2012.12.17.

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Renewable energies: redemption or illusion?

(using the slides of Nate Lewis – who reliedon a paper by Martin I. Hoffert et. al.)

LÁTÓHEGYI KILÁTÓ 36. szám

ForewordUntil recently I have shared the general belief of other environmentalists that

there are no physical limits of replacing fossil energies with renewables. (This idea was propagated in the ’70s by Amory Lovins and underlined –among others – with the conclusions of an European conference on renewable energies held in Brussels, January 2007.)

The message of this belief is that the consumer society may survive in the long th i d t b i ll b ti d hrun, there is no need to basically curb our consumption and change our way

of life.However, scientific research proves that this is not true, there are serious

physical limits of this replacement.The first piece which turned my attention to this problem was a publicistical

writing by Sharon Begley in Newsweek, March 2009. That paper relied on lectures by Nat Lewis, Caltech. And Nat Lewis used the findings of a study by Martin I. Hoffert et al., published in Nature, 1998. A recent study by Vaclav Smil, published in Kovász suggests the same conclusions.

K.K.

European Renewable Energy Policy Conference, Brussels, 29-31 January, 2007

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European Renewable Energy Policy Conference, Brussels, 29-31 January, 2007

European Renewable Energy Policy Conference, Brussels, 29-31 January, 2007

How much can renewable energies replace fossil fuels?• theoretical potential: 3078 times the current

global energy needs• technical feasibility (estimation in 2007)*: 5 times

(on the level of present technologies)i l f ibili ?• economical feasibility? ……

BUT IS THAT PHISICALLY FEASIBLE?

*European Renewable Energy Policy Conference, Brussels, 29-31 January, 2007

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An unfounded optimism:

• with duly high oil prices and/or• if negative externalities are internalized

– i.e. if fossil energies are charged the damages caused by them y

– or if renewables are properly subsidized • renewable energies become competitive • and replace fossil fuels • ⇒ CO2-emission could be reduced to the

proper level

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But:

• fossil fuels will not be depleted• they are inexpensive (without externalities)• renewables could not fully replace them

– because they are of low density,– their land need (with a special view on solar

and biomass) is unsatisfiably large and– the massive use of biomass for energy

purposes would mean a major threat to the bioshere services

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The task: emission and ppm

• by 2050 CO2 emissions will have to be 80 percent below today’s

• to keep atmospheric levels no higher than 450 parts per million450 parts per million – we are now at 386 ppm, compared with 280

before the Industrial Revolution• that’s 80 percent less emissions from

much greater use of energy

Conditions for forecast:• the world used 15 trillion watts (15 terawatts) of power in 2008

• BAU in 2050:– we would need 45 terawatts– 10 TW carbon free power would be produced without policy intervention

• assumptions:– minimal population growth to 9 billion people– slow economic growth (1,6 percent a year, practically recession level)– unprecedented energy efficiency (improvements of 500 percent relative

to current US levels, worldwide)

• the world will use 28 terawatts in 2050

• in order to keep CO2 to 450 ppm, 26,5 of those terawatts must be zero-carbon– 2008: biomass 2,1, hydro 1, nuclear 0,9, renewables 0,2 terawatts,

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The task: in terawattsTotal TW of which

non fossil TW2008 15 4BAU in 2050 45 10Scenario by Nate Lewis in 2050

28 26,5in 2050

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The Formula of CO2 emission(the Kaya identity)

Mc=N(GDP/N)(E/GDP)(C/E)

• M : magnitude of carbon (in CO )• Mc: magnitude of carbon (in CO2)• N: number of population• GDP/N: per capita GDP• E/GDP: primary energy intensity• C/E: carbon intensity of energy sources

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Options• are you a fan of nuclear?

– to get 10 terawatts from nuclear: we should have to build 10.000 reactors, or one every other day starting now

• do you like wind?– if you use every single breeze that blows on land, you’ll get 10 to

15 terawatts15 terawatts– since it is impossible to capture all the wind, a more realistic

number is 3 terawatts, or 1 million state-of-the-arts turbines, and even that requires storing the energy – something we don’t know how to do – for when the wind doesn’t blow

• solar?– To get 10 terawatts by 2050, we should need to cover 1million

roofs with pannels every day from now until than. „It would take an army,” Lewis says. Obama promised green jobs, but still...

