Project purpose

The TransWest Express Transmission Project will provide the transmission infrastructure and transmission capacity necessary to reliably and cost-effectively deliver approximately 20,000 GWh/yr of clean and sustainable electric energy generated in Wyoming to the Desert Southwest region, which for the purposes of the project is Arizona, Nevada and southern California.

Wind map of the United States
This wind resource map shows the mean annual wind speed measured at 80 meters.
Dark orange represents winds of 8 meters per second, and speeds increase
as the orange-red gets darker. (Map by AWS Truewind)

However, California and Desert Southwest utilities do not have a direct way to access the benefits of Wyoming’s rich renewable energy resources without new transmission lines such as the direct current TWE Project.

The TWE Project will make Wyoming's wind-generated electricity available to utilities to serve citizens in more densely populated regions. This electric power is roughly equivalent to three-fourths of the electric power used in Los Angeles alone. In addition, many experts recognize that providing more connectivity between geographically diverse and complementary renewable resources can help smooth grid operations as the grid grows “greener.” Using Wyoming wind to help fill in the times when California’s wind isn’t blowing or the sun isn’t shining, for example, helps utilities reduce their reliance on traditional peak-priced fuels and therefore helps contribute to California’s GHG emissions reduction goals as well as their renewable energy goals. The bidirectional TWE Project also could provide export capacity for Desert Southwest solar resources, particularly during overgeneration events.

Ultimately, the TWE Project will:

  • Broaden consumers' access to domestic, clean, renewable energy sources.
  • Contribute to meeting national, regional and state energy and environmental policies, including state-mandated renewable portfolio standards and greenhouse-gas reduction targets.
  • Help meet increasing customer demand with improved electrical system reliability.
  • Provide system flexibility and increased access to the grid for third-party transmission users.
  • Expand regional economic development through increased employment and enlargement of the property tax base. (TransWest will pay property taxes in every county the transmission line crosses.)
  • Maintain the standard of living associated with highly reliable electricity service

The need for the TWE Project is supported by numerous studies that have documented the increase in demand for renewable energy resources within the Desert Southwest. For purposes of electric supply reliability, the TWE Project will be built in accordance to standards developed and enforced by the North American Electrical Reliability Corporation and the Western Electricity Coordinating Council.

What else is driving the project's need?

  • Renewable Portfolio Standards. Like many other states, Arizona, Nevada and California have adopted renewable energy standards, commonly referred to as Renewable Portfolio Standards. Legislation in these states require utilities to meet a portion of their overall customer energy supply with renewable energy resources by specific dates. For example, 60 percent of California's electricity supply must come from renewable sources by 2030, and it is California state policy that eligible renewable energy resources and zero-carbon resources supply 100 percent of all retail sales of electricity to California end-use customers and 100 percent of electricity procured to serve all state agencies by Dec. 31, 2045. The TWE Project will deliver about 20,000 gigawatt-hours per year of clean electricity, significantly helping address this demand.
  • Greenhouse-gas reduction mandates. Renewable energy like wind energy helps reduce greenhouse-gas emissions because it requires no fossil fuels and generates zero emissions or pollution. Since many states and the federal government are considering various GHG emission reduction policies, having an increased amount of wind energy available will be vital to achieving GHG goals.
  • Large house with lights on, evening
  • More people, more electricity use. The demand for electricity in the Desert Southwest is expected to grow as the population grows. According to the U.S. Census Bureau, the western U.S. has experienced a population growth of approximately 10 percent from 2000 to 2006. Its projection of population growth between 2000 and 2030 for Arizona, California and Nevada is nearly 50 percent. Arizona and Nevada were identified as the fastest-growing states during this period.
  • Strengthening the transmission grid will promote more efficient sharing of energy resources throughout the western United States. While the TWE Project can transmit wind energy southward from Wyoming, the AC segment also can transmit solar energy generated in the Desert Southwest northward to consumers in the Rocky Mountain region. Because wind energy and solar energy may be generated at different times of day, this ability to move power and share resources can benefit both regions.

In addition, the amount of electricity used per person is also expected to increase due to the continued electrification of day-to-day life: more air-conditioning, computers, high-definition televisions, gaming systems, industrial applications, and electric-powered cars. Even with ongoing energy conservation efforts, the demand for electricity is expected to increase about 2 percent per year in the western United States.

Project-specific highlights

  • Provide for the efficient, cost-effective and economically feasible transmission of approximately 20,000 GWh/yr of clean and sustainable electric energy from Wyoming to markets in the Desert Southwest region.
  • Meet North American Electric Reliability Corporation Reliability Standards and Western Electricity Coordinating Council planning criteria and line separation requirements.
  • Maximize the use of existing and designated utility corridors and access roads in order to minimize environmental and social effects of the TWE Project to the extent practical.
  • Provide these benefits to the Desert Southwest region and the broader Western United States in a timely manner to meet the region's pressing environmental and energy needs. TransWest has identified a need for the TWE Project by the expected in-service date of 2015 or as soon as the regulatory reviews can be completed.
  • Provide for flexibility and maximize the use of transmission capacity that may become available by configuring the TWE Project to allow for future interconnection with the Intermountain Power Project transmission system near Delta, Utah.

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In the news

"(Gov. Dave Freudenthal) said Wyoming residents must accept the fact that power lines are going to cross Wyoming because they are required to transport Wyoming's energy to market."

- Wyoming Business Report story, Jan. 11, 2010