The Photovoltaic Class System

Power and Water’s PV Policy divides PV systems into four classes, this applies to PV systems of all sizes and both Residential and Commercial customers.

PV class types

Class 1 systems are open to any applicant. This class is pre-approved and there are no export restrictions.

Note: Pre-approval does not apply to remote customers.

Class Limits 5kVA Single Phase or 7kVA Three Phase, per lot in all regions.
Sized by PV Inverter (AC sizing).
Maximum inverter size 5kVA for Single Phase or 7kVA for Three Phase.
Eligibility Open to any applicant.
Export Limits No export limiting device required.
Engineering assessment Not required, pre-approved .
Power factor requirements Power factor at site must be > 0.9 at all times.
Battery  storage 12min ramp down for PV inverter. Max charge rate is limited by battery inverter (max 10kVA per phase). Batteries are permitted but not compulsory.
Timeline Six weeks total for application processing and meter upgrade.


For forms and agreements see the Connections page

Class 2 systems are open to any applicant. Applications are pre-approved provided zero-export is achieved at all times.

Note: Pre-approval does not apply to remote customers.

Class Limits10kVA Single Phase or 30kVA Three Phase, per lot in all regions.
Sized by PV Inverter (AC sizing).
Maximum inverter size 10kVA for Single Phase or 30kVA for Three Phase.
Eligibility Open to any applicant.
Export Limits Zero-Export Limiter Device required.
Engineering assessment Not required, pre-approved.
Power factor requirements Power factor at site must be > 0.9 at all times.
Battery storage 12min ramp down for PV inverter. Max charge rate is limited by battery inverter (max 10kVA per phase). Batteries are permitted but not compulsory.
Timeline Six weeks total for application processing and meter upgrade.

For forms and agreements see the Connections page

Class 3 systems are available to three-phase commercial customers only.

An engineering assessment is required for all applications and an engineering assessment fee is required to be paid upon application. This class may be an exporting or non-exporting connection, pending engineering assessment and customer requests/requirements.

You must have approval from Power and Water Corporation prior to any installation works commencing.

Class limits
  • 200kVA, per lot in Darwin region.
  • 100kVA, per lot in Alice Springs, Katherine and Tennant Creek regions.
Sized by Inverter Bank (AC).
Maximum inverter bank size
  • 200 kVA Darwin region.
  • 100 kVA Alice Springs, Katherine and Tennant Creek regions.
Eligibility Restricted to three phase customers on a commercial tariff.
Export limits Export or zero-export permitted pending engineering assessment
Engineering assessment Required.
Engineering assessment fee Refer to Class 3 PV Assessment in the Acceptance of Charges form.
Power factor requirements Power factor at site must be > 0.9 at all times.
Battery Storage 12min ramp down for PV inverter. Max charge rate to be determined by assessment.
Timeline Six weeks for engineering assessment, plus six weeks total for application processing and meter upgrade.
Required documentation

To commence the assessment, you or your installer must submit:

  • Completed and signed Class 3 Application Form
  • Payment of the Class 3 PV assessment fee
  • Technical data and wiring diagram, including:
    • Metering
    • Zero-export device (as applicable)
    • Grid protection relay
    • Circuit breakers/switches
    • Inverter(s)
    • PV array(s)
    • Earthing equipment
    • Distribution circuits
    • Protection, synchronisation and tripping or interlocks.

Following approval being issued, you or your installer must submit:

  • Completed and signed Embedded Generation User Agreement: Formal Instrument of Agreement. Available pending engineering assessment.
  • Payment of applicable meter fee. Refer to the Acceptance of Charges form.

Your solar installer must submit to the Connections Officer, Power Networks, Power and Water Corporation:

Class 4 systems are available to three phase commercial customers only.

An engineering assessment is required for all applications. Due to size of systems in this class a more detailed engineering assessment will be required on a quoted basis. Outcomes of the engineering assessment may include increased protection requirements.

Class 4 PV systems must have ramping with level to be assessed.

You must have approval from Power and Water Corporation prior to any installation works commencing.

EligibilityRestricted to three phase customers on a commercial tariff.
Export limitsExport or zero-export permitted pending engineering assessment.
Engineering assessmentRequired.
Engineering assessment feeQuoted basis.
Power factor requirementsPower factor at site must be > 0.9 at all times.
TimelineQuoted basis.

Required Documentation

To commence the assessment, you or your installer must submit:

  • Completed Class 4 PV application letter. Please email the Network Development and Planning team for the letter template.
  • Payment of the quoted engineering assessment fee.
  • Technical data and wiring diagram, including:
    • Metering
    • Zero-export device (as applicable)
    • Grid protection relay
    • Circuit breakers/switches
    • Inverter(s)
    • PV array(s)
    • Earthing equipment
    • Distribution circuits
    • Protection, synchronisation and tripping or interlocks.

