Research & Development


The electric power industry is evolving rapidly. SPP and its members are serving customers with unprecedented levels of renewable energy resources. These variable resources introduce new technical, planning and operational challenges for reliability.

For example, wind, solar and battery storage are connected to the grid by high-voltage, direct-current power electronics. The rapid deployment of these new technologies, combined with a decreasing percentage of traditional thermal generation, affects grid strength, the ability to control frequency and the grid’s resilience against high impact events like ice storms, heat waves and tornadoes.

SPP’s research department leverages expertise from members, consultants, universities, Department of Energy laboratories, research institutions and other system operators. Together, we are safely and reliably integrating new technologies to the grid and taking advantage of the capabilities they bring for grid reliability and operations.

SPP participates in research with the following organizations: EPRIPSERCIEEEPower and Energy SocietyGRAPES.


SPP’s staff of 600+ professionals have the talent and training to maintain a reliable and economic bulk electric system. SPP analyzes the skills we need for the future and trains and hires to meet the challenges of tomorrow.

Our development program explores and evaluates new planning tools and methods and creates and new training sessions and programs. Our research also leads to new policy development that enhances member value. All of this creates a more efficient and effective SPP, and helps us prepare for the challenges and opportunities of the future.

Development Programs: Engineering-U | Engineering Development Program | Engineering Rotation Program | P.E. Test Preparation | Biennial Technical Expo

Inverter-Based Generation Integration Study (IBIS)

The strength of our bulk electric grid is changing due to an increase in inverter-based resources (IBR). SPP commissioned a study to evaluate the effect of IBR on grid short-circuit ratio and on the need to coordinate controls between IBR and conventional generation to maintain frequency control.

The Electric Power Research Institute (EPRI) used the Grid Strength Assessment Tool to screen potential locations for weak grid conditions that could cause IBR control instability. EPRI performed its Electromagnetic Transient Program analysis on an identified group of variable generation resources. Please see the study for details and recommendations and presentation for overview.

Grid Studies

There are four separate alternating current (AC) electrical grids in the United States and Canada: the Western Interconnection (WI), Eastern Interconnection (EI), the Texas Interconnection managed by the Electric Reliability Council of Texas (ERCOT) and the Quebec Interconnection.

These interconnections span four time zones, have dispersed geographic wind and solar energy potential and a high diversity of load. A total of nine high-voltage, direct-current (HVDC) ties between the interconnections allow a limited, bidirectional transfer of power between the EI and WI, and between the EI and ERCOT. Numerous studies have been conducted to examine opportunities to expand existing transmission capacity and to allow low-cost power to be delivered between markets, across interconnections, from coast to coast.

Studies of increased transmission capacity have considered multiple options to allow greater interregional transfers of electric power, including:

  • Bypassing existing HVDC ties with AC transmission.
  • Increasing existing HVDC ties capacity.
  • Adding HVDC transmission links.
  • Constructing a HVDC multi-terminal overlay.

Each of these options would require substantial AC transmission upgrades to reliably transport energy from the new inverter based resources, which is typically in remote areas, to large load centers across the continent. To learn more, see some recent AC and HVDC national grid studies below:

Note: Southwest Power Pool does not express endorsement for non-SPP reference material

AC Western and Eastern Interconnection Studies

  • Shetye, Overbye, Li, Thekkemathiote and Scribner (IEEE): Considerations for Interconnection of Large Power Grid Networks (on IEEE Explore)

    Abstract: "Interconnection i.e. the wide-area synchronous operation of large power systems using AC interties has provided opportunities to improve system reliability and better connect the ever-increasing renewable generation locations to load centers. While some of these goals are achievable with DC ties, ac connections and synchronous operation have unique advantages as well as certain challenges that need to be carefully studied. This paper aims to highlight the key issues that need to be considered in assessing the feasibility of the synchronous interconnection of large power grids, with a focus on dynamics. To provide realistic results without revealing confidential information about the actual grid, the paper makes use of synthetic grid models for the US Eastern and Western Interconnect footprints."

  • Overbye and Shetye (PSERC Publication 21-02): Feasibility Assessment of Synchronous Operations of the North American Eastern and Western Interconnections (on PSERC)

    Key finding: “The key limiting characteristic on interconnecting the EI and WI is that during generator loss contingencies in the WI, approximately 75 to 80% of the lost power will flow through the Interface from east to west. This is due to the governor response that takes place uniformly through the interconnect and most of the generation is east of the Interface.… The grids are stable when AGC response is considered.”

  • Overbye, Shetye, Wert, Trinh and Birchfield (2020 North American Power Symposium): Techniques for Maintaining Situational Awareness During Large-Scale Electric Grid Simulations 

High-Voltage DC Interconnection Studies

  • Department of Energy (DOE) National Renewable Energy Laboratory (NREL): Interconnection Seam Study

    Key finding: “The power system can balance generation and load. Additional transmission enabled lower total installed capacities, especially in the High VG scenario. There are substantial positive benefit-cost ratios for increasing the transfer capability between the interconnections. Cross-seam transmission has a substantial impact on the location of wind and solar generation additions. Wind shifts to the Eastern Interconnection and solar to the Western Interconnection.”

  • DOE NREL: North American Renewable Integration Study (NARIS)

    Description: NARIS is analyzing pathways to modernize the North American power system which includes Canada, Mexico, and the United States through the efficient planning of transmission, generation and demand. Please visit the provided webpage link for more study details and contact information.

Have questions or comments? SPP’s Request Management System (SPP RMS) is the preferred method for inquiries and data submissions. Click on this link and then “Register Now” if you are not already registered.