Tuning of the ESKOM plexos® model for market forecasting, trading and valuation studies.

• This RFI is for the Tuning of the Eskom PLEXOS® Model for Market Forecasting, Trading and Valuation Studies.
• Eskom Distribution is preparing for the competitive multi-market environment (SAWEM), distribution-level trading, and capacity remuneration and flexibility mechanisms.
• Eskom requires specialist support to tune, calibrate and extend its PLEXOS® Integrated Energy Model to trading-grade standard.
• The RFI seeks information from qualified consultants and PLEXOS® implementation partners on capability, methodology, indicative effort and pricing to inform subsequent competitive procurement.

• Closing date for submission: 07 August 2026 at 10h00 South African Standard Time.

• Contact person: Tsepiso Moloi (Assistant Officer Procurement).
• No specific email, phone, or address provided in the extracted text.

• Submit electronically via Eskom E-tendering page: https://etendering.eskom.co.za.
• Closing date: 07 August 2026 at 10h00 South African Standard Time.
• Upload documents in PDF and Excel format only.
• Maximum upload size per document is 500 MB; total submission restricted to 4 GB.
• Do not submit zip/compressed files; no hard copies accepted.
• If resubmitting, only the latest version will be considered; previous submissions become null and void.
• Ensure submission status is marked as complete.
• Refer to the Supplier Help Manual and video on the Eskom E-Tendering page for guidance.

• All documents must be submitted in PDF and Excel format.
• Maximum upload size per document is 500 MB; total submission restricted to 4 GB.

Corporate Capability: Must be a verifiable PLEXOS® implementation partner with minimum 5 years' experience tuning/deploying PLEXOS for ISOs, TSOs, utilities, or large trading houses, with at least 3 referenced projects covering ST, MT, and LT horizons. Team must include certified PLEXOS modellers. Market Knowledge: Demonstrated expertise in competitive electricity multi-markets, capacity remuneration mechanisms (CRMs), PPAs, and the Southern African Power Pool (SAPP), with understanding of SAWEM and NERSA context. Local Content: South African presence or partnership, B-BBEE credentials, and a local skills-transfer plan are evaluated. Commercial Compliance: Must address financial standing, conflict-of-interest, professional indemnity, IP ownership, and POPIA/data security compliance.

Scope of Work:

• Mobilise, audit and design: Review architecture, assumptions, horizons, topology, objects/constraints, datasets, solver/licences, workflows and outputs; identify defects and confirm target architecture, priorities and data responsibilities.
• Tune and extend: Calibrate technical/economic constraints and price formation; parameterise evolving SAWEM/SAPP rules; link LT, PASA, MT and ST workflows and improve runtime without omitting material constraints.
• Back-cast, validate and stress-test: Test normal, scarcity/load-shedding, high-VRE/low-demand and constrained periods. Compare price bias, MAE/RMSE, distributions/duration curves, dispatch, outages, flows, reserves, unserved energy and curtailment; agree tolerances at inception.
• Industrialize and integrate: Build scenario/change sets, batch/API execution, run controls, regression tests, dashboards and data exports to Eskom and the ETRM. PLEXOS is the analytics engine — not the deal-capture, credit, invoicing or dynamic-study system.
• Transfer capability: Train modellers, analysts and traders through shadow studies and administrator/advanced-user training; provide manuals, model governance, change control, a validation calendar and post-implementation support.

Deliverables and Minimum Acceptance:

• Inception and audit pack: roadmap, licence/configuration gap, target architecture, data-responsibility matrix and prioritised backlog.
• Tuned model suite: version-controlled ST/MT/LT models, governed data, assumptions/data dictionary and automated input-output pipeline.
• Executable study packs: templates, scenarios, test cases, runbooks, dashboards and executive outputs for all six capabilities.
• Validation pack: back-cast and stress results, limitations and recommendations; agreed accuracy, completeness and runtime tolerances must be met.
• Full handover: models, source scripts, interfaces, manuals and competency assessment. Eskom requires unrestricted operational use; disclose all third-party restrictions.

