As California moves toward its goal of generating 33% of its electricity from renewable energy sources by 2020, the electric grid will be undergoing a series of targeted upgrades and new construction to bring wind and solar energy from relatively remote parts of the state to major population centers. As a leader in providing analytic support to power project developers, utilities, regulators, and municipalities, Nexant works to ensure that power and transmission projects are planned and executed in the most efficient manner, taking into account cost, environmental, and social impacts.
One such project—Southern California Edison’s (SCE’s) Tehachapi Renewable Transmission Project (TRTP)—is comprised of transmission lines and facilities spanning some 250 mi, delivering renewable wind and solar energy from Kern County southward to Los Angeles County. The project includes installation of a high-voltage (500 kV) overhead transmission line passing through the City of Chino Hills. SCE began constructing 200-ft transmission towers near city residences in 2009 when the project was first approved by the California Public Utilities Commission (CPUC). Local residents and community leaders, concerned that placing high-voltage transmission towers above ground could have a significant impact on the city, teamed with industry experts, including Nexant, to study placing the line underground.
A team of six Nexant experts provided technical services to model the electric grid system in the Chino Hills area and assess the potential impacts. The team assessed impacts on renewable generation, transmission project capacity that might be utilized under different scenarios, and electric transmission costs associated with alternative configurations for undergrounding the 3.5-mi portion of the transmission line through the city. Nexant also provided a review of the cost estimates and financial projections submitted by SCE for the underground segment of the project.
Ajit Kulkarni, head of Nexant’s Grid Management consulting practice, led Nexant’s Chino Hills support effort, and testified before the CPUC. “Our analysis included a detailed, hourly electric generation and transmission simulation comparing overhead and underground configurations of the project for the years 2016 and 2020,” said Dr. Kulkarni. “We found no significant negative impacts on system operations due to the time required to underground the line, or to fix the line in the event of an outage after it is in service.”
Nexant’s analysis and testimony, together with the testimony of other industry experts contributed to the CPUC’s recent decision directing SCE to change its original plan and opt for one of the alternative underground configurations, at a maximum cost of $224 million (click here to read the CPUC decision). Work is now under way to complete this segment of the line.