Size the Market for EV Charging Stations

What interviewers evaluate

• Do you define which market you're sizing (charging revenue vs hardware vs software) before computing?
• Do you avoid the fleet-vs-new-sales trap (EV share of the fleet is much lower than of new sales)?
• Do you decompose via energy (miles → kWh → public share → price)?
• Do you recognize the today-vs-trajectory distinction and make it the insight?
• Do you name the sensitivity drivers (fleet size, home-charging share)?

A framework to structure your answer

1. Define the market - annual revenue from public charging sessions; note hardware/installation and software as separate pools.
2. EVs on the road - start from the total vehicle fleet and the EV share of the FLEET (not of new sales - fleets turn over slowly).
3. Energy per EV - annual miles ÷ efficiency (mi/kWh) = kWh/year.
4. Public share - most charging is at home; estimate the public fraction and note who skews it (apartment dwellers, road trips).
5. Price & compute - public $/kWh × public kWh × fleet = today's revenue.
6. Trajectory & sensitivity - re-run at projected fleet size; state the dominant sensitivities and the strategic takeaway.

Try structuring your own answer first, then reveal a strong worked example.

Common variants

• Size the market for residential solar installation.
• Estimate the annual revenue of a national coffee chain.
• How big is the market for last-mile delivery robots?

Pitfalls to avoid

• Using EV share of new sales as if it were share of the fleet - off by several x.
• Not defining which market (session revenue vs hardware vs software) before computing.
• Forgetting that most charging happens at home - public share is a minority of energy.
• Presenting today's number without the trajectory - the strategic content of this case.
• No sensitivity analysis on the assumptions that dominate (fleet size, public share).

Likely follow-ups

• Which assumption moves the answer most, and what data would pin it down?
• How does the market change if most new EV buyers live in apartments?
• You're advising a charging startup: given this math, where should they focus?