Ringside: Californian Energy Use Compared to the USA and the World

As we celebrate one of America’s finest traditions this week, one of the things we are surely thankful for is the energy we often take for granted. We are particularly lucky in America, because the energy we use is nearly always reliable and abundant. Just how abundant? Here are some numbers.

Most energy economists report all forms of energy production and consumption in joules. A joule is one watt-second, i.e. 3.6 million joules equals one kilowatt-hour. For reporting per capita energy use per year, gigajoules (1 million joules) are used. When measuring very large amounts of energy use per year, such as for states and nations, exajoules are used. An exajoule is one billion gigajoules, or one quintillion joules. For comparison’s sake, note that one exajoule is the energy equivalent of 278,000 gigawatt-hours.

If you find this tedious and abstruse, relax. To quantify how thankful we should be that we live in America, it’s the proportions that matter.

Total global inputs of primary energy in 2023 – that’s the energy contained in all fuels; coal, gas, oil, nuclear, solar, wind, geothermal, and biomass – is estimated to have been 604 exajoules. The United States accounted for 96 exajoules (16 percent), and of that, California accounted for 7.1 exajoules (1.2 percent). But here’s where it gets interesting.

If you examine per capita energy use, stark contrasts emerge. People living in the United States had per capita energy consumption of 285 gigajoules in 2023, whereas people in the rest of the world had per capita energy consumption of 75.3 gigajoules. Talk about disproportionality. Americans consume more than four times as much energy per person as people in the rest of the world.

This simple distinction, the difference between total energy use and per capita energy use, is often lost on, for example, those who criticize the energy footprint of China. The reason China generates more pollution is because their annual inputs of primary energy are 153 exajoules, 67 percent greater than the U.S. But China’s per capita consumption of energy was only 133 gigajoules. Americans consume 2.5 times as much energy per person as someone living in China.

To fully appreciate the disproportionate gift of energy Americans enjoy, consider the continent of Africa. With a population of 1.5 billion, roughly equivalent to China’s population, they only consumed 20 exajoules of energy in 2023. This equates to per capita energy consumption of 13.3 gigajoules. The average American consumes more than 21 times as much energy as the average African.

It is generally true that the more energy a person can use, the more income they’ll have. So what is a realistic target for per capita energy use by, say, 2025, when the world population is estimated to begin leveling off at around 9.4 billion people? For everyone to consume as much energy as Americans consume, total primary inputs of energy worldwide would have to reach 2,689 exajoules, which is 4.5 times what we currently produce. Absent an extraordinary breakthrough in energy technology within the next 20 years, this is probably impossible. But what about California?

Maybe it’s merely attributable to our mild climate, or maybe it’s also thanks to the billions we’ve invested in energy efficiency, but Californians only have a per capita energy consumption of 192 gigajoules per year. This surprised me, but it checks out. Californians use 35 percent less energy per person than the average American in the other 49 states.

This is an encouraging fact. It means that if everyone on Earth consumed as much energy as the average Californian, global energy production would “only” have to increase to 1,810 exajoules per year, “only” three times current worldwide production. But the story doesn’t end here.

Primary energy inputs refer to raw fuel, whether its oil, natural gas, coal, nuclear, hydro, or renewables. All of these raw sources have to be turned into a practical, transportable fuel, then that fuel has to be turned into something useful – light, heating, cooling, communications, computing, mobility. At every step in these conversions, energy is lost. A natural gas power plant loses energy spinning a turbine to generate electricity; a gasoline engine loses energy turning combustion into actual horsepower.

Currently only about 40 percent of primary energy inputs are actually realized as useful energy. What if we could increase that to 80 percent? That’s an ambitious goal, but some applications already achieve this. An EV charged with photovoltaic generated electricity incurs losses in transmission, battery charging, battery discharging, and by the motor converting electricity into traction. But altogether, more than 80 percent of the original photovoltaic electricity makes it to the road in the form of horsepower.

So for the sake of argument, what if our energy economy was 80 percent efficient turning raw energy into useful energy, instead of only 40 percent efficient? Under that scenario, for everyone on Earth to enjoy the same per capita access to useful energy, worldwide primary energy inputs would only have to increase to 905 exajoules per year. That’s only 50 percent more than what we consumed in 2023, and we’ve got just over two decades to get there. This is within the range of feasibility.

We may be thankful that in America we have the best access to energy in the world today, and we may be thankful we live in California, the global epicenter of innovation. If anyone can figure out how to deliver affordable, sustainable, abundant energy to everyone in the world, it is us.