For a long stretch in my own solar business, I had one supplier and I thought that made me smart. The pricing was good. The rep knew me by name and knew how I worked. Orders went through without friction, credit terms were sorted, and when something went sideways I had one number to call. It felt like a strength. It was actually the single biggest operational risk in the business, and I could not see it because nothing had gone wrong yet.

That is the thing about single-supplier dependency. It does not announce itself. It feels like a good relationship right up until the morning it stops being one.

How the trap actually forms

Nobody decides to become dependent on one supplier. It is not laziness and it is not a strategy. It builds out of convenience, one sensible decision at a time.

You find a distributor who treats you well. Their pricing is competitive, the rep is responsive, the warehouse is reliable. So you give them more of your volume, because why wouldn’t you. The more you order, the better your pricing and your standing get, which gives you even more reason to keep funnelling everything their way.

Then, quietly, you stop qualifying anyone else. You stop taking the calls from other reps. You let the second relationship you used to have go cold because you do not need it this month. None of that feels like a mistake at the time. Every step is rational on its own. The problem is that convenience has hardened into dependency, and you will not notice until something tests it.

What actually goes wrong

When it breaks, it usually breaks at the worst possible time, because the things that stress a supplier are the same things that stress you. Here is what I have seen take operators out, including me.

Stock allocation disappears when you need it most. The classic is the December to January window, when everyone is trying to get jobs in before the holidays and panel and inverter stock gets allocated tight. If you are not a priority account, or your one supplier simply runs dry, you have no second door to knock on. Your installs stall while your competitors who spread their buying keep fitting.

A product gets discontinued with little warning. A panel or inverter line you have built quotes and accreditations around goes end-of-life. With one supplier you find out late and scramble. With two, you usually hear it earlier and you have somewhere to pivot.

Your pricing leverage quietly vanishes. This one is invisible until you look for it. When a supplier knows you have nowhere else to go, there is no commercial pressure on them to keep your pricing sharp. You are not getting their best number, you are getting the number they can get away with. You will not even know what you are leaving on the table.

Your rep leaves. This is the one that stings, because so much of a good supplier relationship lives in one person. They know your accreditations, your typical orders, your credit history, the favours you have banked. They leave, and you are suddenly an account number to someone who has never heard of you. Years of relationship reset overnight.

The supplier itself changes. Financial trouble, an acquisition, a restructure. Terms change, credit limits tighten, the people you dealt with disappear. None of it is in your control, and if your whole supply chain runs through that one business, neither are you.

The two preferred suppliers rule

The fix I landed on, and the one I would tell any operator to run, is simple: maintain at least two qualified preferred suppliers who can each cover your core product set.

Not ten. Two.

The distinction matters. The point is not to have a long list of contacts you ring around in desperation chasing the best price on the day. That is not a relationship, that is a spreadsheet, and it earns you priority with nobody. The point is two genuine relationships, both of which see you as a real account worth looking after.

Two gives you redundancy without fragmenting your volume so badly that you become a nobody to everyone. It is enough to keep both suppliers honest and enough to keep you covered when one of them has a bad month. It is also few enough that you can actually maintain the relationships properly, which is the part most people get wrong.

How to do it without drowning in admin

The fear I hear most is the admin. Two sets of price lists, two ordering processes, two reconciliations, two relationships to feed. For an operator already buried on the back-office side, that sounds like the last thing you need. It is real, but it is overstated, and the structure that makes it manageable is straightforward.

Run a primary and a secondary, not a 50/50 split. Send roughly 70 to 80 per cent of your volume to your primary. That keeps you as a serious account where it matters most, with the pricing and priority that come with it. The remaining 20 to 30 per cent goes to your secondary, consistently.

That word, consistently, is the whole game.

Keeping the second relationship alive

The mistake that kills the two-supplier setup is treating the secondary as an emergency-only line. You only call them when your primary has let you down. From their side, you are an account that orders nothing for months and then turns up wanting a favour, fast, at a good price, usually when stock is tight for them too. You are exactly the account they deprioritise.

So your “backup” is coldest at the precise moment you need it to be warm. That is not a backup. That is a wish.

