The tough calculus of emissions and the future of EVs, According to TechCrunch Investors and politicians embracing a vision of an all-electric car future believe that path will significantly reduce global CO2 emissions. That’s far away from clear.
A growing body of research points to the likelihood that widespread replacement of conventional cars with EVs would likely have a comparatively small impact on global emissions. And it’s even possible that the result would increase emissions.
The issue isn’t primarily about the emissions resulting from producing electricity. Instead, it’s what we all know and doesn’t realize what happens before an EV is delivered to a customer, namely, the “embodied” emissions arising from the labyrinthine supply chains to get and process all the materials needed to fabricate batteries.
A growing body of research points to the likelihood that widespread replacement of conventional cars with EVs would likely have a comparatively small impact on global emissions. And it’s even possible that the result would increase emissions.
All products entail embodied emissions that are “hidden” upstream in production processes, whether it’s a hamburger, a house, a smartphone or A battery. to ascertain the implications at the macro level, credit France’s High Climate Council for a study issued last year. The analysis found that France’s claim of achieving a national decline in CO2 emissions was illusory. Emissions had actually increased and were some 70% above reported once the embodied emissions inherent within the country’s imports were counted.
Embodied emissions are often devilishly difficult to accurately quantify, and nowhere are there more complexities and uncertainties than with EVs. While an EV self-evidently emits nothing while driving, about 80% of its total lifetime emissions arise from the mixture of the embodied energy in fabricating the battery then in “fabricating” electricity to power the vehicle. The remaining comes from manufacturing the non-fuel parts of the car. That ratio is inverted for a standard car where about 80% of lifecycle emissions come directly from fuel burned while driving, and therefore the rest comes from the embodied energy to form the car and fabricate gasoline.
Virtually every feature of the fuel cycle for conventional cars is well understood and narrowly bounded, significantly monitored if not tightly regulated and largely assumption-free. That’s not the case for EVs.
For example, one review of fifty academic studies found estimates for embodied emissions to fabricate one EV battery ranged from a coffee of about eight tons to as high as 20 plenty of CO2. Another recent technical analysis put the range at about four to 14 tons. The high end of these ranges is almost the maximum amount CO2 as is produced by the lifetime of fuel burned by an efficient conventional car. Again, that’s before the EV is delivered to a customer and driven its first mile.
The uncertainties come from inherent — and certain unresolvable — variabilities in both the number and sort of energy utilized in the battery fuel cycle with factors that depend upon geography and process choices, many often proprietary. Analyses of the embodied energy show a variety from two to 6 barrels of oil (in energy-equivalent terms) is employed to fabricate A battery which will store the energy equivalent of 1 gallon of gasoline. Thus, any calculation of embodied emissions for an EV battery is an estimate supported by myriad assumptions. the very fact is, nobody can measure today’s or predict tomorrow’s EV CO2 “mileage.”
As more dollars flood into government programs and climate-tech funds — 2021 is on target to blow past record 2020 climate-tech investments, with three firms alone, BlackRock, General Atlantic, and TPG, each announcing new $4 billion to $5 billion cleantech funds — we’re overdue for paying serious attention to embodied emissions of EVs and other presumed technological panaceas for reducing CO2 emissions. As we’ll see shortly, the eye might not reveal the expected outcomes.
Data (on) mining
The goal for any vehicle is to possess the equipment take as small a share of total weight as possible, leaving room for passengers or cargo. Lithium batteries, as revolutionary and Nobel prize-worthy as they’re, still constitute a foreign second place within the metric of merit for powering untethered machines: energy density.
The inherent energy density of lithium-class chemicals (i.e., not A battery cell, but the raw chemical) are often theoretically as high as about 700 watt-hours per kilogram (Wh/kg). While that’s roughly fivefold greater than the energetics of lead-acid accumulator chemistry, it’s still a little fraction of the 12,000 Wh/kg available in petroleum.
To achieve an equivalent golf range as 60 pounds of gasoline, an EV battery weighs about 1,000 pounds. Not much of that gap is closed by the lower weight of an electrical versus gasoline motor because the previous is usually only about 200 pounds lighter than the latter.
Manufacturers offset a number of a battery’s weight penalty by lightening the remainder of the EV using more aluminum or carbon fiber rather than steel. Unfortunately, those materials are respectively 300% and 600% more energy-intensive per pound to supply than steel. employing a half-ton of aluminum, common in many EVs, adds six plenty of CO2 to the non-battery embodied emissions (a factor most analyses ignore). But it’s with all the opposite elements, those needed to fabricate the battery itself, where the emissions accounting gets messy.