Renewables integration involves deploying and operating enough flexible, controllable resources to ensure grid reliability given the variability and uncertainty associated with intermittent renewable power generation. Nationally and internationally, much recent research and analysis has focused on quantifying integration needs and costs associated with various renewables scenarios.
In Track I of the 2010 LTPP proceeding, the Commission is seeking to identify resource need to meet system or local resource adequacy in California through 2020 and will consider procurement authorization to meet that need. Additionally, beyond generic capacity, the Commission is also seeking to identify resource need for renewables integration. The CAISO and PG&E have developed two independent models for estimating California renewables integration needs and the associated cost, both of which are being reviewed via the LTPP proceeding in workshops and stakeholder comments.
Renewables Integration Workshops in the LTPP
The CAISO and PG&E presented methodologies, inputs and assumptions for their renewable integration models during several Energy Division workshops. The first was held on August 24 and 25, 2010, where CAISO and PG&E each presented information regarding their models. At a second workshop on October 22, PG&E made additional presentations on its model and presented initial model results using 2009-vintage renewables scenarios for 2020, and CAISO presented further information regarding its model. At a third workshop, on November 30, CAISO presented model results using 2009-vintage renewables scenarios for 2020, as well as further information on model methodologies. Following each workshop, parties were given the opportunity to provide written comment on the models’ inputs, assumptions and methodologies.
The December 3, 2010 LTPP Scoping Memo lays out updated renewables planning assumptions and directs CAISO and PG&E to rerun their renewables integration models using these updated assumptions. Energy Division staff anticipate at least one additional workshop to review further model results in 2011.