Southern Company (SO)

Regulated Footprint, Nuclear Overhang

Southern Company is the regulated Southeast plus large-project risk case. State-regulated electric and gas utility rate base was about $60 billion on a Q2 2025 investor-relations plan-base (projected to $72 billion by 2029; no consolidated 10-K total is filed), with management targeting 9% growth through 2030. FY2025 adjusted EPS was $4.30 against an 8% long-term growth target through 2030.

Vogtle Units 3 and 4 sit in Georgia Power's rate base after completion. The path there consumed years of capex and regulatory scrutiny before earned ROE caught up to allowed. For the regulated comp set, Southern pairs Southeast wires-and-poles scale with a completed nuclear megaproject.

Business Overview

Southern operates Georgia Power, Alabama Power, Mississippi Power, and Southern Company Gas across the Southeast. The ~$60 billion plan-base is state-regulated electric and gas utility rate base from the Q2 2025 IR deck, not a single consolidated line from the 10-K. Treat it as a management planning anchor, labelled explicitly, when comparing dollar bases to Duke's $103.1 billion regulated earnings base or Dominion's $48.2 billion filed rate base. The rate base guide explains why issuers use different labels and which figures are filed vs plan-base.

Georgia Power's 10.50% authorised ROE is a settlement-band name above the 9.70% industry median, comparable to FPL's 10.80% midpoint. Alabama at 9.60% and Mississippi at 9.85% bracket the median from below and above. The allowed vs earned ROE guide uses Southern's Georgia ROE as the above-median jurisdictional example.

Vogtle Units 3 and 4 are in Georgia Power's rate base after completion. Construction risk is largely behind the project, but O&M, fuel, and depreciation on new nuclear plant flow through customer bills and regulatory proceedings. Earned ROE in the Vogtle ramp years sat below allowed because of the lag between capital placed in service and full rate recovery.

How Regulated Utility Economics Work Here

The regulated EPS build on Southern's plan: 9% rate-base CAGR through 2030, blended allowed ROEs centred on Georgia's 10.50%, and industry-average equity ratios support high-single-digit regulated earnings growth. Management's 8% adjusted EPS CAGR through 2030 is slightly below the mechanical rate-base growth because of financing costs, parent expenses, and tax effects.

FFO-to-debt (funds from operations against debt, the sector's core credit metric) at 14.8% matches Duke exactly and sits inside the 14%–16%+ range this site uses as its investment-grade (IG) credit convention. With 9% rate-base CAGR, Southern is at the edge of the equity-issuance watch (RB CAGR >9% with FFO/debt near the floor) but 14.8% clears the 50 bps cushion above ~14%, so credit passes the screen without much headroom.

Dividend payout near 68% on a derived basis uses calendar 2025 dividends of $2.94 ($0.72 + 3 × $0.74) against adjusted EPS of $4.30. There is no stated payout policy band in the filed figures comparable to Duke's 60%–70%; the ratio is toward the upper end of typical utility practice, leaving less retention than American Electric Power at ~63% against a 50%–60% target.

Valuation Framework

Southern's 9% rate-base CAGR and Georgia's 10.50% allowed ROE, above the 9.70% industry median, are the two inputs the P/E-premium framework weighs against Duke's ~9.6% CAGR and 9.8%–10.3% ROE range on a like-for-like Southeast comparison. The P/E premium guide uses the D vs DUK calibration pair; the primer's Valuation Summary sheet extends it to Southern.

On the 10 June 2026 close, the share price divided by FY2025 adjusted EPS of $4.30 gave a trailing P/E of about 22.0x, on a market capitalisation of roughly $105.6 billion.

Sum-of-the-parts adds limited value because the regulated opcos dominate. The analytical split is Georgia (Vogtle) versus Alabama and Mississippi versus gas distribution; Southern carries no major non-regulated earnings slice like NextEra's NEER.

Key Risks

Vogtle operating risk. Nuclear O&M, outage duration, and capacity factor drive earned ROE on the largest capital investment in company history. Allowed ROE does not protect against operational underperformance until regulators act.

Georgia regulatory cycle. The 10.50% ROE set point is favourable; the next rate case or cost-of-capital review could reset it. Load growth in Georgia supports capex plans but also invites scrutiny of customer bill impacts.

Plan-base rate-base figure. The ~$60 billion base is a management planning figure rather than a consolidated 10-K line. Peer comparisons on dollar rate base require label discipline; growth rates are more comparable than absolute dollars.

Payout and capex. ~68% payout against 9% rate-base growth leaves thinner retained earnings than lower-payout peers. FFO/debt at 14.8% leaves little cushion if Vogtle O&M surprises or storm costs spike.

What the Screening Shows

Against the Regulated Utilities Sector Primer thresholds:

• Rate base: ~$60B state-regulated plan-base (Q2 2025 IR); 9% CAGR through 2030; label differs from filed consolidated totals.
• Allowed ROE: Georgia Power 10.50% above median; Alabama 9.60% near median. Jurisdictional dispersion within one holding company.
• EPS growth: 8% through 2030 off $4.30 adjusted. Faster than Duke's 5%–7%, slower than NextEra's 8%+.
• FFO/debt: 14.8%. Pass on IG screen; watch zone with 9% RB CAGR.
• Payout: ~68% derived. Upper end of typical utility range; no stated policy band.

The open question is whether 8% EPS growth and 14.8% FFO/debt fund the next capex wave at 9% rate-base CAGR without equity issuance. Vogtle construction risk is largely behind the project; Georgia's 10.50% allowed ROE and Southeast load growth set the regulated earnings path from here.