G98 form guide UK: how to fill in a plug-in solar DNO application
Filling in a G98 form can look more complicated than it really is, especially if you are only trying to notify a small plug-in solar or balcony solar system.
This guide walks through the form step by step, showing where to find your MPAN number, where to find the manufacturer reference number on the ENA Type Test Register, what capacity to enter, what to do with the battery section and how a completed example should look.
Important: this guide is written to make the G98 form easier to understand. It is not a replacement for your DNO’s latest form, the latest ENA guidance, manufacturer instructions, electrical design advice or site-specific checks.
Plug-in solar and balcony solar in the UK is still a developing area. The form process may become simpler in the future, but until then many people are still faced with forms originally written for installers rather than ordinary homeowners.
Always use the latest version of the form from your own DNO and check the exact details for your equipment.
Quick answer: what information do you normally need for a G98 form?
For a simple small solar microinverter setup, the G98 form usually needs a few main pieces of information. The wording can vary depending on the DNO, but the same details come up again and again.
| Form item | What it means | Example for a small 800W microinverter system | Where to find it |
|---|---|---|---|
| Customer name | The person responsible for the electricity supply or installation. | Joe Bloggs | Your own details. |
| Installation address | The property where the solar microinverter will be connected. | 1 High Street, Leeds, LS1 1AA | Your home address. |
| MPAN | The electricity supply number for your property. | A 13-digit supply number from your electricity bill. | Your electricity bill or online energy account. |
| Registered capacity | The registered AC output of the microgenerator, usually the inverter output, not the solar panel wattage. | 0.8kW for an 800W microinverter. | ENA Type Test Register or manufacturer datasheet. |
| Energy storage capacity | The capacity of any battery connected as part of the system. | 0kWh if there is no battery. | Battery specification, or 0kWh if no battery is installed. |
| Manufacturer's reference number | The ENA Type Test Register reference for the exact inverter. | ALTEN/12127/V1/A1 for the EZ1-M example shown in this guide. | ENA Type Test Register. |
Simple version:
For many small plug-in solar style systems, the form is mainly asking:
- Who are you?
- Where is the system being installed?
- What is your electricity supply number?
- What inverter is being connected?
- What is its registered AC capacity?
- Is there a battery?
- What is the ENA manufacturer reference number?
What is G98?
G98 is an engineering recommendation used for small-scale generation connected in parallel with the public electricity network. In plain English, it is one of the routes used when a small generator, such as a solar inverter, is connected to a property that is also connected to the grid.
A plug-in solar or balcony solar system may look small, but the microinverter is still generation equipment. It is not just an appliance using electricity. It can produce electricity and feed it into the installation.
That is why the local Distribution Network Operator, usually shortened to DNO, needs to know about it.
DNO means Distribution Network Operator.
Your DNO is not always the same as your electricity supplier. Your supplier is the company that bills you. Your DNO owns and operates the local electricity network in your area.
For example, your bill might be with Octopus, British Gas, EDF or E.ON, but your DNO could be Northern Powergrid, UK Power Networks, National Grid Electricity Distribution, SP Energy Networks, Scottish and Southern Electricity Networks or Electricity North West.
Who is my DNO?
If you are filling in a G98 form, one of the first things you may need to know is who your local Distribution Network Operator (DNO) is.
The DNO owns and operates the electricity network in your area. This is often different from the company that supplies your electricity and sends your bill.
| DNO | Typical Area Covered |
|---|---|
| Northern Powergrid | North East England, Yorkshire and Northern Lincolnshire |
| Electricity North West | North West England |
| National Grid Electricity Distribution | Midlands, South West England and South Wales |
| UK Power Networks | London, East of England and South East England |
| SP Energy Networks | Central & Southern Scotland, Merseyside, Cheshire and North Wales |
| Scottish and Southern Electricity Networks (SSEN) | North Scotland and Central Southern England |
Not sure who your DNO is? Use the official ENA postcode checker linked above.
