Headquartered in Little Rock, the Southwest Power Pool (SPP) has published the results of its long-awaited Future Energy and Resource Needs Study (FERNS), offering a robust and nuanced view of how the regional power system could evolve through 2050. For stakeholders in the utility-scale renewable energy sector—particularly those focused on wind, solar, storage, and transmission—the FERNS findings reinforce both the opportunity and responsibility that come with accelerating electrification and decarbonization. By 2050, SPP is projected to generate up to 90% of its annual energy from renewable resources—demonstrating that high clean energy penetration is both technically feasible and economically sound. During some periods, SPP is already managing a nearly 90% renewable energy grid.
A Forecast Grounded in System Needs and Economic Efficiency
FERNS asks the fundamental question: What is the most cost-effective way to meet SPP’s long-term system needs under various decarbonization and electrification futures? Using a dynamic, hourly simulation model and coordinating with SPP’s Integrated Transmission Planning (ITP) and Consolidated Planning Process (CPP) teams, the study examines five scenarios across multiple decades. The results are clear: SPP can maintain reliability affordably—without significant rate impacts—through strategic investment in renewables, storage, and transmission.
Key Takeaways for the Renewable Industry
1. Large-Scale Buildout, Especially Solar + Storage
Between 60–180 GW of new wind and solar capacity will be needed by 2050. Notably, solar significantly outcompetes wind on a capacity basis in most scenarios, with 42–130 GW of solar additions expected versus 20–48 GW of new wind. This solar growth is tightly coupled with a projected need for 22–59 GW of battery storage, often co-located.
2. $88–$263 Billion in Generation Investment
FERNS estimates that up to $263 billion in new generation capital will be needed depending on the scenario—primarily solar and storage. Yet, thanks to load growth, tax credits, and fuel cost savings, total system costs per MWh remain flat or only modestly increase, even in high-investment pathways.
3. Transmission is Essential
To deliver low-cost renewables from high-resource areas (notably the Southern and Central SPP zones) to load centers, 4–21 GW of new interzonal transmission will be required. This aligns with the regional imperative for integrated long-range transmission planning and underscores the economic rationale for proactive, multi-value grid investments.
4. Reliability Depends on Winter Resilience and Diverse Supply
FERNS highlights evolving resource adequacy challenges, particularly during winter peaks and post-sunset hours. Even with high renewables penetration, fossil resources continue to supply 40–60% of accredited capacity in 2050. This reinforces the value of a balanced portfolio that includes firm dispatchable resources, interregional transfers, and eventually, longer-duration storage.
5. Land Availability and Regional Advantages
SPP's geography remains a strategic asset. FERNS confirms that land availability is not a barrier to renewable expansion—even under high-deployment scenarios. The region's high-quality solar and wind resources, paired with export capability, position SPP to become a net exporter of clean energy by mid-century.
Implications for the Southeast
While SPP’s footprint does not include SREA's southeastern states directly, the trends outlined in FERNS carry critical implications:
- Transmission Interconnection: With MISO South and Entergy operating in Arkansas, Louisiana, and Mississippi, SREA members should track FERNS-aligned regional transmission expansion closely. Strategic interties between MISO, SPP, and the Southeast can unlock export opportunities and resilience benefits.
- Policy Framing: The FERNS narrative supports a market- and reliability-centered case for renewables, emphasizing affordability, private investment, and infrastructure modernization—critical themes for engagement in statehouses and regulatory commissions.
- Resource Adequacy Reform: The study’s dynamic resource adequacy methodology—focused on hourly risk and weather variability—could influence future resource accreditation and planning reserve margin frameworks across the country. This is particularly relevant for stakeholders engaging in IRPs or capacity accreditation discussions in vertically integrated states.
Looking Ahead
SPP's FERNS is a powerful blueprint for how a regional transmission organization can lead on future system planning. It demonstrates that renewables, when integrated with thoughtful transmission expansion and reliability planning, are not just compatible with resource adequacy—they are central to it.
For SREA members, FERNS offers not only a modeling framework but a roadmap for articulating the value of utility-scale renewables and transmission expansion in the Southeast’s evolving grid landscape.
Download materials on SPP’s FERNS study, here!
Want to explore how FERNS insights could inform SREA’s policy strategy in the Southeast? Contact SREA to discuss partnership opportunities, and complete our survey.
