How would you go about calculating how many solar panels are used in a country ?

estimation market sizing
New answer on Feb 28, 2021
4 Answers
Anonymous A asked on Feb 20, 2021

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Content Creator
replied on Feb 21, 2021
Strategy&| ex-interviewer | 170+ coached over career |95% success @ MBB, S&, RB, LEK, OW, Big4 [SUCCESS STORIES BELOW]

There's a lot of great content on PrepLounge on how to structure a market sizing e.g.


Think through this problem from first principles which means there are different approaches you can take e.g.

  1. Residential vs Business solar panel owners/operators - assume a certain % penetration of solar power usage, estimate avg panels/user
  2. Landmass based - total roof size in a country, average % dedicated to solar panels, avg size per panel
  3. Energy usage basis - total energy used in a country, % renewable, % solar, kWH generated per panel, therefore inferred number of panels
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Content Creator
replied on Feb 20, 2021
MBB | 100% personal interview success rate (8/8) and 95% candidate success rate | Personalized interview prep

Hi there,

The best way to learn is by doing :) Post your approach here and we can provide feedback!

General Tips for Market Sizing

  1. Just like in a case, make sure you understand the question - what are you really being asked to calculate
  2. Decide whether a top-down or bottom-up approach is best
  3. Figure out what you know you know, and what you know you don't know, but could estimate
    1. This helps you determine how to split out buckets
  4. Stay flexible - you can start with a "high-level" market sizing, but gauge your interviewers reaction....if it looks like they want you to do more...then go along level deeper in terms of your splits
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Content Creator
replied on Feb 22, 2021
McKinsey | Awarded professor at Master in Management @ IE | MBA at MIT |+180 students coached | Integrated FIT Guide aut


I would always recommend you to give it a shot and then post it here, this would help you the most.

This is a very typical market sizing case, where the key steps are:

Calculate the total population

Calculate the % of population that could be interested in this product (this could be done by clustering -the classical ones are age groups, purchaching power, etc.-)

Hope it helps!



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Content Creator
replied on Feb 28, 2021
Ex-Mckinsey|Certified Career Coach |Placed 500+ candidates at MBB & other consultancies

It's a nice market sizing question.. First of all, it really depends on the country and what kind of energy is used in which proportions. I would start with that.


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Raj gave the best answer


Content Creator
Strategy&| ex-interviewer | 170+ coached over career |95% success @ MBB, S&, RB, LEK, OW, Big4 [SUCCESS STORIES BELOW]
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