G98 Explained: Grid Notifications, Limits, and Whether Plug-In Solar Can Sell Electricity Back to the Grid
When I first started researching plug-in solar seriously, G98 was the piece that confused me most. It sounds like a filing cabinet reference. Most articles mention it in passing and move on. But G98 is the specific piece of engineering law that governs how your solar system connects to the electricity network, what you have to tell your distribution company, and whether you can ever get paid for electricity you generate but do not use.
This article covers all of it. G98 in full, what it means for a plug-in solar install, the one-per-household limit and why it exists, what G99 is and when it applies, and then a plain honest account of whether plug-in solar can earn you money through grid export. Some of what you read elsewhere on this topic is out of date or wrong. Here is what the position actually is as of August 2026.
What G98 is
G98 is the Engineering Recommendation issued by the Energy Networks Association (ENA) that governs the connection of small electricity generators to the low-voltage distribution network. Its full name is Engineering Recommendation G98: Requirements for the Connection of Fully Type Tested Micro-generators (up to and including 16A per phase) in Parallel with a Public Low Voltage Distribution Network.
In plain English: G98 is the set of rules covering any device in your home that generates electricity and runs in parallel with the grid. “In parallel” means running at the same time as the grid supply, feeding power into the same circuits. A solar microinverter does this. So does a wind turbine, a micro-CHP unit, or any other micro-generator below 16A per phase output — which translates to around 3.68kW on a single-phase supply, which is what all UK domestic properties have.
G98 defines what technical requirements those generators must meet (anti-islanding protection, voltage and frequency limits, type testing to EN 50549-1), what the DNO notification process looks like, and what the limits on connection are. It is not a piece of government legislation — it is an engineering standard developed by the ENA with input from the DNOs, Ofgem, and industry. But it has the force of a requirement because your electricity supply agreement, your home insurance in many cases, and the regulatory framework around grid connections all reference it.
The two things G98 requires for plug-in solar
There are two requirements that directly affect plug-in solar owners in the UK as of August 2026.
Requirement 1: Type testing of the inverter
G98 requires that any micro-generator connecting to the grid is fully type tested to the relevant standard. For a solar microinverter, the relevant standard is EN 50549-1. This covers anti-islanding performance, voltage and frequency response, power quality, and electromagnetic compatibility. A type-tested inverter has been assessed by an accredited test laboratory and its performance verified against these parameters.
Under SI 2026/848 — the legislation that legalised plug-in solar from 27 August 2026 — certified plug-in solar kits must have their inverter listed on the ENA G98 Type Test Register. This is a public register maintained by the ENA showing every inverter that has been type tested and approved for connection to the UK network under G98. If an inverter is not on the register, it cannot legally be connected under the socket-connection route.
As of the date this article was written, no plug-in solar kit has yet appeared on the ENA G98 Type Test Register for the socket-connection route under IPS v2. The register is updated when manufacturers complete certification. EcoFlow, given their government partner status, is expected to be among the first. Check the ENA register at energynetworks.org/g98 before buying if socket connection is what you need.
Requirement 2: DNO notification
G98 requires that before you connect a micro-generator to the grid — which includes a plug-in solar system — you notify your Distribution Network Operator. This is the electricity network company that owns and operates the cables and transformers in your area, not your energy supplier. The six DNOs in Great Britain are: Northern Powergrid, Electricity North West, National Grid Electricity Distribution (NGED, covering the Midlands, South West, and South Wales), SP Energy Networks (covering the North West and Scotland), Scottish Hydro Electric Power Distribution (SHEPD), and UK Power Networks (South East and East of England).
The notification process is a free online form, typically taking 10 to 15 minutes to complete. It tells the DNO your name, address, the generator’s rated output, the inverter model, and confirms that the system meets G98 requirements. Under G98, the DNO cannot refuse a notification for a compliant system. They have 28 days to respond, and if they do not respond within that period the connection is deemed approved. In practice most DNOs acknowledge notification within a few days.
One important nuance: the G98 notification is required before connection, not within 28 days afterwards as is sometimes stated. The 28-day figure is the DNO’s response window, not a grace period for your notification. Submit the form before you plug in or connect the system. You can find your DNO and their G98 notification portal via the ENA postcode lookup tool at energynetworks.org.
The one-per-household limit: what it is and where it comes from
This is the part of the G98 rules that causes the most confusion in 2026, because the product specification and the network connection rules are currently saying slightly different things.
What G98 says
G98 Issue 2 Amendment 1 — the current version, updated in 2026 to accommodate plug-in solar — limits certified plug-in solar to one device per household. One kit, one household, regardless of how many ring circuits or floors or rooms the house has. This is the live restriction as of 27 August 2026.