G98 vs G99: which one applies?
For most small plug-in solar and balcony solar discussions, G98 is the route people are usually talking about. G99 is generally used for larger or more complex generation systems.
This guide is focused on small single-phase plug-in solar style systems, such as an 800W microinverter connected to one or two solar panels.
| Route | Typical use | How it relates to plug-in solar |
|---|---|---|
| G98 | Small-scale generation within the G98 limits. | Often the relevant route for small microinverter systems, including many 800W balcony solar style products. |
| G99 | Larger, more complex or higher-capacity generation arrangements. | Normally not the route people expect for a very small single microinverter setup, but it can become relevant if the system is larger or more complex. |
Do not guess the route.
If the system is more than a simple small microinverter, if there are multiple inverters, batteries, export control, three-phase supplies or anything unusual, check with the DNO or a competent electrician before assuming it is a simple G98 notification.
Step-by-step: how to fill in the G98 form
The form may look formal, but for a small plug-in solar system most of the fields are straightforward once the right information has been found.
The example images in this guide use an APsystems EZ1-M style 800W microinverter example because it is a good real-world type of product for small balcony solar and plug-in solar discussions.
Have these ready:
- Your name and installation address
- Your electricity bill or online energy account
- Your MPAN number
- The exact inverter make and model
- The inverter registered AC capacity
- The ENA Type Test Register manufacturer reference number
- Battery capacity, if a battery is part of the system
Step 1: find the inverter on the ENA Type Test Register
The ENA Type Test Register is where you can look up generation equipment that has been registered against the relevant requirements. For a G98 form, the important part is finding the exact device reference for your inverter.
In the example below, the search is for the APsystems EZ1-M. The register shows one device found, with the manufacturer, model, category, registered capacity and number of phases.
On the search result, check the following:
- Compliance status: it should show as compliant.
- Manufacturer: make sure it matches the product being installed.
- Model: make sure it is the exact model, not just a similar product name.
- Category: for a solar microinverter this will normally show as inverter.
- Type: for solar it should normally show PV.
- Registered capacity: this is the figure you use for the form, not the total solar panel wattage.
- No. of phases: most small home plug-in solar systems will be single phase.
For the example shown:
- Manufacturer: ALTENERGY POWER SYSTEM INC.
- Model: EZ1-M
- Category: Inverter
- Type: PV
- Registered capacity: 0.8kW
- No. of phases: One / single phase
Useful websites for completing a G98 form
Two websites are particularly useful when completing a G98 notification:
-
ENA Type Test Register:
Search for your inverter, check its registered capacity and find the manufacturer's reference number.
https://www.ena-eng.org/gen-ttr/ -
Find your local DNO:
Use the official postcode checker if you are unsure which DNO covers your property.
https://www.energynetworks.org/customers/find-my-network-operator
Your DNO is the company that owns and operates the local electricity network in your area. It is not always the same company that sends your electricity bill.
Step 2: open the device details and check the G98 status
Once you click into the device on the register, you should see the detailed entry. This is where you can confirm the compliance status, software version, hardware version, applicable standard and the Type Test Register reference.
The most important point here is to avoid guessing. Do not use a product advert, an online shop listing or the name printed on a box if the form is asking for the manufacturer reference from the register.
The form is normally asking for the reference that identifies the product on the ENA Type Test Register.
Important:
Make sure the device on the register is the exact inverter model being installed. A similar product name is not enough. If your inverter is an EZ1-H, HMS-800, STREAM Microinverter or another model, search for that exact model and use the reference for that exact product.
Step 3: find the manufacturer's reference number
One of the most confusing parts of the G98 form is the box that asks for the manufacturer’s reference number. Many people assume this means the model number printed on the inverter.
In many cases, what the DNO really wants is the ENA Type Test Register reference for the equipment.
