How many electric charging stations are there in Germany?

brainteaser estimation guess-estimates Market sizing
New answer on Apr 19, 2023
3 Answers
Anonymous A asked on Apr 18, 2023

I would like to share my approach to the question "How many electric charging stations are there in Germany"?
1. demand per day / 2. met demand per charging station per day / 3. percentage lost to domestic charging.

1.1. #Electric cars+hybrid cars / 1.2. after how many days a car has to refuel on average
1.1. #electric cars = #number of cars x %electric/hybrid cars = population / number of people per household x %electric/hybrid cars 80 mio / 2 x 2% (based on the observation that on average there is 1 car per household and in a large car park near me every 50th car is approx. an electric car) = 800,000

1.2. after how many days a car has to refuel on average: average driving distance of an e-car / average consumption per day = 350km / 50km = refuel every 7 days

1 = 800,000 / 8 => 115,000 electric cars refuel per day

2. covered demand per charging station per day = 1 charge takes approx. 6h, then approx. 2 charges can be completed per day, as hardly anyone takes their car away for charging between 23.00 - 08.00, therefore on average 2 cars can be served per day

3. 50% of the charging takes place at home: Observation through charging behaviour of our e-car

=> 115,000 / 2 x 0.5 = approx. 28,500 charging stations

I look forward to feedback!

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Content Creator
replied on Apr 19, 2023
#1 McKinsey Coach by rating & recommendation rate

Hi there, 

You have a sound approach. 

For market sizing questions, I'd recommend you also try and have some fun with ChatGPT. Try asking for several approaches and try to learn from how it chooses to do the sizing differently based on the inputs you give it. 


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Content Creator
replied on Apr 19, 2023
#1 Bain coach | >95% success rate | interviewer for 8+ years | mentor and coach for 7+ years

Hi there,

I would be happy to share my thoughts on it:

  • First of all, I think both your overall, very nuanced approach and key assumptions for this market size estimation are great.
  • However, given that demand is currently not met in Germany, a supply-based approach might be equally, if not even more, meaningful here.

If you would like a more detailed discussion on how to best prepare for your upcoming interviews, please don't hesitate to contact me directly.



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Anonymous A on Apr 19, 2023

What do you mean by it is not met - in which way ? Are there more stations than electric vehicles or less stations than electric vehicles ? By saying a supply approach would be more suitable do you mean to do a bottom up approach like: how many charging stations are in my neighbourhood and extrapolate this number to overall area of Germany ? Thank you for you comment.

Hagen on Apr 19, 2023

First of all, I apologize if my answer was unclear. There is significantly too little public charging infrastructure in Germany, i.e., not enough charging stations for the EVs on the roads. Yes, you might operationalize a supply-based approach by estimating the number of charging stations in your neighborhood or city and extrapolating from there.

Content Creator
replied on Apr 18, 2023
MBB | 100% personal interview success rate (8/8) and 95% candidate success rate | Personalized interview prep

It's always funny to me to see how much this question gets recycled! Same question, different country/city.

I think your approach is mostly valid - well done.

By the way, another approach, as I reflect further, is a bottom up approach. Essentially, observing what you're seen around neighborhoods etc. an extrapolating out. When you think about it, supply make a lot more sense here because, before we hit critical mass of EVs, we actually need more charging stations than cars (as government wants to reduce range anxiety). Just another approach :)


Here's how I approached the question for Ho Chi Minh city (same approach should be applied to Germany).



Question: Number of electronic charging station (For electric car vehicle) in Ho Chi Minh City, Vietnam in the next 10 years? 

This one could be answered top-down (as I did) by estimating population of the city, # of drivers/ cars, etc. etc.

OR, it could be answered bottom-up by estimating # of stations you see per block (or # of gas/petrol tanks), % increase this might be over time (or # of EV stations that would be needed per gas tank given EV stations take 10 times as long), and # of blocks you'd estimate the city to have.

By # of Electric Cars

  1. Population of Ho Chi Minh - Around 8 million?
  2. # of adults - Around 5-6 million
  3. # of cars per person - around .5 (probably 1 per household)
  4. % of electric vehicles expected in 10 years -
    1. highly variable based on country.
    2. While Vietnam is a developing country (points against), they are also command-and-control communist and are capable of big change (points for).
    3. The global rate of EV uptake will probably equate to 1% of the global fleet each year (obviously less now, more later). So, perhaps 10% globally? Let's place vietnam around there
  5. ​Big consideration: Charging stations are a leading investment to electric cars. So, you need capacity there before demand hits. We will probably need around 1 charging station per vehicle (docking at night). And this would need to lead by a few years. So, we might need charging stations for 15% of the Vietnamese car fleet (instead of 10%)
  6. Answer = 375,000 - 450,000 charging stations:
    1. (5 - 6 million people) X (.5 cars per person) X (15%)

Market Sizing Explanation 1

Remember that there's rarely a "best" answer with market sizing. What's important is that you break down the problem the way it makes sense to you. Importantly, break it down so that the assumptions you make are the ones you're most comfortable in.

For example, do you know all the major brands? Great go with that. Do you understand all the segments of that country's population (either age or wealth or job breakdown)? Go with that. Do you know the total market size of the tourism (or hotel) industry? Then break it down that way.

Market Sizing Explanation 2

Do the approach the is the easiest for you given the question.

Are they asking you to estimate something where you don't even know where to begin from the top (maybe you have 0 clue as to the market size of the industry, the GDP of that country, etc. etc.)? Then do bottom-up!

Alternatively, does it seem impossible to do a realistic from-the-ground-up estimation of something (perhaps it requires just far too many steps and assumptions)? Then do top-down!

Fundamentally, you need to take the approach that just makes the most sense in that circumstance. Quickly think about the key assumptions / numbers required and whether you 1) Know them or 2) Can reasonably estimate them. If you can, go ahead!

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