What the IPS v2 says
The Interim Product Specification version 2 (published July 2026 and written into law by SI 2026/848) says one certified device per final ring circuit. A two-storey house with a downstairs ring circuit and an upstairs ring circuit could theoretically have one device on each under the IPS rules. This is a less restrictive limit than G98.
The conflict and how it resolves
The IPS v2 itself acknowledges the conflict. It contains a note that the G98 network connection rules restrict installations to one device per household “unless and until G98 is amended.” Since G98 has not been amended to match the IPS v2 per-circuit rule, the G98 one-per-household limit governs in practice. The IPS sets a future direction; G98 sets the current reality.
DESNZ acknowledged during the consultation that G98 would need amending to unlock the per-circuit allowance. That amendment has to go through the ENA’s engineering governance process, which involves the DNOs, Ofgem, and technical review. There is no confirmed timeline. “Once G98 is amended” is the honest answer on when multiple socket-connected systems per household become possible.
What this means practically
Under the socket-connection route: one certified plug-in system per household, until G98 is amended.
Under the hardwired route: a CPS-registered electrician connecting a system to a dedicated circuit at the consumer unit is not using the socket-connection route and is not subject to the same restriction. Two hardwired systems on two separate dedicated circuits, each notified under G98, is possible — but it requires an electrician for both and a combined G98 notification covering the total output, which must stay within the 3.68kW G98 threshold.
G99: when it applies and what it involves
G99 is the Engineering Recommendation for generators above 16A per phase — above around 3.68kW on a single-phase domestic supply. G99 involves a formal application to the DNO rather than a simple notification, a technical assessment by the DNO’s network planning team, and in some cases physical network upgrades before connection is permitted. It can take weeks and DNOs charge application fees that vary by network and system size.
For plug-in solar, G99 becomes relevant in one specific scenario: when the total generation capacity at your property — existing rooftop solar plus the new plug-in system — exceeds 3.68kW combined AC output.
The G98 to G99 threshold is cumulative per property. If you have a 3kW rooftop system and you add an 800W plug-in system, you have 3.8kW total. That is above the 3.68kW G98 threshold, and the addition requires a G99 application rather than a simple G98 notification. G99 is not a refusal — it is a more detailed assessment — but it takes longer and costs more. If your rooftop system is 2.5kW or less, adding 800W keeps the total at 3.3kW and G98 applies.
The practical implication: check the nameplate output of your existing rooftop inverter (it is on the inverter itself or in your MCS certificate) before adding plug-in solar, and calculate whether the combined total triggers G99. If it does, budget for extra time and potentially a small application fee from your DNO.
Finding your DNO and submitting the notification
Your DNO is determined by where you live, not by who you buy your electricity from. The two are completely separate companies. Your energy supplier (Octopus, British Gas, OVO, and so on) is not your DNO.
To find your DNO: the ENA postcode lookup at energynetworks.org/customers/find-my-network-operator tells you which of the six networks covers your address.
Northern Powergrid covers Yorkshire, the North East, and parts of the East Midlands. Electricity North West covers the North West of England. NGED (National Grid Electricity Distribution) covers the Midlands, South West England, and South Wales. SP Energy Networks covers South Scotland and North West England as separate divisions. SHEPD (Scottish Hydro Electric Power Distribution) covers the Highlands and Islands of Scotland. UK Power Networks covers South East England, the East of England, and Greater London.
The notification form asks for your name, address, the system’s rated AC output in kW, the inverter manufacturer and model, confirmation that the inverter is G98 type tested, and the date you intend to commission the system. For a certified socket-connected kit, the inverter model should already be on the ENA register — the notification confirms the connection, it does not seek approval. Submit it, keep the confirmation, and you are done.
Can plug-in solar sell electricity back to the grid?
This is the question that comes up in almost every comment thread on plug-in solar and the answer is more nuanced than a simple yes or no.
The official position: no
The Smart Export Guarantee (SEG) is the UK scheme that pays homeowners for electricity they export to the grid. Rates in 2026 range from around 4p per kWh (basic rates from large suppliers) to 15p per kWh (Good Energy Solar Savings), with some time-of-use tariffs paying higher rates at peak. Over a year, a 4kW rooftop system exporting 1,500 kWh earns £60 at 4p or £225 at 15p. That is real money.
SEG access requires MCS certification of the installation. MCS — the Microgeneration Certification Scheme — requires that the installation is designed, specified, and commissioned by a registered MCS contractor following their quality framework. Plug-in solar is self-installed (or installed outside the MCS framework under SI 2026/848) and cannot achieve MCS certification. No MCS certificate means no SEG eligibility, regardless of how much electricity you generate or export.
