NorthWestern Energy (South Dakota) Rate Selection Guide
NorthWestern Energy's South Dakota division serves roughly 65,000 electric and 180,000 gas customers across eastern South Dakota (plus Nebraska gas). As a fully regulated investor-owned utility under the South Dakota PUC, it provides billing and interval data through its My Energy Account portal and specialized programs for property managers and large key accounts.
NorthWestern Energy (South Dakota) Rate Schedule Comparison
| Schedule | Type | Rate | Best For |
|---|---|---|---|
| Rate 24 | commercial | Customer charge $8.00 + ~$0.08077/kWh total (all kWh) | Small to mid-size commercial without demand metering |
| Rate 25 | commercial | Customer charge $17.00 + demand-indexed energy blocks (~$0.061-$0.177/kWh) | Demand-metered commercial customers |
| Rate 33 | industrial | ~$16.71/kW demand + tiered energy (~$0.047-$0.106/kWh) | Large commercial/industrial, single demand block |
| Rate 34 | industrial | Tiered demand ~$13.70-$16.71/kW + tiered energy (~$0.041-$0.090/kWh) | Largest industrial loads |
| Rate 16O | agricultural | Customer charge $55.00 + demand ~$154.38 + ~$0.07720/kWh | Agricultural irrigation |
Market Overview
South Dakota is a fully regulated, vertically integrated market. NorthWestern Energy is the exclusive provider of bundled electric and gas service in its certificated territory, with rates and tariffs approved by the South Dakota Public Utilities Commission. There is no competitive retail supplier choice.
Need to pull your actual usage data to compare rates? See the NorthWestern Energy (South Dakota) Data Access Guide →
Current Rate Schedules
NorthWestern Energy's South Dakota electric rates are regulated by the SDPUC and published in the South Dakota Electric Rate Schedule, with a tariff summary effective May 1, 2026. A 2024-2025 rate review settlement produced an electric revenue increase of about $21.52 million (~11.4%), phased into rates. C&I bills combine a fixed customer charge, demand charges ($/kW) for demand-metered schedules, tiered energy charges ($/kWh), and an Electric Fuel & Purchased Power Adjustment (about $0.02876/kWh as of May 2026).
Effective: May 1, 2026 · Full Tariff Book →
| Schedule | Type | Applicability | Structure | Rate |
|---|---|---|---|---|
| Rate 23/24 — General Service | commercial | Small to mid-size commercial customers without large demand metering. | Fixed customer charge ($8.00) plus an all-kWh energy charge (Rate 24 base ~$0.03288/kWh; ~$0.08077/kWh total with transmission, ad valorem, phase-in, and fuel adjustments as of 5/1/2026). | — |
| Rate 25 — General Service (Demand) | commercial | Commercial customers with demand metering (block-by-demand energy pricing). | Customer charge $17.00; energy priced in demand-indexed blocks (first 100 x demand ~$0.17723/kWh total, declining to ~$0.06142/kWh over 300 x demand), inclusive of transmission, ad valorem, phase-in, and the ~$0.02876/kWh fuel adjustment (5/1/2026). | — |
| Rate 33 — Large General Service | industrial | Large commercial/industrial customers, single-block demand. | Demand charge ~$16.71/kW (all kW, including transmission and ad valorem) plus tiered energy charges (~$0.10612/kWh for the first 100 x demand declining to ~$0.04740/kWh over 500 x demand) with the fuel adjustment (5/1/2026). | — |
| Rate 34 — Large General Service (Tiered Demand) | industrial | Largest industrial customers with tiered demand blocks. | Tiered demand: ~$16.71/kW (first 100 kW), ~$15.20/kW (next 400 kW), ~$13.70/kW (over 500 kW); tiered energy ~$0.08963/kWh declining to ~$0.04103/kWh, plus fuel adjustment (5/1/2026). | — |
| Rate 16O — Irrigation / Power Service | agricultural | Agricultural irrigation and similar seasonal power loads. | Customer charge $55.00 with a demand charge increasing to ~$154.38 and an all-kWh energy charge (~$0.07720/kWh total) as of 5/1/2026. | — |
Rate Recommendations by Use Case
Small to mid-size commercial site (office, retail)
General Service (Rate 24) customers should track usage and watch whether demand metering changes their best schedule.
Rate 24's flat ~$0.08/kWh suits low-demand sites; rising usage may justify a demand schedule.
- Use Detailed Energy Usage to monitor monthly trends
- Enable e-bill for record-keeping
- Re-evaluate schedule if demand metering is added
Demand-metered commercial facility
Rate 25 customers should focus on flattening load to push energy into lower demand-indexed blocks.
