Best Time-of-Use Energy Tariffs UK 2026: Ranked for Solar Homes

If there's one decision that determines whether solar saves you £100 or £500 per year, it's your tariff.

The Ofgem price cap covers the basics: a flat rate of roughly 24p/kWh for electricity, 7p/kWh for gas. But time-of-use (ToU) tariffs break this into windows: cheap off-peak hours, standard rates, and expensive peak hours.

For homes with plug-in solar or battery storage, the difference between a standard tariff and the right ToU tariff is genuinely life-changing. We're talking £200–400 extra per year in value capture.

So which ToU tariff is actually best? It depends on your setup, not just your postcode.

Why ToU Matters for Solar

When you have an 800W solar system generating 750kWh annually, timing is everything.

On a flat-rate tariff (24p/kWh), that 750kWh is worth £180. But if you export 300kWh unused to the grid, you get nothing—it just vanishes. On a ToU tariff, you can strategically time consumption and storage around price windows.

If you own battery storage (like the EcoFlow DELTA 2), the economics become genuinely powerful. You charge the battery during cheap off-peak windows (7–9p/kWh), use the stored energy during expensive peak windows (28–30p/kWh), and solar covers your daytime baseline.

The arbitrage value can add £150–300/year to your system's net output. That's not a rounding error.

The Rankings for Solar Households

1. Octopus Go — Best for Solar + Battery

Off-peak window: 23:00–05:00 (8 hours), 4p/kWh Standard rate: 24p/kWh Peak: No separate peak window

Who it's for: Homes with battery storage or controllable loads (heat pump, EV charger). The 4p off-peak rate is the lowest in the market, full stop. If you have 5kWh of battery, you can charge at 4p during the night, discharge at 24p during the day, and pocket the 20p/kWh arbitrage on every kWh cycled. For a battery system running 2,000 cycles per year, that's £400 in pure arbitrage value.

Why it's brilliant for solar: Solar offsets your expensive daytime usage, then during the day you're only buying grid electricity if solar isn't generating. At night, your battery (charged cheaply overnight) covers demand. You barely touch the standard 24p rate.

Caveat: Octopus Go requires smart metering and a degree of behavioural flexibility. You need to concentrate consumption around the off-peak window or own storage. If you're passive about timing and don't have battery, you'll miss most of the value.

2. Octopus Intelligent Go — Best for EV + Solar

Off-peak window: 23:00–05:00, 4p/kWh, plus EV-specific rates Intelligent Octopus feature: Optimises EV charging automatically Standard rate: 24p/kWh

Who it's for: Homes with both electric vehicles and solar. Octopus's algorithm automatically charges your EV during the cheapest windows, so you never have to think about timing. If you also have battery storage, the off-peak 4p window stacks with solar generation for devastating efficiency.

Why it's brilliant for solar: It does the thinking for you. Your EV charges when electricity is cheapest, your solar covers daytime demand, and your battery (if you have one) fills in gaps. It's the closest thing to a fully integrated energy management system from a major supplier.

Caveat: Requires compatible EV infrastructure. Not all vehicles support Intelligent Octopus yet, though adoption is accelerating.

3. Octopus Agile — Best for Tech-Savvy, Dynamic Pricing

Rate structure: Changes every 30 minutes based on national grid demand Typical range: 2p/kWh (low demand periods) to 50p/kWh (peak stress) Average: Often 16–18p/kWh

Who it's for: Homes with battery storage, monitoring, and willingness to optimize actively. Agile's real-time pricing rewards flexibility. You can monitor rates via app and decide when to charge batteries, run appliances, or export.

Why it's brilliant for solar: If you own battery storage and monitor rates, you can charge when rates dip to 2–5p and discharge when rates spike to 40p+. The value capture is extraordinary—potentially £400–600/year. But this requires engagement.

Caveat: Price volatility is real. Some days you'll buy at 50p/kWh, and that stings. It's only worth switching to Agile if you're willing to monitor and optimise. Passive users on Agile often end up paying more than on flat rates.

4. Octopus Flux — Best for Export-Focused Homes

Off-peak window: 02:00–05:00, 7p/kWh Export rate: 24p/kWh (significantly higher than standard suppliers) Standard rate: 24p/kWh import

Who it's for: Homes with rooftop solar (which qualifies for SEG and can export) and moderate battery storage. Flux pays you generously for exports, so if your rooftop system is exporting heavily during daytime, Flux maximises the income.

Why it's brilliant for solar: The high export rate (24p) is unique. Most suppliers pay 15–20p for SEG exports. Flux's 24p means your exported solar electricity is worth more. However, Flux doesn't have the super-cheap off-peak window (4p) that Octopus Go offers, so it's a trade-off.

Caveat: Plug-in solar doesn't qualify for SEG, so Flux is only relevant if you have rooftop solar. The export advantage doesn't apply to you otherwise.

