Energy Challenges

Energy Challenges

Dr. Robert MacKay

Because of long time delays for the carbon cycle, drastically different scenarios yield very similar results for a 20 year time horizon, but drastically different result for a 50 to 100 year time horizon.

Red A1F1 scenario with business as usual growth.

Green. Fixed fossil fuel emission from 2013 on (about 10 GtC/yr)

Emission Scenarios

Emission scenarios for previous slide

Turning off all emissions in 2015 (very unrealistic) will still leave atmospheric CO2Levels over 390 ppm in the year 2110.

http://www.newscientist.com/article/dn10507-carbon-emissions-rising-faster-than-ever.html

Global per capita emission have held steady for past 30 to 40 years. For the past 30 to 35 years emissions have been closely linked to population.

• http://www.eia.doe.gov/oiaf/ieo/world.html • http://www.eia.doe.gov/oiaf/ieo/emissions.html

495 x1015 BTU x 1054 Joule/BTU=5.11x1020 J = 511 ExoJoules

Average Power consumption in Watts = Yearly used/ (# of seconds in Year)

Average 2007 Power Consumption =5.11x1020 J/3.15 x107 s=16 TerraWatts

Organisation for Economic Co-operation and Development (OECD)

How much non-Fossil Fuel energy must be created in the next 25 years?

Top Fossil Fuel Emitters (Absolute)

Top four emitters in 2012 covered 58% of global emissionsChina (27%), United States (14%), EU28 (10%), India (6%)

With leap year adjustment in 2012 growth rates are: China 5.6%, USA -4.0%, EU -1.6%, India 7.4%.Source: CDIAC Data; Le Quéré et al 2013; Global Carbon Project 2013

UNEP mid level projections

Fossil fuel supplies will become harder to find in the future and as supply drop prices will increase making alternative energies more attractive.

http://www.eia.doe.gov/pub/oil_gas/petroleum/feature_articles/2004/worldoilsupply/oilsupply04.html

For oil

http://en.wikipedia.org/wiki/World_energy_consumption

In 2005 84% of all energy worldwide came from fossil fuels

In 2010 81% of all energy worldwide came from fossil fuels. The 2005 to 2010 difference is likely an artifact of how energy supplies were estimated.

Emissions from Coal, Oil, Gas, Cement

Share of global emissions in 2012: coal (43%), oil (33%), gas (18%), cement (5%), flaring (1%, not shown)

With leap year adjustment in 2012 growth rates are: coal 2.5%, oil 0.9%, gas 2.2%, cement 2.2%.Source: CDIAC Data; Le Quéré et al 2013; Global Carbon Project 2013

More Carbon emissions from coal but less energy from coal than oil suggesting that coal is much less efficient than oil for producing energy.

Data from http://www.bp.com/content/dam/bp/pdf/statistical-review/statistical_review_of_world_energy_2013.pdf

Most recent BP estimates of 50 yearSupply for oil and Nat GasAnd 100 yrs for coal

Wind energy generation is growing at about 30% per year

Cost of Solar energyHas dropped dramatically

From 2007 to 2011 the growth in solar energy usage increase by about 65%

2012 Solar enrgy supplies very little of our world’s usage

However with a sustained growth rate of 65%/yr it will only take 15 yrs or so for solar to provide most of the world’s needs

• 1000 exa-Joules per year = 31 TWattshttp://en.wikipedia.org/wiki/World_energy_consumption

• Liquid biofuels are less than 1 % efficient at converting sunlight to liquid energy.

• Engines that run on liquid fuels are 20 % efficient at best.

• So for every 100 W/m^2 0.2 can be used

• http://www.withouthotair.com/c6/page_43.shtml

• Solar PV panel are close to 20 % efficient and electric motors are close to 80 % efficient

• So for every 100 W/m^2 of energy 16 are usable.

• This arguments suggest that Photovoltaic (PV) solar energy collection is 80 times (16/0.2) better than biofuels

Also

For every 10 TerrWatts of fossil Fuels used for electric power generation or transportation, only 2.5 TerraWatts of PV energy are needed.

From “The Technology Path to Deep Greenhouse Gas Emissions Cuts by 2050: The Pivotal Role of Electricity” Science Vol 335, 6 January 2012.

From “The Technology Path to Deep Greenhouse Gas Emissions Cuts by 2050: The Pivotal Role of Electricity” Science Vol 335, 6 January 2012.

Artificial leaves CCS (Carbon capture and storage)

http://ngm.nationalgeographic.com/big-idea/13/carbon-capture-pg2

http://news.nationalgeographic.com/news/energy/2011/08/110811-quest-to-capture-carbon-dioxide/

Artificial Leaves

• http://www.sciencefriday.com/blog/2011/05/faux-tosynthesis-clean-energy-of-tomorrow/

http://www3.imperial.ac.uk/energyfutureslab/research/grandchallenges/artificialleaf