New National Grid Connection Charges From 1st April – What It Means for Solar, Batteries, EV Chargers and Heat Pumps in South West Wales

On the 18th March, we received a Connection Letter from National Grid Electricity Distribution announcing significant changes to the way low-carbon technologies are connected to the electricity network.

From 1st April, installations involving solar PV & battery storage, as well as larger applications for multiple technologies such as EV chargers and heat pumps in South West Wales will be subject to formal notification and feasibility assessment charges.

You can review their latest charges here: National Grid - Connections charging statements 

For many homeowners planning renewable energy installations, this will increase project costs — in some cases by £425 (and for larger installs £1,182) [see page 149]. 

At Limitless Energy, we wanted to share this news with all our customers and clients as soon as possible; so the homeowners, business owners, architects and developers in Swansea, Neath Port Talbot, Brecon, Bridgend, Cardiff and Carmarthenshire have some notice to support shared understanding of what this 176 page document means in practice for every renewable application from 1st April 2026.  

Solar installation on Gower

Why These Changes Are Being Introduced

The electricity network was originally designed to supply power from power stations to homes.

However, the rapid growth in technologies such as:

• Solar PV

• Battery storage

• Electric vehicles

• Electrified heating such as Air Source Heat Pumps

  
  

means homes are now generating and exporting electricity back to the grid.

As a result, National Grid Electricity Distribution must carry out more detailed technical assessments before approving connections. 

These assessments now come with formal application and feasibility charges. 

Solar PV and Battery Storage – New Cost Categories

Solar PV and battery systems fall under the embedded generation rules outlined on page 149.

The key thresholds are based on export current (Amps) and inverter and/or battery size (kW).

Microgeneration (Lowest Cost Category)

Microgeneration is defined as:

• Single inverter ≤3.68 kW

• 16 A per phase export limit

This falls under the G98 process.

Typical characteristics:

• Export limited to 3.68 kW (16 A)

• Usually single-phase domestic systems

• SUM of all equipment is under 3.68kW 

Typical cost:

• Notification / administration fee around £200

  
  

These systems can normally be installed first and notified afterwards.

With household electrical demand on the rise, we rarely install G98 systems as most clients would like to enjoy the benefit of a battery system. 

Small Systems With Export Limiting

Some slightly larger systems may fall within the lower fee category if they fall into a G99 Fast Track application, however this is currently ambiguous within the document.

Previously a G99 Fast Track was for systems where

• All individual pieces of equipment are below 5 kW (that means, your battery and inverter are each sized 5kW or under)

• Export is limited to 3.68 kW (16 A)

• SUM of proposed kit is below 7.5kW

  
  

For example:

• Solar array

• 3 kW hybrid inverter

• 4.5 kW battery storage

  
  

If export is electronically limited to 3.68 kW, the system may still qualify for the lower processing charge.

Typical charge:

• ~£200+ notification / assessment fee

  
  

Medium Domestic Systems (Standard Assessment)

Larger domestic systems are also assessed under the G99 process.

This generally applies when:

• Inverter sizes exceed 5 kW 

• Export exceeds 3.68 kW

• SUM of proposed kit is above 5kW and below 20kW.

  
  

Typical fees:

• £425 for network assessment

  
  

Larger Domestic / Small-scale Commercial Systems

More detailed feasibility studies are required where systems reach higher capacities.

Triggers include:

• Any single piece of equipment above 7.5 kW

• SUM of total installed capacity above 20 kW and below 50KW

• Multi inverter and battery systems

  
  

In these cases, the DNO will carry out a full network feasibility study.

Typical cost:

• £1182+ for a full network feasibility study

  
  

These studies by National Grid's local planning teams examine:

• Local transformer loading

• Cable capacity

• Voltage rise from exported generation

  
  

EV Charger Connection Charges

EV chargers increase electrical demand, which also requires notification.

Typical categories include:

Standard Domestic Charger

Typical installation:

• 7 kW charger

• 32 A single-phase

Usually requires:

• Notification to the DNO

If installed as a single piece of kit then there is unlikely to be a notification fee.

Higher Power or Multiple Chargers

If installations include:

• Multiple EV chargers

• Chargers above 7 kW (for example a 22kW charger on single phase)

• Sites with high electrical demand

  
  

Then the DNO may require:

• Network feasibility assessment

Heat Pump Connections

Heat pumps increase electrical demand on a property and must also be applied for or notified upon connection.

Typical domestic heat pumps:

• 3–12 kW thermal output

• Electrical input typically 2–5 kW

  
  

For most homes this can result in a free fuse upgrade to 80A.

However larger properties or new build systems combined with:

• EV chargers

• Solar export

• Battery systems

may trigger additional feasibility studies of £1,182+.

Fuse Upgrades and Service Changes

Another important cost to be aware of is service fuse upgrades.

Many homes currently have:

• 60 A main fuse

• or 80 A main fuse

Current policy within the National Grid is that every home is entitled to an 80A main fuse. This is a currently a free upgrade. 

With multiple technologies installed (EV charger + heat pump + solar inverter), National Grid, as the district network operator may require:

• Upgrade to a 100 A fuse

• or potentially three-phase supply

Any required service alterations or fuse upgrades are chargeable and will be quoted separately by the National Grid.

What This Means for Homeowners

These new rules mean that from 1st April:

• Most installations will require formal notification

• Many will require paid feasibility studies

• Costs for solar and battery installations could increase by £200 - £1,182

• However, response times have been decreased from 45 working days to 25 working days from submission.

  
  

While these changes may increase installation costs slightly, renewable technologies remains the best way for households to:

• Reduce electricity bills

• Increase energy independence

• Lower carbon emissions

  
  

Considering Solar or EV Charging Before the Deadline?

If you are planning to install solar panels, battery storage, EV charging or a heat pump, starting the process before 1st April may allow your project to be submitted under the current connection rules.

This could potentially avoid several hundred pounds in additional network fees.

Final Thoughts

South Wales is seeing rapid growth in low-carbon technologies, and the electricity network must adapt to support them.

These new connection processes introduced by National Grid Electricity Distribution are part of preparing the grid for a future where homes both consume and generate electricity.

For homeowners planning upgrades, early planning and understanding these new thresholds will help avoid unexpected costs.

***Please note - this is a rapid review of the new charge plan and is subject to our interpretation. National Grid will better be able to confirm their charges and costs directly.***

Read the full technical document here: National Grid - Connections charging statements