Only Two Energy Sources

 

This incisive (cutting to the core) essay is from Darrin Qualman There are just two sources of energy  Excerpts below in italics with my bolds.

Our petro-industrial civilization produces and consumes a seemingly diverse suite of energies: oil, coal, ethanol, hydroelectricity, gasoline, geothermal heat, hydrogen, solar power, propane, uranium, wind, wood, dung. At the most foundational level, however, there are just two sources of energy. Two sources provide more than 99 percent of the power for our civilization: solar and nuclear. Every other significant energy source is a form of one of these two. Most are forms of solar.

When we burn wood we release previously captured solar energy. The firelight we see and the heat we feel are energies from sunlight that arrived decades ago. That sunlight was transformed into chemical energy in the leaves of trees and used to form wood. And when we burn that wood, we turn that chemical-bond energy back into light and heat. Energy from wood is a form of contemporary solar energy because it embodies solar energy mostly captured years or decades ago, as distinct from fossil energy sources such as coal and oil that embody solar energy captured many millions of years ago.

Straw and other biomass are a similar story: contemporary solar energy stored as chemical-bond energy then released through oxidation in fire. Ethanol, biodiesel, and other biofuels are also forms of contemporary solar energy (though subsidized by the fossil fuels used to create fertilizers, fuels, etc.).

Coal, natural gas, and oil products such as gasoline and diesel fuel are also, fundamentally, forms of solar energy, but not contemporary solar energy: fossil. The energy in fossil fuels is the sun’s energy that fell on leaves and algae in ancient forests and seas. When we burn gasoline in our cars, we are propelled to the corner store by ancient sunlight.

Wind power is solar energy. Heat from the sun creates air-temperature differences that drive air movements that can be turned into electrical energy by wind turbines, mechanical work by windmills, or geographic motion by sailing ships.

Hydroelectric power is solar energy. The sun evaporates and lifts water from oceans, lakes, and other water bodies, and that water falls on mountains and highlands where it is aggregated by terrain and gravity to form the rivers that humans dam to create hydro-power.

Of course, solar energy (both photovoltaic electricity and solar-thermal heat) is solar energy.

Approximately 86 percent of our non-food energy comes from fossil-solar sources such as oil, natural gas, and coal. Another 9 percent comes from contemporary solar sources, mostly hydro-electric, with a small but rapidly growing contribution from wind turbines and solar photovoltaic panels. In total, then, 95 percent of the energy we use comes from solar sources—contemporary or fossil. As is obvious upon reflection, the Sun powers the Earth.

The only major energy source that is not solar-based is nuclear power: energy from the atomic decay of unstable, heavy elements buried in the ground billions of years ago when our planet was formed. We utilize nuclear energy directly, in reactors, and also indirectly, when we tap geothermal energies (atomic decay provides 60-80 percent of the heat from within the Earth). Uranium and other radioactive elements were forged in the cores of stars that exploded before our Earth and Sun were created billions of years ago. The source for nuclear energy is therefore not solar, but nonetheless stellar; energized not by our sun, but by another. Our universe is energized by its stars.

There are two minor exceptions to the rule that our energy comes from nuclear and solar sources: Tidal power results from the interaction of the moon’s gravitational field and the initial rotational motion imparted to the Earth; and geothermal energy is, in its minor fraction, a product of residual heat within the Earth, and of gravity. Tidal and geothermal sources provide just a small fraction of one percent of our energy supply.

Some oft-touted energy sources are not mentioned above. Because some are not energy sources at all. Rather, they are energy-storage media. Hydrogen is one example. We can create purified hydrogen by, for instance, using electricity to split water into its oxygen and hydrogen atoms. But this requires energy inputs, and the energy we get out when we burn hydrogen or react it in a fuel cell is less than the energy we put in to purify it. Hydrogen, therefore, functions like a gaseous battery: energy carrier, not energy source.

Knowing that virtually all energy flows have their origins in our sun or other stars helps us critically evaluate oft-heard ideas that there may exist undiscovered energy sources. To the contrary, it is extremely unlikely that there are energy sources we’ve overlooked. The solution to energy supply constraints and climate change is not likely to be “innovation” or “technology.” Though some people hold out hope for nuclear fusion (creating a small sun on Earth rather than utilizing the conveniently-placed large sun in the sky) it is unlikely that fusion will be developed and deployed this century. Thus, the suite of energy sources we now employ is probably the suite that will power our civilization for generations to come. And since fossil solar sources are both limited and climate-disrupting, an easy prediction is that contemporary solar sources such as wind turbines and solar photovoltaic panels will play a dominant role in the future.

Summary

Understanding that virtually all energy sources are solar or nuclear in origin reduces the intellectual clutter and clarifies our options. We are left with three energy supply categories when making choices about our future:
– Fossil solar: oil, natural gas, and coal;
– Contemporary solar: hydroelectricity, wood, biomass, wind, photovoltaic electricity, ethanol and biodiesel (again, often energy-subsidized from fossil-solar sources); and
– Nuclear.

Footnote:  The author ends with support for windmills and solar panels, but drops nuclear without explanation.  Also there are presently unsolved problems when substituting those intermittent power sources for fossil fuels.  Details are at Climateers Tilting at Windmills

Fortunately, we have time to adapt to the ongoing slight fluctuations in weather while assembling the longer-term transition to nuclear and other energy sources. Unfortunately, a recent study of energy subsidies in the US shows only a small amount is directed toward nuclear, and the sole purpose is decommissioning.

Update April 27

Some good news today: Secretary of Energy Rick Perry Announces $60 Million for U.S. Industry Awards in Support of Advanced Nuclear Technology Development

WASHINGTON, D.C. – U.S. Secretary of Energy Rick Perry announced today that the U.S. Department of Energy (DOE) has selected 13 projects to receive approximately $60 million in federal funding for cost-shared research and development for advanced nuclear technologies. These selections are the first under DOE’s Office of Nuclear Energy’s U.S. Industry Opportunities for Advanced Nuclear Technology Development funding opportunity announcement (FOA), and subsequent quarterly application review and selection processes will be conducted over the next five years. DOE intends to apply up to $40 million of additional FY 2018 funding to the next two quarterly award cycles for innovative proposals under this FOA.

“Promoting early-stage investment in advanced nuclear power technology will support a strong, domestic, nuclear energy industry now and into the future,” said Secretary Perry. “Making these new investments is an important step to reviving and revitalizing nuclear energy, and ensuring that our nation continues to benefit from this clean, reliable, resilient source of electricity. Supporting existing as well as advanced reactor development will pave the way to a safer, more efficient, and clean baseload energy that supports the U.S. economy and energy independence.”