What’s the best electricity tariff in the UK for homeowners with solar panels (and batteries)?

If you’ve got solar panels (and maybe a battery), your electricity tariff stops being a boring admin detail and becomes a lever you can pull to get a much better return from your system.

The “best tariff” isn’t one single deal for everyone. It depends on:

• whether you export power (and how much)

• whether you can shift usage into cheap periods (battery helps massively)

• whether you have an EV (big flexible load)

• whether you’re on SEG export, deemed export (FiT legacy), or a smart export plan

• whether your home’s biggest loads are heat pump / immersion / EV / appliances

This guide walks you through how to pick the right setup, what to compare, and the common traps that cost solar owners money.

1) How solar changes the tariff game

With solar, you have two money streams:

1. Import cost (what you pay the supplier for electricity you buy)

2. Export revenue (what you get paid for electricity you send back to the grid)

The “best tariff” usually means the best overall net outcome across both.

The 3 ways solar owners win on tariffs

1) Maximise self-consumption

Use more of your solar in the home (especially in daytime). Batteries and smart scheduling make this far easier.

2) Get paid properly for exports

If you export a lot (e.g., large array, small household, daytime empty house), export rate matters a lot.

3) Use cheap import windows

With a battery (and/or EV), you can buy electricity when it’s cheap and use it later, reducing expensive peak imports.

2) Know your solar setup type (it changes what “best” means)

Type 1 — Solar only (no battery)

• You’ll typically import most power in the evening/night

• You’ll export excess in the middle of the day

• Your best plan often prioritises:

  • a good export rate

  • a reasonable standard import unit rate

  • potentially time-of-use if you can shift some usage (dishwasher, washing machine, immersion, etc.)

If you’re out all day, you’ll export more, so export becomes a bigger deal.

Type 2 — Solar + battery

• You can store excess solar and use it later

• You can also “charge from grid” in cheap windows if your tariff allows and your battery/inverter supports scheduling

Your best plan often prioritises:

• a smart time-of-use import tariff (cheap off-peak)

• export terms that don’t penalise you if you export less (because you’re using more at home)

Type 3 — Solar + battery + EV

You’ve got the ultimate flexibility. Your EV and battery can soak up cheap power and solar, then avoid peak prices.

Your best plan usually prioritises:

• an EV-friendly time-of-use import rate

• smart control (charger scheduling + battery scheduling)

• export rate becomes secondary unless you export a lot (big array, small usage)

3) The UK tariff types explained (in plain English)

A) Single-rate (flat) tariff

Same unit price all day.

Best for:

• solar-only homes that don’t want complexity

• people who can’t shift usage

• households with low export and no battery/EV

Downside: You miss out on cheap periods that batteries/EVs can exploit.

B) Economy 7 / Economy 10

Cheaper night rate for 7 or 10 hours, higher day rate.

Best for:

• battery owners who can charge overnight

• EV charging overnight

• homes with night-heavy usage (storage heaters, etc.)

Watch out: Some Economy 7 day rates can be meaningfully higher. If you don’t shift enough kWh into the cheap window, you can lose money.

C) Smart time-of-use (TOU) tariffs

Rates vary by time, and sometimes by day.

Best for:

• battery owners (biggest winners)

• EV owners

• tech-friendly households happy to schedule charging/heavy loads

Watch out: Peak rates can be very high. If you forget to schedule, you can get stung.

D) Export tariffs (SEG)

This is the payment you receive for exporting to the grid. Some suppliers offer fixed rates; some do time-varying export; some bundle export with import.

Best for:

• solar-only homes with big midday export

• households at home less in daylight

• anyone with a large array vs consumption

Watch out: Some export deals come with conditions (e.g., must take import from same supplier, or need a smart meter, or certain MCS paperwork).

4) What “best” looks like in real life: 5 common household profiles

Profile 1: “We work out all day” (solar-only)

• You export a lot because no one’s home to use it

• Battery would help, but if you don’t have one…

Usually best approach:

• Choose a supplier with a strong export rate

• Keep import rate competitive

• Consider a simple “export-friendly” setup before chasing complex TOU

Profile 2: “Family home, people in and out” (solar-only)

• Some daytime usage (cooking, devices, laundry)

• Moderate export

Usually best approach:

• Solid all-round import rate

• Decent export

• Add simple automation: run dishwasher/washing midday, heat water during solar hours if you have immersion control

Profile 3: “We’ve got a battery and a smart inverter”

• You can charge/ discharge on schedule

• You can avoid expensive evening peak import

Usually best approach:

• A time-of-use tariff with a cheap overnight window

• Configure battery:

  • charge from solar first

  • top-up from grid only in the cheap window (if it makes sense)

  • reserve enough battery to cover evening peak

Profile 4: “Battery + EV”

• Your EV is a huge controllable load

• Your battery can do the house, EV does the miles

Usually best approach:

• EV TOU tariff with a very cheap window

• Smart charger scheduling (Ohme, Zappi, Wallbox, etc.)

