PV system integration

California Solar Initiative program evaluation

Overseen by the California Public Utilities Commission (CPUC), the California Solar Initiative (CSI) is the largest customer-owned solar incentive program in the United States. The CSI program offers performance- and capacity-based incentives for solar projects up to 1 megawatt (MW) in size to customers among the territories of the state’s investor-owned utilities (IOU): Pacific Gas & Electric (PG&E), Southern California Edison (SCE), and San Diego Gas & Electric (SDG&E). The program’s goal is to reach 1,940 MW of installed solar capacity by 2016. As customers take advantage of these incentives, the state aims to determine a way to integrate grid-connected photovoltaic (PV) systems with its generation resources. It also seeks to understand how these systems will impact the state’s transmission and distribution (T&D) system, and whether energy efficiency could be used to reduce the size of PV systems.

Project
The CPUC selected the Itron/KEMA team to conduct the landmark 2009 CSI Impact Evaluation. KEMA focused on the following tasks:
> Quantified CSI energy savings and environmental benefits, including hourly savings profiles and avoided CO2, NOx, and PM10 emissions
> Assessed CSI progress towards meeting its MW generation goals and impact on T&D systems
> Gauged adoption level of energy efficiency measures by residential electric customers with PV systems, compared with all electric customers
> Conducted a load profiling analysis
> Analyzed PV systems’ impact on residential rate tiers
> Assessed program awareness and satisfaction

Objectives
The primary purpose of the 2009 CSI Impact Evaluation study was to assess the CSI program’s impact during 2009 to help the CPUC gauge if the program is meeting its goals.

Benefits
The study identified that there is potential to adopt more energy efficiency measures prior to PV system installation. It also found potential to install energy efficiency measures with customers that already have PV systems, which will reduce their energy demands from the grid. The Itron/KEMA team provided recommendations and strategies to leverage these energy efficiency measures. The load profiling analysis identified that residential customers who participated in CSI used more energy than average customers, but they have less impact on the grid at time of system peak.

Client
> Itron, Inc., United States
> California Public Utilities Commission (contracted by SCE), United States

Project partners
> Pacific Gas and Electric
> San Diego Gas and Electric

Project details
> Duration: November 2008 – June 2010