Understanding Exponential Growth

 “When I turned 2, I was really anxious, because I’d doubled my age in a year. I thought, if this keeps up, by the time I’m 6 I’ll be 90.” – Stephen Wright, Standup Comedian

All of us at CHARGE come up against a wall at least once a week: the inability of people (investors, car buyers, or dopey friends) to understand exponential growth. Stephen Wright got it at the age of two. But for everybody else here is: Exponential Growth – The Basics.

But first an illustration from the classics.

The story goes that a bored eastern ruler commissioned an underling to devise a boredom reliever. He came up with the game of chess. The energized king asked him to name his reward. The underling said he didn’t want money, merely one grain of rice on the first block of the chess board, two grains on the second block, four on the third block, and so forth. The king – thinking linearly instead of exponentially immediately agreed. A day later his finance minister sheepishly informed him that the reward would come to more rice than there was in the entire empire. Can you do the maths, should I draw you a picture, or do you want to watch the YouTube video?

Exponential growth

Square

Grains

1kg of rice = 15000 grains

1

1

0

2

2

0

3

4

0

4

8

0

5

16

0

6

32

0

7

64

0

8

128

0

9

256

0

10

512

0

11

1 024

0

12

2 048

0

13

4 096

0

14

8 192

1

15

16 384

1

16

32 768

2

17

65 536

4

18

131 072

9

19

262 144

17

20

524 288

35

21

1 048 576

70

22

2 097 152

140

23

4 194 304

280

24

8 388 608

559

25

16 777 216

1 118

26

33 554 432

2 237

27

67 108 864

4 474

28

134 217 728

8 948

29

268 435 456

17 896

30

536 870 912

35 791

31

1 073 741 824

71 583

32

2 147 483 648

143 166

33

4 294 967 296

286 331

34

8 589 934 592

572 662

35

17 179 869 184

1 145 325

36

34 359 738 368

2 290 649

37

68 719 476 736

4 581 298

38

137 438 953 472

9 162 597

39

274 877 906 944

18 325 194

40

549 755 813 888

36 650 388

41

1 099 511 627 776

73 300 775

42

2 199 023 255 552

146 601 550

43

4 398 046 511 104

293 203 101

44

8 796 093 022 208

586 406 201

45

17 592 186 044 416

1 172 812 403

46

35 184 372 088 832

2 345 624 806

47

70 368 744 177 664

4 691 249 612

48

140 737 488 355 328

9 382 499 224

49

281 474 976 710 656

18 764 998 447

50

562 949 953 421 312

37 529 996 895

51

1 125 899 906 842 620

75 059 993 790

52

2 251 799 813 685 250

150 119 987 579

53

4 503 599 627 370 500

300 239 975 158

54

9 007 199 254 740 990

600 479 950 316

55

18 014 398 509 482 000

1 200 959 900 632

56

36 028 797 018 964 000

2 401 919 801 264

57

72 057 594 037 927 900

4 803 839 602 529

58

144 115 188 075 856 000

9 607 679 205 057

59

288 230 376 151 712 000

19 215 358 410 114

60

576 460 752 303 423 000

38 430 716 820 228

61

1 152 921 504 606 850 000

76 861 433 640 457

62

2 305 843 009 213 690 000

153 722 867 280 913

63

4 611 686 018 427 390 000

307 445 734 561 826

64

9 223 372 036 854 780 000

614 891 469 123 652

Total

18 446 744 073 709 600 000

1 229 782 938 247 300

Eighteen zeroes denote a quintillion. Eighteen quintillion is five thousand times China’s total rice production in 2022. I.e., it would take China 5000 years to pay the underling, assuming no one else eats any rice in that time. He understood exponential growth – the ruler didn’t.

To get back to the point.

Some people are dismissive of the uptake of EVs, often citing the low sales figures. I have two words for them: exponential growth.

Let’s take those low sales figures and put them on a chessboard.

Year EVs sold % Increase
2018 58
2019 64 10%
2020 118 84%
2021 218 85%
2022 502 130%
2023 1064 112%
Year Projected sales % Increase
2024 2 117 99%
2025 4 214 99%
2026 8 385 99%
2027 16 686 99%
2028 33 205 99%
2029 66 078 99%
2030 131 496 99%
2031 261 677 99%
2032 520 738 99%

Since full EV sales became a thing growth has been between 84 and 130% per annum. That’s an average of 107% growth per annum, but I’m going to round it down to 99% and project it to 2032. Which predicts sales of 520 000 units per annum. “But that’s coming off a Base!” “It’s not sustainable!” “This is Africa!”

Okay so let’s rearrange the grains of rice, by halving the growth to a more conservative, more sustainable 49% growth per annum.

Year Projected sales sold %Increase
2024 1 585 49%
2025 2 362 49%
2026 3 520 49%
2027 5 244 49%
2028 7 814 49%
2029 11 643 49%
2030 17 348 49%
2031 25 848 49%
2032 38 514 49%

Projected at 49% growth per annum gives us sales of 38 514 units in 2032. Making a total of 115 902 EVs on SA roads if you add the previous 10 years’ sales to the 2032 total and assuming there haven’t been too many Saturday night prangs in Boksburg. At plus-minus R500 000 per car that’s a R19 billion-rand car industry. Not bad for an African country.

Those cars need to be charged somewhere. The average SA motorist spends R55k on fuel costs per year. Multiply that by 115 905 EVs and you’re looking at a 6.3-billion-rand industry, another sizable industry. Part of it will come out of the ICE car and petroleum industries, and the rest of it will be to satisfy population growth and longevity.

Exponential growth is a great thing – unless of course it is on the outstanding amount on your credit card – but it takes some thinking ahead or a pencil and an old envelope. EVs are coming. Lots of them. Just do the maths.


Thanks for reading. If you disagree with my figures, please engage with me at [email protected]. I will gladly post a retraction if I am proved wrong. If you like my figures, please forward them to a friend.

Ps. The King beheaded the underling for making him look like a fool. Bummer! It doesn’t always pay to be a smart aleck.

This site uses cookies to offer you a better browsing experience. By browsing this website, you agree to our use of cookies.