JAO document reveals fuller NSL rulebook: implicit GB-NO2 short-term coupling detailed alongside explicit long-term FTR-Option auctions, plus 2027 CBAM flow-tariff provision

The primary source is the same Ofgem-approved NSL Access Rules and Charging Methodology (effective 13 Aug 2026) already logged, but the full text now surfaces material content not previously extracted: (1) Part 1 Day-Ahead and Intraday implicit auction rules coupling GB and NO2 bidding zones via NGNSL's appointed power exchange, including ID1/ID2 intraday auction timings, a day-ahead auction closing at 09:50 UK time, a marginal-pricing algorithm description, and a phased move from hourly to half-hourly/15-minute settlement granularity; (2) an explicit provision that NSL flows may become subject to a flow tariff from 1 January 2027 to cover Operators' CBAM compliance costs under EU Regulation 2023/956, calculated per a Norwegian NRA-approved methodology; and (3) granular Part 2 Long-Term Allocation Rules mechanics including two-stage Auction Specification publication timelines, Credit Limit calculation via Maximum Payment Obligation methodology, and detailed Bank Guarantee/cash-deposit collateral specifications (minimum BBB+/Baa1 issuer rating, EUR-denominated).

These details clarify that NSL operates a bifurcated capacity allocation architecture: implicit day-ahead/intraday coupling for short-term physical flow allocation alongside the previously logged explicit long-term FTR-Option auctions for hedging. The newly surfaced CBAM flow-tariff mechanism signals that from 2027 cross-border flows on this GB-Norway link may carry an additional cost component tied to EU carbon border adjustment compliance, a novel interaction between carbon policy and interconnector economics not previously captured. The granular collateral and credit-limit mechanics also clarify the operational barriers to entry and risk-management obligations Registered Participants face when competing for long-term transmission rights.

Interpretively, the coexistence of implicit short-term coupling and explicit long-term explicit auctions on the same interconnector suggests a hybrid design intended to preserve efficient day-ahead/intraday price formation via algorithmic matching while still allowing participants to hedge long-term cross-zonal price risk through FTR-Options — a structure common on other GB-continental links but here documented NSL-specifically. The prospective CBAM flow tariff (from 2027) is presented as conditional ('potentially'), suggesting the Operators have not yet committed definitively to its application, which could affect flow economics and marginal pricing outcomes on the link once EU CBAM rules for electricity imports fully bite. The heavy specification of collateral, credit-limit and Bank Guarantee requirements (with strict counterparty credit-rating thresholds) indicates JAO/NGNSL are prioritizing counterparty risk mitigation over broadening market access, which could constrain participation by smaller or lower-rated entities relative to larger utilities and traders.

NSL Access Rules and Charging Methodology (Parts 1-3), approved by Ofgem and Norwegian regulatory authorities under Applicable Law including GB Grid Code, Balancing and Settlement Code and Norwegian equivalents, EU Regulation (EU) 1227/2011 (REMIT), eIDAS Regulation No.910/2014, Directive (EU) 2015/849 (AML), and European Regulation 2023/956 (CBAM)

Potential application of CBAM-related flow tariff on NSL flows · 1 Jan 2027

Primary sources