Transmission/Resource Library/Planning

From Open Energy Information

Transmission Planning

Planning Regions

Planning regions.png

Transmission planning is required for all public utility transmission providers to meet future electricity demand and maintain reliability of the electric supply system. Transmission providing utilities must undergo transmission planning by creating 10-year plans on a regular basis and 20-year plans periodically. Generally these long range plans are published every other year or every third year. These long-term plans are used to predict electric use in the region, identify specific transmission needs, and improve the overall reliability of the system. These plans take into consideration factors such as population projections, cost, needs driven by public policy, and expanding or new industry needs.

Federal Transmission Planning Requirements

The Federal Energy Regulatory Commission (FERC) oversees the reliable and economic operation of the transmission grid, including requirements transmission providers participate in a coordinated, open and transparent planning process at sub-regional (local)and regional levels.

Order No. 890 – FERC Order 890 requires local and regional transmission planning that is coordinated among affected entities and that is open to stakeholders. Requires coordinated, open and transparent regional transmission planning processes.

Order No. 1000 – Requires transmission planning at the regional level to consider and evaluate possible transmission alternatives and produce regional and sub-regional transmission plans.

Within the Western Interconnection there is a single reliability organization, the Western Electric Coordinating Council (WECC) and four transmission planning regions; WestConnect, ColumbiaGrid, California ISO (CAISO), and The Northern Tier Transmission Group (NTTG).

WECC – Western Electricity Coordinating Council

The Western Electricity Coordinating Council (WECC) is the Regional Entity responsible for coordinating and promoting Bulk Electric System reliability in the Western Interconnection. In addition, WECC provides an environment for coordinating the operating and planning activities of its members as set forth in the WECC Bylaws.

WECC conducts a variety of studies and assessments required for the reliable planning and operation of the bulk electric system in the Western Interconnection. Included in these activities are long-term planning studies on five- and ten-year horizons, congestion studies, and assessments of loads and resources. The work of WECC in this area is accomplished under the direction of the Transmission Expansion Planning Policy Committee and the Planning Coordination Committee.

WECC released their first 10-Year Regional Transmission Plan in 2011. The plan includes information to support decision-makers in determining where and when to build new transmission, or to take other related actions to help ensure the Western Interconnection is reliable, low-cost, efficient, and environmentally sound. WECC also released their first 20 Year Transmission plan in 2013 in coordination with the second 10 year plan.

WECC, through the Regional Transmission Expansion Planning (RTEP) committee, is coordinating with the Western Interstate Energy Board and the Western Governors Association to develop the first interconnection-wide transmission plan covering all eleven western states, British Columbia and Alberta. The joint effort will develop long-term, interconnection-wide transmission expansion plans. Each of the four key sub-regional transmission planning groups actively participate in the RTEP effort.


WestConnect is composed of utility companies providing transmission of electricity in the western United States. The members work collaboratively to assess stakeholder and market needs and to develop cost-effective enhancements to the western wholesale electricity market.
Transmission providers established a WestConnect sub-regional planning process by signing the WestConnect Project Agreement for Sub-regional Transmission Planning (STP Agreement).

Columbia Grid

ColumbiaGrid is a non-profit membership corporation formed to improve the operational efficiency, reliability, and planned expansion of the Pacific Northwest transmission grid. It does not own transmission, but its members and the parties to its agreements own and operate an extensive network of transmission facilities. ColumbiaGrid is responsible for transmission planning, reliability, Open-Access Same-Time Information System (OASIS), and other required development services.
Transmission providers define these tasks and provide funding through a series of “Functional Agreements” with members and other participants, including broad public participation.

Northern Tier Transmission Group

The Northern Tier Transmission Group (NTTG) is a group of transmission providers and customers that are involved in the sale and purchase of transmission capacity for the delivery of electricity to customers in the Northwest and Mountain States. NTTG coordinates individual transmission systems operations, products, business practices, and planning of their high-voltage transmission network to meet and improve transmission services that deliver power to consumers. Transmission owners serving this territory work in conjunction with state governments, customers, and stakeholders to improve operations and chart the future of the transmission grid.

California ISO (CalISO)

The ISO manages the flow of electricity across the high-voltage, long-distance power lines that make up 80 percent of California’s and a small part of Nevada’s power grid. The ISO grants access to the power grid and facilitates a competitive wholesale power market. While utilities still own transmission assets and conduct planning, the ISO acts as a traffic controller by routing electrons, maximizing the use of the transmission system and its generation resources, and coordinates regional transmission planning.