If you have looked into solar or battery storage, you may have hit a confusing number: 3.68kW. It is often quoted as the most you can export to the grid without extra paperwork, and it catches people out. Why would a network operator care what you export, and why is the limit that oddly specific figure? And more usefully: if 3.68kW is not enough for your system, what do you actually do about it?
What a DNO is, and who covers your area
A Distribution Network Operator owns and runs the local wires and substations that carry electricity from the transmission network to homes and businesses. It is a separate company from your electricity supplier. It is who you contact for a power cut, and it is who has to approve any generating equipment connecting to its network, whether that is solar panels, a battery that can export, or wind.
There are 14 DNO licence areas in Great Britain, run by six ownership groups. Lincolnshire is not covered by a single one. Most of the county, including Lincoln, Boston, Sleaford, Grantham and Skegness, sits in National Grid Electricity Distribution’s East Midlands licence area. North and North East Lincolnshire, including Scunthorpe and Grimsby, sit instead with Northern Powergrid.
The boundary runs by postcode rather than by district name, so confirm your own DNO using National Grid’s distribution area postcode search before relying on anything below. If your property is anywhere near the Lincolnshire and Yorkshire boundary, do not assume.
G98: connect first, notify after, for small installations
G98 is the fast route. It applies to micro-generating installations, which covers most domestic solar and home battery setups, with an aggregate registered capacity of 16 amps per phase or less.
That is where 3.68kW comes from. It is not a marketing number. It is 16 amps multiplied by the UK’s standard 230 volt single-phase supply, which gives 3,680 watts. If your property has a three-phase supply, the same 16 amps applies to each phase, giving 11.04kW in total.
Under G98, for a single premises, the installer can install and commission the system before telling the DNO about it. The installer then submits a G98 Installation Document and an operation diagram to the DNO within 28 days of commissioning. It is genuinely a notify-after process, which is why it is the quickest route when a system qualifies.
G99: apply first, wait for approval, for anything bigger
G99 is the route for anything above the G98 threshold, meaning above 16A per phase, or anything that does not otherwise meet G98’s requirements. That covers most solar arrays over about 3.68kW and many battery systems that can export at a high rate. It also catches systems that are individually small but combine with existing generation on site to cross the threshold.
Unlike G98, you cannot energise the system first. The DNO has to assess and formally approve the connection before it goes live. What it is checking is whether your generation could push local voltage or fault current outside safe limits, or overload the section of network your property sits on, given everything else already connected nearby. That is a network capacity question, not a judgement on the quality of your equipment.
How long does a G99 application take
There is no single answer, and anyone who gives you one should be treated with caution. The timescale depends on which distribution network operator covers your area, what you are connecting, and whether your local network needs reinforcing to accept it. Published accounts range from a couple of months to well over a year.
G99 itself does not set a deadline for the network operator to respond. What it does require is that the commissioning date on your application falls between ten working days and three months after you submit it, which is a duty on you, not on them.
The only timescale worth planning around is the one your own network operator gives you for your own application. Ask your installer to obtain that in writing, and to confirm it is still current, before you agree an installation date or pay a deposit against one.
G100: the export limitation route
If your proposed array or battery is larger than the G98 threshold but you cannot get, or do not want to wait for, full G99 approval, there is a middle path: export limitation under ENA Engineering Recommendation G100.
A G100-compliant scheme uses an approved control device to hold what actually leaves the property at or below the G98 threshold, even though the equipment installed is larger than that. In effect the property is allowed to generate and use more than 3.68kW, or 11.04kW on three phase, but is prevented, automatically and continuously, from pushing more than that back onto the network.
This is often the pragmatic answer for a household that wants a bigger array for self-consumption, or a battery sized for real winter resilience, without taking on a full G99 application. The trade-off is that any generation above the cap is not exported for payment, so you are choosing self-use and speed over maximum export income. That is a design decision worth making deliberately rather than discovering later, and worth having your installer confirm with the DNO before you commit to it.
How to find out who your network operator is
Your network operator is not your supplier, and it is not always the company whose name you associate with the area. Enter your postcode on the Energy Networks Association tool to find out who yours is. You can also call 105 free in England, Scotland and Wales, which connects you to your local distribution network operator.
Source: Energy Networks Association, “Who’s my electricity network operator?”, checked 17 August 2026. https://www.energynetworks.org/customers/find-my-network-operator
Who actually submits the application
The DNO application, whether it is a G98 notification or a G99 application, is submitted by the installer, not by you. The installer completes the technical forms, because the DNO is assessing how the installed equipment will behave on the network, and specifying and certifying that equipment is the installer’s responsibility.
That does not leave you with no role. It is entirely reasonable to ask your installer for the DNO reference or the acceptance confirmation before final payment, rather than assuming it has been done.
Compliance is the responsibility of the customer, who is usually, but not always, the owner of the generation. In practice a competent installer handles the submission, but the obligation sits with you, so ask who is doing it and get written confirmation that it was done.
If someone installs first and applies later
For G98-eligible systems this is not an issue. Notifying within 28 days of commissioning is the designed process.
For anything requiring G99 it is a different matter. If a system needs G99, it should not be switched on and exporting until the network operator’s written approval is in hand. Energising first is a breach of the connection terms, and the network operator can require the system to be disconnected. It can also count against you if you apply again at the same property later. There is no upside to going early, because the approval is not a formality you can backfill.
Why this matters for your export payments
There is a second reason to get this right, and it is financial. Suppliers require evidence that the connection went through the correct route before they will put a system onto a Smart Export Guarantee tariff, normally the G98 notification or the G99 acceptance alongside the system’s compliance paperwork.
A connection that skipped the process is not only a compliance problem. It can be the reason an export payment application is refused or delayed, which turns a paperwork shortcut into lost income for as long as it takes to put right.
What to ask before you sign
Four questions worth putting to any installer quoting for solar or battery storage:
- Which route does this system need, G98, G99, or G100 export limitation, and why?
- If it needs G99, what timescale has our DNO given for applications like this one, and can you confirm that in writing?
- If you are proposing G100 export limitation, how much generation will that cap prevent us exporting, and what does that cost us against an unlimited connection?
- Will you provide the DNO reference or acceptance confirmation before final payment?
Because the network operator works to its own timescale, the connection application is usually the item that sets the overall date for a project. Buy solar in winter, fit it in spring sets out how to sequence the rest of the work around it.
Adding capacity to an existing installation raises the same connection question again, and on a legacy Feed-in Tariff it raises a metering one too. See adding panels when you are on a legacy Feed-in Tariff.
What Eco Connect does, and does not, do here
Eco Connect Services provides independent advice on renewable energy decisions, including helping you work out which connection route is realistic for your property before you commit to anything. We do not install equipment and we do not submit DNO applications. Installation and the DNO application that goes with it are carried out by your chosen installer.
