Time-of-Use Tariffs & Solar: Save More
Want to know what system suits this tariff?
Export tariffs pay very differently depending on your system size and whether you have a battery. See what setup would actually earn you the most at your home.
Size a System for This TariffFree. Uses your postcode and usage — no phone number needed.
How do time-of-use tariffs work with solar?
Time-of-use (ToU) tariffs charge different electricity rates at different times of day — typically: cheap overnight (7–10p), standard daytime (~24p), and expensive peak (~30–36p). For solar + battery owners, this creates a profit opportunity: charge the battery from solar (free) or overnight cheap rate, then export or self-consume during expensive peak periods. ToU tariffs add £200–£520/year to solar + battery savings compared to flat-rate tariffs.
How Time-of-Use Tariffs Create Value
The arbitrage opportunity:
With a flat tariff, every kWh costs the same (~26.11p) regardless of time. With a ToU tariff, prices vary:
| Period | ToU Rate | What You Do |
|---|---|---|
| Overnight (cheap) | 7–10p | Charge battery + EV from grid |
| Morning (standard) | ~24p | Battery powers home until solar kicks in |
| Midday (solar peak) | N/A (free solar) | Solar powers home + charges battery |
| Peak demand (expensive) | 30–36p | Battery exports at premium OR powers home (avoiding expensive import) |
| Evening (standard) | ~24p | Battery covers remaining evening |
Value per kWh cycled through your battery: - Buy overnight at 10p → use during peak at 36p = 26p profit per kWh - On a 10kWh battery: £2.60/day = £949/year in pure arbitrage
Combined with solar self-consumption: - Solar (free) → charge battery → export at peak (24–36p) = 24–36p value per kWh - Far higher than SEG fixed rate (4.5p)
Source: Octopus Flux/Go rate structures; arbitrage calculations.
Best Time-of-Use Tariffs for Solar
Want to know what system suits this tariff?
Export tariffs pay very differently depending on your system size and whether you have a battery. See what setup would actually earn you the most at your home.
Size a System for This TariffOctopus Flux (best for battery owners): - Off-peak: ~10p (02:00–05:00) - Standard: ~26p (05:00–16:00 & 19:00–02:00) - Peak import: ~36p (16:00–19:00) — AVOID importing - Peak export: ~24p (16:00–19:00) — MAXIMISE exporting - Best for: solar + battery (export stored energy at peak)
Octopus Go (best for EV owners): - Off-peak: 7.5p (00:30–05:30) - Standard: ~26.11p (rest of day) - No premium export or peak penalty - Best for: solar + EV (cheap overnight EV charging)
Octopus Agile (for advanced users): - Half-hourly pricing (changes every 30 minutes based on wholesale market) - Can be as low as 0p (or negative!) during oversupply - Can be as high as 50p+ during peak demand - Best for: tech-savvy users with automated battery management - Risk: unpredictable — requires active management or smart inverter
Intelligent Octopus Go (for smart EV owners): - Extends the 7.5p overnight window based on when your EV needs to be charged - Smart scheduling optimises charging around your departure time - Best for: EV owners with compatible smart chargers
Source: Octopus Energy tariff details March 2026.
Setting Up Your System for ToU Tariffs
- Get a smart meter (required for all ToU tariffs) — free from your supplier
- Choose a battery with ToU automation (GivEnergy has built-in Flux/Go modes, Tesla supports Octopus)
- Set charge/discharge schedules — your inverter manages when to charge from grid and when to discharge
- Avoid peak import (16:00–19:00 on Flux) — use battery or solar during this window, never grid
- Run heavy appliances during solar hours or overnight cheap window — NOT during peak
- Monitor your savings — your app shows how much you save from tariff optimisation vs flat rate
- Review every 6 months — tariff rates change. Ensure you are still on the best deal.
Frequently Asked Questions
Related guides
Related: Home Heating Systems
Solar panels are most powerful when combined with an efficient heating system. Heat pumps use solar-generated electricity to heat your home at 300-400% efficiency — making them the ideal partner for solar.
Heat pumps use electricity at 300-400% efficiency, making them ideal partners for solar.
From our sister site Home Heat Pump Guide
You might also like
Want to know what system suits this tariff?
Export tariffs pay very differently depending on your system size and whether you have a battery. See what setup would actually earn you the most at your home.
Size a System for This TariffFree. Uses your postcode and usage — no phone number needed.