The future of energy

Wind and solar are the energy past, not the energy future.

Many people seem to think the future holds an inevitable shift away from fossil fuels toward solar panels and wind turbines, but this perception is incorrect. As California demonstrated in mid-August, these technologies are not up to the task of powering our lives, and pretending otherwise is both naive and dangerous.

California politicians spent decades passing legislation mandating ever-increasing amounts of wind and solar onto the electric grid. On August 14 and 15, these policies came back to bite them in a big way.

That weekend, more than two million Californians experienced rolling power outages during a record-breaking heatwave because there wasn’t enough electricity on the grid as the sun set, rendering the state’s solar panels useless for electricity generation.

The California politicians who patted themselves on the back for shuttering coal, nuclear, and natural gas power plants had killed off the sources of electricity that weren’t reliant upon the weather. The results were tragic, but predictable. Thankfully for Minnesotans, similar results are preventable.

To help Minnesotans understand why wind and solar are not the future, it helps to understand the history of energy. When we do, we find that solar and wind are the energy past, fossil fuels are the energy present, and nuclear power is likely the energy future.

The history below is an abridged version of our energy history, but if you’re interested in the long version, I suggest the book Energy and Civilization by Vaclav Smil.

What is energy?

What is energy, exactly? In its most basic form, energy is the ability to perform work.

For almost all human history, energy was scarce. Humans were an energy-starved species constantly thirsting for more and more-useful forms of energy. Doing so enabled us to do more work and raise our standard of living.

The energy past: Solar, biomass, water, and wind

It might come as a shock to Freshman Congresswoman Alexandria Ocasio-Cortez, but nearly all the energy used by humans until a few hundred years ago was renewable, and life was not a heaven on Earth.

The graph nearby shows the amount of energy used by humans from 1800 through the present. In 1800, humanity used 452 times less energy than humans in 2019, and nearly all of it came from biomass.

The “Low Energy” world humans lived in was no paradise. Average life expectancies were less than 40 years. In Germany, every second child died. People’s statures were shorter because poor nutrition and illness limited human growth.

Life was indeed nasty, brutish and short, and it remained this way until humans began using coal at scale in the 1800s.

Solar power, the original energy

Solar power was the first form of energy used by humans. The sun energized plants through photosynthesis, allowing them to grow and store that solar energy. Humans ate those plants, or we ate the animals that ate plants and other animals to provide the energy we needed. We performed work by using the energy obtained from eating food to power our muscles. We used our muscles to hunt, gather, build shelters, and get to our destinations.

This was the state of human energy consumption for much of human history. Then came fire.

Fire changed the game by expanding access to solar energy that had been stored in plants that were not readily edible. With fire, humans could use the energy stored in inedible woody plants by burning them for heat, light, and cooking.

Heat from fire increased the number of climates humans could live in, light scared away predators and allowed humans to work at night, and cooking food increased the efficiency of digestion, allowing our bodies to get more energy out of the food we ate.

Domesticated animals

Human energy consumption was amplified again when we domesticated animals. Humans were able to harness and control more solar energy by raising animals who could eat a wider variety of plants such as grasses, which human stomachs are unable to turn into useful energy, to perform useful work.

At first, this increase in available animal energy went straight to our stomachs, as sheep, goats, and cattle were domesticated and raised for their meat. Later, draft animals such as cattle, donkeys, and horses were used for plowing fields, grinding grain at mills, and riding for transportation.

Adding animal energy to our portfolio exponentially increased the amount of energy humans could harness, leading to increasingly productive work. For example, a human can work at a rate of about 0.13 horsepower, meaning a horse can perform about 7.5 times more work than a human over the course of a day.


The invention of the waterwheel added the kinetic energy of rivers to the human energy arsenal. Water was first used by the ancient Greeks to mill grain. By the 1500s, waterpower was the most important source of motive power in Europe, with as many as 20,000 watermills by the 19th century.

The waterwheel freed humans and animals to perform other work, and hydropower offered distinct advantages over animal labor.

Unlike a waterwheel, animals require feed. Draft animals performing work use more energy than nonworking farm animals. Animals can only work so many hours in a day before they need to be rested. Animals also get sick and die unexpectedly.

As is the case with all increases in energy use, hydropower increased the amount of work that could be performed by fewer people. For example, even early medieval watermills replaced 30-60 people from the task of grinding flour. Later, the uses of hydropower expanded to running sawmills, mining operations, making textiles, and eventually generating electricity.

The biggest problem with hydropower is that there isn’t nearly enough of it. Rivers are powerful, but they are in limited supply, and only a certain number of rivers are large enough to perform useful work, which is one reason why the invention of windmills increased human access to energy once again.


Wind had first been used for sailboats in Mesopotamia, and until the first windmills were invented by the Persians to grind grain and pump water between 500 and 900 A.D., wind was primarily used for transportation. Windmills became widespread in Europe in the 17th century, and approximately 200,000 windmills operated at the peak of the technology.

Windmills increased the amount of energy humans were able to harness to perform work because new development could occur in more areas, and it could creep away from riverbanks.

Of course, the disadvantages of wind we experience today were still present back then.

Because wind power cannot be stored, this energy source was used primarily to mill grain into flour, pump water into livestock tanks, and saw lumber into boards.

Wind is also dependent on the weather, meaning it cannot be relied upon to provide energy at all hours of the day. In fact, horses were used as “backup” sources of power for milling grain during calm stretches in Europe, similar to how natural gas power plants “back up” wind turbines for generating electricity when the wind isn’t blowing.

While each of these sources of “renewable” energy increased the human standard of living, they also had limited availability and reliability. However, the discovery and widespread use of coal enabled humans to access vast supplies of reliable energy on demand. This energy powered the industrial revolution.

