Electric cars vs. smart cars

Over the past year or so, there has been a growing awareness that autonomous, self-driving cars could disrupt transportation in a big way and might even do so sooner rather than later. Some of us who closely follow automotive technology have seen this potential for a number of years. The topic is now getting a lot of airplay, sparked in large measure by Google's announcements about its R&D of self-driving cars.

I've been mulling over what it means for other automotive technologies, especially those associated with energy use, such as electric vehicles (EVs) that plug into the the power sector for fuel rather than rely on a liquid fuel such as gasoline. As noted in a post from a few years ago, EVs are not close to being cost effective for cutting carbon compared to ongoing improvements in gasoline vehicle efficiency. Hence my belief that policies that try to push EVs into the market are misguided, and that for the time being it makes more sense to foster the adoption of connected and automated vehicles.

This thinking has been explained in several short pieces published elsewhere, so no point in rehashing those arguments here (though thoughtful comments are welcome). Those posts on other sites include:

Of Carts and Horses, Cars and Smarts, on the University of Michigan Conversation blog.

The Smarter Road to Electric Cars, on Automotive Engineering International Online.

Driverless Cars before Electric Ones, on The Energy Collective. 

Cars Should Tune In Sooner, Plug In Later, as self-published on my AutoEcoRating site.

This last piece listed was the first one published and although it is substantively the same as the Energy Collective version, it may still be of interest because it's gotten the most flaming comments to date.

Postscript: I've since written an essay on "What's Next for the Automobile?" published as the introduction to a Scientific American special issue entitled The Rise of the Automobile, in January 2015.

Enjoy!

Alternative fuels: maybe not so fast

Someone long ago pointed out that we'd run out of atmosphere -- meaning its ability to safely soak up excess CO2 -- well before we ran out of coal. Now that global warming has progressed from a seemingly remote risk to a clear and present danger, it's heartening that U.S. leaders are finally starting to tackle greenhouse gas (GHG) emissions from power plants where coal use is concentrated. Addressing such energy sector emissions is a centerpiece of the new climate plan announced by President Obama in July.

As it turns out, such action to address GHG emissions upstream, meaning in the energy and resource systems that supply the fuels used downstream in our everyday lives, is also the next important step needed to control CO2 emissions from cars and other forms of transportation.

Automotive carbon-cutting bang-for-buck

Fuel efficiency is clearly the low-hanging fruit when it comes to reducing CO2 emissions from cars and trucks. But what if we need to reach higher on the technology tree to get on track to cutting carbon as much as eventually will be needed? 

Alternatively fueled vehicles (AFVs), meaning cars designed to run on something other than gasoline or diesel fuel made from petroleum, are commonly touted as "clean fuel vehicles," and green-leaning policymakers promote them as a key part of sustainable energy strategy. 

Although various AFVs have gone in and out (and in again) of favor over the years, some form of all-electric drive is often seen as a leading contender for the car of the future. In 1990, California issued a zero-emission-vehicle (ZEV) mandate to push battery electric vehicles (BEVs) and eventually hydrogen fuel cell vehicles (FCVs) into the market. Originally justified as the solution to smog-forming tailpipe pollution, ZEVs are now thought to be crucial for cutting carbon. Given the range limitations of BEVs, plug-in hybrid electric vehicles (PHEVs) that can both charge up with electricity and fill up on gasoline have been added to the portfolio as well. 

The Fuel Efficiency Horizon study, however, shows that the supply of low-hanging fruit is more ample than many people think. The adjoining chart compares the relative cost to the relative GHG reduction benefit for several competing technology options. 

The vertical axis gives the costs as a percentage increase over the price of a baseline vehicle, taken as a 2005 midsize car. The horizontal axis gives the percentage cut in GHG emissions relative to the baseline, counting emissions both downstream at the tailpipe and upstream at locations where fuels or electricity are produced. All of the options reflect projections of lower costs and improved performance attainable by 2035, drawing results from the MIT On the Road in 2035 report. The BEV, FCV and PHEV points assume modest reductions in upstream GHG emissions for electricity and hydrogen. No upstream GHG reduction or CO2 offset is assumed for the gasoline or diesel vehicles. 

The upshot? Efficiency improvement remains the least costly way to cut auto sector CO2 emissions for the foreseeable future. This fuel efficiency horizon involves only vehicles that still rely solely on gasoline or diesel, up to and including "grid-free" (non-plug-in) hybrid electric vehicles (shown as the "gasoline hybrid" point on the chart). These ongoing efficiency gains offer GHG reductions greater than those from the battery electric, hydrogen fuel cell and plug-in hybrid technologies at a lower cost (a cost that is far lower in comparison to BEVs). 

In short, an evolutionary technology pathway, highlighted as the shaded band in the lower portion of the chart, will enable quite a lot of progress over the next 25 years, and do so without the high costs, consumer acceptance concerns and fuel infrastructure barriers faced by the alternatives.