For the EZ1-M example
The manufacturer’s reference number shown on the ENA Type Test Register is:
ALTEN/12127/V1/A1
This is the type of reference that should be entered in the manufacturer reference section of the G98 form.
- Do not enter only: EZ1-M
- Do not enter only: APsystems
- Use the register reference: ALTEN/12127/V1/A1
Plain English explanation:
The model name tells people what the product is. The ENA reference tells the DNO which tested and registered device entry you are relying on.
Step 4: find your MPAN number
The MPAN is one of the fields that catches people out. It is not normally the number printed on the front of the meter, and it is not your energy account number.
MPAN stands for Meter Point Administration Number. It identifies the electricity supply point at the property. Your DNO uses this to know exactly which supply the generation is being connected to.
Where to look
The easiest place to find your MPAN is normally your electricity bill or online electricity account. It may be shown as:
- MPAN
- Supply number
- Electricity supply number
- Meter point number
The key number is usually the long 13-digit number at the bottom of the supply number box.
Common mistake:
The meter serial number on the front of the meter is not usually the MPAN. If the form asks for MPAN, use the supply number from your bill or online account.
Step 5: fill in the customer and site details
The first part of the form is normally the easiest. It is asking who the customer is and where the microgeneration equipment is being installed.
Use the actual installation address, not a postal contact address somewhere else. The DNO needs to know the supply point where the inverter will be connected.
For most homeowners, the customer section will usually include:
- Customer name: the person responsible for the electricity supply or installation.
- Address: the property where the microgenerator is being connected.
- Postcode: the installation postcode.
- Telephone number: a contact number in case the DNO needs to query the notification.
- Email address: use an email address you can access, as the DNO may reply there.
If the form asks for installer details:
Some forms are written mainly for professional installers. If you are completing a homeowner notification, only complete the sections that apply and follow your own DNO’s instructions. If you are not sure whether a section is required, contact the DNO before submitting the form.
Step 6: enter the registered capacity
This is one of the most important parts of the form.
For a plug-in solar or balcony solar system, the registered capacity is normally based on the AC output of the inverter or microinverter, not the total wattage of the solar panels.
For example, if a system has two 460W solar panels connected to an 800W microinverter, the panels add up to 920W DC, but the inverter output is limited to 800W AC.
In that type of example, the G98 registered capacity would normally be entered as:
0.8kW
For the EZ1-M example shown in this guide:
- Registered capacity shown on the ENA register: 0.8kW
- Number of phases: One / single phase
- Technology type: PV
Do not use panel wattage by mistake.
If you have two 450W panels on an 800W microinverter, do not automatically enter 0.9kW just because the panels add up to 900W.
The DNO form normally wants the registered generator capacity, which for a microinverter system is usually the AC output rating shown on the registered inverter entry.
Step 7: enter the energy storage capacity
Some G98 forms include a section for energy storage. This is where you would enter the battery storage capacity if the system includes a battery.
If the system is only solar panels and a microinverter with no battery, this will usually be:
0kWh
If the product includes a battery, you need to use the correct battery capacity details from the manufacturer’s specification. Do not guess this figure.
Simple version:
No battery usually means 0kWh. If there is a battery, use the manufacturer’s battery storage capacity and check whether the DNO needs any extra information.
Step 8: enter the manufacturer reference number
In the manufacturer reference section, enter the ENA Type Test Register reference for the exact inverter model.
For the EZ1-M example shown earlier, that reference is:
ALTEN/12127/V1/A1
If you are using a different microinverter, search the ENA Type Test Register for that exact inverter and copy the reference shown there.
Do not copy this reference unless you are using the same exact inverter.
The reference in this guide is an example for the EZ1-M entry shown in the screenshots. Different inverters need their own correct reference number.
Step 9: check the completed form example
The completed example below shows how a simple small plug-in solar style notification might look once the key fields have been filled in.
This is only a sample using made-up customer details. Use your own details, your own MPAN and the correct inverter reference for your actual product.
