Mid-South Electric Cooperative Association Rate Selection Guide
Mid-South Electric Cooperative Association serves about 41,300 electric members in rural South Central Texas, uniquely operating in both ERCOT and MISO wholesale markets and running a Virtual Peaker DERMS with 600+ smart thermostats. Customer data access is limited to the online portal and MSEC mobile app — no Green Button, API, or EDI programs are documented for retail customers.
Market Overview
MidSouth operates in both ERCOT and MISO wholesale footprints while serving members as a traditional distribution cooperative. Retail members do not shop for competitive suppliers through the cooperative; the dual-market position primarily affects wholesale cost management (hence the DERMS deployment).
Need to pull your actual usage data to compare rates? See the Mid-South Electric Cooperative Association Data Access Guide →
Current Rate Schedules
MidSouth Electric Co-op bills by rate class — residential, Commercial Service (CS), Large Commercial Service (LCS, secondary or primary voltage), and street lighting. Every bill has three components: a Wholesale Power Cost adjustment that floats (debit or credit) with generation fuel costs, a per-kWh Energy Charge covering distribution from substation to meter, and a Service Availability minimum charge. The co-op's published rate calculator shows a small commercial account paying about $0.0939/kWh energy plus a $41.15 single-phase availability minimum. Large commercial rates add demand billing — see the MidSouth Tariff PDF for current LCS charges.
Effective: January 1, 2025 · Full Tariff Book →
| Schedule | Type | Applicability | Structure | Rate |
|---|---|---|---|---|
| Commercial Service (CS) | commercial | Small commercial accounts — shops, offices, small farms taking single- or three-phase secondary service. | Availability charge ($41.15/month single-phase minimum), Energy Charge of $0.0939/kWh, and Wholesale Power Cost adjustment that can be a debit or credit (e.g., -$0.003/kWh in the co-op's published example). No demand charge. | $0.0939/kWh + WPC adjustment |
| Large Commercial Service (LCS) | commercial | Larger commercial and industrial accounts with measured demand, served at secondary distribution voltage. | Availability charge, demand charge per billing kW, energy charge per kWh, and Wholesale Power Cost adjustment. See the MidSouth Tariff PDF for current demand and energy charges. | —+ Per-kW demand billing applies; see tariff for current rates |
| Large Commercial Service — Primary Voltage (LCS-P) | industrial | Industrial-scale loads taking service at primary distribution voltage and owning their own transformation. | Same structure as LCS with reduced charges reflecting primary-voltage delivery (customer owns transformers, lower line losses). See tariff for current rates. | —+ Per-kW demand billing at primary-voltage rates; see tariff |
| Street & Security Lighting | commercial | Municipal street lighting and member security lights. | Flat monthly charge per fixture by lamp type, plus Wholesale Power Cost adjustment on associated kWh. See tariff for current fixture rates. | — |
Rate Recommendations by Use Case
Small commercial — retail, offices, agricultural shops
Small businesses without significant demand bill under Commercial Service (CS) with a flat $0.0939/kWh energy charge and no demand component.
CS billing is simple: availability minimum, flat energy rate, and a Wholesale Power Cost line that floats with fuel markets. Because WPC can swing either direction, month-over-month bill changes usually trace to that line rather than usage.
- Separate the WPC line from the energy charge when analyzing bill trends — it is the volatile component
- Compare against LCS once peak demand grows; high-load-factor accounts may pay less under demand billing
- Use MidSouth's online rate calculator to model bills before expanding load
Manufacturing, gins, and processing facilities
Demand-metered industrial loads in the Navasota-area territory take Large Commercial Service with per-kW demand charges.
Under LCS, the monthly kW peak drives a meaningful share of the bill, so demand management is the primary cost lever. MidSouth also runs a demand response program (600+ smart thermostats today) and participates in ERCOT markets, signaling openness to flexible-load arrangements.
- Stagger motor and compressor starts to cap the billing-period kW peak
- Ask MidSouth about demand response enrollment for curtailable load
- Verify whether a demand ratchet applies in the current tariff before adding seasonal load
Large industrial loads at primary voltage
Facilities able to take 3-phase primary service and own their transformation qualify for the primary-voltage LCS rate.
