{"id":"great-britain","rid":"GB","name":"Great Britain","flag":"🇬🇧","group":"europe","type":"market","parent":null,"regions":null,"tier_range":null,"tier":4,"tier_name":"Constrained","score":41,"pillar_score":44,"pillar_tier":4,"pillar_tier_name":"Constrained","reliability":{"assessed":true,"level":"watch","dock":3,"provisional":false,"confidence":"Med-High","delivery_transmission":{"level":"watch","measure":"measured","note":"Transmission-level Energy Not Supplied was 359 MWh in 2024/25 against a regulated incentive neutral point of 147 MWh, so the operator missed its reliability target by roughly 2.4 times on the measure Ofgem actually holds it to. Average network availability was 99.9998%. For a large load the target miss is the signal: bulk supply is highly available but the trend on the regulated measure moved the wrong way.","sources":[{"label":"National Grid Electricity Transmission RIIO-T2 reliability performance","url":"https://www.nationalgrid.com/electricity-transmission/who-we-are/riio-t2-performance/safe-and-reliable-network"}]},"delivery_distribution":{"level":"none"},"forward_capacity":{"level":"watch","measure":"assessed","note":"Winter margins are wind-dependent and have been tight in the past, though the 2025/26 base-case margin of 6.1 GW (about 10%) is the strongest since 2019/20, helped by storage, gas availability and the Greenlink interconnector.","sources":[{"label":"NESO winter 2025/26 margins","url":"https://www.neso.energy/neso-sets-out-expectations-strongest-winter-electricity-margins-six-years"}]},"read":"Minor flags found","level_means":"reviewed; flags found"},"reliability_dock":3,"regulatory_momentum":{"level":"mixed","direction":"improving","why":"NESO's TMO4+ reform is issuing Gate 2 offers and reordering a roughly 96 GW queue toward first-ready-first-connected, targeting historic waits of up to 15 years.","what_would_change_it":"Firm pre-2030 connection offers materialising at scale for new large loads.","scope":"The regulatory and permitting environment for connecting a new large load. An opinion on a dated record, not a measurement.","vocabulary_version":"regulatory-momentum-1.0","beyond_the_grid":{"text":"Land and water permitting is contested even as access improves: ministers have approved hyperscale sites on green belt land, but a 90 MW Buckinghamshire approval was quashed in 2026 after the government admitted a serious error over power and water concerns, and data centres have now been folded into the centralised NSIP planning regime.","sources":[{"label":"Leigh Day","url":"https://www.leighday.co.uk/news/press-releases/2026-news/government-admits-to-serious-error-as-permission-granted-for-legal-case-opposing-hyperscale-data-centre-in-buckinghamshire/"},{"label":"The Register","url":"https://www.theregister.com/on-prem/2026/07/07/uk-guts-planning-red-tape-so-datacenters-can-bypass-the-neighbors-faster/5266865"}]},"for_new_supply":"NESO's first-ready-first-connected reform is issuing Gate 2 offers against a roughly 96 GW queue, so a ready generation project can now advance."},"scheduled_changes":[{"date":"H2 2026","event":"Next NESO connections application window opens","why":"The route to a Gate 2 offer under the reformed queue; its timing gates when a new large load can enter.","source":{"label":"NESO connections reform","url":"https://www.neso.energy/industry-information/connections-reform/connections-reform-results"}},{"date":"2030","event":"First reform-era firm demand connections targeted","why":"NESO estimates about 13 GW of firm demand can connect before 2030, with more between 2030 and 2035.","source":{"label":"NESO connections reform","url":"https://www.neso.energy/industry-information/connections-reform/connections-reform-results"}}],"queue":{"active_gw":283,"wait_months":null,"has_detail":true,"wait_band":"4-5 years"},"friction":null,"connection_pathway":{"operator":"National Energy System Operator","role":"system operator","process":"Connections reform, Gate 2 application","note":"Demand connection terms are mid-reform and the reform reaches existing offers; distribution-level demand is in scope.","url":"https://www.neso.energy/industry-information/connections"},"service_evidence":{"contractual_service_held":true,"local_capacity_state":"published_checkable","local_capacity_depth":4,"cost_basis":"triangulated","territory_count":0},"reliability_metrics":{"saidi_min":39.71,"saidi_year":"2024/25","forward_adequacy":null,"measure":"historical utility-territory delivery performance","standard":null,"standard_note":null,"evidence_role":"market_context","by_serving_utility":[],"evidence_role_basis":"Ofgem