Alice Springs Future Grid tri­alled the North­ern Territory’s first res­i­den­tial Vir­tu­al Pow­er Plant (VPP). The Solar Con­nect VPP tri­al explored how a VPP in Alice Springs could help keep the grid sta­ble while increas­ing the amount of clean ener­gy in the local pow­er system.

The tri­al ran from Octo­ber 2022 to Octo­ber 2023, launched by NT Min­is­ter for Renew­ables and Ener­gy Sele­na Uibo, along with Min­ster for Desert Knowl­edge Aus­tralia, Chansey Paech. 

What is a Vir­tu­al Pow­er Plant?

A Vir­tu­al Pow­er Plant (VPP) is typ­i­cal­ly a col­lec­tion of solar and bat­tery stor­age sys­tems that are treat­ed like a sin­gle source of ener­gy. VPPs use smart tech­nol­o­gy to con­trol the ener­gy flow to and from the grid on demand – ben­e­fit­ting the house­hold, grid and the community.

Why Vir­tu­al Pow­er Plants?

Solar pow­er has become very pop­u­lar in our town. How­ev­er, on bright sun­ny days, when solar pan­els are gen­er­at­ing lots of ener­gy, it can cre­ate chal­lenges in bal­anc­ing sup­ply and demand in our grid.

Alice Springs Future Grid explored ways to store and dis­trib­ute the pow­er of the sun, includ­ing through our VPP trial.

The Solar Con­nect trial

Solar Con­nect was a town wide VPP solar and bat­tery tri­al link­ing house­holds via a Vir­tu­al Pow­er Plant. House­holds in the VPP shared solar and bat­tery pow­er in ways that ben­e­fit­ed the Alice Springs grid and informed how the next gen­er­a­tion of more sus­tain­able ener­gy solu­tions will be created.

House­holds in Alice Springs with either rooftop solar, or solar with a bat­tery sys­tem signed up to the tri­al in 2022.

To be eli­gi­ble for the tri­al, par­tic­i­pants were required to: 

• Be a Jacana Ener­gy customer
• Be an own­er-occu­pi­er of the home you wish to reg­is­ter in the trial
• Have a con­tin­u­ous inter­net connection
• Own an *eli­gi­ble solar and/​or bat­tery stor­age sys­tem (or have one installed one with­in a nom­i­nat­ed timeframe)

The Solar Con­nect tri­al involved:

• Solar only participants
  
• Super­size solar participants
• Solar + bat­tery participants

This ele­ment of the tri­al involved house­holds with an exist­ing, eli­gi­ble solar PV sys­tem <5kVA.

Data from the Solar-Only tri­al was used in mod­el­ling and fore­cast­ing a way in which to help man­age the tran­si­tion to renew­ables in Alice Springs. There was also a dynam­ic export com­po­nent of this tri­al that could occur up to 12 days per year to allow PV invert­er exports to be changed for sys­tem testing.

Super­size Solar allowed house­holds and small busi­ness­es to increase the size of their solar sys­tems while still being allowed to sell an amount of excess ener­gy back to the grid. In addi­tion to increas­ing the size allowance, Super­size Solar was tri­alling dynam­ic export control.

Cur­rent­ly, sys­tems larg­er than 5kVA (sin­gle phase) and 7kVA (three phase) are not per­mit­ted to export. This is a require­ment of the Net­work Oper­a­tor (Pow­er and Water). Dynam­ic export deliv­ered via the VPP meant that larg­er PV sys­tems could export ener­gy into the grid under appro­pri­ate conditions.

The dynam­ic export com­po­nent of this tri­al allowed:

• Vari­able exports between 0kW and 10kW (per phase) tri­alled for an equiv­a­lent of up to 7 days per month. (Vari­able exports were set at the Net­work Operator’s dis­cre­tion, via the VPP).

• Sta­t­ic export lim­it of 5kW (sin­gle phase) or 7 kW (three phase) at all oth­er times.

Exports from these sys­tems were eli­gi­ble for Jacana Ener­gy’s stan­dard Feed-in-Tar­iff* and cred­its appeared on the elec­tric­i­ty bill.

Par­tic­i­pants in the solar-bat­tery part of the tri­al had their invert­er data being used for analy­sis relat­ing to pow­er qual­i­ty, host­ing capac­i­ty, mod­el­ling and solar fore­cast­ing. This assist­ed with both real-time oper­a­tions and longer term plan­ning for a high­er renew­able pen­e­tra­tion pow­er system.

Par­tic­i­pants with bat­ter­ies test­ed a new tar­iff designed to opti­mise when a bat­tery charges and dis­charges such that customer’s inter­ests and those of the pow­er sys­tem are aligned. This effec­tive­ly meant ensur­ing the bat­ter­ies were charg­ing in the mid­dle of the day when we expe­ri­enced net­work con­ges­tion and min­i­mum demand issues and dis­charg­ing in the evening peak when sys­tem load was highest.

Sup­port­ed Inverters

*Eli­gi­ble solar sys­tems are typ­i­cal­ly those less than five years old (installed after 2016) with an invert­er from the sup­port­ed invert­er list below.

1. SB#000 and STP#000 series are exclud­ed
2. Sun­grow SG5K‑D invert­er is excluded

What are the tar­iff rates and solar/​battery behaviour?