Over 11 GW studied in 2022 Cluster Study, almost doubling the 2021 requests

The Cluster Study is BPA’s primary means of processing and offering service to customers with requests for long-term firm transmission service over the BPA network. 

The 2022 Cluster Study was BPA’s largest yet, with 144 transmission service requests studied, comprised of 11,118 MW. Solar, storage and wind projects made up the bulk of requests, as study participants mostly seek to move renewable energy from east of the Cascades and the Mid-Columbia area to Portland and Seattle. 

Renewable mandates such as Oregon House Bill 2021 and Washington’s Clean Energy Transformation Act drove the influx of requests from new generation developers. The resource mix in the 2022 study included a dramatic increase in the amount of solar combined with battery storage. This year also saw a prominent arrival of offshore wind requests amounting to 2,200 MW.

Following completion of the 2022 study, customers representing over seven GW of requests elected to receive next step agreements, allowing these participants to move on to the next phase of the TSR Study and Expansion Process. Through the study process, BPA was also able to offer 130 MW of transmission service, which will generate revenue without needing a transmission build. For customers who elected not to proceed further with the study results, BPA removed those requests from its transmission queue. 

This marks the fourth consecutive year BPA completed a Cluster Study.

Study enhancements

Each year, BPA’s Long-Term Transmission Planning engineers evaluate and select scenarios and sensitivities to determine which constraints may require increased capacity. Refreshing assumptions helps manage the growing complexity of participating transmission requests. 

Speculation is on the rise, as indicated by a significant number of requests submitted from a single generating facility to multiple potential delivery points (Portland area and Seattle area, for example). In this and similar instances, customers intentionally submit transmission requests in excess of the identified generating resource in order to bid into different competitive solicitations for new capacity and energy to meet utilities’ future load needs.

The study teams also dealt with requests from generation developers that did not have associated generator interconnection requests or information. This meant fewer details about the projects were known. The absence of generator interconnection information added significant complexity and time required to study transmission service.

New this year for the 2022 Cluster Study, BPA transitioned its Conditional Firm Service from using a capacity inventory to a power flow based study methodology, providing a more precise determination of Conditional Firm Service capability and conditions. 

“Conditional Firm Service has proven to be a very appealing service option for customers when BPA’s transmission system shows constraints,” said Chris Jones, manager of Long-Term Commercial Planning. “It presents a flexible, scalable transmission solution that also provides transmission revenue benefits.” 

This year, participants representing over 3,600 MW expressed interest in receiving Conditional Firm Service. These changes helped BPA efficiently process requests that far outpaced forecasted load growth for the region. 

TSEP transmission projects

The 2022 Cluster Study identified numerous new transmission reinforcement projects, many of which increase transfer capability in its central network across the Cascade range and between the Seattle and Portland regions. In total, the 2022 Cluster Study identified transmission projects totaling nearly $2 billion in direct capital costs. Additionally, BPA’s planning engineers identified potential impacts to neighboring transmission systems, so these other utilities will need to be consulted, and may identify their own transmission system mitigations.

From previous study cycles, the new Schultz – Raver series capacitor project, first identified in the 2020 Cluster Study and again in the 2021 Cluster Study, was recently greenlit by BPA’s capital approval process. The approval allows BPA to construct the new facilities and award almost 1,600 MW of long-term firm service, connecting generation hubs on the Columbia River in Eastern Washington to load centers in Puget Sound area and other parts of Western Washington. The project has an estimated in-service date of November 2025.

Next steps

Work has begun on next step agreements for customers moving on in the process. This includes Preliminary Engineering Agreements, which refine and clarify project scope and cost estimates, and extend offers for available Conditional Firm Service. These actions will close the book on the 2022 Cluster Study.

Looking ahead, BPA recently posted public notice that it will conduct a 2023 Cluster Study. The deadline for customers to submit eligible transmission requests is Aug. 19, 2022. The 2023 Cluster Study is estimated to begin Jan. 6, 2023.