Towards a sustainable biomass energy supply for rural households in semi-arid Shinyanga, Tanzania. A cost/benefit analysis. W. Wiskerke. V. Dornburg, A.
Towards a sustainable biomass energy supply for rural households in semi-arid Shinyanga, Tanzania A cost/benefit analysis
W. Wiskerke V. Dornburg, A. Faaij, R.E. Malimbwi, C.D.A. Rubanza
Sokoine University of Agriculture
Introduction - Energy in Tanzania • Traditional biomass 92% of TPES • 10% electrification (2% rural) • Oil import 30% foreign expenditures • Deforestation 1.1 % per year • Energy poverty in drylands (30% semi-arid) • Prices fuelwood: 500 – 700 Tsh/headload => Sustainable bioenergy production desirable Sokoine University of Agriculture
Research objective
Compare the economic feasibility and the socio-economic impacts of three different sustainable small-scale biomass energy supply systems for rural smallholders using a cost/benefit analysis.
Sokoine University of Agriculture
Case Study: East Shinyanga • High livestock concentration • Severe land degradation • Low staple crop yields (maize) • Long dry season • Large fuelwood deficit • No rural electricity Sokoine University of Agriculture
Three small-scale bioenergy systems • Carbon forestry - fuelwood • Rotational woodlot – fuelwood/charcoal • Jatropha plantation - jatropha oil
Sokoine University of Agriculture
Carbon forestry • • • • • •
Small-scale CDM methodology: Max 8 ktCO2/yr Medium scale on community land ~ 1500 ha Above-ground biomass increment: 2 tdm/ha/yr Benefits from voluntary carbon credits 10% fuelwood harvest Indirect benefits – forest products, avoided deforestation, land reclamation, increased biodiversity
Rotational woodlot • Acacia Polyacantha • Mean annual biomass increment: 10 tdm/ha/year • Small-scale on agricultural land • Intercropping with maize (also monoculture) • Fuelwood or charcoal • Use of leguminous fodder • Also harvest of poles
BASELINE
WOODLOT
BASELINE
YEAR 1
YEAR 8
YEAR 2
YEAR 9
YEAR 3
YEAR 10
YEAR 4
YEAR 11
YEAR 5
YEAR 12
YEAR 6
YEAR 13
YEAR 7
YEAR 14
Maize Fallow Intercropping trees and maize Tree fallow Intercropping with increased maize yield
WOODLOT
Jatropha production • Monoculture or intercropping • Small-scale on agricultural land (intercropping) or degraded land (monoculture) • Use of jatropha for several purposes possible – – – –
Trade of seeds, oil Electricity generation Soap production (Heat use)
Methodology • Cost-benefit analysis against ‘baseline’ – Maize cropping and cattle in dry season
• Calculation of – NPV: US$/ha (using shadow cost of labour) – Return on Labour: US$/man-day – Cost of Energy: US$/GJ
Sokoine University of Agriculture
Baseline assessment • Maize cultivation – Maize-fallow system: 2 years maize, 3 years fallow
• Opportunity cost of land – Renting price agricultural land – Wet/dry season ~ 34 or 16 US$//ha/season
• Shadow cost of labour - ~ US$ 1.43 /man-day – Return on labour (US$ 1.88 /man-day) minus opportunity costs land
Sokoine University of Agriculture
$90
Traditional bioenergy $80
$70
$60
$50
$40
$30
$20
$10
$0
Kerosene stove Kerosene Electricity stove Electricity Ceramic liner stove Traditional stove
Sokoine University of Agriculture
Charcoal legal Ceramic liner stove Traditional stove Charcoal illegal Burnt brick stove Mud stove 3-stone stove Fuelwood
Cost of energy and cost of utilized heat (US$/GJ)
Costs of energy in baseline
NPV costs of carbon forestry
$ 23,304 , 2% $ 148,268 , 16%
$ 79,741 , 8% $ 114,268 , 12%
CDM transaction costs Planting material costs Fixed investment costs Specific investment costs
$ 54,738 , 6%
Annual costs Cost of land
$ 226,824 , 25% $ 145,042 , 15%
