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Distributed generation

Installing distributed generation and connecting it to EA Networks’ electricity network

Distributed generation (DG) is one of a number of different terms used in the electricity sector to describe private generation sources such as solar or diesel. If you don't already have an electricity connection to our network, we recommend that you request a new ICP online at the earliest possible stage of your distributed generation project. We also recommend that you obtain expert technical advice on how to correctly install, connect and operate your distributed generation system.

Please see below for further information based on your generator size:

Distributed Generation - 10 kilowatts or less

Distributed Generation - above 10 kilowatts

Applying for Distributed Generation

To complete an application for Distributed Generation, fill in one of our application forms below:

To obtain a paper copy of this form or clarify any questions you might have on distributed generation, don't hesitate to reach out to our Generation team at generation@eanetworks.co.nz or call 0800 430 460. 

After receiving your application, we will start our approval process as outlined in Part 6 of the Electricity Industry Participation Code.

Planning your Distributed Generation (solar) connections

We keenly support the development of solar generation and for consumers to be able to unlock the benefits for their homes and business.

It's important for anyone seeking to install generation (usually solar) to know that the distribution network has limits. As more generation is connected, the ability to accept new generation exported into the network reduces until there is no more available capacity and significant asset upgrades are required. If you are in a congested area, your export potential will be reduced due to current network limitations – we recommend that you carefully review the following information before committing to a solar connection if you hope to export your generated energy to the market.  

To help support your planning process, we have created the following maps:

  1. Generation Hosting Capacity: this shows our remaining substation capacity available to accept new generation exported into our network.
  2. Generation Export Congestion: this shows more detail regarding areas where generation export may be limited, or not.

It always pays to talk to us early – you can contact us on 0800 430 460 or email your plans to generation@eanetworks.co.nz for the latest information.  

Generation Hosting Capacity

To help consumers plan, we've created a map showing how much electricity generation export capacity (in megawatts, MW) is available at our substation locations during normal network operations. This should help you plan solar generation projects to find suitable locations across our network. Unfortunately, if you seek to export generation, location does matter. Not all parts of our network can support full export from a generation connection due to the high growth in generation across our network.   

What this map shows 

This ‘hosting capacity’ map is a tool for you to plan before submitting a formal ‘Distributed Generation’ (solar) application. It is a guide. The capacity numbers shown are estimates based on current network conditions and other assumptions. The numbers don't guarantee your project will be approved or declined. We encourage you to contact us anytime to discuss your specific situation.  

The map shows the maximum amount of electricity generation export each substation location can support (host) while maintaining a stable and reliable power supply to consumers. A value of zero at a substation does not mean that you cannot connect solar – it simply means that you will not be able to export all your generation all the time. We will need to limit your export, at times entirely, since the network does not have capacity to accept it. But you will always be able to consume your own generation behind your meter.  

What do we mean by ‘capacity’? 

Think of it like a canal where the water going in is the electricity generation exported into our network or water going out is electrical load taken off the network. There is a limit to how much water can flow through a canal at any point in time. As you add water (generation export), there is less room for more since the canal has fixed volume. If you want to put more water through, you need a bigger canal or you need the canal draining out at the same time (this is the equivalent of people using power for lighting, heating, irrigation etc.).  

In the case of an electricity network, there is only so much room (capacity) to absorb generation export after accounting for the load on the network. Once full, we need to limit export to ensure the network remains stable and is not damaged. To accept more generation, we would need to upgrade assets (e.g. bigger substations, transformers, and lines connecting the substations back into the rest of the network). Until assets are ultimately upgraded, limits are the only way to manage short term export capacity issues.   

Important things to know 

  • The map is based on today’s network (size). It doesn't include potential future upgrades that could increase capacity. We assess upgrades case-by-case as part of our long-term network planning (balancing network investment with affordability of lines charges). 
  • Available export capacity decreases as more generators connect to our network at each substation location. Conversely, it increases as more load is added. As such the values are dynamic - we have based the values on forecast usage (load) at each substation location.  
  • We update the map whenever a significant new generator (>0.5MW) is approved, or at least twice a year (last updated: 10 November 2025). As such the values should be considered a guide only and you will still need to confirm your plans with us.  

We hope this map helps you plan your new generation connection – in all cases, contact us early to discuss your plans so we can best support your connection and provide the latest information.  

Generation Hosting Capacity - more information

How we calculate capacity

Each substation services an area (indicated by the coloured areas across the map). We model the impact of adding new generation to the relevant substation until we reach a physical network limit (like voltage or equipment constraints) at that substation. Our modelling is based on real-world prudent scenarios. For example, summer conditions when irrigation load can reduce after a rain event, but solar panels continue to produce maximum power when the sun comes out. Because generation export reflects electricity output not used behind the meter of the home or farm where it’s located, network constraints are most likely during daylight hours when total network load is lowest.  

Technical comment 

Our calculations assume fixed power factor and that generators can absorb up to 30% reactive power to help manage voltage level constraints. If your equipment can't do this (i.e. has limited reactive power capability), it may reduce how much generation you can connect.  

Your location matters (unfortunately)

If you want to export into the distribution network, where you connect matters. As more generation is connected in one substation location, the capacity available to connect additional generation for export reduces.   

Due to the addition of new large ‘grid scale’ generators, some substation areas now have all available unconstrained capacity allocated (i.e. those existing generators can export without any limits). Available export capacity is indicated by a ‘hosting capacity’ of ‘0MW’ at the substation indicated on the map and this applies to the wider area (marked in colour) supplied by that substation. However, we can always offer constrained generation export capacity in these areas. In simple terms this means that whilst you can connect new generation, you may not be able to export energy into our network all the time. This may affect your business case (ROI and payback) if you are relying on export credits (getting paid for your exported generation).  

