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

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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!