minute time blocks, with at least 70% accuracy. If actual generation varies more than 30% from the forecast, operators will bear so-called unscheduled interchange charges. The larger the variation is, the larger the charge.
The Central Electricity Regulatory Commission (CERC) had hoped to impose the policy by January 1, 2011, but put off implementation by one year after wind firms said they could not work out how to comply by the original deadline. There is currently no requirement on wind farms operators to forecast output.
Indian states where wind farms are located will shoulder charges caused by variations smaller than 30%. Known as the Renewable Regulatory Charge (RRC), this will be shared across all Indian states and calculated based on each state's portion of peak electricity demand in the previous month. The Renewable Regulatory Fund will oversee the RRC.
CERC will apply the forecast requirement to plants with installed capacity of at least 10MW connected to the grid at 33kV and above. Wind farm operators will be able to revise forecasts if notice is given a day in advance. A maximum of eight revisions can be made every three hours.
It is expected that proper scheduling of output will lead to a substantial increase in stable power supply in areas with abundant wind, with positive knock-on effects for local economies.