Labour cost land workers Labour cost educated labour
$ 72,929 , 8%
$ 73,219 , 8%
Sokoine University of Agriculture
Fuelwood harvest
$200
1.600
$100
1.400
$0
1.200 -
2
4
6
8
10
-$100
1.000
-$200
800
-$300
600
-$400
400
-$500
200
Woodlot area (ha)
NPV (1000 US$)
Carbon forestry and wood yields
NPV Area
Mean annual above-ground biomass increment (tonne dm/ha/year)
• Small-scale CDM limitation not profitable at low yields Sokoine University of Agriculture
NPV per ha of rotational woodlots $1,300
NPV (US$)
$1,100
Monoculture, tax
Intercropping, tax
Monoculture, no tax
Intercropping, no tax
$900 $700 $500 $300 $100 -$100
• • • •
Fuelwood
Charcoal
Poles + Fuelwood
Poles + Charcoal
NPV (RoL) increases with multiple products (poles, intercropping) NPV higher for charcoal production (labour intensive) RoL higher for fuelwood production Taxes on fuelwood plantation (per woodlot) high Sokoine University of Agriculture
Jatropha production and use • Intercropping and monoculture comparable production costs – difference in land used
• Trade of seeds – Price of seeds 100 Tsh/kg; NPV: -180 to - 230 US$/ha
• Trade of oil – Price of oil 0.75 US$/l; NPV: - 230 to – 1200 US$/ha
• Cooking on jatropha oil – Not competitive with other heat sources; NPV: - 1400 US$/ha
• Electricity production – Electricity production costs as difference to diesel 0.6 US$/kWh – NPV: 1600 -2100 US$/ha
• Soap production – NPV: 19300 - 23200 US$/ha Sokoine University of Agriculture
NPV costs of jatropha oil production
• Largest part of costs in labour – Harvest – Manual oil pressing
5.1% 13.7%
0.2% Opportunity cost land
7.9%
Manure Labour Seedlings
• Labour demand:
Ram press
– 299 man-days/ha/year 73.1%
Sokoine University of Agriculture
NPV (US$/ha)
$10,000 $9,000 $8,000 $7,000 $6,000 $5,000 $4,000 $3,000 $2,000 $1,000 $0 -$1,000 -$2,000 -$3,000 -$4,000 -$5,000 -$6,000 -$7,000 -$8,000 -$9,000 -$10,000 -$11,000
Comparison: NPV Carbon forestry
Woodlot poles & charcoal Woodlot fuelwood Jatropha seed trade
Jatropha oil for cooking Jatropha oil trade Jatropha oil elektrification
•Results comparable for RoL •Main uncertainties: Yields, market prices, shadow costs of labour Sokoine University of Agriculture
Carbon forestry - fuelwood Woodlot poles & charcoal Woodlot fuelwood Jatropha oil
Cost of energy (US$/GJ)
Comparison: Costs of energy
$125 $120 $115 $110 $105 $100 $95 $90 $85 $80 $75 $70 $65 $60 $55 $50 $45 $40 $35 $30 $25 $20 $15 $10 $5 $0
Sokoine University of Agriculture
Cost of energy
Cost of utilized heat
Comparison: labour intensity
8 7
Jatropha oil elektrification
Po le
s Sokoine University of Agriculture
l ch ar
co a
al +
Jatropha oil
+
Fu
Woodlot fuelwood
s
Woodlot poles & charcoal
0
ha rc o
Carbon forestry
20
Po le
-
40
C
1
60
oo d
2
lw
3
80
fu e
4
100
d
5
120
el w oo
6
ze
9
M ai
10
Labour demand (Man-days/ha/year)
Labour intensity (man-days/GJ)
Per ha, multi-product decreases labour intensity and intercropping comparable to maize
Per GJ: labour intensity of jatropha oil and charcoal + poles high
11
Conclusions • Rotational woodlots preferable for household energy – Cost-effective measure against land degradation, energy poverty
• Jatropha oil as diesel substitute – Trade or electricity substitution – Contributes to rural electricifiation
• Trade-off between scarce land and scarce labour – In wet season, labour might be scarcer in Shinyanga
• Small-scale carbon forestry economically not feasible – But, large potential socio-economic, environmental benefits – Carbon forestry can finance forestation programmes partially
Sokoine University of Agriculture
Report available: www.chem.uu.nl/nws
Sokoine University of Agriculture