Training and Model Support:

• Role-based training curriculum – separate tracks for administrators, modellers, analysts and traders/risk users; foundation, advanced and study-specific modules with assessments and competency certification.
• Shadow-study and on-the-job coaching – Eskom staff paired with the consultant on each capability to co-build, run and interpret studies, with staged transfer of ownership.
• Documentation and knowledge base – user manuals, model governance and change-control procedures, runbooks, worked examples, validation calendar and an internal knowledge base maintained during the engagement.
• Post-implementation support – tiered help-desk, defined SLAs, incident response, model hot-fixes, and quarterly/annual re-calibration and health-check services for a defined support period.
• Continuous improvement – version upgrades, new-feature enablement, and adaptation to evolving SAWEM/SAPP market rules, regulatory changes and Eskom study needs.
• Competency assurance – pre- and post-training assessments, minimum pass criteria, and independent sign-off that Eskom teams can operate the tuned model without ongoing consultant dependency.

• Provide clear methodology for audit, tuning, calibration, back-casting, validation and stress-testing.
• Describe approach to linking LT–PASA–MT–ST workflows.
• Include runtime optimisation without omitting material constraints.
• Agree tolerances for price bias, MAE/RMSE, dispatch and unserved energy.

• Provide indicative effort and pricing model.
• Link payment milestones to deliverables and acceptance.
• Include financial standing, conflict-of-interest declarations, professional indemnity, IP ownership and data-security/POPIA compliance.

• This RFI seeks indicative effort and pricing information.
• Pricing model and payment milestones should be tied to deliverables and acceptance.
• Provide financial standing information.
• Include conflict-of-interest declarations.
• Address professional indemnity, IP ownership, and data-security/POPIA compliance.

• B-BBEE credentials and local skills-transfer plan are required.
• South African presence or partnership is expected.
• No specific tax, CIDB, CIPC, or CSD requirements mentioned in the extracted text.

• Assess curtailment and congestion: quantify hourly/sub-hourly curtailment by cause, node/zone/project and technology (oversupply, minimum stable generation, network congestion, system/security limits, must-run rules).
• Evaluate lost energy/revenue, compensation and mitigation through BESS, demand response, interconnection, network or plant flexibility.

• Demonstrate capability in system marginal-price forecasting: short term at native market interval (intraday, day-ahead, week/month ahead) and medium/long term; produce SMPs, infra-marginal rents, marginal units/fuels, drivers, duration curves, volatility, scarcity and confidence bands.
• Model electricity multi-market: parameterised sequence for day-ahead, intraday, balancing/imbalance and ancillary-service/reserve markets, with bilateral, forward, PPA and SAPP positions.
• Perform PPA and hedge valuation: buyer and seller valuation of physical and financial PPAs (pay-as-produced, baseload/shaped, fixed/escalating/floating, take-or-pay, CfD, floors/caps, storage-linked structures); report NPV/mark-to-market and distributions for shape, volume, basis, imbalance, cannibalisation and curtailment exposure.
• Model demand response and flexibility: elastic and dispatchable demand, aggregator blocks, baselines, availability, notice, duration, rebound/fatigue and non-delivery; quantify price effects and value stacking across energy, balancing, reserves and capacity, including avoided system cost, curtailment and participant value.
• Optimise trading and portfolio risk: gross margin and net power cost across owned/contracted assets, spot, bilateral, forward and cross-border positions; include storage/hydro dispatch, hedge effectiveness, P&L/position outputs, VaR, CVaR/expected shortfall, EaR, stress tests and scenario comparison.
• Deliverables: inception and audit pack; tuned model suite; executable study packs; validation pack; full handover with unrestricted operational use for Eskom.
• Data integration: ability to build scenario/change sets, batch/API execution, run controls, regression tests, dashboards and data pipelines to Eskom systems and the ETRM; version control and model governance; interoperability with existing Eskom data architecture.

• Responses will be scored on evidence provided (referenced projects, methodology, CVs, tools and pricing).
• Weightings are indicative and will be finalised in the subsequent RFI.