SEG for Businesses: Rates & Registration

The Feed-in Tariff (FiT) is closed to new applicants; SEG is the successor mechanism with a different design. The table above contrasts the key cash-flow characteristics.

Do not model a new system on FiT assumptions. The two value streams from your array are displacement of imported kWh (your primary financial benefit) and SEG export income (secondary). A CFO should model import displacement first and export tariff shopping second. The distinction is not academic: FiT paid for every kWh generated, regardless of where it was used, whereas SEG only pays for the surplus that crosses the export meter. This changes the payback calculus for commercial arrays, making load profile and self-consumption behaviour material to the investment case. For business leaders assessing this shift, understanding the strategic role of solar in a net zero plan can help contextualise its evolving financial value.

Unused surplus has a price, but self-consumed kWh often beat export because they avoid the full import rate. Prioritise displacing imported kWh before optimising export income. For a deeper dive into the overall financial picture, readers can explore the full breakdown of potential savings for UK businesses.

Qualitative arbitrage strategy: time-of-use import tariffs combined with export timing and battery storage can act as a "virtual battery." Smart inverters with export limiting allow precise control of what is sent to the grid versus consumed on-site. However, this strategy only works if your chosen SEG product and import contract actually price that timing. Grid charges, battery capex, and degradation must be factored into the decision. The key nuance is that a battery's arbitrage value is not simply the SEG tariff it enables; it is the delta between the import rate avoided and the export rate received, minus charging losses and any demand charges. For a site with high peak demand, shifting load may deliver more value than maximising export. Reviewing various commercial solar battery storage options is a practical first step in this analysis.

When not to pursue arbitrage:

• High daytime self-use: your site already consumes most generation.
• SEG contracts that do not pay time-varying export.
• Assuming arbitrage profit without modelling actual load and export profiles.

If timing is not rewarded by your contracts, justify batteries on bill reduction, not SEG income. To quantify these scenarios, our commercial solar ROI calculator can provide a baseline assessment.

Eligibility for SEG requires: MCS certification (or equivalent), total capacity of not more than 5MW, measured export via an export meter, and connection evidence (DNO, G98/G99 where relevant). PV is the primary technology; other eligible technologies (wind, hydro, mCHP, AD) are a minor consideration for most commercial solar sites. For complex installations, it is crucial to understand the G99 and G100 connection requirements early in the project.

Measured export is the requirement; SMETS smart meters are common evidence but not the only conceptual path. Commercial half-hourly metering may be required in some cases, but do not assume a specific threshold, confirm with the chosen licensee. Flexi-Orb may be accepted by some licensees as alternative certification, not a universal substitute. MCS and DNO approvals belong in the install programme, not a finance afterthought. A consumer-style "photo of the smart meter" is incomplete for commercial sites; missing schematic, DNO, or G99 evidence is a typical payment delay. The distinction matters because a half-hourly settled site may have metering infrastructure that a smart meter does not substitute; the licensee will specify what evidence it needs to verify export volume, and that may include import/export half-hourly data for larger connections.