The line item most solar quotes hide is not a component — it is the scope split. A quote you can genuinely compare separates hardware, labour, electrical work, mounting, compliance and commissioning into distinct lines, because until those buckets are visible you are not comparing suppliers; you are comparing how differently each one words the same unknowns. Find the split, or the comparison you are busy with is a fiction with a rand sign in front of it.
I learned that at my kitchen table, three quotes fanned out under a mug of coffee that had stopped being coffee an hour earlier, a highlighter dying in my hand. The cheapest one was a single line: supply and install a hybrid solar system. One number. The other two ran to three pages each. I remember thinking the short one was tight and the long ones were padding. Then I did what I now do with every quote that arrives at this house. I drew columns on the back of an envelope and rewrote all three into the same shape. The cheap one collapsed in about twenty minutes.
What it was missing wasn't a panel. It was the distribution board work. The surge protection. The Certificate of Compliance. The SSEG application to the municipality. And every word about mounting onto a corrugated roof that has been repaired twice in fifteen years. None of that was listed as excluded. It simply wasn't there. An exclusion you can phone about and argue with. A silence you can't.
Rewriting every quote into the same seven buckets
I use the same columns every time, and I don't let a supplier's own headings decide them for me.
Hardware. Panels by make, model, wattage and quantity. Inverter by make, model and rated output. Battery by make, model, usable capacity and chemistry. Then the balance of system, which is where quotes go vague first: combiner box, DC isolators, AC breakers, cable sizes, fuses, earth spike and the earthing conductor itself.
Labour. Who is physically on site, how many of them, for how many days, and whether the person who did the design is the same person who climbs the roof. Design and install split across two companies is not automatically bad, but I want to know before I sign, not after something leaks.
Electrical work. New distribution board or reusing the existing one? Earth leakage replaced or retained? Surge arrestor fitted at the DB? Essential-load sub-board for the circuits you plan to keep alive when the grid is down — fridge, lights, Wi-Fi, gate motor, the plug the television sits on? This bucket carries the biggest invisible differences between quotes that look almost identical on page one.
Mounting. Rails, brackets, hooks for tile or IBR or corrugated sheet, the sealing method at every single penetration, and what happens if the timber underneath turns out to be soft. Roof work is the part of a solar job that fails slowly and quietly.
Compliance. The CoC issued under SANS 10142-1, the inverter's NRS 097-2-1 certification, and who drives the SSEG application with the municipality — you, or them. A quote that says "compliance included" without naming those three things is a quote with a hole in it.
Commissioning and handover. Who configures monitoring, who labels the board, who walks you through a blackout switchover, and what documentation lands in your hand on the last day. Ask for the handover pack in writing.
Sundries and assumptions. Scaffolding, cable routes, trenching, meter changes, tree work — and everything the site visit didn't reach.
When I finished that first envelope I had three quotes with blanks in different places. That's the whole discovery. A blank cell isn't a saving. It's a question you are about to pay someone to answer later, at their price.
The words that do the hiding
Some phrases appear in almost every quote and mean almost nothing until you force them open.
"Installation" — whose installation? Mounting only, or mounting plus wiring plus commissioning? "DB work" — a new board, or a breaker swapped into the old one? "Standard installation" — standard for which roof, which cable run, which municipality? "Battery ready" — a cable gland or a full hybrid inverter with the right voltage window? "Compliance included" — the CoC, or the CoC plus the SSEG paperwork plus the meter change?
I don't argue with the phrase. I ask for the sentence underneath it. Every one of those words can be made specific in a single reply, and the reply either comes quickly or it doesn't.
Certification is a yes-or-no line, and it's often absent
Municipal approval of a grid-tied or hybrid system depends on the inverter being certified to NRS 097-2-1, and on the paperwork matching the equipment actually installed. So the quote should name the exact inverter model and its certification status, and the exact make and model of the battery and panels. Not "Tier 1 panels". Not "SABS approved inverter". A model number.
That matters beyond the application form. Battery and inverter compatibility is a real constraint — not every battery talks properly to every inverter, and the pairing on the quote needs to be one the manufacturer supports, because that's the pairing your warranty depends on. I've seen a cheap quote win on price purely because it paired two boxes that were never meant to sit on the same wall.
Four warranties wearing one word
When a quote says "5-year warranty", my next question is: on what? Workmanship, inverter, battery and panels are four different warranties, often held by four different parties, with four different claim paths.
So I want the quote to state, per item, how long the term is and who administers the claim — the installer, the importer, or the manufacturer. I want to know whether the workmanship warranty survives if I move a panel myself, whether a battery warranty is pro-rated or full replacement, and which number I phone in year three when the battery derates. I don't care what the industry norm is. I care what's written on my page.
A production number with no plumbing
A single annual kWh figure on a quote is unfalsifiable. It could be modelled properly or pulled from a spreadsheet template with my address left in it.
What I want is the assumptions behind the number: roof orientation and tilt, the azimuth the array will actually face, shading from that tree or the neighbour's second storey, and the consumption profile the design is aimed at. If the estimate assumes I use most of my production on site, I want to see what happens to the maths if I don't. A number with no assumptions attached is decoration.
Exclusions do more damage than missing components
Every quote should carry a written exclusions and assumptions page, and it should be as long as it needs to be. Roof repairs if the battens are shot. Tree trimming that only becomes obvious after the site visit. A meter upgrade the municipality requires before it will approve the connection. Scaffolding above a certain height. Trenching for a cable run that turns out to be longer than the tape measure suggested.
Those are the items that turn a fixed price into a series of variations. I'd rather read them up front, disagree with one, and negotiate, than discover them mid-install when the roof is already open and the crew is standing on it.
Payment should follow milestones, not enthusiasm
A large upfront deposit transfers all the risk to me before anyone has delivered anything. What I look for is payment tied to stages: a modest amount to secure the order, then payments as hardware lands on site, as mounting and wiring are completed, and as the system is commissioned. A slice held back until the CoC and the handover documentation are in my hand gives me something more useful than trust — leverage.
What normalising a quote does not do
It doesn't tell you which quote is best. Two quotes with identical scope can still deliver wildly different workmanship, and no spreadsheet shows that. It doesn't tell you the design is right for your roof and your consumption — that's a separate conversation. It doesn't tell you whether the battery chemistry suits how you'll actually use the system.
What it does is remove the fake differences. Once every quote is in the same buckets, the only differences left on the table are the real ones: what's included, what's excluded, what's certified, and who stands behind it. That's a conversation you can have.
Now, when a quote arrives with no exclusions page, I don't start rewriting. I send one line back: please list everything that is not included in this price. The reply tells me more about the supplier than the quote did.
