Guest blog by SA Shelley: The amount of energy consumed to light our modern civilization would surprise most people. In the not too distant past, residential and commercial lighting consumed about 20% of all electricity produced. Basically, every fifth coal, nuclear or gas turbine power plant built was used to just to light cities, factories and homes. However, since the advent of the LED, there has been a remarkable drop in the amount of electrical power required to light our modern world. Depending upon where you live and work, recent data suggests that residential and commercial lighting now consumes only between 7% to 12.5% of all the electricity produced. That’s a drop in energy consumption for lighting by almost 1% per year over the last 10 years. The good news is that the energy for lighting continues to decline and will only get better as more LED lighting replaces inefficient technologies (see Fig. 1 and Fig. 2).

The cost for LED lighting has also been falling at an incredible rate (see Fig. 3).

Yet, there is still room for additional drops in energy consumption using LEDs. In the typical U.S. residence, about 10% of total energy costs still go to producing light. For sure, the bulk of residences in the U.S. still rely upon many of those outdated lighting technologies, though folks are adapting, as currently half of all lighting sales in the U.S. are LEDs. Doing a bit of math for the U.S. we can see how much power could still be saved, all other thing equal, if we were to hit 90% LED usage for lighting.

Using households as a proxy for residences, there are approximately 127 million households in the United States. Each household uses an average of about 28.5 kWh of electricity each day. Supposing that by LED sales, at 50%, that we’re already at 50% utilization for LED residential lighting. So if we aim for 90% target, then a household should be able to save another 4% of its total electrical power consumption, or about 1.1 kWh each day. Now, multiplying this number by the number of households in the U.S. yields a total electrical energy savings of about 140,000 MWh each day. The total energy production by all coal fired plants is 3,140,000 MWh per day. Ergo, just by switching to LED lighting in residences it is very likely that about 5% or about 17 of the remaining coal power plants in the U.S. will no longer be needed.  

Bow to the LED, the little lightbulb has become a killer of king coal.