Explainer: Bloomberg Analysis Highlights Inefficiency of Fossil Fuels
The argument that overhauling the energy system is too daunting is easily undercut by the fact electrification can offer efficiencies in excess of 100%—a figure that makes fossil fuel combustion look spectacularly inefficient. And throwing more light on this under-reported comparison could make the carbon-free transition a whole lot more saleable, says a UK-based energy analyst.
The critical thing, writes Akshat Rathi in a recent post for Bloomberg Green, is to grasp the difference between “primary energy” (the energy found in a particular raw fuel source, like crude oil or coal), “final energy” (the energy found in consumable fuel, like gasoline or electricity), and “useful energy” (the fraction of final energy that is actually used to move a bus or run a fridge).
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“Even though fossil fuels meet roughly 80% of the world’s primary energy demand, they are responsible for only 60% of its useful energy,” Rathi explains, citing data from BloombergNEF. The remaining 20% of primary energy demand currently met by renewables, meanwhile, delivers 40% of the world’s useful energy.
The fundamental revelation about just how little bang we get for our fossil fuel buck (and how much more we get out of renewables) needs to be broadcast far and wide, Rathi urges. Standing in the way of our making more efficient use of the energy contained in, say, a lump of coal is the fact that the average efficiency of a coal-fired power plant stands at about 33%. And when it comes to vehicle efficiency, “many modern internal combustion engine cars have an efficiency of about 20%, transforming only a fifth of gasoline’s energy into motion.” By comparison, EV motors convert more than 80% of battery power into useful energy.
Changing the game to the more efficient side of the playing field seems like a given, but it will take a lot to make a dent in the climate crisis, Rathi writes. By 2050, many business-as-usual projections for the trend toward cheaper renewables and more electric vehicles still show fossil fuels providing 70% of the globe’s primary energy, translating to 55% of its useful energy. To keep average global warming below 1.5°C, fossils’ share of primary demand must fall below 30% by that date.
That will happen by aggressively accelerating electrification in all sectors—thereby increasing efficiency and reducing the need for primary energy.
Rathi acknowledges that the focus on primary energy demand has held sway for a very long time. “But that history isn’t serving the current moment when the world needs to move away from fossil fuels quickly,” he writes.