NERSA's April 2026 network charge rules have replaced South Africa's obsolete 2012 wheeling methodology, introducing use-of-system charges for both generators and loads and removing the affordability subsidy credit from wheeled energy — changes that raise the wheeling cost floor and force C&I buyers to rebuild every delivered-price PPA model before signing.

The Regulatory Ground Has Shifted — And Your PPA Model Probably Hasn't Caught Up

If your commercial or industrial energy procurement team is still pricing wheeled solar PPAs against a pre-April 2026 cost stack, you are almost certainly underestimating your all-in delivered tariff floor. NERSA's publication of its finalised regulatory rules on network charges for third-party wheeling is not a procedural footnote — it is the most consequential rewrite of wheeling cost architecture South Africa has seen in over a decade, and every C&I buyer with an in-flight or recently signed delivered-price PPA needs to rerun the numbers now.

What NERSA Actually Published — and Why the 2012 Rules Are Now Dead

NERSA published its regulatory rules on network charges for third-party wheeling of energy on 15 April 2026, including the methodologies for developing both transmission and distribution use-of-system (UoS) charges. The significance of this is hard to overstate: the transmission and distribution tariff codes developed by NERSA mean the methodologies described in the 2012 rules are now obsolete.

The existing rules, introduced in 2012, governed the pricing of network access and energy transportation across transmission and distribution systems. However, those rules had become outdated due to new tariff codes and failed to cover aspects such as grid access and contractual agreements. Put simply, twelve years of market evolution — from small rooftop exemptions to multi-hundred-megawatt cross-jurisdictional wheeling deals — had outgrown the regulatory scaffolding. April 2026 replaced it entirely.

UoS Charges Now Apply to Both Generators and Loads

One of the most commercially impactful changes is the explicit application of use-of-system charges on both sides of the wheeling transaction. The amended rules are intended to determine applicable charges for the use of the system by both generators and loads connected to the transmission and/or distribution network.

Use-of-system charges are designed to recover the costs associated with the use of and making capacity available on an electricity network. These charges are the unbundled regulated tariffs, charged by the network service provider for making transmission or distribution capacity available to generators and loads. Critically, both the generator and the buyer shall pay all charges associated with the third-party wheeling transaction.

This double-sided cost structure fundamentally changes the economics of a wheeled PPA. An IPP that previously absorbed only generation-side grid costs must now account for network charges as a generator; a C&I off-taker that assumed its UoS obligations were limited to its existing retail tariff must now understand exactly how those charges interact with the wheeled energy credit mechanism and the underlying network tariff structure.

The Affordability Subsidy Credit Is Gone for Wheeled Energy

Perhaps the single most immediately pocketbook-relevant change for C&I buyers is the removal of the affordability subsidy credit on wheeled energy. Wheeling customers must now fairly contribute to inter-tariff subsidies through the removal of the affordability subsidy credit for wheeled energy. Wheeling customers must now fairly contribute to inter-tariff subsidies, with the affordability subsidy credit for wheeled energy removed.

In practical terms, this means the effective delivered cost of wheeled energy is higher than it appeared in models built even six months ago. Any PPA that baked in a subsidy credit as a cost offset has been repriced upward by the regulator — with no grandfathering mechanism for existing models that haven't yet reached financial close.

Non-Bypassable Charges: The Floor Beneath the Floor

The April 2026 rules also land alongside NERSA's broader trading rules framework, which introduces a non-bypassable charge (NBC) architecture. All grid-connected customers must pay these charges regardless of supplier, to ensure cost recovery for network, capacity, and policy costs. An IPP with a direct wheeling PPA to a customer faces the same volume restrictions, the same contestable customer thresholds, the same NBC framework, and the same reconciliation and reporting obligations as a licensed trader.

NERSA describes the rules as a critical regulatory instrument for governing retail electricity trading activities during the transition to a competitive market, aimed at ensuring competitive neutrality, preventing uneconomic bypass of network and policy-related costs, and protecting consumer interests. The phased implementation of retail competition introduces contestability for consumers and establishes mechanisms such as non-bypassable charges, volume restrictions, and wheeling arrangements — measures intended to balance the development of a competitive market with the financial sustainability of the electricity supply industry.

Loss-Adjusted Pricing Transparency Is Now a Compliance Requirement

The new rules also tighten the reconciliation and transparency obligations that sit inside every wheeling billing cycle. Rules for physical and virtual wheeling now include loss adjustments, reconciliation, and billing frameworks. All settlement and billing processes must be transparent, auditable, and applied fairly across all network users. Customers will receive an invoice from the network service provider for total metered consumption at the full applicable tariff, while generators or traders will issue a separate invoice for wheeled energy delivered under bilateral agreements.

This creates both an opportunity and an obligation for C&I buyers: the opportunity to demand granular, loss-factor-adjusted unit pricing transparency from their IPP or trader counterparty, and the obligation to ensure their own metering and data infrastructure can support the reconciliation requirements the rules now mandate.

What This Means for Behind-the-Meter BESS Economics in Q4 2026

The April 2026 rules do more than reprice wheeled PPAs — they recalibrate the competitive baseline against which behind-the-meter BESS displacement economics are measured. South Africa's renewable energy market currently presents two key investment areas for C&I users: large-scale solar PV and wind with associated BESS, and behind-the-meter solar PV with BESS for commercial and industrial users. The typical BESS-to-solar ratio in the C&I sector is 0.21 MWh of storage for every 1 MW of solar PV.

As wheeled PPA delivered costs rise to reflect the full UoS charge stack — generator-side charges, load-side charges, NBCs, and the removal of the subsidy credit — the gap between wheeled-and-delivered tariffs and behind-the-meter generation narrows. For sites where grid infrastructure allows it, behind-the-meter solar and BESS remain the most bankable route to electricity cost certainty. The competitive wholesale market will eventually compress grid tariffs, but the transition period — likely five or more years — means tariff risk is very real today. On-site generation locks in a known cost per kWh for 20 years.

Three Things Every C&I Energy Buyer Must Do Before Year-End

Rebuild your delivered-price model from scratch. Any all-in PPA price built on pre-April 2026 wheeling cost assumptions is obsolete. Re-model generator UoS charges, load UoS charges, NBC components, and loss adjustments as separate, additive line items — not a blended wheeling levy.
Demand loss-factor and billing transparency from your IPP or trader. The new rules give you the regulatory basis to require granular, auditable billing. Use it. Insist on time-of-use-period-level reconciliation statements, not aggregate monthly credit notes.
Reassess your behind-the-meter BESS sizing against the new wheeling floor. As wheeled energy costs rise, peak-shaving and self-consumption BESS dispatch strategies improve in relative return. Re-run BESS displacement economics using the post-subsidy-credit delivered tariff as your grid avoidance benchmark — the payback period will likely be shorter than your existing model shows.

The April 2026 rules are not a temporary adjustment — they are the permanent cost architecture of South Africa's emerging competitive electricity market. C&I buyers who rebuild their PPA models around this new floor will make better procurement decisions. Those who don't will sign contracts at prices that leave value on the table — or, worse, lock in delivered prices that become commercially uncompetitive the moment the next tariff cycle begins.