This is a meaningful financial difference. If your plug-in system exports any electricity — which it will on days when you are out and the sun is shining — that electricity goes to your neighbours’ homes via the grid and you receive nothing for it. There is no mechanism for payment and no way around this under current rules.
The reality of plug-in solar and export
How much are plug-in solar owners losing by not being able to access SEG? Less than you might think. Plug-in solar is optimised for self-consumption — the system generates into the same circuits your appliances draw from, so generation is consumed immediately where possible. A battery-integrated system like the EcoFlow STREAM can store surplus for later use, further reducing what gets exported.
A typical 800W plug-in system with no battery and average household usage self-consumes around 25 to 40% of what it generates. At 30% self-consumption on 640 kWh of annual generation, that is around 190 kWh consumed and 450 kWh exported. At the best current SEG rate of 15p per kWh, those 450 kWh would be worth £67.50 per year. That is the annual SEG value you are currently giving up. Not nothing, but it is not the dominant factor in the economics.
With a battery pushing self-consumption to 75%, the exported fraction drops to around 160 kWh per year. The forgone SEG income drops to around £24. At that point the SEG gap is genuinely minor.
The informal Octopus route
There is one grey area worth knowing about. Several plug-in solar owners have reported that after contacting Octopus Energy directly and explaining their setup, Octopus has enabled export readings on their SMETS2 smart meter and started paying for exports — informally, outside the official SEG framework. This is not guaranteed, not documented as official policy, and could change. But if you are on Octopus Energy and have a SMETS2 meter and believe you are exporting meaningfully, it is worth a direct conversation. Ask whether they can enable export readings and pay you for what you export. The worst outcome is that they say no.
What might change
A simplified SEG pathway for certified plug-in systems is widely discussed for 2027. The logic is straightforward: once plug-in systems are on the ENA G98 Type Test Register, certified, traceable, and safely connected, the argument that they cannot access SEG because they are “not properly installed” becomes harder to sustain. A consultation on SEG eligibility for certified plug-in solar is a logical next step once the first products appear on the register.
If and when it comes, the change would be meaningful. An 800W plug-in system exporting 400 to 450 kWh per year at 12p per kWh earns £48 to £54 annually. That improves payback by one to two years on a £700 kit. Worth watching, but not worth waiting for before buying if the self-consumption case already makes sense for you.
The G98 compliance checklist for plug-in solar
Is the inverter on the ENA G98 Type Test Register? Check at energynetworks.org/g98 before buying. For the socket-connection route under SI 2026/848, the inverter must be on the register. For a hardwired installation by a CPS electrician, the electrician confirms G98 compliance as part of their work.
Is this your first generator at this address? If yes, you are under the 3.68kW G98 threshold and simple notification applies. If you already have rooftop solar, calculate whether the combined output exceeds 3.68kW. If it does, G99 applies instead.
Submit the G98 notification before connecting. Find your DNO at energynetworks.org, complete their notification form, keep the confirmation. Free, around 15 minutes.
One certified socket-connected system per household. The one-per-household limit under G98 is live as of August 2026. Multiple hardwired systems with a combined G98 notification via a CPS electrician are possible subject to the total output threshold.
Keep your notification confirmation. If you sell the property, the G98 notification is part of the installation documentation. If you disconnect and move, a fresh notification is required at the new address.
The honest financial picture
After all of the above, here is what G98 compliance and the current absence of SEG access actually means for the economics of plug-in solar.
An 800W system generating 640 kWh per year in central England. At 30% self-consumption with no battery, you save around 192 kWh from the grid — worth £50 per year at 26.11p. At 75% self-consumption with a battery, you save around 480 kWh — worth £125 per year. The 450 kWh of exports at 0p represents a missed opportunity of up to £67 at current best SEG rates. With a battery, the forgone SEG income is around £24.
These are the numbers the economics of plug-in solar should be built on. Not headline figures that assume high generation, high self-consumption, and SEG export payments simultaneously — none of which are guaranteed for a plug-in install. The self-consumption savings are real and predictable. The SEG income is currently zero for plug-in solar. If you buy a system today expecting export payments, you will be disappointed. If you buy knowing you are saving on self-consumption with SEG potentially arriving in future, the case is honest and defensible.
For a breakdown of what 800W actually generates across the year and how that translates to bill savings by tariff, the savings calculator runs the PVGIS dataset for your postcode. For the full regulatory picture on SI 2026/848, see our August 2026 regulations article. For how tariff choice interacts with the economics, see our energy tariff guide. And for the SEG situation in full detail, including the informal Octopus route and what 2027 might bring, see our dedicated SEG article.
If you have been through the G98 notification process and hit any unexpected complications, or if your DNO responded in an unusual way, leave a comment below. Real experience from people going through the process is useful for everyone who comes after.