Electricity North West: G99 Solar Application Guide

Connecting solar generation to the Electricity North West network requires following ENA Engineering Recommendation G98 or G99, depending on system size. ENW serves one of the most geographically varied service territories in England — from dense urban areas in Greater Manchester to rural upland networks in Cumbria — and that variation directly affects how quickly connections can be made and whether export limitation is needed.

This guide covers the full G98 and G99 application process for ENW, the documents you need, ENW’s SSEG connection pathway, export limiting in constrained areas, and the timelines you should plan around.

Electricity North West Service Territory

ENW is the distribution network operator for the North West of England. Its licence area covers:

• Cumbria — includes the Lake District, Barrow-in-Furness, Carlisle, and remote upland areas
• Lancashire — Preston, Blackburn, Burnley, Lancaster, and the Fylde Coast
• Greater Manchester — the ten metropolitan boroughs including Manchester, Salford, Trafford, and Stockport
• Cheshire — Chester, Warrington, Crewe, and Macclesfield

The network topology varies significantly across this area. Greater Manchester is a dense urban network with high load density and generally good capacity on feeder circuits. Cumbria and parts of rural Lancashire have long overhead line circuits serving sparse loads — conditions that create voltage and thermal constraints that can slow or complicate generation connections.

Understanding which part of the ENW network your site sits on is the first step in gauging how straightforward your G99 application will be.

G98 vs G99: Which Applies to Your System?

The dividing line is 3.68 kW per phase at the point of connection.

For most residential rooftop systems, G98 applies. For commercial rooftop systems and ground-mount arrays of any meaningful scale, G99 is required.

For a detailed comparison of the two standards, see the G98 vs G99 guide.

ENW Connections Portal

All G98 notifications and G99 applications are handled through the ENW connections portal at enwl.co.uk/connections. The portal allows you to:

• Create and manage connection applications
• Upload supporting documents
• Track application status
• Receive and accept connection offers
• Submit commissioning test results

Before accessing the portal, you need to register as a contractor or designer. ENW requires a company name, contact details, and confirmation that the applicant is a qualified electrical engineer or is working under one.

G98 Notification Process

For systems up to 3.68 kW per phase, the process is notification rather than application. The installer or designer notifies ENW that a compliant system has been connected.

Required information for G98 notification:

• Site address and MPAN (Meter Point Administration Number)
• Installed capacity in kW and kVA
• Inverter make, model, and type test certificate reference
• Date of commissioning
• Installer details and qualification reference (MCS certificate number for domestic systems)

ENW does not issue a formal approval for G98 systems — the notification is a record that the connection has been made in accordance with the standard. However, ENW may carry out spot checks on notified installations, and any system found not to comply with G98 technical requirements will need to be rectified.

G99 Application Process

G99 applies to any generation system at or above 3.68 kW per phase. The process has two stages: a pre-application or feasibility stage, and a full application stage.

Stage 1: Pre-Application / Feasibility

Before submitting a full G99 application, it is good practice — and for larger systems, practically necessary — to request a pre-application feasibility study from ENW. This costs a fee (typically £200–£500 depending on system size) and provides:

• Confirmation of the available network capacity at the connection point
• An early indication of whether reinforcement will be required
• Guidance on whether export limitation would be an acceptable alternative to reinforcement
• An indicative programme for the connection

Stage 2: Full G99 Application

Once you have a design developed to a sufficient level of detail, submit the full G99 application through the portal. ENW requires the following documents:

Mandatory documents:

Optional but useful:

• Pre-application correspondence from ENW
• Load flow study results
• Planning permission reference (if applicable)

ENW Technical Assessment

After submission, ENW’s connections engineers carry out a technical assessment. This involves load flow modelling of the relevant network section to check:

• Thermal ratings of cables and transformers
• Voltage rise at the point of connection and across the feeder
• Fault level contributions
• Protection coordination with existing network protection

For straightforward connections on well-meshed urban networks, this assessment is fast and usually confirms connection without reinforcement. For rural connections or systems in areas where ENW has identified network constraints, the assessment may identify the need for network reinforcement or export limitation.

Connection Offer

ENW issues a connection offer setting out:

• The agreed connection point and voltage level
• Any reinforcement works required and their cost
• Protection settings and requirements
• Export conditions (maximum export level if export-limited)
• Programme for connection works
• Offer validity period (typically 90 days)

You must accept the offer in writing within the validity period and pay any quoted charges before ENW will proceed.

ENW-Specific Standard Conditions

ENW applies the ENA G99 standard with the following supplementary requirements specific to its network:

Protection settings: ENW specifies particular under/over voltage and under/over frequency protection settings that must be programmed into inverters or protection relays. These are broadly in line with the G99 defaults but ENW may specify tighter settings for sites in constrained areas.

Power factor: ENW requires generation systems to operate at or near unity power factor or, for larger systems, to operate with reactive power capability as specified in the connection offer.

Metering: For G99 systems, ENW requires a metering point at the point of connection. The meter arrangement must comply with ENW’s metering specifications and be accessible to ENW staff.

