Big Oil’s electric shock

This article first appeared on the website of Better Place

A great indicator that disruptive innovations are nearing the all-important tipping point is when powerful incumbents start peddling nonsense masquerading as facts, to sow doubt about the viability of the emerging technology or business model.  There’s nothing particularly sinister about this.  By scrambling to erect roadblocks to new market entrants that threaten their hegemony, oligopolies are only doing what comes naturally to an organism under attack by an existential threat.  And if your job is to find, extract, refine, distribute and sell liquid fuels, then electric cars certainly qualify.

I’m thoroughly heartened when I read statements from Big Oil about the “many barriers” that must be overcome before electrons can make a significant dent in a mobility sector dominated by petroleum.  Heartened because as recently as two years ago I would have been hard pressed to find any commentary at all from the oil majors about transport electrification.  Back then, the tune was all about the prospects for second generation biofuels and the supposed holy grail that is hydrogen.  But today, barely an eyebrow is raised when senior executives from the likes of ExxonMobil or Shell claim that electric cars hold genuine future promise, but not before we decarbonise the power supply.  In other words: “You EV guys are very well meaning – and we wish you well – but until the world stops burning coal, allow motor manufacturers to continue tinkering with incremental efficiency gains while we drill, baby, spill!”.

The decarbonised grid storyline is becoming the new conventional wisdom.  And like much conventional wisdom, when examined closely it turns out to be patent nonsense, though on the surface it appears reasonable.  We begin to understand why it is flawed when we examine what I call the Four Truths that we can hold to be self-evident.  They hold whenever we elect to set fire to carbon-based fuels in order to benefit from motorised kilometres:

(1) Large is better than small

Megawatt (MW) scale plants are able to run hotter, therefore more efficiently, than the kilowatt (kW) scale engines that power motor cars.  This truth has its roots firmly in the basic laws of thermodynamics, which are not subject to revision.

(2) Constant load is better than variable load

Combustion facilities have an optimal operating efficiency that is achievable more or less continuously in a power plant.  In vehicles, the engine speed is seldom constant, as it is dictated by the variable driving conditions.

(3) Stationary is better than mobile

In practical terms it is far easier to manage, collect, and process combustion emissions from stationary plants than from mobile vehicle tailpipes.

(4) Few is better than many

The greater the number of emissions sources, the harder it becomes to do anything about them.

Notice that truths (1) and (2) relate to energy efficiency, while (3) and (4) are all about emissions control – this is why (1) and (4) are not merely different ways of expressing the same point.  And what should we conclude from these truths?  It is better to burn fuel – be it coal, crude oil, natural gas, or biomass – in hundreds of large, stationary power plants running at constant speed rather than millions of small, mobile internal combustion engines running variably.  Put differently, all else being equal electricity beats liquid fuels on energy efficiency and emissions control.

The real killer for Big Oil is that for years we’ve been led to believe that petroleum was too valuable to turn into electricity.  It’s true only if your core business is shackled to the liquid transport fuel paradigm.  From an energy efficiency, energy security and environmental perspective, crude oil is far too valuable to waste in automobiles.  The same goes for coal, natural gas, and biomass.  Biofuels – the tenuous lifeline of the liquid fuel company – break against the rocks here.  Far better to convert the biomass into heat and electricity to displace dirty coal.

So back to the conventional wisdom.  Let’s imagine a world in which 100% of our primary energy comes from fossil fuels.  Electric mobility wins, hands down.  But of course, we don’t live in such a world.  The world we live in has a steadily decarbonising electricity supply, while oil majors are forced to exploit ever-more exotic and energy-intensive forms of black gold.  They’ll have a helluva job making diesel or gasoline from wind turbines and solar panels.

How Green are Electric Cars?

This article first appeared on the Energy Bulletin website

I have been reading and watching with some bemusement a number of stories appearing in the British press and on television this past week on the subject of electric cars.  The media interest is largely a reaction to the UK government’s recent announcement of plans to provide cash incentives to buyers of plug-in vehicles, designed to stimulate the market for highly efficient vehicles.  A number of articles, some of which have hot-links from the ODAC website, have ‘experts’ variously dismissing the environmental benefits of electric cars as fiction, claiming their mass adoption will cause blackouts, or accusing the government of a cheap gimmick.  Whatever the rights and wrongs of the proposed stimulus package, its lack of sophistication should not be allowed to undermine the fact that electric cars are fundamentally a good idea.  Shifting transport away from liquid hydrocarbon fuels towards electricity can make a significant contribution to the twin challenges of climate change and energy security.

Frequently repeated is the lazy sound bite that “electric cars are only as green as the electricity they run on”.  Sounds obvious, doesn’t it?  But it neglects the fact that based on today’s UK electricity mix – still heavily reliant on natural gas and coal – electric cars can cut CO2 emissions in half compared with conventional mechanical vehicles running on petroleum.  Even taking into account transmission and distribution losses, it is always more energy efficient to burn carbon-based fuels – coal, oil, gas, and biomass – in large stationary power plants running at constant load than it is to waste additional energy converting them into liquid transport fuels and then burning them in small mobile internal combustion engines running at variable speeds. 

