Mississippi Power Company Rate Selection Guide
Mississippi Power Company is a Southern Company investor-owned electric utility serving roughly 192,000 customers across southeastern Mississippi. C&I customers access billing via the online portal and EDI (810/820/997), with daily AMI usage data through My Power Usage; Green Button and a public API are not offered.
Mississippi Power Company Rate Schedule Comparison
| Schedule | Type | Rate | Best For |
|---|---|---|---|
| GS-HV-17 | Commercial | Base + per-kVA demand + energy (see tariff) | Mid-size high-voltage commercial |
| LGS-LV-13 | Commercial | Per-kVA demand + tiered energy | Large low-voltage commercial |
| LGS-HV-13 | Industrial | Per-kVA demand + tiered energy + delivery-voltage credit | High-load-factor industrial |
| LPO-TOU-17 | Industrial | Time-of-use demand + energy | Largest loads with shiftable operations |
Market Overview
Mississippi Power operates as a regulated monopoly under MPSC oversight. There is no retail electric choice or community choice aggregation in Mississippi. C&I customers manage cost through tariff selection (e.g., LGS vs. time-of-use), demand management, and applicable riders rather than supplier shopping.
Need to pull your actual usage data to compare rates? See the Mississippi Power Company Data Access Guide →
Current Rate Schedules
Mississippi Power's C&I rate schedules became effective June 18, 2025 and are filed with the MPSC. Large C&I service is demand-based, billed on a per-kVA billing requirement (with ratchet provisions) plus tiered energy charges that decline as hours-use of demand increases, plus base/customer charges and the Fuel Cost Recovery (FCR), Environmental Compliance Overview (ECO), and other adjustment clauses. Specific cents-per-kWh and per-kVA figures vary by schedule and are published in each tariff sheet; the representative figures below illustrate the LGS-HV rate structure (from a prior filed version) and should be verified against the current LGS-HV-13 sheet.
Effective: June 18, 2025 · Full Tariff Book →
| Schedule | Type | Applicability | Structure | Rate |
|---|---|---|---|---|
| General Service - High Voltage (GS-HV-17) | commercial | Commercial/industrial three-phase service at greater than 600 volts, below the Large General Service threshold. | Base charge plus per-kVA demand charge and energy charges; subject to FCR, ECO, and other MPSC adjustment clauses. Per-unit figures published in the filed tariff sheet. | — |
| Large General Service - Low Voltage (LGS-LV-13) | commercial | Large commercial customers taking service at low voltage (600 volts or below) with substantial demand. | Demand-based: monthly base charge, per-kVA billing-requirement charge (with summer ratchet/minimums), and tiered energy charges declining by hours-use of demand; FCR/ECO and other clauses added. | — |
| Large General Service - High Voltage (LGS-HV-13) | industrial | Large industrial/commercial customers served at high voltage (greater than 600 volts), generally up to ~40,000 kVA. | Monthly base charge (~$1,050 in prior LGS-HV-9 version), per-kVA billing-requirement charge (~$7.25/kVA prior version, with 75% summer ratchet and 500 kVA minimum), tiered energy charges (~2.36¢ then 2.11¢ then 0.77¢ per kWh by hours-use in prior version). Transmission-voltage delivery credit applies. Verify against current LGS-HV-13 sheet. | — |
| Large General Service Time-of-Use (LGS-TOU-18) | industrial | Large general service customers electing time-of-use pricing to shift load off peak. | Time-differentiated demand and energy charges with on/off-peak periods; rewards load shifting. Per-unit figures in the filed tariff sheet. | — |
| Large Power Time-of-Use (LPO-TOU-17) | industrial | Largest power customers (industrial loads) electing time-of-use service. | Time-of-use demand and energy charges for large industrial loads; demand ratchets and adjustment clauses apply. Per-unit figures in the filed tariff sheet. | — |
Rate Recommendations by Use Case
High-load-factor industrial facility (high voltage)
Industrial sites operating steadily benefit most from high-voltage large general service, where tiered energy charges decline sharply at high hours-use of demand.
The lowest energy tier applies above 400 hours-use of demand, rewarding flat, high-utilization load shapes; a transmission-voltage delivery credit further reduces cost for sites taking 115kV+ service.
- Take service at the highest practical voltage to capture the delivery-voltage credit
- Maximize load factor to reach the lowest energy tier
- Watch the 75% summer demand ratchet when planning shutdowns
Large commercial with peaky load (low voltage)
Low-voltage large commercial sites with variable demand should evaluate LGS-LV-13 against time-of-use, and prioritize demand management.
