How to buy solar & batteries in Australia — the plain-English guide.

Buying solar is not like buying a fridge. A fridge dies in ten years and you replace it. Solar lives on your roof for 20–25 years, exposed to weather, and gets harder to fix the older it gets. The difference between a good install and a bad one isn't visible on day one — it shows up in year five, when the inverter dies and the company that sold it to you has gone bust.

This guide walks through the buying process the way the Clean Energy Council (CEC) recommends — and what your consultant should be doing for you at each step. Read it before your first sales call. It'll save you weeks and probably thousands.

The seven steps. In order.

1. Work out what you actually need. Pull out your last four power bills. Note the quarterly kWh figure (not the dollar figure — the kWh). That's the number every honest sizing conversation starts from.
2. Get at least three quotes — from CEC-Approved Solar Retailers. The CEC publishes the list. Anyone not on it is a maybe at best. (Or use a broker who's already pre-vetted them for you. That's us.)
3. Insist on a written quote with line items. Panels named, inverter named, mounting named, warranties named separately. "$8,990 installed for 6.6 kW" is not a quote — it's a marketing line.
4. Compare on the components, not the headline price. Two systems at the same kW can be $4,000 apart in lifetime value because of the inverter alone.
5. Read the warranty terms BEFORE you sign. Not "25 years" — read what is covered for what period, and who pays for the labour to swap a faulty inverter in year seven.
6. Verify the install meets your DNSP's connection rules. Your local distribution network has rules about inverter size, export limits, single-phase vs three-phase. Your installer should handle the application; you confirm it's done.
7. Get the commissioning paperwork and the monitoring login. No paperwork = no warranty. Save the certificate of compliance, the STC assignment form, and your installer's contact details somewhere you'll find them in five years.

Step 1: Size it to your bill, not the truck.

Most cowboys quote a default 6.6 kW kit because it pairs with the cheapest single-phase inverter and fits the most favourable STC rebate ratio. This has nothing to do with your house. A 6.6 kW system is undersized for households with electric hot water, ducted air-con, an EV, or a pool. It's oversized for a small unit with two adults out at work all day.

The CEC's guidance is: start from your annual kWh consumption and work backwards. As a rule of thumb in Australian capital cities:

• Under 4,000 kWh/year → 5 kW system
• 4,000 – 6,500 kWh/year → 6.6 kW system
• 6,500 – 9,000 kWh/year → 8.8 kW system
• 9,000 – 13,000 kWh/year → 10 kW system
• Above 13,000 kWh/year → 13.2 kW+ system, likely with three-phase inverter

A consultant who suggests a system without first asking for your kWh usage is sizing by salary, not by science. Walk away.

Step 2: CEC-Approved Solar Retailers — and why it matters.

There are two CEC programs and people regularly confuse them:

• CEC-accredited installer — the individual electrician who climbs onto your roof. Required by law for grid-connected systems. The baseline.
• CEC-Approved Solar Retailer — the company that sells you the system. Voluntary. Signs up to the CEC's Solar Retailer Code of Conduct, which requires written quotes with specific disclosures, honest marketing claims, deposit and refund protections, after-sales support, and warranty fulfilment commitments above the legal minimum.

Both labels are useful — but Approved Solar Retailer status is the one that protects you when things go wrong. Always check the CEC's Approved Retailer directory before you sign.

Step 3: What a real quote looks like.

A quote that's worth anything names every component by brand and model. Here's the minimum a solar quote should disclose:

For a battery, add: usable capacity in kWh (not nominal), continuous AC output in kW, depth of discharge, chemistry (LFP / NMC), warranty cycles and years, and whether it qualifies for the federal Cheaper Home Batteries Program rebate.

If any of these are missing or vague — "premium tier-1 panels", "high-quality inverter" — the quote is incomplete. Ask for specifics. The honest answer should land within 24 hours.

Step 4: Questions to ask before you sign.

Print this list. Take it to every consult.

Step 5: Warranties — read them properly.