The energy present: Coal, oil, and natural gas

Coal is considered a fossil fuel, but it is really a form of long-term solar energy storage. Ancient plant life in swamps accumulated over millions of years and was eventually buried by sediment and exposed to geological heat and pressure. This process converted plants, which store solar energy, into coal.

Coal was used as far back as the cave people, but it gained widespread adoption in the 1800s for cooking and home heating. Coal offered several advantages over wood because there is about 42 percent more energy in the best coals than hardwood. As a result, coal lasts longer, produces less smoke when burned, and requires less material.

The invention of the steam engine near the start of the 1700s turned coal into the most important fuel in industrializing societies, allowing humans to turn millions of years of stored solar energy (coal) into useful work.

Unlike water or wind power, coal could be transported and used anywhere. Also, coal can be burned at all hours of the day, rain or shine, giving humans around-the-clock energy, which increases industrial capacity at mines, manufacturing facilities, steelmaking sites, and mills.

Steam-powered trains—which revolutionized transportation—are the type of steam engine most people conceptualize. These engines used coal to heat water. The boiling water produced steam. Steam created an enormous amount of pressure, pushing the pistons to drive the train.

Soon, steamships replaced sailboats, and railroads hauled more freight faster and farther than wagons pulled by draft animals would allow. The Pony Express gave way to Thomas the Tank Engine.

Oil, natural gas, and electricity

Coal’s reign at the top of the energy pyramid was relatively short-lived because natural gas, oil, and electricity offered superior value in terms of energy density and in ease of transportation. Both natural gas and oil had been used in limited capacities in ancient China but did not become widely used in Europe or North America until the 1800s.

Natural gas was used to produce light in Baltimore around the 1830s, but gas use remained limited until after World War II because it is more difficult to transport than oil. Oil became widely used after it was discovered in Pennsylvania in 1859, touching off the first oil boom in the United States.

Oil has about twice the energy density as bituminous coal, and its liquid form allowed it to be used in many different capacities. Kerosene became the fuel of choice for lamps, displacing expensive whale oil and doing more to save the whales than the environmental organization Greenpeace ever has.

The invention of the internal combustion engine in the late 1800s transformed transportation by allowing for smaller, personal vehicles to be built and fueled, rather than relying on big bulky railroads. This led to a revolution in personal transportation, farming, mining, and other industrial uses, replacing the steam engine and animal labor.

Oil is now the largest source of energy for Americans, powering most of our transportation sector and also heating our homes.

The electric era

The widespread use of oil for lighting was short-lived, however, because in 1882, Thomas Edison built his first commercial electricity plant, ushering in the era of electricity. When it comes to energy, nothing is as powerful, versatile, safe, easy to use, or clean as electricity.

Lighting was the first thing to become electrified. Edison’s lightbulbs were 10 time brighter than lamps and 100 times brighter than candles. They also produced no soot and were safer. By the early 1900s, the use of electricity had been expanded to washing machines, water heaters, refrigerators, kettles and sewing machines. Obviously, we have found exponentially more uses for this energy since then and the possibilities for the future are limitless—if we don’t screw it up.

The perils of bad public policy

Most of the energy policies crafted today are aimed at changing the way we generate electricity.

Unlike other forms of energy, electricity is not a source of energy by itself. Instead, electricity must be generated by converting primary energy sources (such as coal, natural gas, oil, uranium, water, solar, or wind energy) into electric power.

Coal and hydroelectric power became the early favorites for generating electricity. Coal was burned to heat water, creating steam, which caused turbines to spin. In hydroelectric dams, water spins the turbines. These two generating sources provided about 80 percent of U.S. electricity in 1950.

Attempts to kill off the coal industry during the Obama administration were quite successful. Coal is largely being replaced by natural gas, and to a much lesser extent, non-hydro renewables (i.e., wind and solar).

Wind and solar don’t produce much power because they are unreliable and because they are the exact opposite of energy dense, requiring vast buildouts to produce only a small amount of electricity. As a result, they have an exceedingly low energy return on investment (EROI). The EROI is the ratio of the amount of useable energy delivered by an energy source compared to how much energy it took to obtain the resource.

In the graph nearby, the blue bars indicate the EROI if we don’t consider the energy needed to store energy produced by intermittent renewables, and the yellow bars take this into account. For an energy source to be economically viable, it must have an EROI above eight. As you can see, solar, biomass, and wind all fall below this threshold, and therefore cost more energy to produce than is returned once storage is considered.

The energy future: Nuclear power

As you can see in the EROI graph, nuclear is the clear winner, and this is why the future of energy is almost certainly nuclear power. Nuclear power is the only source of energy that is denser than fossil fuels.

For example, the energy density of 2.2 pounds (1 kilogram) of coal contains about 33 units of energy (megajoules), but 2.2 pounds of uranium has 3.9 million. One pellet of uranium—about the size of a pencil eraser—has the same amount of energy as 149 gallons of oil or 1 ton of coal.

In fact, if all the electricity you used for 70 years was generated at nuclear facilities, the amount of uranium used would fit inside a soda can.

The high energy density of uranium is why nuclear power has the potential to someday generate electricity at a lower cost than fossil fuels and is why it is most likely the future of electricity generation. Unlike wind and solar, it produces carbon-dioxide free electricity around

the clock, so a grid powered by nuclear power won’t experience California-style blackouts.

The low reliability and high cost of wind and solar are deal breakers. There is no inevitable shift toward these energy sources. I predict that they will soon
go the way of the Beanie Babies—here today and “huh?” tomorrow. Nuclear power will likely fill the void.