Following approval being issued, you or your installer must submit:

  • Completed and signed Embedded Generation User Agreement: Formal Instrument of Agreement. Available pending engineering assessment.
  • Payment of applicable meter fee. Refer to the Acceptance of Charges form.

Your solar installer must submit to the Connections Officer, Power Networks, Power and Water Corporation:

PV SpecificationsStorage Specifcations
ClassApplicantsDarwin RegionAlice SpringsKatherineTennant CreekMax charge rateRamp periodComments
1Private/residential

≤ 5kVA single phase

OR

≤ 7kVA three phase

Limited by battery inverter (max. 10kVA per phase)12 min ramp down nominal PV inverter output to zero

Pre-approved

Sized by Inverter (AC)

2Private/residential
Small Commercial
≤ 30kVA three phase with zero export limiterLimited by battery inverter (max. 10kVA per phase)12 min ramp down nominal PV inverter output to zero

Pre-approved

Sized by Inverter (AC)

3Medium Commercial≤ 200kVA three phase≤ 100kVA three phaseAs determined by assessment12 min ramp down nominal PV inverter output to zero

Requires Assessment

Sized by Inverter (AC)

*Zero-export only

4Large Commercial>200kVA three phase>100kVA three phaseAs determined by assessmentAs determined by assessment

Requires Assessment

Sized by Inverter (AC)

Ramping required

*Zero-export only

Zero-Export limiting Devices

A zero-export limiter is a device that is used to ensure that PV systems generates as much power as the user requires onsite but not excess energy. Utilities around the world encourage the use of these devices as they reduce adverse impacts within the local distribution network while still allowing users to significantly offset their consumption.

list of zero-export limiting devices, approved from a technical standpoint as being capable of achieving zero-export by Power and Water is available. Please ensure that any device on the list that offers protective functions can be set to match protection requirements for inverters as specified in Technical Requirements for Grid Connection of Photovoltaic Systems via Inverters.

If you have a zero-export limiter device that is not approved by Power and Water, Power Networks Engineering will review the device. Please complete the Zero-Export Limiter Device Approval form and send to the Network Development and Planning team.

The following list contains devices from a technical perspective that are capable of achieving zero-export for PV systems. Some of these devices offer protection functions similar to the internal protection found within a CEC approved inverter.

It is up to the PV system designer to ensure that the protection functions provided by the zero-export limiter are capable of meeting Power and Water's protection setpoints as detailed in Technical Requirements for Grid Connection of Photovoltaic Systems via Inverters.

  • Devices capable of achieving Zero-Export:
  • ABB inverters with compatible meter
  • BCJ Controls Grid Protect
  • ComAp InteliMains
  • ComAp InteliPro
  • Crisp Power and Control – Zero Export Solar System
  • EBA Grid Control Unit GCU-30C
  • Enphase Envoy S-Metered + DRM
  • Fronius – Datamanager with Fronius Smart Meter
  • GNT Engineering ZED series
  • HLP Controls PE200
  • HLP Controls PE200-SILG
  • HLP Controls PE200-Z
  • Integrelec SPS01303-ABB Feed in limiter
  • Integrelec SPS01330-ABB Feed in limiter
  • Integrelec SPS023150-ABB Feed in limiter
  • Magellan Solar Gate
  • PM Control - SolarTune
  • Power & Drive Renewable Solutions Non Export Unit
  • S4Solar Zero Export Controller
  • Schneider Electric Modicon M241 (limited inverter compatibility)
  • Selectronic SP PRO/SP PRO GO series
  • SMA Solar Technology – Cluster Controller with SMA Energy Meter
  • SMA Solar Technology – Data Manager M with compatible energy meter
  • SMA Solar Technology – Sunny Home Manager 1.0 with SMA Energy Meter
  • SMA Solar Technology – Sunny Home Manager 2.0
  • Sol Distribution Sol-0-X Grid Export Limiting System for SMA Inverters
  • Solar Log 1200 PM+
  • SolarEdge Feed-in Limitation
  • Solarmatrix Compact Level 1
  • Solarmatrix LOF
  • SolaX Power Hybrid Series
  • Voltlogic VLI105P1
  • Zero Export Controls Australia CEC3000
  • Zeus Appollo Anti Reverse Current Box (limited inverter compatibility)
  • Zeus Appollo Z21 Hybrid Series

Last updated 16 June 2017