5. E.ON Next Drive — Best EV-Only Alternative

Off-peak (EV): 23:30–05:30, 5p/kWh Standard rate: 24p/kWh No battery arbitrage focus

Who it's for: EV owners without solar or battery storage. E.ON's off-peak window is slightly longer than Octopus Go's, but the rate is higher (5p vs 4p).

Why it's decent: If you have an EV but no solar, this removes one decision layer. E.ON will auto-optimise your EV charging without you needing to think about it. But for pure price, Octopus Go beats it.

Caveat: E.ON's other rates are less competitive. If you're also heavy users during the day, you'll pay more during standard hours compared to Octopus.

How to Calculate Whether ToU Saves vs Flat Rate

Don't just switch based on marketing. Do the maths.

Step 1: Get your usage data Ask your supplier for your half-hourly metering data (you're legally entitled to it). Plot it against the ToU windows you're considering.

Step 2: Calculate consumption by window

If you consume 3,000kWh annually:

• Off-peak (23:00–05:00): roughly 500kWh (nighttime baseline + any EV or heat pump charging)
• Standard (05:00–16:00, 20:00–23:00): roughly 1,500kWh
• Peak (16:00–20:00): roughly 1,000kWh

Step 3: Calculate the saving

Flat rate cost: 3,000 × 24p = £720

ToU cost (Octopus Go example):

• 500kWh @ 4p = £20
• 2,000kWh @ 24p = £480
• Total: £500

Saving: £220/year

Step 4: Factor in solar

If you have 750kWh of solar annually, offset that from your standard window first (since solar generates during 05:00–20:00 when you're away). Reduces standard consumption to 1,250kWh.

New ToU cost:

• 500kWh @ 4p = £20
• 1,250kWh @ 24p = £300
• Total: £320

Combined solar + ToU saving: £400/year

That's where the real value lives.

The "Wrong Tariff" Trap

Most UK homes with solar are on flat-rate tariffs. They've installed an 800W system, it generates 750kWh, they offset maybe £180 of consumption, and they think that's the end of the story.

They've missed the other £200–300/year by not switching tariff.

Equally, some homes switch to Agile or complex ToU without understanding the trade-offs. If you're not willing to monitor rates or own storage, complex tariffs can cost you money.

The sweet spot for most solar homes: Octopus Go if you have battery, or a standard ToU with a reliable 4–7p off-peak window if you don't.

Practical Implementation

For plug-in solar without battery:

1. Switch to Octopus Go today (takes 5 minutes online)
2. Try to concentrate consumption in the 23:00–05:00 window (run dishwasher, laundry, charge devices then)
3. During daytime, let solar offset grid usage passively
4. Expect to save £100–150/year from tariff alone, plus your solar offset

For plug-in solar + battery storage:

1. Switch to Octopus Go or Agile depending on engagement level
2. Set battery to charge during 23:00–05:00 at 4p/kWh
3. Discharge battery during 16:00–20:00 (highest daytime rates)
4. Let solar offset midday demand
5. Expect to save £300–400/year from combined tariff + arbitrage

For rooftop solar with high daytime export:

1. Consider Octopus Flux for the high export rate (24p)
2. But compare Flux's 24p export rate against your actual consumption timing
3. If you consume heavily during daytime, Octopus Go is probably still better (cheap charging at night, expensive discharge during day saves more than export gains)

Smart Metering: Non-Negotiable

All modern ToU tariffs require smart metering. If you don't have one, request it from your supplier (free, usually installed within 8 weeks). Without smart metering, you can't access the half-hourly data you need to calculate savings or monitor Agile pricing.

Monitoring Your Tariff's Performance

Once you've switched, use a smart plug like the TP-Link Tapo P110 (£15) on key loads to understand timing. Monitor your monthly bills. After 6 months, calculate actual savings and decide if the tariff still matches your situation.

Energy behaviour changes. Kids grow up, work patterns shift, heat pumps replace boilers. Every 12–18 months, revisit your tariff choice. What was optimal a year ago might be suboptimal today.

The Integration with Battery Storage

If you're considering battery storage like the EcoFlow DELTA 2, the tariff choice becomes critical. With the right tariff (Octopus Go at 4p/kWh off-peak), a 5kWh battery that cycles once daily can generate £300–400 of arbitrage value annually.

But pair that same battery with a flat-rate tariff, and arbitrage value collapses. The battery still stores solar generation (valuable), but the cheap nighttime charging advantage vanishes.

Tariff + battery + solar is a three-part system. Get any one part wrong, and the whole stack underperforms.

Summary: Which Tariff for Which Situation

Still unsure? Use our savings calculator to estimate your solar generation, then map your consumption against the off-peak windows of Octopus Go. The difference often speaks for itself.

Then switch. It's free, it takes 5 minutes, and it unlocks real money.