Example values for the completed form
| Form field | Example value | Why this is used |
|---|---|---|
| Customer name | Joe Bloggs | Example customer name only. |
| Installation address | Example property address | This should be the address where the inverter is connected. |
| MPAN | Example MPAN from electricity bill | This identifies the electricity supply point. |
| Registered capacity | 0.8kW | Based on the registered AC output of the microinverter example. |
| Energy storage capacity | 0kWh | Used where there is no battery storage in the example system. |
| Manufacturer reference number | ALTEN/12127/V1/A1 | The ENA Type Test Register reference for the EZ1-M example shown. |
Common G98 form mistakes with plug-in solar
Most problems with the form come from using the wrong number in the wrong box. These are the mistakes to avoid.
1. Entering the panel wattage instead of inverter capacity
A system with two 460W panels may have 920W of DC panel capacity, but if the inverter is limited to 800W AC, the registered capacity is normally 0.8kW.
2. Using the meter serial number instead of the MPAN
The MPAN is normally on the electricity bill or online account. The meter serial number is usually printed on the meter itself and is not the same thing.
3. Entering the product name instead of the ENA reference
The form may ask for the manufacturer’s reference number. For the example in this guide, that means the ENA reference such as ALTEN/12127/V1/A1, not just “EZ1-M”.
4. Forgetting the battery section
If there is no battery, the energy storage capacity is normally 0kWh. If there is a battery, use the correct manufacturer figure and check whether the DNO needs more information.
5. Using a reference for the wrong inverter
Do not copy a reference from another product just because the wattage looks similar. Search the exact make and model.
Plug-in solar examples: what capacity might be entered?
The examples below show the general idea. Always check the exact ENA entry and product documentation before submitting a form.
| Example setup | Panel wattage | Microinverter output | Likely capacity entered | Important note |
|---|---|---|---|---|
| One 430W panel with small microinverter | 430W DC | 400W AC | 0.4kW | Use the inverter registered output, not just the panel wattage. |
| Two 460W panels with 800W microinverter | 920W DC | 800W AC | 0.8kW | Common balcony solar style arrangement. |
| Two 500W panels with 800W microinverter | 1000W DC | 800W AC | 0.8kW | Panel oversizing does not automatically change the AC registered capacity. |
| Solar and battery system | Depends on panels | Depends on inverter | Use registered inverter capacity | Battery capacity may also need to be entered separately. |
Does submitting G98 mean the installation is automatically safe?
No. This is an important point.
The G98 notification is a network notification process. It tells the DNO about generation connected to the electricity network.
It does not automatically prove that your final circuit is suitable, your protective devices are correct, your socket arrangement is acceptable, your cable route is safe, your mounting is suitable or your installation complies with all relevant requirements.
G98 is not the whole safety check.
A plug-in solar system still needs to be suitable for the electrical installation it is connected to. Circuit loading, RCD/RCBO suitability, bidirectional current, cable routing, weatherproofing, isolation, labelling and manufacturer instructions all matter.
Should a homeowner fill in the G98 form or should an installer do it?
For a traditional solar installation, the installer normally handles the DNO paperwork.
Plug-in solar is different because many people are looking at small systems they may buy directly. That is one reason the current forms can feel awkward. They are often written in installer language even when the system is small.
Until the UK has a simpler process specifically designed for plug-in solar, homeowners may still need to work through forms that were not really designed for ordinary readers.
Practical advice:
If the form asks for something you do not understand, do not guess. Ask your DNO, supplier, manufacturer or a competent electrician. It is better to ask one boring question than submit incorrect technical information.
Why plug-in solar needs a simpler G98 route
The current form process is not ideal for normal homeowners. Many of the people interested in plug-in solar are not trying to install a large rooftop solar system. They may only want one or two panels and a small microinverter.
The problem is that the electricity network still needs proper information. Even a small inverter is still grid-connected generation equipment.
