The Cost of Lighting and Computing

June 23, 2022

Amidst all the challenges with the current cost of living, including the cost of energy, we sometimes forget how far we have come in making valuable resources widely available and how much better we have it compared to previous generations.

A great example of this is the cost of lighting.  A typical 60-watt equivalent LED lightbulb costs about 1 cent per day in electricity.  In historical terms, as can be seen in the chart below, that is practically free. 

https://ourworldindata.org/grapher/the-price-for-lighting-per-million-lumen-hours-in-the-uk-in-british-pound

There are two drivers to this low cost. 

The first is the ongoing improvement in the efficiency of the source of lighting.  The source of lighting has gone from sesame oil to talcum candles to whale oil to gas lamps to incandescent lightbulbs to compact fluorescent light (CFL) bulbs to light emitting diodes (LED) bulbs.  This improving efficiency has come about in two ways.  The first is the source of light.  As we have moved from various oils to gas to electricity, we have moved to mediums that are more efficiently converted into light.  The second is the improvements in the conversion process.  As we have moved from fire to incandescence to fluorescence to LED we have moved to more efficient processes.

The second driver is the cost of electricity.  Over the past twenty years we have got used to the cost of electricity rising but historically the cost of electricity has fallen.

https://www.open.edu/openlearn/ocw/mod/oucontent/view.php?printable=1&id=4962

The cost of computing has followed the same trajectory but in an even more extreme fashion.  Moore’s law states that the number of transistors on a microchip doubles every two years.  The corollary of this is that the cost of the computing falls logarithmically as can be seen in the chart below.

https://www.hamiltonproject.org/charts/cost_of_computing_power_equal_to_an_ipad2

If you are using light and computing for everyday purposes (as opposed to growing cannabis or mining cryptocurrencies) then your costs will be very low. 

To me, this is a source of inspiration.  We face a generational challenge to de-carbonize our world and this will be primarily transportation and heating.  If we can innovate to de-carbonize and reduce the cost of transportation and heating the same way we have done with lighting and computing we can meet this challenge.

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