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Weizsäcker on the biomass energy

• The biofuel mania (even madness) can concludein a world wide nightmare

• in some cases the energy loss may be 22 folds• a hundred years ago biomass was the most

important energy source• by now it has become the biggest energy sink

• The renewables will not bring the solution; a substantial dicrease in energy demand is needed.

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Vaclav Smil on the limitations and dangers of the use of biomass for energy

• Even if the most efficient biomass (ethanol from Brazilian sugar cane) was to satisfy the fuel needs of world transport, the total land requirement would be 550 mn hectars.– This is more than one third of the total agricultural lands of the world.– Or this almost equals the land area of tropical agriculture.

• If the motor fuel need of USA was to be satisfied with maize-ethanol, more ,than double of its agricultural land would be needed.

• The total energy requirement of the USA would need more than six times its agricultural lands or 75% of the world.

• To supply the world’s iron and steel furnaces with charcoal would need half of the Brazilian forests.

• A further increase in energy plantations would accelerate the decline of biosphere services.

• The damage in nitrogen circulation due to human intervention is bigger than in the carbon cycle.

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Steven Chu, Department of EnergySecretary, USA

• we need breakthroughs in physics and chemistry that are beyond our presentreach

• we need Nobel caliber breakthroughs and• we need Nobel-caliber breakthroughs and discoveries

• political will and a price on CO2 won’t be enough to bring about low-carbon energysources

New energy sources are needed

• methanol-economy– CO2 → methanol– the DMFC (Direct Methanol Fuel Cell) directly transforms methanol to electric power;

residual: water (György Oláh, a Hungarian Nobel laureate energy-chemist)• controlled nuclear fusion

– the task to be solved: creating a huge laser which can force a deuterium nucleus to merge with a tritium nucleus →controlling fusion so that instead of a one time blast you get a series of tiny controllable– controlling fusion so that instead of a one-time blast you get a series of tiny, controllable explosions

– promising experiments in the Lawrence Livermore National Laboratory, California, and in other countries as well

– 10 gallons of water could produce as much energy as a supertanker of oil• artificial photosyntesis

– a material (to be determined) absorbs sunlight and water and produces hydrogen for fuel but zero CO2

• transmission lines– presently they leak 80 percent of what they carry– „We’re going to have to discover yet another family of superconductors which do not lose

current that are easily made into wires and that work at the temperature of liquid nitrogen, a coolant.” David Pines, UCLA)

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The capital demand:

• to get the right energy mix in 2050, breakthroughs are needed soon– given how long it takes to capitalize and

deploy new technologiesdeploy new technologies• despite the pressing need, DOE spent a

pitiful $2 to $3 billion on basic energy R&D in 2008– Brookings Institution calls for $20 to $30

billion a year

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My conclusions:

• Replacement of fossil fuels with renewables has serious physical limits

• As a result,ith i t t h– either consumer society must change

towards less energy use– or Nobel prize caliber innovations in creating

new carbon-free energies must happen • considering the needs in capitalization of the new

energies, the technical breakthroughs should happen soon…

Literature• Begley, Sharon : We Can’t Get There From Here. Newsweek, March

23, 2009• Energy 2050. International Conference, Stockholm, October 21-22,

2009• European Renewable Energy Policy Conference, Brussels, 29-31

January, 2007• Guterl, Fred: How to Fix a Climate Emergency. Newsweek, April 27,

2009• Hoffert, Martin I. et al.: Energy implications of future stabilization of

atmospheric CO2 content. Nature, Vol 395, 29 October 1998. www. nature.com

• IPCC reports, different years, web• Lewis, Natan: The Future of Power and Energy int he World,

Caltech, 2004. web • Lyons, Daniel: Could this tiny pellet power the Earth? Newsweek

November 23, 2009• Smil, Vaclav: Energia-válaszút előtt. Kovász, 2009 1-4. szám.

Látóhegyi Kilátó 36. szám Bp. 2010. márc. 14.Szerkeszti Kiss Károly