Recently, Southwest Power Pool (SPP) released a wave of Markets+ documentation, including the SPP Markets+ Settlements Calculation Guide, updated Markets+ protocols, and technical Application Programming Interfaces (APIs). This marks an important milestone—not because of the depth of the documentation but because of what it represents.
It signals that now is the time for market participants to plan and align their systems, data, and workflows in preparation for Markets+.
We broke down what this shift means and how our team and solutions can help your team begin preparing today for operational success in Markets+.
At roughly 450 pages, the guide lays out the formulas, charge types, and logic defining how settlements will be calculated in Markets+.
Experienced market participants recognize that this level of detail isn’t unusual. Every organized market requires extensive documentation to define how it will determine financial outcomes.
SPP recently published technical APIs for both market and settlement interfaces. The Market APIs enable participants to submit, receive, and manage data regarding energy transactions, ancillary services, and congestion management. Meanwhile, the Settlement APIs facilitate the transfer of financial invoices, charges, credits, and underlying billing determinants.
Markets+ will use Representational State Transfer (REST) APIs for data exchange as opposed to Simple Object Access Protocol (SOAP) APIs, which SPP Integrated Marketplace uses. REST APIs are more modern and facilitate improved performance, enhanced scalability, and more flexible data formats. This means that participants will need to assess how their systems ingest, process, and operationalize market data.
Markets+ is moving from market design into operational execution.
Until now, much of the focus has been on understanding how the market will function: products, participation models, and high-level settlement constructs. The calculation guide, protocols, and technical APIs translate those concepts into precise, testable logic.
That’s where the real work begins.
Organizations must now:
In practice, this is where complexity becomes tangible—it’s a cross-functional challenge spanning market operations, IT, settlements, and finance.
Settlement logic is not static. It evolves with market updates, new charge codes, and ongoing refinements. What starts as a defined set of equations quickly becomes an ongoing operational responsibility that spans multiple teams and systems.
Furthermore, settlement workflows are rarely linear. Data lives in different systems. Logic evolves with market updates. Teams often rely on manual processes or disconnected tools to reconcile outcomes. Over time, that fragmentation introduces risk, delays, and a lack of confidence in results.
This is especially important for utilities and market participants preparing for Markets+.
Initial participation is only one part of readiness. The longer-term challenge is ensuring that settlements can be consistently validated, explained, and trusted.
Teams that plan for this early—by aligning systems, data, and workflows—will be better positioned to manage complexity from day one. Those who don’t may find themselves reacting to issues after they surface in financial results.
The calculation guide, protocols, and technical requirements provide the foundation for how organizations should operate—but translating that into a working validation framework requires more than interpretation.
Solutions like PowerCore’s shadow settlements use this logic to build calculation engines that independently replicate and verify ISO results. By systematically applying the same rules to your own data, teams can identify discrepancies earlier, reduce manual reconciliation effort, and gain confidence that settlement outcomes are accurate and defensible.
If you’re preparing for Markets+, now is the time to evaluate how your organization will operationalize settlements, validation, and ongoing workflows from day one.
To learn how Yes Energy is helping utilities navigate SPP’s complexity—from market data to bid-to-bill operations—explore our Markets+ resource hub.