The CMDs of AP-DISCOMs on Thursday said that the normative availability of energy for the generators under Power Purchase Agreements (PPAs) was 3,289.30 Million Units (MU) between December 17, 2020 and January 15, 2021. However, the actual energy availability declared for supply was 2,470.79 MU.
Responding to a letter written by the Andhra Pradesh Electricity Regulatory Commission (APERC) regarding power purchaseson Wednesday, the CMDs said the actual energy supplied by the generators was 2,253.27 MU and there was a shortfall of 819.3 MU compared to the commission’s orders. DISCOMs scouted for the cheapest power available to bridge the shortfall and saved ₹22.70 crore through market purchases.
They said that 3,289.3 MU was the availability based on the full capacity of the generating stations as per the commission’s tariff orders and it would be fully available to the DISCOMs only if the generating stations declare their ability to supply the energy, which was only 2470.79 MU.
The generators declare the energy availability on a day-ahead basis and their ability to supply it on a given day is always less than the normative availability under full capacity operating conditions. The actual energy declared by the generators depends on machine maintenance needs and fuel availability.
The power procurement plan for the next day is finalised by the State Load Dispatch Centre on the basis of the power plants’ declaration of the energy availability.
The energy availability declared on a day-ahead basis is always less than or equal to the normative availability as per the PPAs. The generators forgo fixed costs for the energy not made available.
Further, the CMDs said the average price of market purchases for the above period was ₹3.38 per kWh (excluding ₹0.19 /kWh AP TRANSCO charges which are refunded). The average price of alternate power available during the same period from the approved sources was ₹3.68 per kWh (excluding Transco charges). Thus, there was a saving of ₹0.30 per kWh.
The APERC ought to have considered real-time availability as declared by the approved sources. Instead, it factored in the normative approved availability given in the retail supply tariff order. The commission has thus erroneously calculated the loss compared to energy from power plants which was unavailable at that time.