• Make sure your battery doesn’t “fight” the EV schedule (control logic matters)

Profile 5: “Big solar array, small household” (high export)

• Export dominates your financial outcome

Usually best approach:

• Prioritise export rate and export terms

• Consider whether battery ROI makes sense (it can, but export may already be strong)

5) The key comparisons that actually matter

When comparing tariffs, don’t just look at a headline p/kWh.

Import side

• Day unit rate(s) (and peak vs off-peak if TOU)

• Standing charge

• Off-peak window timing (e.g., 00:30–04:30 vs longer)

• Rules: can you switch easily, any exit fees, price caps, etc.

Export side

• Export unit rate (fixed or variable)

• Smart meter requirement

• Whether export is only paid if you also import from them

• Payment method (credit to bill vs bank transfer)

• Any export caps or minimums (less common, but check terms)

Your capability to take advantage

Ask yourself honestly:

• Can I schedule EV charging every night?

• Can I schedule battery charging/discharging?

• Can I shift laundry/dishwasher/immersion?

• Will I actually maintain the habit?

If the answer is “not really”, a simpler plan may beat a “clever” tariff in practice.

6) The solar-owner traps (that catch people out)

Trap 1: Chasing the highest export rate but ignoring import cost

If you’re a net importer overall (common in winter), a high export rate won’t rescue an expensive import rate.

Trap 2: Time-of-use tariffs without automation

TOU can be brilliant… or brutal. If you regularly cook, shower, and run appliances in peak time without battery cover, costs jump.

Trap 3: Battery schedules set once and forgotten

Seasonality matters. What works in July can be wrong in January.

• Summer: you might want less grid charging

• Winter: cheap grid charging can make sense to cover peak hours

Trap 4: EV charging at the “wrong cheap time”

Some tariffs have short cheap windows. If your EV needs more energy than that window provides, the rest may spill into expensive periods unless you manage it.

Trap 5: Exporting when you didn’t mean to

Some setups export battery energy at the wrong time if settings are incorrect. If export rates are low but import rates are high, that’s backwards value.

7) A practical step-by-step: how to choose your best tariff

Step 1 — Pull 12 months of import/export data

Ideally from:

• your smart meter / IHD

• your supplier portal

• your inverter/battery monitoring app (SolarEdge, Sunsynk, SigEnergy, Tesla, GivEnergy, etc.)

Note:

• total annual import (kWh)

• total annual export (kWh)

• seasonal differences (summer vs winter)

Step 2 — Identify your controllable loads

Tick what applies:

• EV charging ✅/❌

• battery can charge from grid ✅/❌

• immersion / hot water control ✅/❌

• heat pump ✅/❌

• smart plugs / automation willingness ✅/❌

Step 3 — Choose the tariff “shape” that matches your life

• Solar-only & high export → strong SEG export + competitive flat import

• Battery → TOU with meaningful cheap window

• EV → EV TOU tariff + smart charger scheduling

• Low flexibility → flat rate with good standing charge and decent export

Step 4 — Model it quickly (even roughly)

You don’t need perfect maths. A simple comparison helps:

• Estimate what % of your import could move into cheap hours

• Estimate how much export you’ll still have with your current habits

• Compare annual standing charge difference (it adds up)

Step 5 — Set up your controls properly

This is where most people leave money on the table.

• Battery: set charge/discharge windows, reserve, and export limits correctly

• EV charger: set schedules and “smart charging” features

• House loads: simple timers for immersion / appliances

8) Quick checklist: what to ask before you switch

• Do I have a smart meter installed and working reliably?

• Am I MCS-certified for SEG eligibility (or do I meet the supplier’s export criteria)?

• Does my battery/inverter support:

  • scheduled charge/discharge?

  • grid charging?

  • export limiting?

• Can my EV charger do:

  • scheduled charging?

  • solar surplus charging (if desired)?

• Are there exit fees or fixed-term penalties?

9) Bottom line: what’s “best” in one sentence?

• High export, no battery: prioritise a strong export tariff and a competitive flat import rate.

• Battery (with or without EV): prioritise a time-of-use import tariff with a meaningful cheap window, and set schedules properly.

• EV owner: prioritise a tariff that matches your charging routine, then optimise solar usage second.

Ready to get more from your solar or EV setup?

At Optimum Electrics, we design bespoke solar and EV charging systems that work hand-in-hand with the right tariff to maximise your savings and future-proof your home.

Whether you’re planning a new installation or want to optimise what you already have, our expert team is here to help.

01733 601698

enquiries@optimumelectrics.co.uk