The 3.5GW SunZia Wind facility, thought to be the largest onshore wind project in the Western Hemisphere, is being constructed across Torrance, Lincoln, and San Miguel Counties in New Mexico. The power it generates will be routed from New Mexico to south-central Arizona via the 3000 MW SunZia Transmission bi-directional HVDC link, a 550 mile (885 km) ±525 kV connection. Pattern acquired the link development project from SouthWestern Power Group, a wholly owned subsidiary of MMR Group, in 2022. SunZia Transmission had previously awarded the full 3 GW of capacity on the transmission line to Pattern Energy.

“It feels great to be through the financing and on to the build”, said Hunter Armistead, CEO of Pattern Energy, speaking at CERAWeek in Houston in March. But currently “the pace of load growth is like nothing we have ever seen” and future such projects must not take 16 years to get to this point, as SunZia has.

Talking about lessons learned from his experience of getting the project over the line to the build phase, he said “collaboration is key”, for example, with NGOs, local communities, lenders and contractors. He particularly recommends “having a deep and early partnership with the people who are actually going to build it” and having “personal relationships that go all the way up to the most senior levels of those contractors.” For a very large project such as SunZia this becomes “developing a relationship of mutually assured destruction”, ie “this deal either happens or we all fall down.”

For SunZia, the wind turbines are being supplied by Vestas and GE Vernova and the HVDC technology supplier is Hitachi Energy. The EPC contractor for the transmission line is Quanta Infrastructure Services Group and for the wind project is Blattner Energy, a Quanta-affiliated company. SunZia Transmission and Pattern Energy have partnered with the New Mexico Renewable Energy Transmission Authority (RETA) on the development of the New Mexico part of the transmission line.

As to wind turbine selection, Hunter Armistead said the project had “ended up basically with turbines nearly designed perfectly for our site.” He noted that the “turbine world has gone through a tough time” and costs have gone up significantly, contributing to SunZia project cost escalation. “But we went in early with both our vendors, and we started talking about exactly what [the SunZia] wind resource is…it’s very low turbulence, very consistent flow, but relatively high altitude…And so we worked with both vendors.” Initially “they both wanted the whole thing, but I think in the end they were real happy with the way it worked out, two-thirds to one [GE] and one-third to the other [Vestas].”

Vestas is supplying 242 of its V163-4.5MW wind turbines, its “newest high-capacity factor” machine, totalling 1089 MW of installed capacity.

The Vesta’s scope includes commissioning of the turbines, as well as a multi-year Active Output Management 5000 (AOM 5000) service agreement, designed to ensure optimised performance.

This is Vestas’ first onshore order of more than 1 GW in the US market and follows its recent commitment to invest $40m in its US domestic footprint to manufacture the V163-4.5MW turbine.

The V163-4.5 MW turbine is based on Vestas’ proven 4MW platform and leverages an established supply chain. The design takes into account US conditions, the company notes, addressing transportation, installation, and operational aspects to support the rapid deployment of wind energy in response to growing demand.

GE Vernova supplies 674 of its 3.6-154 “next-generation workhorse turbines” with an installed capacity of 2.4GW.

“The project is a great example of how the policy certainty created by the IRA [Inflation Reduction Act] is helping to drive significant investments in the US wind power market,” said Scott Strazik, CEO of GE Vernova

According to Vic Abate, CTO GE and CEO, GE Vernova’s Wind business, “This project demonstrates GE Vernova’s ability to deliver on our workhorse strategy in onshore wind – producing fewer variants in large quantities…to drive quality and reliability across the fleet.”

Designed specifically for the USA, the 3.6-154 delivers “the highest efficiency in the market,” according to GE Vernova, “with an optimised size for ease of logistics and installation”, as well as reduced complexity. It is a machine that can be delivered and installed rapidly relative to larger turbines and is for example compatible with commercially available construction cranes in the vicinity of SunZia.

GE Vernova notes that the 3.6-154, “built on the back of the 2.8-127”, is the result of three years of R&D and is “the most tested and validated wind turbine in GE’s history.”

GE Vernova says it has collaborated with Pattern on SunZia to “optimise site layouts and performance while minimising unnecessary variants – following GE Vernova’s workhorse philosophy.”

The SunZia project will be supplied through GE Vernova’s nacelle facility in Pensacola, Florida, as well as tower manufacturing facilities in Belen, New Mexico, Pueblo, Colorado, and Amarillo, Texas, reinforcing its focus on “taking full advantage of the Inflation Reduction Act.”

Among previous Pattern projects for which GE Vernova has supplied wind turbines is Western Spirit, located over four sites in central New Mexico, with a total installed capacity of 1050 MW. This employs 377 turbines of various sizes in the range 2.3-2.7 MW, mainly 2.7 MW turbines with rotor diameters of 127 m. It entered service in 2022, supplying power to the existing grid in northwest New Mexico via a 241 km long 345 kV AC line.

SunZia Transmission will use some of the same corridors as the Western Spirit transmission line.

For SunZia Transmission, which gives SunZia Wind access to markets in Arizona and California, Hitachi Energy is supplying HVDC Light plus other advanced technologies.

At 3000 MW, the HVDC Light system will be the largest voltage source converter (VSC) installation in the USA and one of the largest worldwide, as well as one of the USA’s longest HVDC connections.

The link will run between Corona, New Mexico and Pinal County, Arizona, with a converter station at each end.

Hitachi Energy has partnered with Quanta Services, Inc. to develop a turnkey solution for the SunZia transmission project, including managing the HVDC construction and building installation at the associated project sites. The collaboration with Quanta is designed to leverage the core competencies of the two companies to deliver “a best-in-class solution for the project.”

Hitachi Energy has also signed a multi-year agreement with Pattern Energy to support the HVDC technologies it is supplying, including scheduled maintenance, cyber services, on-site engineering support and life cycle assessment of the HVDC Light converter stations.

The HVDC converter stations are expected to be in service by the end of 2025 to support the final testing and commissioning of the SunZia Wind facilities in 2026.

To find the optimal solution that considers the impact of the new facility on the existing grid, a system study and a comprehensive interconnection and system impact analysis were conducted by Hitachi Energy´s consultants.

Hitachi Energy is also supplying ‘AC chopper’ technology to help restore power if the power flow on the DC line or in the AC grid in Arizona is temporarily interrupted by weather and other contingency events.

This article first appeared in Modern Power Systems magazine.