all-DNO average across the fourteen GB licence areas"},"forward_cost":{"level":"Low","price":"£27.10 per kW-year","period":"2029/30 (T-4)"},"tariff":null,"realized_cost":{"low_usd_per_mwh":118,"mid_usd_per_mwh":138,"high_usd_per_mwh":168,"aggregation":"band","estimate_usd_per_mwh":null,"estimate_kind_note":null,"total_derivation":"compiled_band_allocated_across_categories","total_derivation_note":"The band is the compiled result and the component lines apportion its midpoint, which is why they sum exactly.","tariff_basis":null,"scenarios":null,"confidence":"triangulated","public_fragments":3,"contributed_points":0,"basis":"USD per MWh recurring, delivered to the standard 100 MW high-load-factor case, excluding customer-funded connection capital and excluding refundable taxes","cost_components":[{"name":"Wholesale energy","usd_per_mwh":75,"source":null,"provenance":{"provenance_state":"estimated_allocation","provenance_state_label":"Estimated allocation","provenance_state_means":"Apportioned from a compiled total or midpoint by analyst judgement. Not independently calculated, and not corroborated by anything outside the band it came from.","derivation":"allocation_of_compiled_midpoint","derivation_note":"This line apportions the compiled midpoint. Its value was not separately observed.","source_of_band_not_line":"UK electricity price components (IEA Electricity 2026)","source_url_of_band_not_line":"https://www.iea.org/reports/electricity-2026/prices","band_as_of":"2026","customer_applicability":"100 MW contracted demand, 95% load factor, HV service","band_confidence":"triangulated","as_of":"2026","method":"analyst apportionment of the compiled midpoint across categories","confidence":"allocation","confidence_note":"Apportioned from the compiled delivered-cost midpoint by analyst judgement. Not separately observed.","covers_categories":["energy"],"corroborated_by":null,"state_vocabulary_version":"provenance-state-1.0","what_would_upgrade_it":"A separately sourced figure for this category with its own date, method and confidence. Until then the band's provenance establishes the total only, not this line.","version":"line-provenance-1.1"},"evidence":"estimated_allocation"},{"name":"Network charges","usd_per_mwh":33,"source":null,"provenance":{"provenance_state":"estimated_allocation","provenance_state_label":"Estimated allocation","provenance_state_means":"Apportioned from a compiled total or midpoint by analyst judgement. Not independently calculated, and not corroborated by anything outside the band it came from.","derivation":"allocation_of_compiled_midpoint","derivation_note":"This line apportions the compiled midpoint. Its value was not separately observed.","source_of_band_not_line":"UK electricity price components (IEA Electricity 2026)","source_url_of_band_not_line":"https://www.iea.org/reports/electricity-2026/prices","band_as_of":"2026","customer_applicability":"100 MW contracted demand, 95% load factor, HV service","band_confidence":"triangulated","as_of":"2026","method":"analyst apportionment of the compiled midpoint across categories, covering transmission, distribution in one line","confidence":"bundled_allocation","confidence_note":"Apportioned, and covering more than one cost category in a single line. Neither the total nor the split within it was separately observed.","covers_categories":["transmission","distribution"],"corroborated_by":null,"state_vocabulary_version":"provenance-state-1.0","what_would_upgrade_it":"A separately sourced figure for this category with its own date, method and confidence. Until then the band's provenance establishes the total only, not this line.","version":"line-provenance-1.1"},"evidence":"estimated_allocation"},{"name":"Policy & levies","usd_per_mwh":18,"source":null,"provenance":{"provenance_state":"estimated_allocation","provenance_state_label":"Estimated allocation","provenance_state_means":"Apportioned from a compiled total or midpoint by analyst judgement. Not independently calculated, and not corroborated by anything outside the band it came from.","derivation":"allocation_of_compiled_midpoint","derivation_note":"This line apportions the compiled midpoint. Its value was not separately observed.","source_of_band_not_line":"UK electricity price components (IEA Electricity 2026)","source_url_of_band_not_line":"https://www.iea.org/reports/electricity-2026/prices","band_as_of":"2026","customer_applicability":"100 MW contracted demand, 95% load factor, HV service","band_confidence":"triangulated","as_of":"2026","method":"analyst