Question 1

What does Sunnn actually do?

Accepted Answer

Sunnn designs and installs your solar + battery system, claims your federal rebates and STCs at sale, and configures the battery so it’s ready for wholesale dispatch on day one. The retail relationship, and the dispatch of your battery on the wholesale market, sits with whichever wholesale-passthrough retailer you sign up to. Sunnn does not provide retail electricity.

Question 2

What does “wholesale market” actually mean?

Accepted Answer

Australia’s electricity market (the NEM) clears every 5 minutes, generators bid in, demand is settled, and a single dispatch price falls out per state. That price is what AGL, Origin and the rest pay for power. On a wholesale-passthrough plan, you pay it too, both ways. No retailer margin on the energy. Add a battery and you can buy the cheap intervals and sell the expensive ones.

Question 3

How can the price ever be negative?

Accepted Answer

Around midday in spring and autumn, rooftop solar floods the grid with more energy than households can use. The system pays generators to back off, and the dispatch price goes negative. For a battery owner on a wholesale plan, that’s a free fill-up, sometimes the grid pays you to take it.

Question 4

What if there’s a price spike?

Accepted Answer

The market price cap is $20.30/kWh (raised from $17.50 on 1 July 2025). It’s rare and brief, the regulator triggers an administered cap of $0.60/kWh once a cumulative threshold is hit. Wholesale-passthrough retailers apply the same caps to your import. A wholesale-ready battery is designed to discharge into spike windows rather than draw from the grid, which is what reduces your exposure. It is not a shield: if the battery is empty, or your load is larger than it can cover, you pay the market price for what you import.

Question 5

Why install with Sunnn instead of any installer?

Accepted Answer

Most installers size and configure batteries for self-consumption. A battery tuned for wholesale arbitrage is a different design: bigger usable kWh for evening discharge, an inverter that throttles smoothly across the spot curve, and pre-set control hooks so dispatch works on day one. Designing for a wholesale plan is what we specialise in, and it is built into every system we quote.

Question 6

What hardware do you fit?

Accepted Answer

Tier-1 panels (Trina, Jinko, REC, LONGi) paired with a Fox ESS hybrid inverter and Fox ESS battery. We standardise on Fox ESS for storage and inversion: one ecosystem, one app, properly tuned for wholesale dispatch, backed by manufacturer warranties, plus Sunnn’s own 5-year whole-of-system warranty covering operation, performance and workmanship.

Question 7

What rebates do you handle at sale?

Accepted Answer

STCs on every panel kW, and the federal Cheaper Home Batteries Program rebate on the battery. Both are administered by the Clean Energy Regulator and applied as a discount on your invoice, the number on your written quote is the number you pay.

Question 8

What about state rebates?

Accepted Answer

We check eligibility for NSW PDRS, VIC Solar Homes, ACT Sustainable Household Scheme and SA Home Battery before you sign. Where they stack with the federal program, we apply them too.

Question 9

Which retailer should I switch to?

Accepted Answer

Several Australian retailers now offer wholesale-passthrough plans where you import and export at the AEMO 5-minute dispatch price. We’ll talk you through the options at handover so you can pick the one that matches your usage shape, the install is identical either way.

How it actually works.

Things people ask before they sign.

Get a battery designed for arbitrage.
Switch to a wholesale plan when it’s on.

How it actually works.

Things people ask before they sign.

Get a battery designed for arbitrage. Switch to a wholesale plan when it’s on.

Get a battery designed for arbitrage.
Switch to a wholesale plan when it’s on.