Atlantic Offshore Wind Transmission Study

The Atlantic Offshore Wind Transmission Study, co-led by NREL, evaluated coordinated transmission solutions that would enable offshore wind energy deployment along the U.S. Atlantic Coast, addressing gaps in existing analyses.

Floating wind turbines in the ocean with a ship

The Atlantic Offshore Wind Transmission Study identifies and compares different transmission strategies for enabling offshore wind energy deployment along the U.S. Atlantic Coast, from Maine through South Carolina. Ensuring adequate equitable, affordable, and timely transmission access for offshore wind is critical to achieving state clean energy goals as well as the national goal of 30 GW of offshore wind energy by 2030, which would enable the deployment of 110 GW or more by 2050.

Atlantic Offshore Wind Transmission Study

Executive Summary

Full Report

The study evaluated multiple pathways to enable offshore wind energy deployment through coordinated transmission solutions along the U.S. Atlantic Coast in the near term (by 2030) and long term (by 2050) under various combinations of electricity supply and demand while supporting grid reliability and resilience and ocean co-use.

The study fills gaps in prior analyses by providing a multiregional planning perspective that evaluates offshore wind generation development with transmission planning. It incorporates environmental, ocean co-use, and other siting considerations into defining potential offshore transmission routes. The study also compares different multiregional offshore transmission topologies and their associated costs and benefits. In addition, the Atlantic Offshore Wind Transmission Study analyzes reliability impacts from a multiregional perspective.

The study helped inform the Atlantic Offshore Wind Transmission Action Plan. Researchers from NREL and Pacific Northwest National Laboratory conducted the study, funded by the U.S. Department of Energy Wind Energy Technologies Office.

Atlantic Offshore Wind Transmission Study Intraregional, interregional, and backbone topologies — The intraregional, interregional, and backbone topologies investigated in the Atlantic Offshore Wind Transmission Study, each representing different potential offshore networks. *Illustrations by Billy Roberts, NREL*

Project Objectives

The Atlantic Offshore Wind Transmission Study was designed to:

Identify scenarios and pathways of offshore wind energy deployment with transmission topologies (such as radial lines, backbones, or a meshed network), sequencing, and build-out in U.S. Atlantic waters from 2030 through 2050.
Analyze impacts, such as economics, wind curtailment, and reliability, of multiple offshore wind energy and transmission scenarios.
Characterize and compare transmission technologies for the different scenarios, as well as cost and benefit trade-offs for high-voltage alternating current and direct current technologies.
Evaluate operational, environmental, reliability, and resilience considerations of various transmission topologies.
Collect data and develop models that are readily usable by the offshore wind energy industry for conducting analyses and studies.

All activities closely engaged with and drew expertise from a technical review committee, which provided input throughout the project on assumptions, scenarios, and the modeling framework.

Key Findings

Offshore wind energy development provides a unique opportunity to add transmission capacity offshore that provides value to the electric grid. Key findings of the study include:

Offshore wind energy is projected to be a key part of achieving a low-carbon future for Atlantic states.
Offshore transmission can be planned while considering ocean co-uses and environmental constraints.
Benefits of networking offshore transmission come from reduced curtailment, reduced usage of higher-cost generators, and contributions to reliability.
Offshore transmission networks contribute to grid reliability by enabling resource adequacy and helping manage the unexpected loss of grid components (contingencies).
Benefits of offshore transmission networking outweigh the costs, often by a ratio of 2 to 1 or more. Offshore networks with interregional interlinks provide the highest value.
Building offshore transmission in phases can help reduce development risk, but early implementation of high-voltage direct current technology standards is essential for future interoperability.

Frequently Asked Questions

More than one-third of the value of the interregional network could be at risk if technology standards are not developed for projects delivered in 2035. The hypothetical trajectory described in the Executive Summary shows that 4 of the 11 platforms included in the interregional topology are assumed to be built in 2035, and the value from interlinking those points of interconnection would be at risk.

No. We assumed that the export cables would be sized to accommodate the offshore wind generation, and any excess capacity could be used based on optimal usage of interlink and export cables.

There could be circumstances where onshore transmission upgrade requirements could be lower in interlinked topologies. However, as the assumed maximum injections are the same in all topologies we studied, we assumed the same upgrades.

Platforms that are close together, and are connected to different regions, will likely have the highest ratios of benefits to costs. The majority of costs are cable costs and interlinks that connect interregionally demonstrated the largest value. Note that this study uses illustrative points of interconnection, wind energy areas, and interlinks. We also did not study each interlink individually and cannot give direct guidance on which to build first.

No. Our choice to study 85 GW was motivated by modeling efforts, previous work, and discussions with stakeholders. However, economics, grid needs, and siting constraints on land could potentially motivate developers to deploy more than 85 GW of offshore wind energy in the Atlantic by 2050.

Contacts

Technical Lead

Gregory.Brinkman@nrel.gov

Project Manager

Lanaia.Carveth@nrel.gov