apportionment of the compiled midpoint across categories","confidence":"allocation","confidence_note":"Apportioned from the compiled delivered-cost midpoint by analyst judgement. Not separately observed.","covers_categories":null,"corroborated_by":null,"state_vocabulary_version":"provenance-state-1.0","what_would_upgrade_it":"A separately sourced figure for this category with its own date, method and confidence. Until then the band's provenance establishes the total only, not this line.","version":"line-provenance-1.1"},"evidence":"estimated_allocation"},{"name":"Capacity market","usd_per_mwh":12,"source":null,"provenance":{"provenance_state":"estimated_allocation","provenance_state_label":"Estimated allocation","provenance_state_means":"Apportioned from a compiled total or midpoint by analyst judgement. Not independently calculated, and not corroborated by anything outside the band it came from.","derivation":"allocation_of_compiled_midpoint","derivation_note":"This line apportions the compiled midpoint. Its value was not separately observed.","source_of_band_not_line":"UK electricity price components (IEA Electricity 2026)","source_url_of_band_not_line":"https://www.iea.org/reports/electricity-2026/prices","band_as_of":"2026","customer_applicability":"100 MW contracted demand, 95% load factor, HV service","band_confidence":"triangulated","as_of":"2026","method":"analyst apportionment of the compiled midpoint across categories","confidence":"allocation","confidence_note":"Apportioned from the compiled delivered-cost midpoint by analyst judgement. Not separately observed.","covers_categories":null,"corroborated_by":null,"state_vocabulary_version":"provenance-state-1.0","what_would_upgrade_it":"A separately sourced figure for this category with its own date, method and confidence. Until then the band's provenance establishes the total only, not this line.","version":"line-provenance-1.1"},"evidence":"estimated_allocation"}],"component_status":{"arithmetic_integrity":true,"evidence_reconciliation":"not_independently_reconciled","independently_sourced_lines":0,"total_lines":4,"bundled":[],"text":"The delivered-cost band is the compiled result. The component lines are an estimated allocation of its midpoint, not separately observed figures.","provenance_summary":{"by_state":{"estimated_allocation":4},"usd_by_state":{"estimated_allocation":138},"evidenced_share_pct":0,"lines_awaiting_evidence":["Wholesale energy","Network charges","Policy & levies","Capacity market"],"what_would_close_them":"A separately sourced or tariff-derived figure for each category, with its own date, method and confidence. Until then the band's provenance establishes the total only, not these lines.","version":"provenance-state-1.0"},"category_coverage":{"energy":{"status":"estimated","line":"Wholesale energy","missing_evidence":"An independently sourced wholesale or tariff energy figure with its own date, method and confidence."},"capacity":{"status":"unavailable","missing_evidence":"No capacity or resource adequacy figure is held for this market."},"transmission":{"status":"bundled","line":"Network charges","combined_with":["distribution"],"line_is_sourced":false,"line_provenance_state":"estimated_allocation","source":null,"source_url":null,"effective":null,"formula":null,"missing_evidence":"A separate transmission figure, or a sourced apportionment of the Network charges line."},"distribution":{"status":"bundled","line":"Network charges","combined_with":["transmission"],"line_is_sourced":false,"line_provenance_state":"estimated_allocation","source":null,"source_url":null,"effective":null,"formula":null,"missing_evidence":"A separate distribution figure, or a sourced apportionment of the Network charges line."},"demand_charges":{"status":"unavailable","missing_evidence":"No demand charges figure is held for this market."},"ancillary":{"status":"unavailable","missing_evidence":"No ancillary services and uplift figure is held for this market."},"riders":{"status":"unavailable","missing_evidence":"No riders and unavoidable regulatory charges figure is held for this market."},"carbon":{"status":"unavailable","missing_evidence":"No carbon-related charges figure is held for this market."},"taxes":{"status":"unavailable","missing_evidence":"No recurring taxes figure is held for this market."},"connection_capital":{"status":"not_applicable","reason":"Outside the recurring $/MWh boundary by definition."