LOAD 00001
Published On: 04/26/2021

Question: There is volatility in load year-to-year, and the magnitude of the peak is highly volatile. What method is used to try and assign a capacity value due to volatility in load? Could we get more detail on ELCC methodology?

Answer: In DESC’s service territory, the greatest firm load potential is in the winter and so this is when we forecast peaks to be highest. Previously in the 2020 IRP, DESC evaluated a number of different peak hours and the respective contribution of resources on the system during those peaks. The Commission rejected this method and mandated the ELCC at 4.25% of nameplate capacity.  See Appendix F of the 2020 Modified IRP for descriptions and calculation of the ELCC used.

LOAD 00002
Published On: 12/21/2021

Question: If DESC is having a day when load is high and have forced outages on the system, and you’re in trouble, and you’ve exhausted everything on your system and still in trouble, and need to shed load, is it part of protocol to call neighbor utilities and ask them if they have power that they can sell? Is this included in the LOLE study?

Answer: Yes, this is part of our operational procedure. However, these reserves are not always available even when called. For example, in January 2014 DESC called for reserves from neighboring utilities and these resources were not available.

For operations this is part of the protocol. For the purpose of the LOLE study, it is not necessary to thoroughly assess neighboring utilities since DESC’s goal is to maintain reliability for our own customers.