Rate 25 prices energy in declining blocks tied to demand, so improving load factor lowers the blended rate.
- Identify and stagger peak equipment startups
- Pull interval data to target peak windows
- Track the ~$0.02876/kWh fuel adjustment in budgeting
Large industrial / manufacturing plant
Large loads should choose between Rate 33 and Rate 34 based on demand profile and prioritize peak shaving.
At ~$13.70-$16.71/kW, demand charges dominate; Rate 34's tiered demand can favor very large, steady loads.
- Engage a Key Account Manager for custom load analysis
- Consider storage or process scheduling to cut coincident peak
- Model Rate 33 vs. 34 against your demand block distribution
Agricultural irrigation operation
Seasonal irrigation loads should evaluate Rate 16O and manage the seasonal demand and minimum charges.
Rate 16O carries a $55 customer charge and a demand charge rising to ~$154.38, so seasonal scheduling matters.
- Schedule pumping to limit coincident demand
- Account for the increased minimum-season charge
- Track the fuel adjustment in seasonal budgets
Historical Rate Trends
NorthWestern Energy filed a South Dakota electric rate review in 2024; a settlement approved by the SDPUC reduced the requested increase and phased it into rates, with the latest tariff summary effective May 1, 2026.
July 1, 2025
Settlement-approved electric revenue increase (~$21.52M, ~11.4%) begins phasing in via the phase-in rate rider.
+11.4%May 1, 2026
Updated SD electric rate tariff summary effective; demand and minimum-season charges increase across several schedules.
varies by scheduleOverall trend: Rising — the 2024-2025 settlement raised electric revenue and is being phased in via a rate rider.
Next expected change: Future SDPUC rate proceedings; monitor the South Dakota Rate Review page for the next filing.
Cost Optimization Strategies
Because South Dakota C&I bills are dominated by demand charges and block-priced energy, the main levers are peak demand reduction, selecting the right demand schedule, and using interval data to manage load. There is no supply-shopping lever in this regulated market.
Peak demand reduction
For: Demand-metered Rate 25/33/34 customers
Use the Detailed Energy Usage tool (or Key Account custom reports) to find peak intervals and shave coincident demand; demand charges of ~$13.70-$16.71/kW make peak kW the dominant cost.
Right-size the rate schedule
For: Growing or load-factor-variable C&I sites
Compare General Service (Rate 24), demand Rate 25, and large general service Rates 33/34 against your load factor; high-load-factor sites often benefit from a demand schedule's lower energy blocks.
Improve load factor / off-peak shifting
For: Sites with shiftable or batch processes
Flatten the load profile so demand-indexed energy blocks fall into lower-priced tiers and average $/kW demand cost drops.
Engage a Key Account Manager
For: Largest commercial/industrial accounts
Top-25 SD/NE customers can get custom load reports, demand-response guidance, and demand-management support from a dedicated manager.
To implement these strategies, you need your 15-minute interval data. Learn how to download NorthWestern Energy (South Dakota) interval data →
Frequently Asked Questions
Does NorthWestern Energy support Green Button or an API for South Dakota data access?▾
No. Neither Green Button Download My Data nor Connect My Data is implemented, and there is no documented public API or EDI program. The Detailed Energy Usage tool offers a manual download in a proprietary format. Large customers should contact Key Account Services to discuss custom data integration.
How can a commercial customer get interval usage data?▾
Log in to My Energy Account, open Billing then View Detailed Usage, choose hourly/daily/weekly/monthly and a date range, and use the blue download button. The export is manual and proprietary; for automated or higher-frequency data, top-25 SD/NE accounts can request custom reports through a Key Account Manager.
Which South Dakota rate schedule applies to my commercial or industrial facility?▾
Small commercial loads typically take General Service (Rate 23/24). Demand-metered general service falls under Rate 25, and large general service uses the demand-and-energy Rate 33 or Rate 34. As of the May 1, 2026 tariff, large general service demand charges are roughly $13.70-$16.71 per kW depending on the kW block, plus tiered energy charges and the fuel/purchased-power adjustment.
Can I choose a competitive electricity supplier in NorthWestern Energy's South Dakota territory?▾
No. South Dakota is a fully regulated, vertically integrated market. NorthWestern Energy provides bundled supply and delivery, and the SDPUC sets all rates — there is no retail supplier choice for electric or gas.
How can a property manager access usage across multiple buildings?▾
Enroll in a Continuous Service Agreement (CSA) with NorthWestern Energy and register the CSA portal. It provides up to 24 months of usage per address, account balances, and an Excel export covering all managed properties for portfolio analysis.
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