}},"category_vocabulary_version":"cost-categories-1.0","capacity_cross_check":null,"method_version":"cost-components-1.0"},"component_source":["UK electricity price components (IEA Electricity 2026)","https://www.iea.org/reports/electricity-2026/prices"]},"cost_availability":{"label":"Standardized cost observable","means":"A comparable recurring-cost band can be built from observable, applicable inputs for the standard archetype.","user_action":"Use the band, with its stated confidence and boundary.","class":"standardized_observable","band_published":true},"cost_evidence_state":{"state":"applicable_evidence_incomplete","answerable":"conditionally","label":"Applicable, evidence incomplete","means":"The archetype can buy the service and the band is sound, but some published figures do not yet carry their own source, date, method and confidence.","remedy":"Finish the per-line provenance. No new access or negotiation is required.","also_holds":[],"vocabulary_version":"evidence-state-1.0"},"jurisdiction_evidence":null,"cost_structure":null,"cost_withdrawn":null,"cost_correction":null,"carbon_correction":null,"carbon_official_reference":null,"partial_cost_verified":null,"cost_pillar_calculation":null,"evidence":{"source_reliability":"High","coverage":"Full","coverage_dimensions":3,"last_reviewed":"June 2026","measured_layers":3,"data_layers":4,"layers":[{"layer":"PGIQ Rating opinion","method":"opinion","vintage":"June 2026","freshness":"Current","source_url":"https://powergridiq.com/methodology"},{"layer":"Reliability","method":"measured","vintage":"2024/25","freshness":"Fresh","source_url":"https://www.ofgem.gov.uk"},{"layer":"Forward cost","method":"measured","vintage":"2029/30 (T-4)","freshness":"Fresh","source_url":"https://timera-energy.com/blog/gb-t-4-auction-clears-at-27-kw-following-multiple-years-of-60-kw-prices-as-auction-demand-falls/"},{"layer":"Interconnection queue","method":"measured","vintage":"end-2025 (LBNL 2026)","freshness":"Fresh","source_url":"https://www.neso.energy/neso-implements-electricity-grid-connection-reforms-unlock-investment-great-britain"},{"layer":"Realized cost","method":"triangulated","vintage":"2026","freshness":"Fresh","source_url":"https://www.iea.org/reports/electricity-2026/prices"}]},"outlook":"Positive","confidence":"High","under_review":false,"thesis":"London is a world-tier hub, but a new connection faces historic waits up to 15 years and prohibitive cost (the TMO4+ reform exists because entry stalled). Unlike Northern Virginia, the gate has genuinely stalled new entry, so no up-override; improving as the reform reorders the queue.","pillars":{"access":38,"availability":45,"cost":20,"momentum":82,"carbon":78},"pillar_rationale":{"access":"Severe access: historic waits up to 15 years; the TMO4+ 'first ready, first connected' reform (live 2025) is reordering a ~96 GW queue.","availability":"Tight availability on a constrained system.","cost":"Very high power cost (~$100+).","momentum":"World-tier momentum (London FLAP-D), but entry is gated.","carbon":"Cleaner grid (~155 g), wind-heavy (~30% of generation)."},"offtake_opportunity_index":72,"demand_hunger":67,"build_feasibility":38,"supplier_signals":{"bess_arbitrage_usd_mwh":55,"bess_arbitrage_pct":62,"solar_capture_pct":101,"wind_capture_pct":100,"effective_competing_supply_gw":135.8},"outlook_drivers":{"upgrade":["TMO4+ reform materially shortens new-connection timelines.","Offshore wind and grid build relieve constraints."],"downgrade":["Reform underdelivers and waits persist.","Cost stays prohibitive."]},"risks":["Connection-queue reform execution.","Very high power cost."],"peers":{"like":"Dublin / Amsterdam (world-tier hub, gated)","ahead":"on momentum","behind":"on access and cost"},"sources":[{"label":"GB connection reform, NESO","url":"https://www.neso.energy/neso-implements-electricity-grid-connection-reforms-unlock-investment-great-britain"}],"latest_action":{"date":"Aug 2026","type":"Affirmed","note":"Tier holds. The proposal is a consultation, not in force, and it cuts both ways: a refundable fee of up to GBP 712,500 per MW is a real balance-sheet demand on a credible developer, but the intent is to strip a 125 GW queue of projects that were never going to connect, which is what a serious large load needs. Revisit on the final decision after 16 Sep 2026; a fee at the top of the range with weak refund mechanics would be an Access negative.","trigger":"Ofgem consultation on data centre connection reforms, 29 Jul 