Our map should make it easier to determine whether export constraint (limits) is an issue for you at your location or not. Please contact us to discuss this in more detail if this applies to a location you are interested in. 

Other points about the map
  • Direct substation high-voltage connections (33 kV or 66 kV): The capacities shown assume you connect directly to the substation's high-voltage equipment with adequate capacity. 
  • Direct substation low-voltage connections (11 kV or 22 kV): The capacities shown assume you connect directly to the substation's low-voltage equipment with adequate capacity. This could require a new dedicated feeder or feeders to connect your generation to the substation low-voltage equipment. 
  • Rural feeder connections: Connecting via existing rural 22kV distribution lines typically allows 1-5MW connections, depending on distance from the substation (further away means less capacity) and how much remaining capacity is in the distribution line. 

For specific locations, please contact us directly, as actual capacity varies by site. 

Network Export Congestion

Due to significant uptake of solar generation in our region, we now have areas across our network where generation export is congested. This means any new generation installed in these areas will face export limits – at times we will need to limit their export up to 100%. 

The ‘export congestion map’ provides more granular detail so that you can determine whether your connection is affected by export limits or not. You can still connect generation to these areas, but you must expect to have your export limited at times when the network is experiencing congestion.  

The current export congested areas include: 

  • Lauriston area. 
  • Methven area. 
  • Mt Hutt area. 
  • Overdale area including Rakaia. 
  • Mt Somers, Montalto, and Ashburton Gorge/Lakes area (a pending application will make this area constrained).  
  • A 22 kV feeder east of Tinwald. 

The map shows congested areas in red, pending congested areas in orange, and uncongested areas in green.  

We recommend you check this map regularly as the situation can change quickly when any new large generation is accepted. 

Technical comment 

To reduce future congestion, EA Networks restricts the phase injection difference to 5 kW, which means a single-phase low voltage supply can inject a maximum of 5 kW.  

For further information, please feel free to email our team at generation@eanetworks.co.nz. 

Important information

Statutory, regulatory and safety requirements

If you connect distributed generation to our network, safety equipment and procedures must be put in place to ensure safe interaction between your distributed generator and our network. At times, your distributed generator may be interrupted to comply with our own operation standards.

Familiarise yourself with the following documents:

Approved Inverters

Click here for a list of inverters approved by the Clean Energy Council. If your inverter is not on this list, you will need to supply its technical specifications and Certificate of Approval when you apply.

Fees and Charges

Application Fees

Part

Scale

EA Networks fee (ex GST)

EA Networks fee (inc. GST)

1

Distributed generation 10 kW or less in total

$310.00

$356.50

1A

Distributed generation 10 kW or less in total
(simplified, default service)

$140.00

$161.50

2

Distributed generation above 10 kW but less than 100 kW in total

$770.00

$885.50

2

Distributed generation 100 kW or more but less than 1 MW

$1540.00

$1771.00

2

Distributed generation of 1 MW and above

$7690.00

$8843.50

Connection Charges

We currently charge connections on an incremental cost basis. For small-scale distributed generation installed at an existing premise, this normally means that there is no additional charge. For large-scale distributed generation and dedicated distributed generation connections, we will charge asset-related costs for all assets that we fund, or the incremental portion of assets that we fund. In addition, we charge for operating and maintaining assets that we fund and any assets that are vested to our ownership as part of establishing a new connection.

Transmission Charges

In addition to our charges, we pass on any incremental increase in Transpower’s transmission charges to the generating customer that gives rise to the increase. Transmission charges are determined under the transmission pricing methodology (TPM) which is regulated in Part 12 of the Electricity Industry Participation Code (Code). Of note, adjustments are made under clause 85 when a new large plant is connected, which includes generation totalling 10 MW or more which is owned by the same party or related parties. Our understanding is that the new large plant is notionally assessed as if it was directly connected to Transpower’s grid, and then the resulting charges are added to our charges (which we will pass through to the relevant generators). This establishes a situation where we are charged for supply from the grid and hypothetical export to the grid at the same time.

In the upper South Island grid region there is currently very little grid connected generation installed and we have been advised of an issue, which may be unintended, where the adjustment referenced above leads to a substantial additional charge for early connectors of large scale generation.  An estimate that we have been provided suggests that a large scale solar connection (exceeding 10MW) will give rise to an annual additional transmission charge of around $40/kW/year of connected solar capacity.  We have asked Transpower to provide clarification on this issue and we encourage customers to make their own enquiries before deciding to connect large scale distributed generation.

Deficiency Fee

A deficiency fee of $110 + GST will be applied for any situation where generation is found to be outside of the limits set within the application. The fee applies to situations where we have not approved the following: 

Operating Changes

(a) exporting more power than we have approved

(b) exporting at a higher voltages than we have approved 

(c) altering the mode the inverter operates in, or

(d) making some other alteration that is not in compliance with our connection and operation standards, 

Hardware Changes

(e) altering the generation hardware by adding inverters or swapping in a larger inverter, or 

(f) adding more panels that increases the export where previously it was less than the inverter rating. 

Repeated breaking of the documented and approved limits may result in disconnection. 

Glossary of industry terms

Electricity Networks Aotearoa (ENA) have produced a glossary that defines key terms related to electricity connections and pricing. You can view it on the ENA website here.