A Fact-Based Appraisal of California’s Energy Strategy

The Statistical Review of World Energy is arguably the most authoritative and comprehensive source publicly available for national and global energy statistics. And a funny thing happened between the report issued in 2024 and the report issued in 2025. “Renewables” as a percent of total energy consumed in 2023 was quietly lowered from 9.3 in the U.S. and 8.2 worldwide to only 5.9 and 5.2 percent, respectively (each edition shows reports the most recent two years of data).

This is because in 2025, the energy economists who compile this data finally discontinued the practice of grossing up what “non-combustible” energy sources actually produced. The reporting used to reflect how much more energy input would have been required if that same energy were to come from less efficiently converted combustible fuel. Now at last, they just report how much energy these sources actually generated.

With the 2026 edition released and continuing this new and more accurate reporting method, the percentage of total raw energy consumed worldwide – not including the United States – in the form of oil, natural gas, and coal was 87 percent; in the U.S. it was 83 percent. There are plenty of gigantic nuances to this story, starting with how this compares to 25 years ago.

Back in 2000, when the Statistical Review normalized units of energy into “MTOE” (million tons of oil equivalents), fossil fuel represented 89 percent of U.S. raw energy inputs. In the rest of the world, not including the U.S., fossil fuel delivered 86 percent of raw energy inputs – i.e., its share of total energy is actually slightly greater today than it was 25 years ago.

If you consider absolute quantities of energy, now reported in exajoules, or EJs, there has been an astonishing expansion of fossil fuel use worldwide in the last quarter century. Oil production is up 50 percent from 110 EJs to 165 EJs. Natural gas is up 79 percent from 66 EJs to 118 EJs, and coal is up 127 percent from 69 EJs in 2000 to 157 EJs in 2025.

How does the growth in renewables – biomass, biofuel, geothermal, solar, and wind – compare?

In 2000, the role of renewables was so negligible they weren’t tracked. But by 2025 total production has risen to 5.9 EJs in the U.S., or 6.3 percent of all energy; In the rest of the world another 29.6 EJs were produced, representing 5.8 percent of all energy. But can renewables increase to the point where they will replace fossil fuel?

To answer this, set aside the fact that energy is perfectly correlated with prosperity, and that per capita GDP in the U.S. is 3.6 times greater than in the rest of the world, or that per capita energy consumption in the U.S. is 4.3 times greater than in the rest of the world. After all, between 2000 and 2025, even though U.S. population grew from 282 million to 343 million, and U.S. GDP in inflation adjusted dollars nearly  doubled from $13.9 trillion to over $24.1 trillion, total energy consumption actually dropped slightly, from 96 EJs to 88 EJs. Maybe the vast improvements in energy efficiency achieved in the U.S. since 2000 can continue, and be extended to everywhere else on earth. This is a huge assumption.

So just to maintain global energy production at 600 EJs per year, can the 518 EJs of energy produced in 2025 from oil, natural gas, and coal be replaced by renewables, or, more broadly speaking, by all “non-combustibles” which would add nuclear and hydroelectric?

To do this, we can rule out biomass, biofuel, and hydroelectric. These sources of energy are already maxed and can only deliver incremental increases. Wind energy is a resource hog, a visual and auditory nuisance, and it wreaks havoc on the local environment. Even if it could grow exponentially, it would come at an awful cost. Nuclear power, currently responsible for 5 percent of global energy, is a wild card, as is geothermal and its emerging descendant, enhanced geothermal. And there are other emerging technologies that may be game changers including  advanced nuclear fission, artificial photosynthesis, space-based power, and fusion. But what about solar energy?

It’s important to take a good look at this, because California is relying on solar and battery installations as the foundation of its electrification, net-zero strategy. And in a state as wealthy and as sunny as California, solar can go a long way toward fulfilling those objectives. But it would be cavalier to extrapolate California’s prospects to the entire world. The statistics are unequivocal and daunting.

The growth in solar (photovoltaic) electricity has been exponential. Worldwide photovoltaic output – converting terawatt-hours to exajoules – increased from 1.76 EJs in 2024 to 2.32 in 2025. Photovoltaic energy output is eleven times greater today than it was only ten years ago. But do we have the resources to accommodate another few decades of exponential growth?

Equally pertinent, total global battery storage capacity despite 60 percent per year growth over the past ten years, is still as of 2025 only equal to 1.2 terawatt-hours (ref. page 65 in the 2026 Statistical Review, “Grid-scale battery energy storage systems”). In the context of world energy, that’s nothing. It takes 278 terawatt-hours to equal one exajoule. It’s worth reflecting on this fact.

It means that even if worldwide photovoltaic output increased by another two orders of magnitude, because it would take that much to even begin to make a replacement level contribution to global energy production, we would also have to increase our electricity storage capacity by at least four orders of magnitude from what it is today (current worldwide storage capacity times ten-thousand still only equals 45 exajoules). Notice those battery farms going in all over? Imagine 10,000 of them where one of them now stands. That’s what it will take, at a minimum, if the world’s energy economy electrifies, and does so while relying on intermittent energy sources. Does the earth have the resources to sustain such growth, and what would be the environmental impact?

These are questions California’s policymakers must answer if they are to credibly advocate, much less mandate, a net-zero future. Policies designed to rapidly phase out fossil fuels are based on wishful thinking, and everyone familiar with basic energy statistics knows this. If California is to set an example to the world, it would be more productive if it sets an example the rest of the world is willing and able to follow.

Edward Ring is the director of water and energy policy for the California Policy Center, which he co-founded in 2013. Ring is the author of several books, including The Abundance Choice – Our Fight for More Water in California (2022), and The Analyst’s Cookbook: Making the Case for Abundance Using Numbers (2026).