That is why the UK really needs a clear, simple, consumer-friendly process for small plug-in solar systems. Ideally, the customer should not need to understand every technical term just to notify an 800W inverter.
Until that simpler process exists, this guide is intended to make the current G98 form less confusing.
The aim should be simple:
Make small plug-in solar safe, properly notified and easy enough for ordinary people to understand without pushing them towards poor-quality equipment or guessing on technical forms.
Looking at plug-in solar products?
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Always check UK suitability, connection method, DNO requirements, product certification and installation instructions before buying any plug-in solar equipment.
Mounting your plug-in solar panels
Once the paperwork side is understood, the next question is usually how the panels will actually be mounted.
A good microinverter and a completed G98 form do not make a poor mounting arrangement safe. Solar panels still need to be supported properly for the location, wind exposure, panel size, angle and structure they are fixed to.
Adjustable ground mounting system for full-size solar panels, patios, gardens, flat roofs and ballast-based setups.
PluginSolarHub product Retractable Fence & Wall MountHeavy-duty retractable mounting concept for full-size solar panels on suitable fences and walls.
Mounting disclaimer:
Solar panel mounting systems must be suitable for the structure, location, wind exposure, panel size and intended use. Electrical connection, DNO notification and compliance requirements should always be checked separately.
Related PluginSolarHub guides
If you are filling in a G98 form, these related guides are worth reading as well.
Common questions about the G98 form
What is a G98 form?
A G98 form is used to notify the local Distribution Network Operator about a small generating installation connected to the electricity network. For plug-in solar, this usually means telling the DNO what microinverter is being connected, where it is installed and what its registered capacity is.
Do I use the solar panel wattage or inverter wattage on the G98 form?
For a microinverter system, the figure is normally based on the registered AC output of the inverter, not the total DC wattage of the solar panels. For example, two 460W panels on an 800W microinverter would normally be entered as 0.8kW, not 0.92kW.
Is the MPAN the number on the front of the meter?
Usually no. The number printed on the front of the meter is normally the meter serial number. The MPAN is the electricity supply number and is usually found on your electricity bill or online energy account.
Where do I find the manufacturer reference number?
Search the ENA Type Test Register for the exact inverter make and model. Open the device entry and copy the reference shown on the register. For the EZ1-M example shown in this guide, the reference is ALTEN/12127/V1/A1.
What do I enter for energy storage if I do not have a battery?
If there is no battery storage, this is normally entered as 0kWh. If a battery is included, use the correct battery capacity from the manufacturer’s specification and check whether the DNO needs extra information.
Does G98 approval mean I can plug solar into any UK socket?
No. G98 notification and equipment registration do not automatically mean any socket or circuit is suitable. Circuit design, protective devices, cable routing, RCD/RCBO suitability, manufacturer instructions and UK wiring requirements still matter.
Can I copy the completed example exactly?
No. The completed example is only to show how the form works. Use your own name, address, MPAN, inverter details, registered capacity and manufacturer reference number.
The bottom line
The G98 form looks intimidating because it was not really written for ordinary homeowners trying to understand small plug-in solar.
Once broken down, the form is mainly asking for the customer details, installation address, MPAN number, registered capacity, battery capacity if relevant and the ENA manufacturer reference number for the inverter.
The key is not to guess. Use your electricity bill for the MPAN, use the ENA Type Test Register for the inverter reference and use the registered AC capacity of the microinverter rather than the total panel wattage.
Final practical advice:
Take your time, use the correct documents and keep a copy of what you submit. A small plug-in solar system should be simple for the customer, but it still needs to be properly notified and connected safely.
This page is intended as practical guidance to help readers understand the G98 form. It is not legal advice, electrical design advice, installation instruction or a substitute for current DNO requirements, ENA guidance, manufacturer instructions, BS 7671 requirements or site-specific advice from a competent person. Forms, standards, DNO requirements, product approvals and UK plug-in solar rules can change. Always check the latest official documents before buying, installing or connecting generation equipment.