Load Analysis Subcommittee examines historical data 


At its March 14 meeting, the Load Analysis Subcommittee learned that PJM is working with engineering company AWS Truepower to estimate the historical output of behind-the-meter solar generation, which then will be added back into the unrestricted loads in the long-term load forecast model.

AWS Truepower discussed the specifics and methodology used to create these estimates, and PJM laid out the plan to analyze and use the new data.

Other subcommittee business

  • PJM continued the discussion on potential changes to the forecast model structure introduced in November 2017. PJM described this new model structure and presented the assumptions and methods used to produce baseload history/forecast.
  • PJM discussed the disparity between the weather-normal value and the first year of the forecast. PJM believes some of the problem is due to the weather normalized value being low, and the other part is due to error in the forecast model that showed a slight increase this past summer.
  • PJM showed what the RTO summer forecast would look like if the historical loads used in the estimation of the model were shortened from 19 years to 15 years and 10 years.  PJM does not believe this alone will solve the disconnect from the normalized value to first year of the forecast and the shortening of history limits the model’s ability to accurately estimate parameters across business and weather cycles.
  • PJM reviewed peak loads and weather from winter 2017/18.  The weather on the peak day was more extreme in PJM’s eastern zones and less extreme in the western zones. Final winter peaks will be available once loads are recorded through February.

Summer-Only Demand Resource Senior Task Force

 At the March 9 meeting of the Summer-Only Demand Resource Senior Task Force:

  • Chenchao Lu, counsel – Legal, provided an overview of both the Federal Energy Regulatory Commission’s intent to discuss the concept of seasonal capacity markets at a future technical conference (EL17-32-000 & ER17-367-000) and the technical conference’s impact on the task force. Lu explained that the task force will work in parallel with the FERC activity because seasonal capacity markets are explicitly outside the scope of the senior task force and because the FERC has not released a timeline for the technical conference.
  • PJM provided education on the short-term load forecast and impact of peak-shaving programs on dispatch decisions. BGE presented education on its load curtailment program.
  • The group continued to review and identify design components and options in the task force matrix.
  • The group aims to finalize the design components and options at its April meeting, as well as provide additional education on state-sponsored peak-shaving programs.