Fault ride-through: Systems above certain capacity thresholds must comply with G99 fault ride-through requirements, maintaining connection during specified voltage dip events rather than disconnecting.

Anti-islanding: All G99 systems must have anti-islanding protection that disconnects the generation system if ENW’s network becomes de-energised. ENW requires that this protection meets the response times specified in G99.

Export Limiting in Constrained Areas

Parts of the ENW network — particularly rural feeders in Cumbria and Lancashire — have limited headroom for additional generation export. In these areas, ENW may require export limitation as a condition of connection.

Export limitation means fitting a G100-compliant active export controller (AEC) that monitors the energy flow at the grid connection point and curtails the inverter output to prevent export above an agreed maximum level.

Benefits of export limitation:

• Avoids the cost and time of network reinforcement
• Enables connection in areas that would otherwise be refused
• Faster programme — ENW can often complete an export-limited connection more quickly than a reinforced connection

Drawbacks:

• The system cannot export above the agreed limit, which reduces revenue from export tariffs and Smart Export Guarantee payments
• The export limit is fixed in the connection agreement; increasing it requires a new application

For guidance on G99 commissioning requirements once your connection is agreed, see the G99 commissioning test guide.

SSEG Connection Process

ENW operates a dedicated SSEG (Small Scale Embedded Generation) process for generation systems up to around 1 MW connecting at low voltage or at simple 11 kV points. SSEG sits within the broader G98/G99 framework but is handled by a dedicated team with documentation tailored to smaller-scale applicants.

The SSEG process is designed to be more accessible than ENW’s large-scale connections process. Key features:

• Dedicated SSEG application forms (simpler than full industrial forms)
• SSEG team contact for technical queries
• Pre-application meetings available for projects of any size
• Streamlined feasibility assessment for straightforward connections

For solar design software users designing commercial rooftop systems in the ENW area, the SSEG route is the most relevant path. Systems in the range of 50 kW to 1 MW will typically follow G99 via the SSEG process.

Network Reinforcement

Where the ENW network cannot accommodate a generation system without reinforcement, ENW will set out the required works in the connection offer. Reinforcement may involve:

• Uprating or replacing cables or overhead lines
• Installing or uprating transformers
• Installing or modifying network protection
• Installing reactive power compensation

The cost of reinforcement is shared between ENW and the applicant according to Ofgem’s charging arrangements. For generation connections, the applicant typically pays for shallow connection works (the connection from the generator to the network boundary) while ENW recovers reinforcement costs through its use-of-system charges.

For large systems or systems in constrained areas, reinforcement costs can be significant — sometimes exceeding the system installation cost for smaller projects. Running a pre-application feasibility study to understand reinforcement requirements before committing to a site is good practice.

Application Timelines

These are ENW targets under the Electricity (Connection Standards of Performance) Regulations. ENW is required to compensate applicants if it misses statutory timescales for certain connection types.

Contact Details

ENW Connections Portal: enwl.co.uk/connections

SSEG Team: connections@enwl.co.uk

Telephone: 0800 048 4080 (connections enquiries)

Postal address:
Electricity North West Limited
Connections Team
Borron Street
Stockport
SK1 2JD

For urgent technical queries during the application process, ENW’s connections engineers are contactable by phone or email during normal business hours.

Other UK DNOs

If your project is outside the ENW service area, the following guides cover the other UK distribution network operators:

• UK Power Networks — South East England, East of England, London
• NGED (National Grid Electricity Distribution) — Midlands, South West England, South Wales
• Northern Powergrid — Yorkshire, North East England
• SP Energy Networks — Central and Southern Scotland, Merseyside, North Wales, Cheshire
• SSE Networks — North of Scotland, South of England

See the UK solar compliance hub for the full framework, or read the G99 application guide for a standard-by-standard walkthrough.

Frequently Asked Questions

Does Electricity North West use the ENA G99 standard or its own bespoke process?

ENW implements the ENA Engineering Recommendation G99 for generation systems 3.68 kW per phase and above. For systems below that threshold, G98 self-notification applies. ENW does not operate a separate bespoke standard, but it does have specific technical appendices and supplementary conditions that apply within its network area.

How long does a G99 application take with Electricity North West?

ENW targets a feasibility study response within 30 business days and a full offer within 45 business days for straightforward connections. More complex connections requiring reinforcement can take 90 business days or longer. Export-limited connections generally move faster because they avoid the need for network reinforcement studies.

What is an SSEG connection and how does it differ from a standard G99 application?

SSEG stands for Small Scale Embedded Generation. ENW uses this term to describe generation systems typically up to around 1 MW that connect at low voltage or at simple 11 kV points. The SSEG connection process follows G98 or G99 depending on system size, but ENW provides dedicated guidance documents and a specific SSEG team to handle these applications separately from large-scale industrial connections.

Can I install an export limiter to avoid a full G99 network study?

Yes. ENW accepts export-limited connections in areas where network capacity is constrained. Fitting a G100-compliant active export controller can reduce or eliminate the need for network reinforcement, which lowers both cost and programme time. ENW will confirm whether export limitation is appropriate during the pre-application or feasibility stage.