Technical Overview

The TransAmerica Generation Grid (TAGG) is a breakthrough concept to build a high-capacity energy backbone across the United States. TAGG will connect the existing non synchronous eastern and western AC transmission grids through a 500 kV direct current (DC) transmission line between Illinois and California. This pathway will enable transmission of bulk electrical energy to distant load centers from existing and new generation facilities. To meet increased U.S. electrical load growth, TAGG will provide 18,000 MW of new generation that uses abundant, low cost solid fuel reserves and wind energy from the upper west plains states .

Converter stations at each generation site will transform the electrical energy from AC to DC for economical power transfer. At each terminal load center, the electricity will then be converted back to AC for insertion into the existing transmission infrastructure.

TAGG will employ several sophisticated energy management systems to enhance operations and load flows for maximum system efficiencies and revenues.

Transmission Line

The transmission system will consist of three parallel 3,000 MW HVDC lines, running from Southern California through Nevada, Utah, Wyoming, Nebraska, South Dakota, and Iowa before terminating in the Chicago area. The lines will run through the upper Midwest region to capture low cost power generated from wind, coal, and lignite plants in northern Wyoming, Montana, and North Dakota. For added reliability and operating flexibility, a second set of three parallel 3,000 MW HVDC lines will form a loop around the major power generation centers by diverging in eastern Wyoming and rejoining near Pierre, South Dakota (refer to Proposed Transmission Routing and Generation Sites).

In addition to capturing generated electricity further north, the parallel paths and upper Midwest loop of the transmission system will also function as a backstop against interruptions such as line damage due to severe weather.

Generating Facilities

Coal/Lignite

The proposed project is structured around the development of multiple solid fuel generation stations, each composed of four 700 MW (nominal net electric output) generation units that provide 2,800 MW of generation capacity. Because all of the units plan to burn solid fuel from a common source area, each site will be identical in layout. Therefore, the project will create a standardized approach to design, purchasing and construction activities, which will ultimately increase TAGG’s cost-competitiveness. TAGG’s solid fuel generation units will be located at up to six alternative site locations (refer to Proposed Transmission Routing and Generation Sites).

Wind

The wind energy potential in the upper Midwest is supported by wind data collected from regional weather stations and airports. While varying from day-to-day, average annual wind speeds in a given region are consistent and reliable. Development of the region’s wind resources has been prevented primarily by a lack of local and regional markets, and the inability to economically transmit that energy to more populated areas throughout the eastern, southwestern, and western parts of the United States. TAGG will be the first cost-effective means of tapping this vast renewable energy source, and transmitting it to where it is needed.

Approximately 200 MW of wind energy will be developed near each of the solid fuel generation sites. Additionally, TAGG proposes 3,000 MW of wind energy sited near Pierre, S.D.

US Annual Wind Power Resources (source: NREL)

“The total amount of electricity that could be generated from wind in the United States has been estimated at 10,777 billion kWh annually – three times the electricity generated in the United States today.”
(Source: “Wind Energy Fact Sheet,” American Wind Energy Association)