nav-left cat-right

Regional Transmission Expansion Planning (RTEP)

With funding from the US Department of Energy (DOE), the Western Electricity Coordinating Council (WECC) and Western Governors’ Association (WGA) have launched an initiative to develop the first-ever Interconnection-wide transmission plan covering all eleven western states, British Columbia and Alberta.

The Regional Transmission Expansion Plan (RTEP) initiative is working to develop scenarios that outline low-carbon energy futures for 2020 and 2030 for the Western US. WECC will then evaluate them to identify the infrastructure needed in each scenario. The RTEP process provides an effective forum for advancing discussion of clean energy goals with utilities, regulators and other decision-makers.

Frequently Asked Questions about WECC, RTEP and transmission planning in the western US is available HERE.

Several WCEA members are actively engaged in this effort, and WCEA monitors and supports RTEP work. The Scenario Planning Steering Group (SPSG) at the center of RTEP is made up one-third of NGOs; one-third of state representatives; and one-third of WECC member utilities. WCEA supports NGO members of the SPSG and coordinates its work to the extent possible with state and utility participants in RTEP. Development of the WCEA Clean Energy Vision leverages RTEP scenario planning and modeling work.

WCEA priorities in RTEP Interconnection-wide planning include: evaluation of coal unit retirement; expanded reliance on energy efficiency and demand resources in utility procurement; greater utilization of existing transmission capacity; and inclusion of land, wildlife and water constraints in electric system modeling. These environmental considerations have never before been incorporated into capacity expansion planning or hourly dispatch modeling. WECC has created an Environmental Data Task Force to address the data collection and spatial representation issues involved, and WCEA monitors and supports its work.

The North American Interconnected Grid
The North American electrical grid is made up of the three interconnections shown on this map: the Eastern Interconnection; Western Interconnection; and ERCOT (Electricity Reliability Council of Texas) Interconnection. The three interconnections are not synchronized, and Alternating Current (AC) power must be converted to Direct Current power to be transferred across any of the interconnections.