Olsen, David. 2005. “Transmission Planning to Connect Large Increments of Wind Power: The Tehachapi Study Group.” Washington, DC: American Wind Energy Association.

Abstract

The 4,000 MW of high-quality wind resource in the Tehachapi Mountains of east-central California could supply more than half of the new generation necessary to meet the state’s renewable energy law. No transmission capacity is now available for export of this resource. In June 2004, the California Public Utilities Commission (CPUC) ordered the formation of a stakeholder collaborative, the Tehachapi Study Group, to construct a detailed plan for the phased development of transmission facilities necessary to make Tehachapi wind power accessible to statewide markets.

California law requires that 20% of electricity sold in the state be generated from renewable energy sources by 2017; current policy accelerates this goal to 2010. Implementing this law will require substantial increases in transmission capacity and more importantly, new policy approaches for planning and building transmission to connect wind power in large increments.

Under current policy, approval of new transmission is geared to connect generating projects one or a few at a time, after each project is fully developed and has a signed Interconnection Service Agreement. Given the need to connect many relatively small wind power projects, this policy will not support implementation of the California RPS on the schedule required. Instead, the CPUC has proposed building transmission in increments large enough to accommodate several years of RPS bid winners at a time. This would likely be more cost- effective and much faster than connecting projects one at a time. But such an approach creates cost recovery risks, and will require tariff and regulatory changes.

To contain these risks, Southern California Edison (SCE) has proposed creation of a new category of transmission assets, referred to as Renewable Energy Trunk Lines. SCE’s Petition for a Declaratory Order to this effect is now before FERC.

The Report of the Tehachapi Study Group was filed at the CPUC on March 16, 2005. This report contains a conceptual transmission plan for export of 4,000 MW of wind power from the region. Follow-up work is anticipated to complete the development plan and obtain the approval for the necessary new transmission facilities.

Download full report (pdf) here.