The Smart Export Guarantee (SEG): 2026 rates and access
The Smart Export Guarantee (SEG) requires Ofgem-licensed suppliers above 1,000 customers to offer export tariffs. SEG rates are not regulated — they vary by supplier and by time of day. 2026 SEG market: flat-rate tariffs: 8-12p/kWh (Octopus Agile Export, E.ON Drive Export, OVO Energy Solar). Time-of-use (TOU) tariffs: peak-period export (4pm-7pm weekdays) at 14-22p/kWh; off-peak 4-7p/kWh (Octopus Agile Export is the dominant TOU product). For a warehouse exporting 200,000 kWh/yr flat: flat-rate SEG = £18,000/yr at 9p. Octopus Agile TOU-optimised export (shifting generation profile via battery): £22,000-£28,000/yr. SEG registration: requires MCS certification (mandatory for all our commercial installs). We register on your behalf as part of standard installation scope.
Flexible export: the DNO curtailment option
For large systems (above 1.5 MW) connecting to constrained grid areas, DNOs may offer flexible connection agreements instead of or alongside standard G99 connections. Under a flex connection: you accept DNO curtailment rights (the DNO can instruct the inverter to reduce output when local network is at capacity — typically <5% of generation curtailed annually in practice). In return: faster connection (sometimes 3-6 months faster than constrained G99 standard connection); potentially lower connection cost. Flex connections are becoming increasingly common in SSEN and SP Networks territories (both constrained). They are less common in UKPN territory (better capacity). We evaluate flex connection viability during G99 pre-application for all systems above 1.5 MW.
Grid services revenue: FFR, DC and Balancing Mechanism
For warehouse sites with battery storage co-located with solar PV, grid services revenue is available via: Firm Frequency Response (FFR): National Grid ESO pays for fast-response frequency balancing. FFR revenue: £20,000-£60,000/yr for a 500 kWh battery, depending on tendering. Dynamic Containment (DC): National Grid's primary frequency response service, paying higher than FFR for faster response (sub-1 second). Revenue: £40,000-£90,000/yr for 500 kWh battery. Balancing Mechanism (BM): direct participation in the BM for assets above 1 MW registered with National Grid. BM revenue is highly variable but can exceed DC for well-optimised assets. Aggregation: most warehouse battery assets below 5 MWh participate via an aggregator (Flexitricity, Limejump, Centrica Business Solutions) rather than directly, which reduces admin and optimises dispatch.
Export optimisation strategy for different warehouse types
Distribution centre (daytime operation, high self-consumption): export fraction 15-25% of generation. Primary strategy: flat-rate SEG (keep it simple, minimal admin). Battery not justified unless grid services revenue targets are set. Cold chain (24/7, 90%+ self-consumption): export fraction 5-10%. Very limited export. No SEG benefit worth pursuing. Battery justified only for grid services revenue. Last-mile depot (EV charging, daytime): export fraction 5-15% after EV charging. Primary strategy: TOU SEG (Octopus Agile) to maximise export value. Battery stacking adds grid services to EV/solar arbitrage. Manufacturing (shift pattern, evening gaps): export fraction 20-35% during downtime shifts. Primary strategy: battery storage captures generation during production gaps and exports during evening peak (4pm-7pm at 14-22p/kWh TOU). Best candidate for Octopus Agile TOU + battery + grid services stacking.
Common questions
What are the best SEG tariff rates for warehouse solar in 2026?
Best flat-rate SEG 2026: Octopus Energy Business 11p/kWh; E.ON Next Business 9.5p/kWh; OVO Business Energy 9p/kWh. Best time-of-use (TOU): Octopus Agile Export — peak export 4pm-7pm at 14-22p/kWh (variable, based on Agile pricing). For a warehouse exporting 200,000 kWh/yr: flat-rate SEG adds £18,000-£22,000/yr. TOU with battery optimisation adds £22,000-£30,000/yr. We register SEG on your behalf and advise on the best tariff for your export profile.
Is battery storage worth adding to warehouse solar for export optimisation?
Battery for export optimisation alone rarely justifies the capex (£350-£550/kWh in 2026). Battery makes commercial sense when: (1) grid services revenue (DC, FFR) adds £40,000-£90,000/yr on top of export tariff; (2) TOU tariff arbitrage (export peak, avoid grid peak) adds £5,000-£15,000/yr; (3) EV fleet charging from battery improves self-consumption further. For a warehouse with 500 kWh battery and grid services via aggregator: total annual revenue (SEG + DC + avoided grid) can reach £90,000-£130,000 — justifying £200,000-£250,000 battery capex in 3-4 years.