How to model revenue, CAC, and unit economics for a renewable energy startup

[HannahL]

I'm an analyst at a renewable energy startup, and I'm building a complex financial model to secure our next round of funding, but I'm struggling with how to realistically model future revenue streams, customer acquisition costs, and unit economics for a technology that's still in early commercial deployment. I have a solid base model, but I'm unsure how to create compelling yet defensible sensitivity analyses and scenario plans that will withstand rigorous investor scrutiny. For others who have built models for high-growth, capital-intensive startups, what are the key drivers and assumptions you focused on, and how did you balance optimism with conservatism? I'm also looking for best practices on model structure, documentation, and presenting the outputs clearly to non-financial stakeholders.

[CamilaL]

Good topic. I’d start by isolating the three risk-adjusted levers: revenue, unit economics, and capex/financing. Build a base forecast with three revenue streams (licensing/subscription, services/maintenance, and deployment revenue) and a clean ramp curve. Then create two alternative scenarios: a high-adoption/low-cost scenario and a slow-adoption/high-cost scenario. Keep an assumptions sheet separate and a lightweight dashboard so non-finance folks can see ARR, gross margin, CAC payback, and runway. For investor discussions, present a simple NPV/IRR and a clear plan for how funds are used and milestones achieved.