Why has the network operator limited how much my solar can export?
Short answer
Systems above about 3.68 kW per phase need a G99 application, and where local cables or transformers are already full of solar the network operator can approve only a lower export, enforced by an export limitation device. You can still generate more and use or store it, but surplus above the limit is curtailed.
Last checked 24 September 2026 · 1 source
In more detail
- G98: fully type-tested microgeneration up to 16 A per phase (~3.68 kW single-phase) - connect and notify.
- G99: larger systems need application before connection; DNO may offer export-limited connection or reinforcement.
- Customer Limitation Schemes must comply with EREC G100; reduce export typically within 15 s, max 60 s; settings protected/sealed (NGED).
- A battery can absorb midday surplus that would otherwise be curtailed; export limit also caps how fast a battery can export.
The facts, dated
- 01Customer limitation schemes must reduce export typically within 15 s, max 60 s (NGED) — 15/60 s
regulation · England · checked 24 September 2026 · connections.nationalgrid.co.uk
- 02G98 threshold ~16 A per phase (~3.68 kW single-phase) — 3.68 kW
standard · GB · checked 24 September 2026 · connections.nationalgrid.co.uk
What we saw in the field
[QA review 2026-09-24] C1-4 AGREES. H-11 UNVERIFIABLE: free street-cable upgrade (late 2022, before Ofgem Access SCR changes of 1 Apr 2023) - say 'may', not 'will'. | Earlier notes: Customer 1: DNO capped export at 5 kW (wanted 7.5 kW) due to saturation, bottlenecking battery charge/discharge - consistent with G100 limits applying to battery export too. Homeowner: DNO upgraded street cable at no cost - DNOs may reinforce at their cost for small connections.
Sources
- connections.nationalgrid.co.uk — connections.nationalgrid.co.uk/customer-export-limitation-schemes
Last checked: 24 September 2026