Primary-voltage delivery shifts transformation cost to the customer in exchange for lower per-unit charges — typically worthwhile for loads in the hundreds of kW and up with long planning horizons.
- Run a lifecycle comparison: transformer ownership and maintenance cost vs. secondary-rate premium
- Coordinate with MidSouth's commercial services team early — new large-load interconnections need engineering review
- Confirm power factor expectations; primary-metered accounts are commonly billed on kVA or PF-adjusted kW
Cost Optimization Strategies
MidSouth's three-part bill structure (availability charge, energy charge, floating Wholesale Power Cost) plus demand billing on LCS accounts creates several levers: peak management, WPC-aware budgeting, rate-class optimization as load grows, and the co-op's own demand response program.
Peak demand management on LCS accounts
For: Large Commercial Service (secondary and primary)
Sequence equipment starts, manage HVAC recovery, and consider controls or storage to cap the monthly billing kW that drives the LCS demand charge.
Demand response participation
For: Commercial accounts with flexible HVAC or process load
MidSouth manages 600+ smart thermostats for demand response and participates in ERCOT/MISO markets. Curtailable C&I load can enroll to earn value while reducing the co-op's wholesale peaks.
Wholesale Power Cost tracking
For: All rate classes
The WPC line floats with fuel costs and can be a debit or credit. Track it separately in budgets and bill audits so usage-driven changes aren't confused with fuel-market swings.
Rate-class review as load grows
For: Growing commercial accounts near the demand-metering threshold
Accounts straddling the CS/LCS boundary should compare flat-energy CS billing against LCS demand billing annually; high-load-factor operations often save under LCS, peaky ones under CS.
Voltage-level optimization
For: Industrial loads of several hundred kW and above
Large loads can cut per-unit costs by taking primary-voltage service and owning transformation — evaluate against equipment and maintenance costs.
To implement these strategies, you need your 15-minute interval data. Learn how to download Mid-South Electric Cooperative Association interval data →
Frequently Asked Questions
Can C&I customers get interval data from Mid-South Electric Cooperative?▾
Not through any self-service channel. AMI deployment is underway, but the portal exposes no interval download and granularity is unpublished. Contact Member Services at (936) 825-5100 or memberservices@midsouthsynergy.com, specify the granularity (15-min, 30-min, hourly) and format you need, and expect a manual process.
Does MidSouth support Green Button, APIs, or EDI for retail customers?▾
No. There's no Green Button DMD/CMD, no ESPI implementation, no public API or developer sandbox, and no documented retail EDI trading partner program. MidSouth's ERCOT TX SET and MISO EDI activity is wholesale-market only — not a retail customer data channel.
How does a consultant request data on behalf of a MidSouth member?▾
Via the customer consent model: get a written authorization letter naming your firm with account numbers and scope, submit it to memberservices@midsouthsynergy.com or (936) 825-5100, and specify data types, timeframe, frequency, and format. Expect acknowledgment in 2-3 business days and processing in 5-10.
Why does MidSouth operate in both ERCOT and MISO?▾
Its South Central Texas territory straddles the two wholesale markets — unusual for a cooperative. That dual position drove the 2024 Virtual Peaker DERMS deployment, which manages 600+ smart thermostats for demand response and wholesale cost management across both markets.
What billing data is available in the MidSouth portal?▾
Current bills, 12+ months of billing history, usage history, balances, and alerts at billing.midsouthsynergy.com/onlineportal, plus the MSEC mobile app with usage graphs. Bills save as PDF through the browser only — there's no CSV/XML bulk export.
Automate Mid-South Electric Cooperative Association Rate Analysis with Nectar
Nectar continuously monitors your Mid-South Electric Cooperative Association rate options and alerts you when a better schedule is available. Save 10-30% on energy costs.
Nectar for Energy & Sustainability Teams
Managing utility costs for commercial or industrial buildings? Nectar offers a free rate analysis — we'll review your current rate schedules and identify where switching tariffs or shifting load can save 10-30%.
Get a Free Rate AnalysisNectar for Energy Brokers & Consultants
Advising clients on rate optimization? Nectar works with energy consultants who need reliable interval data and automated rate comparison tools.
Partner with Us