In a Daily Telegraph article, one expert was quoted as saying that modern diesel engines can achieve 45% efficiency.  This is an extraordinarily optimistic estimate, especially considering that automotive engines are seldom running at optimal efficiency but instead are subject to cold start energy losses, frequent short journeys, stop/start urban driving conditions, idling at traffic lights and in queues, fast acceleration and hard braking, all of which combine to reduce the practical efficiency of the mechanical powertrain to around 20%.

The electric motor is a vastly more efficient – and reliable – device in principle than the internal combustion engine.  To get the picture, we need to compare two vehicles sharing the same platform but utilising different powertrains.  This way, we can eliminate variables such as vehicle size and aerodynamics which complicate comparisons from one vehicle platform to another.  I reviewed the US Department of Energy website devoted to vehicle fuel economy and found that in 2003 the electric variant of the Toyota RAV4 was 4.9 times more energy efficient over the standard test cycle than its petroleum-powered equivalent.  4.9 times!  Note also that Toyota’s aim was not to build an energy efficient vehicle per se, but to comply with California’s “Zero-Emissions Vehicle Mandate” (the RAV4-EV used nickel metal hydride batteries, which are less efficient than modern lithium batteries that will power the new generation of electric cars).  In other words, Toyota achieved this factor ~5 efficiency advantage almost by accident! 

Putting this efficiency advantage into context, we can apply the carbon intensity of any given energy source to see what the effective life-cycle emissions would be.  Imagine a run-of-the-mill pulverised coal plant generating power with approximately 1,000 gCO2/kWh.  Factor in grid losses of around 6%, and the electricity at the plug socket contains roughly 1,064 gCO2/kWh.  Meanwhile, petroleum-based fuels contain around 300 gCO2/kWh, taking into account the efficiency of a typical oil refinery.  On this basis it looks as though petrol is better for the environment than coal-fired electricity.  But when you apply the energy efficiency advantage of the RAV4-EV (i.e. 1,064 divided by 4.9), the relative carbon intensity of energy at the wheels is 28% less than the petrol version.  Diesel engines are typically around 25% more efficient than petrol engines, all else being equal.  This means the RAV4-EV charged with electricity from a run-of-the-mill pulverised coal plant would still be marginally better in terms of CO2 emissions than its diesel-powered equivalent. 

But no country, not even China, has exclusively coal-fired electricity.  In Britain, a diverse range of power generating technology means that electricity drawn at the domestic socket emits around 520 gCO2/kWh on average.  On this basis, an electric RAV4 would produce two-thirds less CO2 per mile driven than the petrol version, and half as much as a comparable diesel.

Furthermore, once all those CO2 emissions have been concentrated from millions of vehicle tailpipes into a relatively few stationary point sources, then they lend themselves to a future in which we can capture and lock away the CO2 underground.  Personally, I cannot imagine carbon capture and storage (CCS) from moving car tailpipes, but I can envisage CCS from large stationary power plants situated near suitable geological storage locations.

Further still, electric vehicles can actually help to accelerate the penetration of renewables such as wind and solar power, because one of the limits to renewable electricity generation is storage of energy from intermittent sources.  With millions of electric vehicles connected to the grid we will have created a massive distributed energy storage facility, in the form of automotive batteries.

The more important point is this: if we are to avert catastrophic climate change, then the power sector will need to steadily decarbonise because it represents the single largest source of CO2 emissions.  The good news is that we know how to decarbonise the power sector; we have a range of technologies and policy measures at our disposal and all that’s lacking is a globally inclusive international treaty to put an effective cap on emissions.  In this respect, it is sensible to take: “Power decarbonisation over time” as one of our starting assumptions.

Contrast this with the liquid fuels sector, in which the carbon intensity is heading northwards as oil companies are forced to exploit more energy-intensive forms of liquid hydrocarbon (e.g. oil sands, oil shale, coal-to-liquids, etc.).  Biofuels – even when produced sustainably with real greenhouse gas benefits – will struggle to make up the difference. Oil is going to get dirtier.  And if the worst of electricity (i.e. pulverised coal) compares favourably with the best that petroleum has to offer (i.e. conventional diesel), then over time the advantage of electric vehicles can only increase.

Finally, there is much to be done in redesigning the entire transport paradigm, e.g. through modal shift from private cars to mass transit, encouraging more walking and cycling, and improving urban planning practices to eliminate demand for transport.  Electric vehicles are not a panacea to cure all transportation ills.  However, the clear energy efficiency advantages of electric vehicles, not to mention the crucial energy diversification potential (energy security frequently trumps environmental security in policy discussions), make them a very important part of the solution as we move toward a sustainable energy future.