Towards a sustainable biomass energy supply for rural ... - COMPETE

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.


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


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


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


$90

Traditional bioenergy $80

$70

$60

$50

$40

$30

$20

$10

$0

Kerosene stove Kerosene Electricity stove Electricity Ceramic liner stove Traditional stove


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%


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%


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


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


Report available: www.chem.uu.nl/nws
