Assessment criteria & application outcomes

Some applications to connect a Distributed Energy Resource (DER) system, including rooftop solar systems, battery storage systems and rotating machines that connect to our network, require technical assessment to confirm their compatibility with our network. These assessments ensure safe, reliable, and compliant operation of the electricity network and prevent installations that may not function effectively due to local network limitations.

An application can be submitted via our Portal for all DER connections, and we may assess any application at any time. The assessment and offer will reflect the network conditions at the time of issue.

Why some applications require technical assessment

Certain DER systems can affect electricity network performance. A system that is oversized for its location may cause voltage levels to fall outside statutory limits, leading to system disconnection during high‑voltage events. Assessment is therefore required to identify potential operational issues before installation proceeds.

Preliminary assessment using network capacity information

Prior to submitting an application, you should conduct a preliminary review of potential network constraints by using our Network Load & Export Capacity Map.

This map provides indicative information on existing approved solar and battery inverter capacity, as well as potential available export capacity, and may help anticipate whether restrictions are likely to apply at a given site.

The map does not replace formal assessment but can be used during system design and pre‑planning to identify areas where network limitations are more likely.

Technical assessment process

Our assessments consider system capacity, local network attributes, and existing DER on the supplying transformer. Where our evaluation identifies network risk, a more detailed assessment is undertaken. Where necessary, particularly in rural areas, we may conduct a site visit to verify transformer characteristics and local network configuration.

Assessment inputs include:

• National Metering Identifier (NMI)
• Registered Plan (RP) number and Lot number
• Proposed DER system capacity and export configuration
• Distribution transformer size and configuration
• Total capacity and export limits of DER systems already connected to the same transformer.

The technical assessment does not evaluate:

• Condition of household wiring
• Number of solar PV modules to be installed (assessment focuses on inverter/system capacity rather than panel count).

Installers must assess wiring suitability and confirm that the proposed system will meet performance expectations.

Conditions that result in unsuccessful assessments

DER applications may fail assessment due to limitations within the local low‑voltage network. Common reasons include:

• Transformer capacity constraints - The supplying transformer may not be capable of supporting additional DER systems
• Distance‑related voltage impacts - Where the premises is located at a significant distance from the transformer, voltage fluctuations or voltage rise may cause operation outside statutory voltage limits
• Substantial DER already connected to the transformer - The transformer may already supply multiple DER systems, and even a single additional system can exceed allowable limits.

Applications that trigger these limitations may be declined or approved with restrictions.

Available outcomes when an application fails assessment

When an application for a proposed system cannot be supported, several alternative options may be provided:

• Reduced system capacity - Approval may be provided for a lower‑capacity system. We may specify the maximum allowable inverter capacity the network can support at the premises
• Reduced export configuration - Approval may be issued for a reduced export system of 1.5kW. These systems typically present lower risk to the network
• Dynamic Connection option - A Dynamic Connection may be offered to allow flexible exports up to the nameplate rating under favourable network conditions, instead of applying a fixed export limit
• Phase upgrade - A phase upgrade may be considered to accommodate higher inverter capacity. This option may not be available where local network infrastructure cannot support additional phases
• Network upgrade offer - We may provide a detailed network upgrade offer outlining required upgrades to the customer’s installation, dedicated local network, and shared local network, along with associated costs
• Customer‑funded network upgrades - Where an upgrade offer is not provided, some applicants may have the option to fund network upgrades needed to support the originally requested capacity
• Application withdrawal - Applicants may withdraw the application if they do not wish to proceed with any of the alternative options.

Assessment position and installer responsibilities

Assessment and offers reflect our network capability at the time of review and are not assurances of ongoing system performance. System suitability remains the responsibility of the installer, and we retain the right to assess any application at any time.