What is the Smart Export Guarantee (SEG)?

The SEG requires licensed UK electricity suppliers with 150,000+ customers to offer a tariff for exported renewable electricity. It replaced the Feed-in Tariff (FiT) for new installations from January 2020. You need an MCS-certified installation and a smart or SMETS2 meter to qualify.

What is the best SEG tariff rate in 2026?

Rates vary significantly. Octopus Energy typically offers the highest variable rates (12-15p/kWh with agile export). Most large suppliers offer fixed rates of 3-5p/kWh. Rates change frequently so compare current offers. Some suppliers offer time-of-use rates that pay more during peak hours.

How much can I earn from the SEG?

A typical 4 kWp system exporting 60% of 3,800 kWh generates about 2,280 kWh of exports. At 4p/kWh this earns ~£91/year. At Octopus's 15p/kWh rate, it earns ~£342/year. The real value is in self-consumption: using 1,520 kWh saves ~£373/year at current electricity prices.

Does a battery increase SEG earnings?

A battery typically reduces exports by 20-30% as more energy is stored for self-use. This reduces SEG income but increases import savings (which are worth more per kWh). With a battery, self-consumption can rise from 30-40% to 60-80%, increasing total financial benefit.

Do I need a smart meter for SEG?

Yes, you need a smart meter (SMETS2) or a meter capable of measuring exports to receive SEG payments. If you have an older meter, your supplier must install a smart meter. Some SEG tariffs use half-hourly export data to pay variable rates based on time of day.

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Smart Export Guarantee (SEG) Calculator

Calculate your annual SEG export income and total solar savings. Compare UK supplier export tariff rates and estimate lifetime earnings from your solar PV system.

Annual Generation

Total annual solar output

Self-consumption Rate

% used directly (30-50% typical)

SEG Supplier

Export tariff varies by supplier

Electricity Import Rate

Your current electricity tariff

How We Calculate This

This calculator estimates SEG export income and self-consumption savings.

The formula

Total benefit = (Exported kWh × SEG rate) + (Self-consumed kWh × Import rate)

Exported = Annual generation × (1 - self-consumption %)
Self-consumed = Annual generation × self-consumption %
Battery increases self-consumption by ~25%
Self-consumption worth more than export (24.5p vs 3-15p)

Frequently Asked Questions

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Last updated: March 2026

All calculations are estimates. Verify with your supplier.