Per-kVA demand charges with a summer ratchet make peak control the largest lever; time-of-use can help if load can shift off peak.
- Install demand monitoring tied to the 15-minute peak window
- Stagger large equipment startups
- Model TOU vs. standard LGS using interval data from an aggregator
Multi-location C&I needing automated billing
Multi-site operators should automate invoice intake via EDI and consolidate data through an aggregator.
EDI 810/820 removes manual PDF handling and integrates with AP/ERP; aggregators normalize data across sites and Southern Company utilities for benchmarking.
- Enroll EDI via edisupp@southernco.com
- Use Nectar's API (docs.nectarclimate.com) for cross-site normalization
- Reconcile FCR/ECO rider charges monthly
Largest industrial loads electing time-of-use
The largest power customers that can shift load should evaluate LPO-TOU-17 to capture off-peak energy pricing.
Time-of-use pricing rewards shifting energy out of the on-peak window; large loads see meaningful savings when production schedules are flexible.
- Quantify shiftable load before electing TOU
- Coordinate the on-peak window with operations
- Re-evaluate annually against standard LGS schedules
Historical Rate Trends
Mississippi Power's retail rate schedules are filed with the MPSC and adjusted periodically through base-rate proceedings and pass-through clauses (Fuel Cost Recovery, Environmental Compliance Overview, System Restoration Rider, Performance Evaluation Plan). The most recent standard-application schedules took effect June 18, 2025.
June 18, 2025
Current standard-application C&I rate schedules (LGS-LV-13, LGS-HV-13, GS-HV-17, LGS-TOU-18, LPO-TOU-17) effective per the MPSC index.
N/AOverall trend: Periodic adjustments via the Performance Evaluation Plan and fuel/environmental clauses; the current standard schedules are effective June 18, 2025.
Next expected change: Subject to annual PEP and fuel/environmental clause updates filed with the MPSC
Cost Optimization Strategies
Because Mississippi Power C&I bills are demand-driven with summer ratchets, the highest-impact strategies target peak kVA and load factor. Voltage level, tariff selection, and time-of-use election are the main controllable levers in this regulated market.
Peak demand management
For: All demand-billed C&I (LGS-LV/HV, GS-HV)
Monitor the 15-minute demand window and stagger large loads to lower billing kVA, mindful of the 75% summer ratchet.
Improve load factor
For: High-utilization industrial loads
Flatten consumption to push more kWh into the lowest energy tier (above 400 hours-use of demand).
Optimize service voltage
For: Large high-voltage customers
Take service at the highest practical voltage to earn the transmission-voltage delivery credit and avoid step-down losses.
Time-of-use election
For: Large loads with shiftable operations
Shift flexible load off peak under LGS-TOU-18 or LPO-TOU-17 where production schedules allow.
To implement these strategies, you need your 15-minute interval data. Learn how to download Mississippi Power Company interval data →
Frequently Asked Questions
Does Mississippi Power support Green Button or a public API for C&I data?▾
No. Mississippi Power does not offer Green Button Download My Data, Connect My Data, or a public developer API. For programmatic access, C&I customers typically use EDI 810 for billing or Nectar's API — see docs.nectarclimate.com.
How can a C&I customer automate utility invoices?▾
Enroll in EDI through Southern Company EDI support (edisupp@southernco.com). Mississippi Power supports EDI 810 invoices, 820 payments, and 997 acknowledgements in ANSI X12 v4010 over the Harbinger VAN, which integrates with ERP and accounts-payable systems.
What interval granularity is available for commercial accounts?▾
AMI meters are deployed territory-wide, but customer-facing tools (My Power Usage) resolve to daily intervals with some hourly breakdowns. There is no standardized 15-minute interval export; third-party APIs such as Nectar can provide normalized interval data where supported.
How does a consultant access a client's Mississippi Power data?▾
There is no OAuth third-party portal at the utility. Consultants either use customer-shared portal credentials, receive authorized EDI 810 invoices, or use Nectar's API (docs.nectarclimate.com) to receive normalized bill and usage data.
Which rate schedules apply to large commercial and industrial customers?▾
Large C&I customers typically take service under Large General Service (LGS-LV-13 low voltage, LGS-HV-13 high voltage), the time-of-use options LGS-TOU-18 and LPO-TOU-17, or General Service High Voltage (GS-HV-17). These are demand-based (per-kVA) schedules filed with the Mississippi PSC effective June 18, 2025.
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