Smart Export Guarantee (SEG) and Balcony Solar: Can You Get Paid for Excess Generation?

Section 1: What Is the Smart Export Guarantee?

The Smart Export Guarantee (SEG) is a government-backed scheme requiring energy suppliers with 150,000 or more domestic customers to offer a tariff that pays for electricity you export to the grid. It replaced the Feed-in Tariff (FiT), which closed to new applications in March 2019, and came into effect from 1 January 2020.

Unlike the old Feed-in Tariff, the SEG does not have a fixed government-set rate. Each eligible supplier sets its own export rate, and these vary considerably — from less than 1p/kWh to over 15p/kWh, depending on the supplier and tariff product. Ofgem publishes a register of all approved SEG licensees and their current rates, which is the definitive source for current figures.

The mechanism is simple in principle. You install generation equipment (solar panels, wind, hydro, or other eligible technologies), register with a SEG licensee, and a smart meter records your export. At the end of each billing period, the SEG payment is credited to your account. Payments are based on actual export measured in kilowatt-hours.

To export, your meter must either be a smart meter (first generation SMETS1 or second generation SMETS2) or have a separate export meter. Most UK homes now have smart meters, and SMETS2 meters in particular can measure export directly. If you have an older non-smart meter, export cannot be accurately measured and SEG registration is not possible without a meter upgrade.

Section 2: The MCS Certification Problem

Here is where the good news stops for most balcony solar owners: to register for the Smart Export Guarantee, your installation must hold certification under the Microgeneration Certification Scheme (MCS).

MCS is an industry-managed quality assurance scheme for small-scale renewable energy installations. It certifies both the equipment (panels, inverters) and the installer. For an installation to hold MCS certification:

• The installation must be carried out by an MCS-accredited installer.
• The equipment used (panels and inverter) must each be individually listed on the MCS product database.
• The installer must complete an MCS installation certificate for your specific installation, which is registered with MCS.

Currently, there is no MCS certification pathway for DIY plug-in solar installations. The MCS scheme covers rooftop solar systems installed by qualified contractors — it is not designed for a consumer plugging a cable into a socket. No MCS-accredited installer would certify a plug-in balcony solar installation under the current scheme rules, because the plug-in installation method does not conform to the certified installation standards.

The practical consequence: virtually all UK balcony solar owners cannot currently register for the SEG. You can generate electricity, you can self-consume it, but you cannot earn SEG payments for what you export.

Section 3: Current SEG Rates from Major Suppliers

SEG rates change frequently — suppliers revise them based on wholesale electricity prices, competitive positioning, and policy. The figures below are approximate rates as of early 2026; always check Ofgem's SEG register for current rates before making any financial decisions.

Rates as of early 2026 — approximate only. Verify on Ofgem's SEG register before making decisions.

The spread between the best and worst rates is dramatic: Octopus Energy's export rate is five times that of British Gas. For a household with significant export, switching supplier to maximise the SEG rate (once you are eligible) makes material financial difference.

Section 4: Does This Matter for Balcony Solar Right Now?

For most balcony solar owners, the SEG is currently irrelevant in practice — not because export does not occur, but because you cannot register to receive payment for it.

To put the potential value in context: a 600W south-facing system in London generates approximately 320 kWh per year. For a commuter household with 40% self-consumption, the remaining 192 kWh is exported to the grid. At the best current SEG rate (15p/kWh from Octopus), that would be worth £28.80 per year. At British Gas's rate, it would be £5.76.

These are not transformative amounts, but £28.80/year is not nothing — particularly when it is currently being earned by your energy supplier rather than you. Over a 20-year system life, that is approximately £576 in forgone export income even at the best current rate.

For a household with higher export (larger system, lower self-consumption), the numbers are proportionally larger. And if SEG rates rise — which some analysts expect as the grid increasingly needs to manage distributed generation — the value of export payments will increase further.

Section 5: What Is Changing

The government's March 2026 legalisation announcement explicitly acknowledged the SEG gap for plug-in solar owners. Ofgem has been consulting on whether a simplified SEG registration pathway — potentially without full MCS certification — could be created for plug-in solar devices below a defined power threshold.

The key questions under consultation are:

• Whether export metering accuracy is sufficient for SEG payments without a dedicated generation meter (answer: smart meters can measure export accurately, so yes).
• What the minimum quality standard should be for a plug-in solar device to qualify for SEG export payments — likely tied to the BSI standard currently under development.
• Whether a simple online registration (similar to Germany's Marktstammdatenregister) could replace the full MCS installation certificate for plug-in devices below 1kW.

The expectation in the industry is that a simplified SEG pathway for plug-in solar will be part of the full legalisation package, likely in 2027. Until then, SEG payments remain out of reach for balcony solar owners regardless of installation quality.

Section 6: Octopus Flux and Smart Tariff Interaction

For those with battery storage systems — particularly systems like the EcoFlow STREAM or Growatt NOAH 2000 that combine plug-in solar with an integrated battery — the interaction with smart tariffs is worth understanding, even if SEG registration is not yet available.

Octopus Flux is a tariff product that offers:

• Cheap overnight import — typically around 17–20p/kWh from midnight to 4am, compared to the standard rate of around 24p/kWh.
• Mid-rate daytime import — roughly 24–28p/kWh during normal hours.
• Premium peak export — 28–32p/kWh during the 4pm–7pm peak period, for customers who export to the grid.

The Flux strategy for a battery owner is to charge the battery cheaply overnight (using the cheap import rate), fill any remaining capacity with solar during the day, and then discharge the battery to the grid during the premium peak period — or use it to avoid buying expensive peak electricity.

Currently, balcony solar owners cannot register as SEG exporters, so the export premium on Flux is not accessible. However, the import benefits still apply: charging your battery overnight at 17p and discharging it in the evening instead of buying at 28p is worthwhile independently of solar generation. The solar generation then provides the free daytime charging that makes the system even more effective.

See our smart tariffs guide for a full breakdown of how balcony solar interacts with time-of-use tariffs.