Quantifying the Variables that Determine Our Prosperity

It is nearly impossible to read a policy document on the topic of energy or water that won’t make frequent references to carbon. In California, the race to achieve a “carbon neutral” economy by 2045 has spawned a carbon accounting industry that calculates the carbon impact of absolutely everything we do.

Certain numbers have become familiar: Atmospheric CO2 is currently estimated to be 426 parts per million (PPM). Global CO2 emissions in 2024 were estimated 37.4 gigatons. Atmospheric CO2 is increasing by approximately 2 PPM per year. And California, for its part, emitted 371.1 “MMT CO2e” (million metric tons of CO2 and “CO2 equivalent” gasses) in 2022, which is the most recent data available. We generate almost exactly 1 percent of global CO2 emissions.

If you are among the millions of people convinced that emissions of CO2 and other greenhouse gasses have caused a climate crisis, then it makes sense to track them. But meanwhile, what about the other variables that matter? What about energy and water? These foundational resources of our economy may have a carbon footprint, but to formulate rational energy and water policies, we must also know how much energy and water we currently use, and how much we are going to need.

For water, it’s relatively easy. The unit that matters is million acre feet (MAF). An acre foot is the volume of water required to fill a one acre area one foot deep. One acre foot is equal to 325,851 gallons, or 43,560 cubic feet. In terms of the “CCF” units that show up on household water bills, a CCF is 100 cubic feet, and 436 CCFs equals one acre foot. If one acre foot of water were to fill a regular cube, it would have sides 35 feet in length. If a million acre feet of water were to fill a regular cube, the sides would be 3,519 feet in length. It takes 3.4 MAF to equal one cubic mile.

With that context established, according to data compiled by the California Department of Water Resources, on average California receives about 200 million acre-feet of rain each year. Of that total, around 30 MAF per year is captured for agricultural use, and about 7.5 MAF per year is captured and treated for urban use. We further summarize California’s water use in WC #50, and much more can be found in our policy paper “Achieving Water Abundance.”

We’d better move on, because defining units of energy is much harder, for obvious reasons. Instead of one variable – water – there are dozens of relevant and frequently used terms used to quantify various types of energy. From a state policy perspective, two are indispensable: TBTUs (trillion British Thermal Units) to measure overall energy use, and gigawatt-hours to measure total use of electricity.

Our best source of California’s total energy use comes from the US Energy Information Administration, with 2022 data showing we consumed a total of 7,107 TBTUs. For perspective, total worldwide energy use in 2022 was an estimated 604,040 TBTUs. California’s energy use accounted for 1.2 percent of energy use worldwide in that year.

California’s total energy use includes the energy used to generate electricity, and according to the California Energy Commission, in 2022 Californians consumed 287,220 gigawatt-hours of electricity. Of that, only 203,257 was generated in-state, the rest was imported.

Which brings us to two complicating factors with energy, (1) understanding the equivalents between forms of energy, and (2) differentiating between raw energy inputs, and energy outputs realized in the form of services: horsepower, lighting, heating/cooling, computing, etc. Understanding these concepts enables insight into the goal to electrify California’s economy.

For example, if 7,107 TBTUs were expressed in units of electricity, they would be equal to just over 2 million gigawatt-hours. Conversely, the 287,220 gigawatt-hours of electricity Californians used in 2022 are equal to 980 TBTUs. But because about 45 percent of California’s electricity was generated from “thermal” sources, almost all of it natural gas, the portion of raw TBTU inputs to generate electricity was probably closer to 1,400 TBTUs, or about 20 percent.

Which brings us to the second factor, which is energy conversion. According to research compiled by Lawrence Livermore National Labs, using data from the Dept. of Energy, only 37 percent of California’s raw energy input is realized by Californians in the form of “energy services,” as defined earlier. The rest of that energy input is lost in generation, transmission, combustion, heat, and friction, and is referred to by LLNL as “rejected energy.”

When evaluating the goal of electrifying California’s economy, along with the staggering financial cost, the question we must be asking is how much efficiency will we gain. That is, if our raw inputs of energy – solar, nuclear, hydroelectric, wind, geothermal, natural gas, biomass, and petroleum – total 7,107 TBTUs (2.1 million gigawatt-hours), and the actual energy services we consume are only equal to 2,659 TBTUs (779,330 gigawatt-hours), then how much of that gap can we close by going electric?

We should also be asking how much greater energy efficiency might we again merely by upgrading our natural gas power plants to state-of-the-art technologies, where 60 or even 70 percent of the raw TBTU input of natural gas is returned in the form of outgoing gigawatts of electricity. And we should ask why we are banning the sale of advanced hybrid cars, when ongoing innovations continue to deliver impressive gains in fuel efficiency.  More information on California’s energy economy can be found in WC #48, and much more can be found in our policy paper “Achieving Energy Abundance.” Links to additional information on energy and water can be viewed in our newsletter archives.

Carbon accounting, depending on who you ask, will either save the planet or destroy the economy, or both, or neither. But no matter what, it should not take precedence over an accounting priority of equal urgency – understanding how much water and energy we use, where it comes from, and how much it costs.

Edward Ring is the director of water and energy policy for the California Policy Center, which he co-founded in 2013 and served as its first president. He is also a senior fellow with the Center for American Greatness, and a regular contributor to the California Globe. His work has appeared in the Los Angeles Times, the Wall Street Journal, the Economist, National Review, City Journal, and other media outlets.