An installer's quote and a CFO-ready business case are different documents, even when they're describing the same system. A quote sells the equipment. A business case needs to answer capital-allocation questions a finance leader is trained to ask — and a proposal that skips those questions tends to stall in approval, however good the underlying deal actually is.
Start With the Question a CFO Is Actually Asking
It's rarely just "does this save money." It's closer to: does this investment return more than our capital would earn deployed elsewhere, over what timeframe, with what risk, and what happens to our cash flow in the meantime? A proposal built around "look how much you'll save on electricity" alone misses most of what actually drives an approval decision.
The Core Numbers to Include
- Total capital outlay, clearly separated from any financing cost if the purchase isn't cash
- Payback period, calculated conservatively — using a realistic self-consumption assumption, not a best-case one (see our piece on why commercial solar ROI breaks down without a load profile)
- Total savings over a realistic horizon (10–15 years is a reasonable range), not just the payback-period cutoff, since the investment keeps returning value after payback
- Sensitivity range — a low, expected, and high savings scenario, rather than one single optimistic number, which builds more credibility than false precision
The Number Most Proposals Leave Out: Downtime Cost
If load shedding meaningfully affects your business, the avoided-downtime value (covered in more detail in our piece on how load shedding changes the business case for commercial solar) deserves its own clearly-labelled line — separate from direct bill savings, since it's a different kind of value with a different confidence level. Presenting it as a rough, clearly-caveated estimate is more credible than omitting it entirely or blending it into the "hard" savings number.
Financing Structure: Present the Comparison, Not Just One Option
Rather than presenting a single financing path, a stronger business case shows the comparison across cash purchase, loan, and PPA (detailed in our commercial solar finance comparison) side by side, since a CFO's preference often comes down to capital allocation priorities you may not have full visibility into. Giving them the comparison, rather than a single recommendation, respects that it's ultimately a finance decision informed by more than the solar numbers alone.
Addressing Risk Directly
A CFO evaluating any capital proposal is implicitly asking what could go wrong. Address it directly rather than leaving it unstated: equipment and workmanship warranty terms, what happens if the installer ceases trading, expected maintenance cost over the system's life, and how the payback estimate would change under a less favourable (but still realistic) scenario. A business case that only shows the upside reads as less credible than one that's shown its own downside case.
A Reasonable Structure to Follow
- Executive summary: capital required, payback period, total savings range
- Direct savings calculation, with assumptions stated explicitly
- Avoided-downtime value, clearly labelled as an estimate
- Financing comparison
- Risk factors and how they're mitigated
- Recommendation, with the sensitivity range shown, not a single number
Building the Numbers to Start With
Our solar calculator gives a starting system size and cost estimate — a reasonable figure to build the rest of the business case around before commissioning a full commercial proposal. Get formal quotes and load-profile-based sizing from installers on ADEO once you're ready to build out the full internal case.
Frequently Asked Questions
How conservative should the savings estimate be in a CFO-facing proposal? Conservative enough that the low end of your range is genuinely defensible if challenged — overpromising and later underdelivering damages credibility for future capital requests far more than a modest initial estimate does.
Should the proposal include a recommendation, or just present options neutrally? Both tend to work well together — present the comparison neutrally, then state your own recommendation and reasoning clearly, rather than leaving the decision entirely open-ended.
Is it worth getting installer input on how to structure the CFO presentation itself? Some commercial installers have experience helping clients build this kind of internal business case — worth asking directly whether they can support that process, not just provide the equipment quote.
Writes about solar and renewable energy for South African homes and businesses at SolarTally, and cross-checks every guide against current tariffs and installer standards.
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