2026"},"grid":{"price_usd_mwh":88,"carbon_intensity_g":155,"renewable_pct":44,"renewable_generation_share_pct":44,"low_carbon_generation_share_pct":59,"fuel_mix":{"gas":31,"wind":28,"nuclear":15,"hydro":2,"solar":6,"biofuel":8,"coal":1,"storage":9},"demand_mw":32000,"capacity_mw":70000,"imports_mw":4000,"exports_mw":1000,"firm_capacity_mw":null,"firm_capacity_availability":"insufficient_evidence","firm_capacity_basis":null,"est_peak_mw":45440,"firm_headroom_mw":null,"firm_headroom_availability":"dependency_unavailable","peak_stress_pct":null,"peak_stress_availability":"dependency_unavailable","adequacy_required_input":"capacity_mix_mw with a declared basis, or an official dependable or accredited capacity from the operator","price_cycle":"other","price_basis":"not_reviewed","price_absent_reason":null,"price_source":"modelled-baseline","price_as_of":null,"price_vintage":"undated_modelled_baseline","price_is_live":false,"carbon_intensity_unit":"gCO2eq/kWh","carbon_measurement_boundary":"operational_combustion","carbon_calculation_method":"structural_estimate","carbon_emission_factor_source":null,"carbon_basis_withdrawn":true,"carbon_imports_treatment":"not_accounted","carbon_provenance_state":"structural","carbon_decision_eligibility":"insufficient_evidence","carbon_confidence":"low","source":"modelled-baseline"},"evidence_depth":{"use_case":"project_case","use_case_label":"Standardized Project Case","overall":"M2 Compiled","overall_permits":"Compiled from cited sources: supports investor and institutional analysis.","insufficient_evidence":false,"unassessed_required_fields":[],"project_ready":false,"blocking_fields":["reliability"],"fields":{"cost":"M3 Project-ready","connection":"M3 Project-ready","reliability":"M2 Compiled","carbon":"M2 Compiled","regulatory":"M2 Compiled","local_capacity":"M4 Local"},"by_use_case":{"discovery":{"label":"Discovery and monitoring","matrix_version":"1.0","tier":"M3 Project-ready","ready":true,"blocking_fields":[],"insufficient_evidence":false,"why":""},"market_comparison":{"label":"Market comparison","matrix_version":"1.0","tier":"M2 Compiled","ready":false,"blocking_fields":["reliability"],"insufficient_evidence":false,"why":""},"project_case":{"label":"Standardized Project Case","matrix_version":"1.0","tier":"M2 Compiled","ready":false,"blocking_fields":["reliability"],"insufficient_evidence":false,"why":""},"project_case_carbon":{"label":"Project Case with a carbon requirement","matrix_version":"1.0","tier":"M2 Compiled","ready":false,"blocking_fields":["reliability","carbon"],"insufficient_evidence":false,"why":""},"site_diligence":{"label":"Conditional site diligence","matrix_version":"1.0","tier":"M2 Compiled","ready":false,"blocking_fields":["reliability"],"insufficient_evidence":false,"why":""}},"reliability_layers":{"bulk_historical":{"state":"held","method":"measured"},"forward_adequacy":{"state":"held","method":"assessed"},"local_delivery":{"state":"held","method":"measured"},"contractual_service":{"state":"held","method":"reported"},"designed_site_resilience":{"state":"unknown","method":null}},"definition_version":"carbon_scope@1.0;connection_process@1.0;cost_archetype@1.0;evidence_tiers@1.0;reliability_layers@1.0","scale":"M1 broad / M2 compiled / M3 project-ready / M4 local; cumulative, so each tier includes the ones below it. Assigned per field from held evidence with provenance. Not a rating strength, confidence score or feasibility conclusion."},"next_review":"2027-02-15","report_url":"https://powergridiq.com/rating/great-britain","as_of":"June 2026","evidence_layers":{"version":"evidence-layers-1.0","band":{"state":"independently_compiled","label":"Independently compiled","means":"The band is assembled from multiple sourced, dated and applicable published figures. It is not a single benchmark and it is not a tariff reconstruction.","reproducible":"partially"},"component":{"total_lines":4,"reproducible_lines":0,"states":["estimated_allocation"],"all_lines_are_estimated_allocations":true,"independently_reproducible":false,"illustrative":true,"notice":"Illustrative allocation of the compiled midpoint. Component lines are not separately sourced and should not be interpreted as observed tariff charges.","notice_short":"Illustrative allocation — lines not separately sourced","vocabulary_version":"evidence-layers-1.0"},"cost_pillar":{"state":"analyst_assessment","label":"Analyst assessment","means":"The score is a judgement recorded with a written cost-specific rationale. It is not calculated from a formula and does not claim to be.","reproducible":false},"layers_are_independent":"Band, component and cost-pillar evidence are separate judgments. A market may have a sound, applicable band and an illustrative component breakdown at the same time. Do not read a component-evidence limitation as a statement about the band."}}