The energy transition: more questions than answers

Energy drives prosperity. Globally, approximately eighty percent of today’s energy is provided by oil, coal, and natural gas. These abundantly available resources have fueled advances in world well-being and have the potential for even higher levels of growth. Unfortunately, burning these fossil fuels leads to large carbon dioxide (CO₂) emissions. The desire to reduce these CO₂ emissions has spawned a huge effort to find alternative energy concepts, leading to a great “energy transition” away from hydrocarbons. 

This sought-after energy transition today is similar to the U.S. energy crisis of the 1970s. At that time, the energy crisis started as an oil embargo and changed to a rush to replace oil, driven by a theory that the world was running out of oil. By the early 1980s, no alternative to oil had been found, but it was becoming clear that the world was not running out of oil – thus ending that “energy crisis.”

This was followed by over two decades of relatively abundant energy that aided world stability, trade, and growth. Later, new sources of natural gas and oil were found in the so-called unconventional “tight shale” formations. In the US and Europe, social movements promoting alternatives to fossil fuels also sought bans on hydraulic fracturing (“fracking”) required for natural gas recovery.

Nevertheless, fracking did aggressively progress in North America; this subsequently led to abundant natural gas for the U.S. and for export and allowed some replacement of coal, thereby lowering CO₂ emissions. 

Today, energy transition initiatives provide some alternative energy concepts. For example, wind and solar generation contribute modestly to global electricity, which is about twenty percent of the world's total energy consumption. In 2022, around 8% of the world’s electricity was produced by wind turbines and about 2% by solar photovoltaic systems. (Electricity accounts for about 40% of total energy consumption in the U.S. and Europe, about double the world average). Both wind and solar electricity are increasing worldwide.

Biofuels are being blended in small quantities with petroleum-based gasoline, diesel, and jet fuel. Biofuels in 2022 were about 4% of total world transport-fuel consumption, not including ocean shipping fuel. In 2022, plug-in electric cars and light trucks (electric vehicles or “EV’s”) were about 8% of total vehicles produced worldwide.

These are big steps for new energy concepts. What isn’t clear, however, is how much these steps have reduced world CO₂ emissions. Fossil fuel-related CO₂ emissions for 2022 are estimated at thirty-eight billion metric tons, the highest ever. Projections are that estimates for 2023 will be even higher.

One reason for the uncertainty about worldwide CO₂ emission reductions related to energy transition is that alternative energy concepts are being pursued without considering the complete-cycle emissions. Thus, it is not known how much, or even if, CO₂ emissions are being reduced by a given alternative. This lack of understanding is made worse by a failure to appreciate that no energy source is emissions-free, including wind and solar electricity.

Understanding the CO2 emissions from non-primary energy sources such as hydrogen and biofuels is particularly complicated. Hydrogen may be formed from water, and when burned, only produce water, but that doesn’t make hydrogen CO₂ emissions-free. It must be made from another energy source (not considering naturally occurring hydrogen), stored, moved to market, and ultimately converted to heat, electricity, or used in some chemical process.

The same is true for biofuels. They require an energy source to produce the biofuel from a feedstock, which itself must be produced, collected, and processed. CO₂ emissions are naturally embedded in even the most apparent and promising alternatives.

CO₂ capture and sequestration offer the potential to offset CO₂ emissions from fossil fuels. Unfortunately, CO₂ capture, transmission, storage development, underground storage injection, and required monitoring all require energy and materials that will not be CO₂ emissions-free.

Likewise, EVs may offer CO₂ emissions reduction by eliminating gasoline and diesel fuels. However, EV manufacture and maintenance require materials and energy that produce emissions, as does the electricity to power the EVs. And new critical minerals for EVs will require a huge amount of energy for mining or recycling for minerals recovery and purification, again producing CO₂ emissions.

Nuclear energy also produces emissions from activities including reactor construction, maintenance and decommissioning, uranium fuel mining, processing, and spent-fuel disposal, and therefore also deserves equal complete cycle CO₂ emissions analysis.

The emissions of an alternative energy concept and how the concept would reduce fossil fuel emissions are admittedly complicated to quantify. With respect to CO₂ emissions, often only part of the complete cycle emissions is considered. For example, CO₂ emissions from solar and wind electricity often do not consider emissions from the manufacture, installation, operation/maintenance, and ultimate disposal of the solar or wind electricity system.

For example, there are CO₂ emissions from moving the electricity from generation location to market and from managing the intermittent nature of solar radiation and wind velocity. Solar and wind electricity production are far from CO₂ emissions-free.

Additionally, the complete cycle analysis for wind and solar electricity – just as for any alternative energy concept – must be compared to the fossil fuel energy source that it might replace, for example, coal-fired steam generation or natural gas turbine electricity in the case of wind and solar electricity. This is required to understand if and how much the alternative will reduce emissions. 

Some emissions analyses do exist, and even the understanding provided by a partial cycle analysis can be helpful. For example, biofuel production from converting corn to alcohol has been studied for decades, with data showing questionable (if any) emissions reduction.

EV emissions, when compared to internal combustion engines, show emissions may increase – not decrease – depending on the availability of required minerals and how electricity is produced. For example, the aggressive move toward EVs in China would be expected to increase CO2 emissions as long as the majority of the electricity used to power the EVs comes from coal. 

In other cases, simply considering energy use efficiencies of conversions and processes justifiably gives concern regarding emissions reduction. For energy conversions, more energy is always required than is recovered from the alternative. For example, electricity to hydrolysis to hydrogen is currently about 65% efficient. Too often, an alternative concept is justified based on limited analysis and the assumption of “low emissions” solar or wind electricity without considering the full cycle or the scale-up impacts. 

Over the decades, fallacies in understanding or accepting scientific facts have led to outright missteps regarding energy. These missteps have shown that even apparent meritorious environmental wishes may not be realistic or even desirable. Certainly, impeding natural gas development by deterring hydraulic fracturing and by deterring pipeline or LNG movement of natural gas is one such example.

Another is the unrealistic goal of replacing all fossil fuels with solar and wind-produced energy. Yet another is forgoing fossil fuels without a guaranteed alternate energy supply. And most recently, attempted rapid energy shift is leading to critical minerals uncertainty among many nations. As the energy transition progresses, other missteps may emerge as unrealistic, non-scientific projections continue to be promoted.

Without complete cycle analysis, a rushed transition away from fossil fuels may not reduce CO₂ emissions but could actually increase emissions. Complete cycle analysis is essential to ensure this doesn’t happen.

It is crucial to provide priorities to reduce CO₂ emissions without unduly sacrificing national energy security and prosperity as an unintended consequence. The aggressive pursuit of alternative energy concepts in many ways seems to have forgotten its purpose, the reduction of CO₂ emissions.