Best energy tariffs with solar in South Wales - February 2026
- Ian Mach
- Feb 21
- 5 min read
Choosing the right electricity tariff is no longer a simple matter of comparing unit rates. For households with solar panels, battery storage, electric vehicles or heat pumps, energy pricing has become a strategic decision.
The structure of your tariff — not just the headline price — can materially influence whether your system delivers modest savings or exceptional returns.
In this guide we will cover the key considerations when choosing an electricity tariff, and looking at the best strategies depending on your situation.
This guide is written based on tariffs available in South Wales.
We will also recommend an online tool that you can use to refine your selection.
1) Why tariffs matter once you have renewables
If you’re on a standard single-rate tariff, you mostly pay whatever the fixed rate is whenever you use electricity.
Once you add solar, battery storage, an EV, or a heat pump, you can start using time-of-use tariffs. These feature:
Off-peak windows (cheap electricity, typically overnight, sometimes midday)
Peak windows (expensive electricity, often 4–7pm)
Export payments for energy you send back to the grid (Smart Export Guarantee-type arrangements)
Using the right tariff, and the adequate usage and charging strategy is essential to make the most of your kit.
2) Which scenario are you in?
Scenario A — Solar only (no battery)
Best tariff type:
A strong fixed export rate + a competitive standard import tariff
Why
Without a battery, you can’t choose when to export excess solar exports when it happens.
A strong export rate is therefore one of the biggest levers for solar-only households.
Time-of-use import tariffs can still work, but without storage you’re less able to avoid expensive peak windows if your usage lands there.
Recommended tariff (as of February 2026):
Octopus Outgoing provides an export rate of 15p/kWh paired with a compatible Octopus import tariff
Tip:
When you register for export, suppliers may place you on a low default export rate. You often have to actively switch to a better export option.
Scenario B — Battery storage only (no solar)
Best tariff type:
A time-of-use battery tariff (or an EV tariff if it allows the whole home cheap rate).
Why
This is classic arbitrage: charge the battery during cheap windows and discharge during expensive periods.
Your goal is to avoid buying electricity at peak prices.
Recommended tariff (as of February 2026):
Good Energy EV Charge (Good Energy is the only provider providing a sole tariff available for battery-only households) with its 8.5p/kWh for 5h overnight
Tip:
There are currently no export tariffs available to homes with just a storage battery, which is unlikely to change any time soon.
Good Energy EV Charge is currently the sole tariff available for battery-only households without an EV. If this tariff disappears, the financial benefit of owning a battery would reduce dramatically.
Scenario C — Solar + battery (no EV)
This is where “tariff strategy” matters a lot.
Best tariff types:
Solar + battery specific tariffs (often with different import/export rates by time)
Dynamic/import tariffs if your battery is “intelligent” and can respond to prices
Pair with either:
Fixed export (simple, predictable), or
Time-based export (better if you can export at peak)
Why
Your battery can:
Store excess solar for later (self-consumption)
Charge from the grid when cheap (especially in winter)
Potentially export at higher rates during peak windows
Recommended tariff (as of February 2026):
Octopus Flux, the tariff Octopus designed for solar and battery households
Good Energy EV Charge paired Good Energy Solar Savings with its 8.5p/kWh 5h overnight window and 15p/kWh export rate
Tip:
A lot of people will find that Octopus Flux works best over the winter period when excess generation is lower and Good Energy over the summer when the large excess generation can be exported at the high 15p/kWh rate. Good Energy allows switching tariff with no penalty fees every 6 months and Octopus every 30 days so this could be a good strategy to use.
If you would rather not have to bother switching tariffs over the year, Octopus Flux is a solid choice all year around for most people.
Whilst households with just solar and battery could use EV tariffs with a super cheap off-peak overnight window in the past, typically Octopus Go and E. On Drive, these companies have now clarified in their terms and conditions that this is no longer allowed and they now require proving ownership of an EV before being able to sign up.
Scenario D — Heat pump + solar + battery (no EV)
You’re balancing two things:
Heat pumps can be energy-hungry in cold spells
Time-of-use tariffs can reduce the cost if you can shift consumption or use storage
Best tariff type:
A heat pump tariff, or
A battery-friendly time-of-use tariff, depending on your usage pattern.
Off-peak windows options:
Daytime cheap window tariff can suit people at home during the day (e.g., retirees), because they can heat when it’s cheaper.
Multiple off-peak windows are powerful if you have battery storage and can “top up” several times per day to avoid peak.
Recommended tariff (as of February 2026):
For a typical households (i.e. 3000kWh electricity use, 3000kWh gas use and 4000kWh yearly solar generation), Octopus Cosy if you don't have a large battery (i.e. <10kWh) as the three off-peak windows per day effectively act as virtual battery
For battery greater than 10kWh, Octopus Flux over the summer and Good Energy over the winter where the battery can be charged at the low 8.5p/kWh overnight.
Tip:
Pre-heat during cheap windows, then reduce setpoint during peak (4–7pm). The building’s thermal mass can carry you through the expensive period, reducing peak imports.
Scenario E — EV only
You usually want an EV tariff with an overnight cheap window.
Two EV tariff “types”
Non-intelligent EV tariffs: Fixed cheap window (e.g., midnight–5am). No smart scheduling.
Intelligent EV tariffs: Your EV or charger connects to the supplier, which can schedule charging when it’s cheapest, often with better pricing.
Best tariff
If your EV/charger supports it, intelligent EV tariffs are typically best value because the supplier can shift your charging around and rewards you for the flexibility.
Recommended tariff (as of February 2026):
Octopus Go with its 9p/kWh import for 5h overnight
Octopus Intelligent Go with its 7.5p/kWh import for 6h overnight
Scenario F — Solar + battery + EV
Best tariff type:
An EV tariff that allows whole-home off-peak (and ideally works with your battery charging too), plus a strong export option.
Why this can be the “holy grail”
Charge EV and battery overnight at low rates
Run the home from the battery during peak times
Use solar to top up battery in the day
Potentially export surplus solar/battery at a higher rate (depending on export tariff)
What decides the winner for you:
Do you drive more (EV import savings dominate) or export more (export rate dominates)?
How often do you run out of battery before 4–7pm in winter?
Can your system charge quickly enough in the available cheap window?
Recommended tariff (as of February 2026):
Octopus Go
Octopus Flux
Scenario H — Solar + battery + EV + heat pump (everything)
This is where the “best tariff” is genuinely scenario-specific.
Two common outcomes:
If EV mileage is high, an EV tariff plus battery can outperform heat-pump tariffs because overnight cheap energy can feed both the house and heating.
If heating demand dominates and you need multiple daily cheap windows, a heat pump tariff with several off-peak blocks plus battery can win.
If this is your situation, we recommend using the Tim and Kat Greenwalk tool below.
3) Tariff Comparison Tool
While the scenarios above provide a solid rule of thumb, every household uses energy differently.
If you would like to choose your tariff based on your exact energy data or would like to dig deeper into your strategy, we highly recommend using the Tim and Kat Greenwalk Tariff Comparison Tool. Simply enter your system details (solar output, battery size, EV mileage, heat pump use), and it estimates what each tariff would cost you over a year.
Get in touch and further resources
If you would like a personal advice on choosing your tariff do get in touch with the Ulex Energy team.
To maximise your savings, we recommend you also read our article on Top Tips for Maximising Your Solar Savings.
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