Octopus Flux vs Go vs Intelligent Go in Scotland (2025): best pairings for solar, batteries and EVs

The energy price backdrop in Scotland (Autumn 2025)

• Ofgem’s cap sets typical bill levels for Oct–Dec 2025 at about £1,755/year. Typical electricity unit rates are around 26.35p/kWh with standing charges ~53.68p/day, varying by region.
• When peak/day spreads are wide, time-of-use tariffs (like Flux or Go) can cut bills by shifting EV and battery charging to cheap hours and using stored energy during peak times.

What each Octopus tariff is for

• Octopus Go and Intelligent Go: import‑focused EV tariffs. You get a cheap off‑peak window overnight to charge your EV (and optionally your home battery). Export is separate via Outgoing Octopus (flat) or Agile Outgoing (dynamic SEG).
• Octopus Flux and Intelligent Octopus Flux: designed for homes with PV and often a battery. They have cheap import overnight, higher import at peak (16:00–19:00), and a matched export structure that pays the most when the grid is peaking — ideal if you can schedule charging/discharging.
• Intelligent variants require compatible hardware/integration. All time‑of‑use tariffs need a smart meter and eligibility approval.

Regional note: Stirling, Glasgow and much of the West/Central Belt fall under Southern Scotland (SP Energy Networks). Northern Scotland covers SSEN North (Highlands/Islands). Time bands are similar, but unit prices and standing charges differ by region — always check your Octopus app.

Not with Octopus? Scotland also has EV/off‑peak options and SEG export from other suppliers:

• OVO Charge Anytime: smart EV charging add‑on with very low effective p/kWh for EV miles; pair with OVO import tariff and OVO SEG for export.
• E.ON Next Drive: cheap EV off‑peak window (e.g., overnight period) with E.ON’s SEG for export.
• ScottishPower EV Saver/EV Optimise: overnight cheap EV window or smart charging add‑on; ScottishPower SEG for export.

Today's example: Flux rates in Southern Scotland

Rates correct for Southern Scotland (SP Energy Networks), checked 2025-09-05. Your region and dates may differ — confirm in your Octopus app.

Real‑world math: when Flux wins vs Go

• Battery round‑trip efficiency: assume ~90% (brand‑dependent, typically 85–92%).
• Off‑peak vs peak spread on Flux import today: 36.15 − 15.49 = 20.66p/kWh.

Worked example (simple):

• Charge 10 kWh at 15.49p = £1.55
• After 10% losses, usable ~9 kWh
• Avoided cost if used at peak 36.15p: 9 × 36.15p = £3.25
• Net benefit ≈ £3.25 − £1.55 = £1.70 per cycle (before standing charges)

Note: Exporting that 9 kWh at the 16:00–19:00 peak pays ~£2.45; self‑consumption typically beats exporting on value.

Three common Scottish household profiles

1) EV commuter + PV + 10 kWh battery

• High weekly mileage (e.g., 150–250 miles): Go/Intelligent Go often wins thanks to a longer cheap import window that can fully charge the EV. Keep the battery scheduling separate (charge some at night in winter; rely more on solar in brighter months). Choose an export tariff (Outgoing Octopus flat, Agile Outgoing dynamic). Not with Octopus? Consider your supplier’s SEG (e.g., ScottishPower, OVO, E.ON Next).
• Moderate mileage (e.g., 50–120 miles): Flux/Intelligent Octopus Flux can be simpler. Plan a partial EV top‑up 02:00–05:00, let daytime solar cover some miles via Zappi Eco+ (solar divert), and keep battery energy for the 16:00–19:00 peak.

2) WFH family, PV + 10–15 kWh battery, low EV use

• Flux frequently wins: cheap top‑ups in winter, valuable peak self‑use, and occasional profitable peak export in summer if you have surplus after covering your own load.

3) PV only (no battery), with or without EV

• Go is usually best if you have an EV (cheap night charging). Export your solar on Outgoing Octopus (flat) or Agile Outgoing (dynamic SEG). Flux import is less compelling without a battery to shift energy between time bands.

Settings that make or break savings

Battery/inverter:

• Charge window: on Flux, set 02:00–05:00 in winter; disable overnight charging on bright forecast days.
• Reserve SOC: keep a reserve (e.g., 20–30%) so there’s headroom to capture daytime solar.
• Discharge: prioritise self‑use during 16:00–19:00; only export surplus. Align discharge limits with any DNO export cap.

EV charger:

• Use the app scheduler (Zappi/Hypervolt/Ohme) for cheap windows.
• Zappi Eco+ can divert excess solar to the EV when available.
• Ensure CT clamp placement/load management is correct so the home battery doesn’t unintentionally charge the EV and so the charger “sees” genuine surplus.

DNO/export limits:

• Typical single‑phase G98 export limit is 3.68 kW unless you have G99 approval and/or export limiting configured. This caps potential export revenue during peak windows — settings must respect your limiter.

Costs, funding and VAT in Scotland (2025)

• 0% VAT on installation of energy‑saving materials until 31 March 2027

  • Applies to solar PV, standalone/retrofitted electrical batteries, and smart diverters installed in homes.
  • This can materially reduce installed costs for batteries and diverters.

• Home Energy Scotland (HES) funding

  • The Grant & Loan scheme currently prioritises clean heating (heat pumps) and energy efficiency measures. Standard standalone PV or home batteries are generally not funded (since 2024‑06‑06), except in specific packages (e.g., PV‑T) or where eligible under ECO4 for low‑income households. Always check HES directly as criteria and allocations can change.

Local note (Central & West Scotland)

In Stirling and West/Central Scotland we typically: set batteries to charge 02:00–05:00 in winter on Flux; leave 20–30% reserve for daytime solar; and prioritise self‑use 16:00–19:00. On Go/Intelligent Go, we extend EV charge windows and keep the battery for evening loads. We’ll configure your inverter and charger so the battery doesn’t backfill the EV, CT clamps read correctly, and export limits are respected.

FAQs

Rates last checked: Flux example uses Southern Scotland rates checked 2025-09-05. Your Octopus prices and time bands may differ by DNO region and date. Always confirm in your app/account before making changes.

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Serving Central & West Scotland: Stirling, Perth, Falkirk, Dunbartonshire, Glasgow and beyond.