Grid connection
Grid connection delays, not installer availability, are now the real bottleneck for UK solar, with some South East England DNO applications taking 20 to 24 weeks instead of the standard 4 to 8
Installer waiting lists have stayed manageable at one to four weeks even through the busy spring period, but Distribution Network Operators in constrained areas including South East England and suburban zones around major cities are processing record volumes of larger G99 connection applications, pushing approval times to five to six months in the worst cases.
30 July 2026 · Source: OpenSolar
If you're planning a solar install and picturing the installer as the thing that decides your timeline, the data says otherwise. Installer capacity has kept pace with demand, waits of one to four weeks even in the March-to-May peak season. The genuine constraint has moved upstream to the DNO, the company that owns the local electricity network and has to formally approve your connection before an install can be switched on.
The gap between the standard timeline and the worst-case one is the number that actually matters for planning. A typical G99 application, the paperwork needed for larger domestic or small commercial systems, clears in 4 to 8 weeks in most of the country. In South East England specifically, alongside suburban areas around major cities, that stretches to 20 to 24 weeks, five to six months, because those are exactly the areas where solar uptake has been fastest and local grid capacity is now genuinely constrained.
This is directly relevant if you're in Kent. South East England is named specifically as one of the constrained regions, which means the DNO timeline, not the installer's diary, is realistically the thing to plan around here. A system sized just under the G99 threshold, where that applies to your setup, avoids this queue entirely and is worth asking your installer about explicitly rather than assuming a straightforward domestic system needs the same paperwork as a larger one.
The practical takeaway is to get your DNO application in as early as possible in the process, ideally in parallel with getting installer quotes rather than after you've picked one, since the connection approval is now the longer pole in the tent for anyone in a constrained area. Asking a prospective installer directly what DNO timeline they're currently seeing in your postcode is a fair, specific question, and a good one to distinguish installers who track this from those who don't.
Read the original: OpenSolar. Commentary is Sandwich Solar's own editorial view; the original reporting is credited to its publisher.
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