How to Choose Commercial Solar Quoting Software

In short: most solar quoting software is built to design a roof. Commercial work is won or lost on the bill. If you quote commercial solar and batteries in Australia, the eight things that decide whether a tool fits are: whether it prices the real tariff instead of a blended rate, whether it dispatches the battery hour by hour against the site load, whether it carries the whole Australian incentive set rather than just STCs, whether it ingests and cleans interval data, whether its design model matches your job, whether its financial assumptions are visible, what it outputs at which stage, and how its pricing behaves at your actual job mix. Everything else is preference.

Start From the Bill, Not the Roof

Residential quoting is a design problem. The bill is a single flat or two-period tariff, the load shape is predictable, and the thing the customer wants to see is panels on their roof. Tools built for that market are, reasonably, built around a 3D roof and a module layout.

Commercial is a different problem wearing the same clothes. The bill has a time-of-use structure, a demand charge that may be measured in kVA over a 30-minute window and may ratchet for twelve months, network and market components split across a dozen lines, and a load shape that only interval data reveals. The system size that wins the job comes out of that bill. The roof only constrains it.

So the first question to ask about any tool is not what its designer looks like. It is what happens when you feed it a real commercial bill and a year of interval data. Everything below is a way of asking that question precisely.

1. Does It Price the Actual Tariff?

A blended cents-per-kilowatt-hour rate will produce a savings number. It will be wrong, and it will usually be wrong in your favour, which is worse than being wrong against you. Solar displaces daytime energy, so a site on a tariff whose peak window runs 3 pm to 9 pm saves far less per kilowatt-hour than a blended rate implies.

Ask whether the tool models peak, shoulder and off-peak periods separately, on the timings your customer’s network actually uses. Ask whether it handles demand charges as a separate line driven by the single worst interval, whether it understands kVA tariffs and power factor, and whether it knows about ratchets. A ratchet is the difference between a summer spike costing a few thousand dollars and costing that every month for a year. If a tool cannot express one, it cannot model the site.

Two related traps. Published retail rates are not decision data for commercial work, because C&I rates are negotiated per customer, so what matters is that the tool takes the rates off the bill in front of you. And some networks publish their windows in Australian Eastern Standard Time and never move them for daylight saving, so a tool applying those windows on the local clock misallocates six months of the year. Our cheat sheet of TOU windows by network covers which ones behave that way.

2. Does It Dispatch the Battery Hour by Hour?

This is the single largest divider between tools that look commercial and tools that are. A battery sized against monthly totals behaves nothing like one sized against an hourly simulation, because the value of a battery is entirely a question of timing: whether there is charge left in it at the moment the site sets its peak.

A monthly-average model will tell you a 100 kWh battery shaves a certain number of kilowatts off the peak. An hourly model will tell you that on the three days of the year that actually set your demand charge, the battery was already half empty by 4 pm because it had spent the afternoon arbitraging cheap energy. Those two answers can differ by the whole business case.

Ask to see a dispatch profile for a real site, not a summary figure. Ask what the model does when demand-shaving duty and energy arbitrage want the same stored kilowatt-hour, because they routinely do, and a tool that does not resolve that conflict explicitly is resolving it by accident.

3. Does It Carry the Whole Incentive Set?

Almost every tool sold in Australia handles STCs. Commercial work needs considerably more than that, and the gaps tend to sit exactly where the money is.

The crossover deserves particular attention: on 1 October 2026 it moved from 100 kW to a 1 MW site total, which changes the arithmetic on exactly the system sizes commercial solar professionals quote most. A tool with the boundary hard-coded, or without the install date, will quietly produce wrong numbers on either side of that date. The guide to LGCs walks through both sides of that line.

4. Can It Take Interval Data, and Clean It?

A twelve-month interval file beats any template, because it shows the real daytime plateau, the weekend behaviour, and the interval that sets the demand charge. Accepting an upload is the easy half. The half that matters is what the tool does with a file that is not clean, which is most of them.

Real files arrive with daylight-saving duplicates, missing days, kW where kWh was expected, and timestamps recorded at the start of the interval in one export and the end in another. Ask what happens to each. A tool that silently accepts a file with a 25-hour day is not saving you work, it is moving the error somewhere you will not find it. Ask, too, what it does when there is no interval data at all, since a template shaped to the site type and calibrated back to the bill totals is the difference between a defensible estimate and a guess.

5. Does the Design Model Match Your Job?

This one genuinely cuts both ways, and the honest answer depends on what you sell.

Panel-level layout, where the tool places individual modules on a rendered roof, is the right choice when the customer wants to see their own roof and the render helps close the sale. That is most residential work and a good deal of small commercial.

Face-level design, where you author roof faces by azimuth, tilt and area and split a target capacity across them, is the right choice when the sizing conversation happens before anyone cares about module positions. On a 400 kW warehouse roof the orientation and the shading need to be right, and the time saved not dragging panels is better spent on the bill and the battery. It is the wrong choice if your customer expects a photorealistic render, and you should know which of those you are buying rather than discovering it on a deal.

6. Are the Financial Assumptions Visible?

A payback number with no assumptions behind it is a marketing figure. A CFO will ask, and if the tool cannot show its working you will be defending a number you cannot see.

The six that matter: tariff escalation and whether it applies in year one, panel degradation, inverter and battery replacement capex and the year each lands, operations and maintenance, the discount rate behind any net present value, and how exported energy is valued. That last one catches people constantly, because export at a feed-in tariff is worth a fraction of energy displaced behind the meter.

Year-one escalation is the subtle one. Compounding a tariff rise into year one overstates savings immediately and every year after, and it is the most common single error in quoting spreadsheets. The convention used in NREL’s SAM modelling tool, and in our own model, is that year one carries no escalation and it compounds from year two. Whichever convention a tool uses, it should be stated rather than inferred. We pulled the rest of that list apart in the payback assumptions guide.

7. What Does It Output, and at Which Stage?

A commercial deal has two distinct documents in it, and tools that only produce one will make you build the other by hand.

Early on you are agreeing a size. That conversation needs scenarios side by side, a sizing matrix, and something you can walk a decision-maker through, which usually means a deck. Later, once the size is settled, you need a priced proposal with the tariff detail, the roof, the assumptions and the terms, which means a branded, editable proposal document. Ask which of those the tool produces, and whether the second one inherits from the first or restarts the work.

8. How Does the Pricing Behave at Your Job Mix?

Compare the tier you would actually be working in, not the headline. Per-project pricing looks cheap until you count how many quotes you write that never close, and commercial features frequently sit a tier above where the advertised price sits. Subscription pricing looks expensive until you divide it by the same number.

Do the arithmetic on your real volume: quotes written per month, close rate, and the tier that actually carries commercial sizing and battery modelling. A tool priced per project at a mid tier can cost several times a subscription for a business writing a lot of speculative commercial quotes, and the reverse is true for a business writing a handful of large ones.

Test It on a Real Job, Not a Features Page

Every vendor’s features page says it handles commercial. The only reliable evaluation is to take one real project, ideally a difficult one, through every tool on your shortlist and compare what comes out. A useful test case has a demand charge, a battery, and a load that peaks after the sun drops.

Score the shortlist on how long that took and how much of it you had to redo in a spreadsheet afterwards. That number predicts your next hundred quotes far better than any comparison table, including this one.

Where to Go From Here

If you want the workflow rather than the criteria, the bill-to-quote walkthrough follows one job end to end, and the primer on solar quoting software covers what this category does at all. To put a number on a specific site, the commercial solar calculator and the payback calculator are free and need no signup.