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BIOENERGY
CENTRE FOR ALTERNATIVE TECHNOLOGY
www.cat.org.uk
PETER HARPER
WHAT I AM GOING TO TALK ABOUT
• The energy challenge– Climate change and future energy policy
• Bioenergy and biofuels basic science• Problems with bioenergy• Trying to solve the problems
BIO-ENERGYOUGHT TO PLAY A SIGNIFICANT ROLE IN
FUTURE ENERGY SUPPLY
• It creates a ‘silver bullet’ illusionEspecially with regard to liquid fuels
• It interacts with land-use and farming• It gobbles up huge areas of land• It affects biodiversity• Net carbon reduction is often poor• There are ethical and sustainability
implications for globally traded biofuels
BUT
FOSSIL FUELS ARE MARVELLOUS
• Cheap • Abundant • Self-storing • Easily converted to other useful forms of
energy
• High energy density• Easily transported and traded
BUT…
• Rising demand is outstripping shrinking supply, particularly for oil
• The combustion products are changing the climate
‘PEAK OIL’ THEORY
0
200
400
600
800
1000
1200
1974
1976
1978
1980
1982
1984
1986
1988
1990
1992
1994
1996
1998
2000
2002
US
$ eq
uiv
alen
t ($
m) TOTAL NUCLEAR FISSION/FUSION
TOTAL OTHER TECH./RESEARCH
TOTAL POWER & STORAGE TECH.
TOTAL RENEWABLE ENERGY
TOTAL FOSSIL FUELS
TOTAL CONSERVATION
Source: Data reported to the IEA by IEA Member countries
R&D Energy TrendsThe most depressing graph I have yet seen!
But ‘Peak Oil’ might provoke action where climate change does not
1990s IPCC
“60% global cuts as soon as possible”
2000 RCEP
“60% UK cuts by 2050”
White Paper 2004
Climate Change Bill
2005 Hillman, Monbiot
“80-90% UK cuts by 2050 or sooner”
2007 CAT ZCB
“100% UK cuts by 2027”
Stern Review
2006
IPCC ARs
1995 2001 2007
Compelling evidence for feedback effects
EVOLUTION OF THE CLIMATE CHANGE DEBATE
THREE KINDS OF RESPONSE
CUNNING PLANS
LOWER-CARBON
SOURCES OF ENERGY
USE LESS ENERGY, OR USE IT MORE EFFICIENTLY TO GET THE
SAME BENEFITS
ENERGY AND
CARBON STRATEGIES
B GFEDC HA
Energy services
Primary energy input
Low-carbon sources
Carbon sequestration
BIOENERGY EFW, LFG15-20%
ELECTRICITY
SOLAR THERMAL 5-10%
GEOTHERMAL5%
VARIABLE RENEWABLES30-50%
HYDRO 5%
NUCLEAR0-5%
FOSSIL FUELS10-20%
TRANSPORT
HEATING LOADS
COOLING LOADS
HYDROGEN
CHP
HEAT PUMPS
PUMPED STORAGE
KEY
PRINCIPAL USE SECTORS
SOURCES
ADJUCT TECHNOLOGIES
FIRM SOURCES
ELECTRICAL LOADS
CARBON CAPTURE AND STORAGE
IDEALISED SUSTAINABLE ENERGY SYSTEM FOR UK
BATTERY STORAGE
SCENARIOS FOR THE UKSHOWING A DISTINCTIVE PROBLEM FOR TRANSPORT
CO2 + H2O → Cn(H2O)n + O2
Cn(H2O)n + O2 → CO2 + H2O
ENERGY IN
ENERGY OUT
PHOTOSYNTHESIS IS NOT VERY EFFICIENT
Annual Energy yields in kWh/m2
• Rapeseed oil 1.2• Willow coppice 2.3• Grass via anaerobic digestion 2.5
• Wind, good site 22• Photovoltaic, good site 100
• BUT bio-energy is storable—an essential component of the mix
An interesting combination?
HOW MUCH DO WE WANT?
• Using all UK set-aside land, biodiesel or bio-alcohol production could displace between 4-7% of existing transport fuel demand– UK target 5% biofuel by 2010– EU target 20% substitution by 2020
• Germany is well on the way to 5%• But currently Europe is importing
liquid biofuels from developing countries
WHAT ELSE COULD WE DO?FAR MORE RADICAL APPROACHES ARE
NEEDED
• Ban imports from developing countries?
