Assessing Bioenergy Potentials in Rural Landscapes

Report
Assessing Bioenergy Potentials
in Rural Landscapes
Oludunsin Tunrayo Arodudu
Alexey Voinov
Iris van Duren
INTRODUCTION
Climate change
challenges
Shortage of
fossil fuel
supply
Depletion of global
fossil fuel reserves
Research Problem
Developing a more holistic approach for assessing
bioenergy potential under an SEA framework
Known measures of bioenergy potential
 Available land
 Some biomass are not grown on land
 Biomass yield
Not a function of energy obtainable
 Energy yield
Energy invested not considered
 Money invested and gained
Susceptible to political and market mechanisms
ALTERNATIVE APPROACH:NEG/EROEI
Net Energy Gain (NEG)
NEG = Energy Output - Energy Input
Net Energy Gain becomes a loss when it is less than 0
&
Energy Return on Energy Invested (EROEI)
EROEI = Energy Output / Energy Input
Energy production activity becomes incapable of supporting
continuous socio-economic function when EROEI is less than 3
SCOPE OF THE STUDY (RURAL LANDSCAPES)
Crop residues
Farm manure
Natural grasslands
WHY?
Surplus
pasturelands  Relative benignity and favourability in
terms of existing policy constraints:
Food security
Nature conservation: soil, water, biodiversity
Competitive use of biomass and well being of the local people
Reasons for choice of crop and animal
For crops (Scarlat et al, 2010): Corn, Rye, Triticale, Wheat,
Barley, Oat, Rapeseed
• Availability in commercial quantity
• Good Crop to Residue Yield
For animal (Fehrs, 2000): Beef Cattle, Dairy cattle, Pig,
Chicken
• large Population of animal
• % collectable on barns and hard surfaces
For Grasses on Surplus pasturelands (Prochnow et
al, 2009)- Alfalfa
• Prevent a total change in ecosystem structure
• Meet future fodder needs
Factors influencing potential availability of
biomass for bioenergy production
For Crop residue (Scarlat et al, 2010)
• Use for soil conservation purposes
• Use as substrates for mushroom (Wheat)
• Use for animal beddings
For Animal waste (Fehrs, 2000)
•
% collectable on barns and hard surfaces
For Grasses (van Vuuren et al, 2010)
• Use for animal beddings and animal feed
Method: Combination of Life Cycle Inventory (LCI) and
GIS
From the LCI:
•List of energy inputs and outputs, biomass and energy conversion
models and coefficients
•Estimation of Potential Biomass and Biomass Potentially
available for Bioenergy Production
•Estimation of Energy Input and Output of the different
bioenergy production options
•Estimation of NEG and EROEI of the different bioenergy
production options
From the GIS:
• Estimation of area under natural grassland using GIS
coverages (LGN 6 Land cover map)
RESULTS: PERCENTAGE COMPOSITION
Biomass type
Percentage (%)
Manure
89.56
Crop residue
9.99
Natural Grassland
0.44
Surplus pasturelands
0.01
Manure by far has the largest biomass and
bioenergy potential
RESULTS: FARM MANURE
Large NEG, not necessarily high EROEI
RESULT: CROP RESIDUE
Biomass type
Corn
NEG (TJ)
EROEI
6684.78
16.68
Rye
6.93
9.23
Triticale
7.75
8.52
Wheat
44.80
9.59
1.42
7.91
33.96
8.96
2.55
9.04
Oat
Barley
Rapeseed
Corn residues:
• most energy efficient : High EROEI
• most energy profitable: High NEG
Results: Choice of grass harvest for bioenergy production
Biomass type
NEG (TJ)
EROEI
Natural Grassland:
Early Harvest (< 12cm)
153-256
7.44
Intermediate Harvest (15-20cm)
216-361
11.62
Late Harvest (>25cm)
136-228
13.09
Early Harvest (< 12cm)
2.47
2.12
Intermediate Harvest (15-20cm)
4.71
4.09
3.34
7.06
Surplus Pasturelands:
Late Harvest (>25cm)
Natural grassland (Intermediate Harvest): Natural Grassland
Management Policy in the Netherlands
Surplus Pasturelands (Late Harvest): Highest energy
efficiency value (EROEI).
Comparison of EROEI levels
Evaluation of Overijssel’s bioenergy potential
Form of
energy
Bioenergy Conversion Bioenergy Net Gain
target
Efficiency
potential
to EU
(60PJ)
of biogas
NEG-66PJ targets
elsewhere
Transport
fuel
23PJ
96%
23PJ
-
Heat
(CHP)
13PJ
70%
28PJ
+15PJ of
heat
Electricity
(CHP)
14PJ
35%
14PJ
-
5.94PJ
-3.06PJ
Industrial 10PJ
As liquid
raw
fertilizer
material
Extra 2PJ of biogas still exists.
Conclusions
• NEG/EROEI approach is quite holistic:
Opens up room for broad analysis of bioenergy potential issues
• Alternatives: minimizing constraints and maximizing energy gains
 Unconventional biomass sources
 Farm scale wet anaerobic co-digestion technology
 Better animal management options and farm structures
• Energy efficiency component: EROEI
• Accurate evaluation of bioenergy targets: NEG
• Basis for stakeholder interactions
Thank you!!!

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