How the U.S. energy transition is rewriting the history of electricity 

December 15, 2022

In the 1870s, Thomas Edison began developing a practical application of direct current (DC) to power homes, businesses, and entire cities, including New York City. However, just 10 years later, Edison and George Westinghouse engaged in what became known as the "War of the Currents." They battled over whether DC or alternating current (AC) transmission was the more suitable technology for the large-scale supply of electricity in the U.S. Ultimately, AC power emerged as the supposed winner, and today, electricity is predominantly powered by alternating currents. In recent years, however, DC has experienced a renaissance. The need for power transmission using high-voltage DC (HVDC) transmission is increasing with the growing integration of renewables. Why? HVDC technology plays a fundamentally important role in the energy transition from point-to-point connections over hundreds of kilometers of land, to power connections between different countries, to connecting wind farms on the high seas. It is the most efficient way to transmit power over long distances and a pivotal technology to live up to new challenges in the wake of the U.S.’s ambitious renewable expansion plans.

We have huge modernization tasks ahead of us to increase grid resilience and ensure the grid keeps pace with the accelerating shift toward a renewables-powered U.S. Therefore, governments and industries must review current policy mechanisms and business practices.

Tim Holt

Member of the Executive Board at Siemens Energy


In this section we inform you about planned future projects in the US for which Siemens Energy and its customers has concluded preferred supplier agreements.

TransWest Express selects Siemens Energy as HVDC technology partner

5 December 2022 - TransWest Express LLC has selected Siemens Energy to supply the high-voltage direct current transmission technology for the TransWest Express Transmission Project.The TWE Project is a 732-mile high-voltage interregional transmission system with HVDC and HVAC segments that will connect to the existing grid in Wyoming and Utah as well as directly to the ISO Controlled Grid in southern Nevada.

Siemens Energy and its affiliates are global leaders in HVDC transmission technology products, services and solutions. Under a Preferred Supplier Agreement signed in November, TransWest and Siemens Energy are partners on the final design, specifications and other technical elements of the HVDC converter stations to be located in Carbon County, Wyoming, and in Millard County, Utah. TransWest and Siemens Energy also are negotiating a definitive contract under which Siemens Energy will engineer, procure and construct the HVDC converter stations and ancillary equipment and systems.

Press Releases

Green energy for New York: Siemens Energy will connect state’s first utility-scale offshore wind farm to the grid

27 October 2021 - Siemens Energy has been awarded its first offshore grid connection project in the United States. In a consortium with Aker Solutions, the company will supply the high-voltage direct current (HVDC) transmission system that will bring green energy from Sunrise Wind, New York’s first utility-scale offshore wind project, to the mainland. It’s the first offshore wind project in the U.S. to use HVDC technology. The approximately 924 megawatts wind farm is developed by a joint venture between Danish clean energy company Ørsted and US-based energy provider Eversource. Located about 50 kilometers (30 miles) east of Long Island, Sunrise Wind will supply green energy to nearly 600,000 homes in New York State and support the state to meet its 100 percent clean electricity by 2040 goal.


The World Needs Supergrids, But There's a Problem

For a successful energy transition power grids must be able to move green energy thousands of miles. This documentary from Bloomberg introduces the idea of a continent-spanning grid - and the challenges, such as permitting, that these projects bring. 


Christina Huemmer

Siemens Energy