• Trade for electricity within Europe?• Explore new technologies• Switch transport to electric propulsion• Improve efficiencies• Farm for sequestration credits• Research on biodiversity optimisation• In fact much more research all round!• Rationalise demand• Consider major changes of land use
TRADE ELECTRICITY FOR BIOFUELS?
“SECOND GENERATION”
POTENTIAL IMPROVEMENTS IN EFFICIENCY AND NET CARBON
REDUCTION
Mid-Wales Energy Agency/RRU Sheffield Hallam University
STRAWWHOLE PLANT AT HARVEST
OIL SEED
PRESS CAKE
PRESSING
CLEANING
CLEAN PLANT OIL
RAW OIL
FILTER CAKE
100 kg rapeseed
2-4kg filter cake with 35-50% oil content
62-70 kg cake with 12-17% residual oil content
28-36 kg clean oil
30-38 kg oil
PURIFICATION OF OILCentrifugation, sedimentation, filtering
90 kg dry weight straw
THE LOGIC OF CAR CLUBS
• Some trips need a car• So we all have one, or three• Then nearly all trips are made by car
• Car share schemes break out of this ‘trip trap’
• They reduce car mileage enormously• Biofuels can reduce, even eliminate, the
remaining emissions
LOCAL PRODUCTION FOR LOCAL CONSUMPTION?
A worked example, regional community of 5000 households(Dyfi Valley)
USE SECTOR CONSUMPTION LITRES PER YEAR
TRAINS 555,000
BUSES 305,000
TAXIS 80,000
CAR SHARE AT TYPICAL USAGE 750,000
TOTAL 1,685,000
CALCULATIONS
• Conventional production 1200l oil/ha• Would therefore require 1400ha• Organic yields about 70% conventional, then
2000ha• This is about 0.15ha per head• About 10% of sustainable land area per head• Similar to horses circa 1910• But might be supplemented by vehicles
powered from other sources: electricity from lithium batteries, hydrogen, compressed air
• We would still need more land for other bio-energy crops
AN AGRICULTURAL REVOLUTION?
LIKELY DISPLACEMENT OF STOCK BY BIOENERGY, BIOREFINING AND
SEQUESTRATION CROPS
• If GHGs are priced, net-emitting processes will attract penalties
• If GHG emission targets are very low, such processes will need balancing by net-negative processes or ‘sinks’
• Sinks are going to be scarce and expensive• ‘Carbonomics’ will tend to displace stock in favour
of crops or managed sequestration• This will affect at least 50% of UK agricultural land• Haber-Bosch nitrogen will have to be very carefully
managed or severely reduced
EXAMPLE: THE DYFI VALLEY
COULD THIS HAPPEN?
THE END
Global: Top Down
• Requires Large Areas Because Inefficient (0.3%)
• 3 TW requires ≈ 600 million hectares = 6x1012 m2
• 20 TW requires ≈ 4x1013 m2
• Total land area of earth: 1.3x1014 m2
• Hence requires 4/13 = 31% of total land area
Biomass Energy Potential
QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture.
QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture.
• Land with Crop Production Potential, 1990: 2.45x1013 m2
• Cultivated Land, 1990: 0.897 x1013 m2
• Additional Land needed to support 9 billion people in 2050: 0.416x1013 m2
• Remaining land available for biomass energy: 1.28x1013 m2
• At 8.5-15 oven dry tonnes/hectare/year and 20 GJ higher heating value per dry tonne, energy potential is 7-12 TW• Perhaps 5-7 TW by 2050 through biomass (recall: $1.5-4/GJ)• Possible/likely that this is water resource limited• Challenges for chemists: cellulose to ethanol; ethanol fuel cells
Biomass Energy Potential
Global: Bottom Up
gasifier
WHAT COULD WE DO NATIONALLY?
WHAT COULD WE DO IN WALES?
UK Research
SO….• We have to have far fewer animals in the
farming system, especially ruminants• There is still a place for high quality mixed
farming– No need for vegetarianism as such, but strong dietary
implications for lower consumption of animal products– Similar arguments might limit fish and alcohol
consumption
• BUT potentially this frees up a great deal of land for bio-energy production– 20-40% of agricultural land?– Not that different from the era of horses!
• How can this be used effectively and responsibly?
NON-ENERGY TECHNOLOGIES
Keep it cheap!
No Power
Cuts!
LOTS of it!