Electrification is Cool: How Going Electric Saves Energy

Let’s consider the question of how much electricity the world would need to generate in order to satisfy all the current power demand. We showed that there’s 3.25 TW of electricity generated worldwide, of which 2.75 TW is used. But there are many sectors that use large amounts of energy from fossil fuels that need to be electrified: transportation, industry and fuel for heating and cooking within residential, commercial and public buildings. Electrification is cool: there’s not much waste heat when electricity is used as an energy source instead of fossil fuels. So there are quite substantial efficiency gains possible for some sectors.

Not all power that is consumed worldwide is needed, and ending energy poverty around the world requires a substantial increase in power for many, and this initial analysis will consider neither of these justice concerns.

The total power usage (final energy consumption) is nearly four times the electricity generation, and nearly five times the electricity final consumption. Sectors like transportation use very little electricity. The world moves around with oil, in the form of gasoline or diesel for cars, or kerosene for aircraft.

Source: IEA.

In a gasoline car only 12-30% of the energy in gasoline goes to motion. The fact that they run cooler means that electric vehicles typically require only about 20% of the power as fossil fuel-powered vehicles. Road travel is still the main source of carbon emissions from transportation. As a rough estimate of the extra energy required to run all transportation, we’ll assume 20% of the total final non-electric energy consumption. For 2021, this number amounts to an additional 0.7 TW of electricity.

Industrial processes like steelmaking can be extremely energy intensive, and cause a large fraction of world carbon emissions. The processes used around the world are often quite different in their efficiency. Steel made in Mexico, for instance, has half the carbon intensity of steel made in China, largely because of the use of electric arc furnaces. While there are huge benefits in carbon, particulate matter, and air pollution from electrification of industry, there is less of a power benefit. Energy savings depends largely on the temperature of the process. Lower temperature processes can benefit substantially from electrification, while higher temperature processes have little energy benefit when electricity is used.

For the purposes of constructing a simple estimate, we’ll assume all-electric industrial processes would require 82% of the power, as in Mark Z. Jacobson’s calculations. Industry electrification would then require an additional 2.3 TW of electricity consumption. This is much larger than the transportation number despite the fact that they use a similar amount of fuel in terms of energy content.

Other sectors like residential and commercial heating can be electrified with methods like high-performance heat pumps, so we’ll assume its electrification can be performed with only 20% of the power. Those sectors add another 0.5 TW of electricity consumption. In total, electrifying everything requires around 3.5 TW more consumption. Factoring in transmission and distribution losses, although not as inevitable with renewables, could increase the total power usage of electrification to 3.8 TW. All in all, we end up with a total electricity generation of 7 TW needed to power all activity on Earth right now.

To replace all the fossil fuel generation (currently 2.1 TW) and all the electrified sectors, we need to generate 6 TW more clean electricity, or 6.3 TW if nuclear is replaced as well. Compared with the current clean renewable generation of 0.4 TW, there would need to be a factor of 15 increase. Although solar and wind are growing exponentially, their growth needs to continue to rapidly accelerate for carbon emissions to go to zero at the world’s current power demand.

There is a large amount of regional variability in energy usage in the sectors that require electrification. The estimates are plotted below assuming the same simple formula in all regions.

Of particular note in the regional figure are the transportation emissions, over twice as large in North America than in any other region.  The remaining category, of which heating of buildings is a large component, is largest in the cold climates of Eurasia and smallest in regions with mild climates. The industrial sector would require a large fraction of electricity in all regions if everything were electrified. In the previous section, we showed that 40% of the current electricity usage goes to industry (1.2 TW out of the 2.75 TW consumed). Adding this to the electrification demand shows that over 50% of the electricity used would be for industry.

If all the world were to use the same amount of power as the per capita consumption in North America, the electricity required would be around 17 TW. Economic inequality within the United States is among the largest in the world, so the picture is even more extreme if consumption patterns of the elite are emulated. You can explore the effect of global average energy demand on the amount of clean electricity needed to power the world in the tera strategy interactive below.

Tera strategy interactive tool by EarthGames

In subsequent chapters, we will address the question of how much of each power source is needed to create a tera, that is, 1 TW of average power production. The tera is a unit of effort that allows comparison of how much of each renewable resource is required to power a substantial fraction of the world’s energy usage.