The way you keep it real is to give your secondary steady, genuine business. Enough orders to keep your account active, your pricing current, and your name familiar to the people who allocate stock. It costs you a little of the volume discount you might have squeezed from concentrating everything with the primary. What you buy with that small premium is insurance that actually pays out when you claim on it, plus the leverage I will get to next. It is one of the cheapest forms of risk management in the business.

The leverage is the quiet payoff

Here is the part that makes two suppliers worth it even in a year where nothing goes wrong.

Having a second qualified supplier changes every pricing conversation you have with your primary. You do not have to threaten anyone or play them off. You do not even have to mention it. The fact that you genuinely could move volume is what keeps your primary sharp. A supplier who knows you are captive behaves differently from one who knows you have options, every single time.

You will rarely use the alternative. Its existence is the asset, not its use.

Map the overlap before you need it

One practical trap to close off: make sure your two suppliers genuinely overlap on your core categories, the panels, inverters, and batteries you fit most. The failure case is subtle. You think you have redundancy, but the inverter brand your top installer is accredited on is only stocked by supplier one. So when supplier one has an outage, your “backup” cannot actually supply the thing you need, and your redundancy was a mirage.

Sit down and map it. Map your non-negotiable product set: the panel tiers you quote most, the inverter brands your installers are accredited for, and your standard battery options. Verify that both suppliers can cover that entire list. Where a gap exists, it needs to be closed by qualifying the brand with both suppliers, or know in advance exactly where you are still exposed so it is a decision and not a surprise.

It is worth saying this discipline pays off well beyond stock. Spreading your supply also smooths the cashflow squeeze, because supplier terms, lead times, and stock timing all feed straight into how long your money is tied up between buying gear and getting paid, including the wait on certificate income. Small-scale Technology Certificates, the tradeable certificates created from an eligible system’s deemed generation that liable entities must surrender under the Renewable Energy Target (Clean Energy Regulator, n.d.), are their own cashflow lag on top of supply. The fewer single points of failure you carry across the whole chain, the less often one bad week turns into a bad quarter. I have written more about that side in the admin discipline that quietly decides whether a job made money.

This is exactly the kind of operational risk I am building CurrentFlow to help installers see before it bites: where your supply, your cash, and your jobs are quietly concentrated in one place. The idea is to make the exposure visible so you can manage it on purpose, instead of finding out the hard way like I did.

Get the second supplier sorted while everything is fine. That is the only time you can do it calmly, on your terms, at a good rate, without a stalled job breathing down your neck. The operators who set it up in the quiet months are the ones who barely notice the December stock crunch. The ones who wait are the ones ringing around in January, learning the lesson the way I learned it.

References

Clean Energy Regulator. (n.d.). Small-scale Technology Certificates. Australian Government. https://www.cleanenergyregulator.gov.au

Clean Energy Regulator. (n.d.). How the Small-scale Renewable Energy Scheme works. Australian Government. https://www.cleanenergyregulator.gov.au

FAQ

How many solar suppliers should I actually keep?

Two preferred suppliers who can both cover your core product set, not ten. The goal is genuine working relationships, not a phone list you ring in a panic. One primary takes the bulk of your volume and one secondary gets consistent, real orders. Beyond two you spread your volume so thin that you lose pricing power with everyone and the admin overhead stops being worth it.

Won’t a second supplier just hurt the pricing I get from my main one?

It is usually the opposite. When you have a genuine alternative, every pricing conversation with your primary changes, because they know you can move volume if you need to. You rarely have to use the alternative. Its existence is what keeps the relationship honest. A primary who knows you are completely captive has no reason to sharpen a quote.

How do I keep a backup supplier warm without wasting money?

Give them real orders, not crumbs. The classic mistake is only calling the backup when your main supplier has let you down, by which point you are a low-priority account asking for a favour. A steady trickle of genuine business keeps your account active, keeps your pricing current, and means the relationship is live the day you actually need to lean on it.

Do my two suppliers need to stock exactly the same products?

They need to overlap on your core categories: panels, inverters, and batteries you fit most. The trap is a gap where only one supplier carries the inverter brand your best installer is accredited on. If that one supplier has a stock outage, you cannot just switch, because the alternative cannot supply the thing you actually need. Map the overlap before you need it.