Three things to understand about every warranty:

• It has separate clocks for separate components. Don't accept a single "25-year warranty" number. Panels have a product warranty (5–25 yr) and a performance warranty (25 yr at ≥85% output). The inverter is usually 5–10 yr. The mounting and workmanship are usually 5–10 yr. All four can be different.
• It covers parts, but usually NOT labour. Most product warranties send you a replacement panel for free — and charge you $1,500 to put it on the roof. A retailer warranty that covers labour for the first five years is rare and worth paying for.
• It's voided if the install is non-compliant. If the installer didn't follow AS/NZS 5033 for the wiring, the manufacturer can refuse to honour the warranty. This is why CEC-accredited installation matters even if the panel itself is good.

For batteries, ask specifically about cycle warranties (the battery is warranted for N cycles to X% capacity, e.g. "10 years OR 6,000 cycles OR 70% capacity, whichever comes first"). LFP chemistry typically hits 6,000+ cycles before degrading; older NMC chemistry is shorter.

Step 6: Installation day — what to expect.

Most residential solar installs are completed in a single day. The crew arrives early, isolates your switchboard for an hour or two while wiring is run, and leaves with the system commissioned and the monitoring app handed over to you. Battery installs take longer — typically a half day extra.

The CEC-accredited installer must sign a Certificate of Electrical Safety (or your state's equivalent) and an STC assignment form. Get a copy of both before they leave the property. Without them you can't claim the rebate and your warranty position is shaky.

Connection to the grid is a separate, parallel process. Your retailer applies to your DNSP (Ausgrid, Endeavour, Essential, Powercor, Ergon etc.) for permission to operate. Approval typically takes 3–10 business days. Some networks impose an export limit — 5 kW or 10 kW — which is normal; the inverter just throttles your export when the limit is hit.

Step 7: After the install.

Three things to do in the first month:

1. Check the monitoring app daily for the first two weeks. Generation should match the seasonal expectation in your quote (your retailer should have shared this). If you're seeing 30%+ below expectation, raise it immediately.
2. Wait for your first power bill after install — usually a quarter later. The drop should align with the quote's prediction. If it's significantly worse, ring your retailer with the meter data.
3. Save the commissioning paperwork, panel + inverter serial numbers, and warranty docs to a folder you'll find in five years. A simple cloud folder named "Solar — [year]" works.

The common pitfalls. And how to avoid them.

• "Free upgrade" pitches. Every kilowatt of panel costs $700–$1,200 to install. A "free upgrade" is either a discount that was always in the price, or a swap to a cheaper component. Read about it in our cowboy installer guide.
• "Sign tonight for this price" pressure. A real quote holds for at least 14 days in writing. Anyone pressuring you to sign immediately is selling, not consulting.
• "Tier-1 panels" with no brand named. "Tier 1" is a Bloomberg banking-risk rating, not a quality rating. Insist on the panel manufacturer's name.
• Undersized inverter relative to your panels. A 6.6 kW panel array with a 5 kW inverter caps your generation. Sometimes this is intentional (export limits) — sometimes it's just to hit a price point. Ask.
• Battery sold without solar. A battery without solar is mostly useless — it just charges from the grid at off-peak rates and discharges at peak. You need an existing solar system or you're buying one to add. If a retailer pitches a standalone battery without asking about your solar, they're not paying attention.
• "CEC approved" without specifying which program. "CEC-Approved Solar Retailer" is what matters. "CEC-accredited" alone means only that the installer is registered — the legal minimum.

Where a broker fits in.

You can absolutely do this yourself. The CEC publishes the retailer list. Anyone with an afternoon and four power bills can ring three retailers and compare quotes.

What a broker (like us) does is compress the process: one phone call, three or four pre-vetted retailers we've personally checked for install quality and warranty support, written quotes within a few days, and a single consultant who stays on the line from first call to switch-on. We don't charge you — the retailer pays a flat referral fee only when work is installed. You're not buying from us; we help you buy from them. Read about the economics if you want the full breakdown.

Right-fit, not cheapest. The cheapest quote almost always costs the most over twenty years — we've written about why that is. The cheapest installer wins on the headline and loses on the inverter, the warranty, and the support relationship.