The best Smart Export Guarantee rate cannot be identified by one permanent league table. Suppliers change tariffs, eligibility, time windows, and linked-product conditions. The useful comparison is the annual net value for a specific home's export profile.
Start with measured or realistically estimated half-hourly exports, then compare each offer's full contract.
Why a static best-rate table fails
SEG tariffs can open, close, or change. Some are available to any eligible generator, while premium rates may require the supplier's import tariff, a particular battery, an installation bought from the company, remote control, or a compatible smart meter.
A page that lists rates without an effective date and eligibility details becomes misleading quickly. This framework remains useful when the numbers change.
Check supplier pages directly before applying.
Collect your export profile
Annual exported kWh is a starting point. Time-of-use tariffs also require the time of export.
New solar buyers can use the installer's monthly generation estimate, a realistic self-consumption assumption, and expected battery behaviour. Existing owners should use smart-meter export data when available.
Separate summer daytime exports, winter exports, and any battery-controlled evening exports. A household exporting most energy at midday may receive little benefit from a high evening-only rate unless storage can shift energy economically.
Compare the export rate structure
Record whether each offer is fixed, variable, or time-based. For time-based offers, list every window and rate, not just the maximum.
Estimate annual revenue by multiplying exported kWh in each period by its applicable rate. Do not apply the peak figure to all exports.
For variable tariffs, read how and when the supplier can change the rate. The SEG requires compliant tariffs to remain above zero, but it does not guarantee the advertised rate for the life of the panels.
Include import tariff and standing charge
A premium export offer may require the same supplier for imported electricity. Compare the import unit rates, time bands, standing charge, exit fees, and household usage.
An extra penny earned on 2,000 exported kWh adds £20 per year. Paying two pence more on 4,000 imported kWh costs £80. The higher export headline would lose money in that simplified example.
Run the whole annual bill, not one side of it.
Check eligibility conditions
Create a yes-or-no column for:
- Existing solar accepted.
- MCS certificate required.
- Compatible smart meter and export MPAN available.
- Import customer requirement.
- Installation purchased from the supplier.
- Specific inverter or battery required.
- Grid-charged battery exports accepted.
- Remote-control or flexibility participation required.
- Geographic or technology restrictions.
An attractive tariff that the system cannot access has no practical value.
Battery rules and arbitrage
Some tariffs reward export during expensive grid periods. A battery might store solar or lower-cost grid electricity and export later.
Model charging cost, round-trip loss, usable capacity, inverter power, reserve level, cycle limits, degradation, and warranty terms. Exporting one kWh may require more than one kWh of imported or solar energy because conversion is not lossless.
Confirm that the tariff permits the intended behaviour. A supplier can set conditions for storage exports, particularly where grid energy is involved.
Contract and payment details
Record contract length, rate guarantee, variable-rate notice, exit fee, payment frequency, minimum payment threshold, reading method, billing dispute process, and customer support route.
Check what happens if the import tariff changes, a smart meter loses communication, the battery is replaced, or the homeowner moves. Read the actual terms rather than relying on the marketing summary.
Cash flow matters less than annual value, but long payment delays can still be inconvenient.
A practical comparison table
| Factor | Offer A | Offer B | Offer C |
|---|---|---|---|
| Annual exported kWh by tariff window | kWh by period | kWh by period | kWh by period |
| Estimated annual SEG revenue | ?/year | ?/year | ?/year |
| Import electricity cost | ?/year | ?/year | ?/year |
| Standing charge | ?/year | ?/year | ?/year |
| Battery/control cost or benefit | ?/year or note | ?/year or note | ?/year or note |
| Contract and exit cost | Fees and term | Fees and term | Fees and term |
| Net annual household value | ?/year | ?/year | ?/year |
| Eligibility confirmed | Yes / no | Yes / no | Yes / no |
Use the same annual usage and export data in every column.
Example comparison
Suppose a home exports 2,400 kWh per year. Offer A pays a simple flat rate and produces £360. Offer B advertises a higher peak rate but the home's export timing produces £390. If Offer B's linked import tariff costs £70 more annually, its net position is £320 before any other differences.
Offer A is stronger in that scenario despite the lower advertised maximum. A battery could change the result, but only after losses, charging cost, and additional cycling are included.
Review dates and switching
Set a reminder before the fixed term ends and at least once a year. Download current terms and keep acceptance emails because tariff pages can change.
Before switching, confirm the new supplier's start date, export MPAN process, final reading, and whether there could be a payment gap. Keep the old account open until the final statement is reconciled.
Read the Smart Export Guarantee explained for scheme fundamentals.
Avoid these comparison shortcuts
- Ranking offers only by their maximum p/kWh.
- Ignoring linked import prices and standing charges.
- Using total generation instead of exported energy.
- Assuming all battery exports qualify.
- Valuing every exported kWh in the peak window.
- Treating a current tariff as guaranteed for decades.
- Switching before checking meter and payment continuity.
The best SEG rate is the one that wins a transparent household model and remains operationally suitable. Update the inputs whenever tariffs, usage, storage, or export behaviour changes.