Sustainable use of organic resources for bioenergy, food and water provision in rural Sub-Saharan Africa

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Abstract

This paper reviews use of organic resources in rural Sub-Saharan Africa (SSA), impacts on household energy, and interactions with provision of food and water. Wood, charcoal and dung supply over 70% of household energy in SSA, but with improvements in energy technologies, crop-residues and human excreta could also contribute. Improving cookstoves is not enough to make woodfuel use sustainable, reducing deforestation due to woodfuel demand by only 41-50%. Further reductions of 21% are achieved by using crop-residues and 23% by anaerobic digestion of cattle manure. Taken together, these measures could reduce deforestation due to woodfuel demand by 70-100%. Burning crop-residues loses a large proportion of nitrogen needed for crop production, which could be partially counteracted by applying biochar from pyrolysis cookstoves to improve retention of soil nitrogen. Better nutrient recycling would be achieved by composting, but this precludes energy provision. Both energy and efficient nutrient recycling are provided by anaerobic digestion, but carbon sequestration is reduced compared to composting or pyrolysis. Nevertheless, a wider range of waste materials may be recycled in the closed digester system, so pyrolysis of dry crop-residues together with anaerobic digestion of wet wastes is likely to provide the best solution for both food and energy. However, anaerobic digestion may demand more water than pyrolysis and, if soil carbon is reduced, may also increase the need for irrigation. Therefore, in water limited areas, biogas digesters should only be installed if integrated with water harvesting systems. Governments can encourage adoption of sustainable technologies by providing subsidies to cover fixed costs, facilitating credit and complementary infrastructure investments, and improving standardization and quality control in cookstove and digester markets. Implementation work should involve communities and households, giving women a role in decision-making to ensure community investment in water access.
Original languageEnglish
Pages (from-to)903-917
Number of pages15
JournalRenewable and Sustainable Energy Reviews
Volume50
Early online date2 Jun 2015
DOIs
Publication statusPublished - Oct 2015

Fingerprint

Anaerobic digestion
Crops
Pyrolysis
Deforestation
Composting
Water
Nutrients
Recycling
Nitrogen
Soils
Carbon
Charcoal
Manures
Biogas
Irrigation
Standardization
Quality control
Wood
Decision making
Costs

Keywords

  • biogas
  • pyrolysis
  • composting
  • people-centred discourse approaches
  • local and national governance
  • sustainable organic waste practices

Cite this

@article{8e3aae3fbcf6498995f2527c23f769d5,
title = "Sustainable use of organic resources for bioenergy, food and water provision in rural Sub-Saharan Africa",
abstract = "This paper reviews use of organic resources in rural Sub-Saharan Africa (SSA), impacts on household energy, and interactions with provision of food and water. Wood, charcoal and dung supply over 70{\%} of household energy in SSA, but with improvements in energy technologies, crop-residues and human excreta could also contribute. Improving cookstoves is not enough to make woodfuel use sustainable, reducing deforestation due to woodfuel demand by only 41-50{\%}. Further reductions of 21{\%} are achieved by using crop-residues and 23{\%} by anaerobic digestion of cattle manure. Taken together, these measures could reduce deforestation due to woodfuel demand by 70-100{\%}. Burning crop-residues loses a large proportion of nitrogen needed for crop production, which could be partially counteracted by applying biochar from pyrolysis cookstoves to improve retention of soil nitrogen. Better nutrient recycling would be achieved by composting, but this precludes energy provision. Both energy and efficient nutrient recycling are provided by anaerobic digestion, but carbon sequestration is reduced compared to composting or pyrolysis. Nevertheless, a wider range of waste materials may be recycled in the closed digester system, so pyrolysis of dry crop-residues together with anaerobic digestion of wet wastes is likely to provide the best solution for both food and energy. However, anaerobic digestion may demand more water than pyrolysis and, if soil carbon is reduced, may also increase the need for irrigation. Therefore, in water limited areas, biogas digesters should only be installed if integrated with water harvesting systems. Governments can encourage adoption of sustainable technologies by providing subsidies to cover fixed costs, facilitating credit and complementary infrastructure investments, and improving standardization and quality control in cookstove and digester markets. Implementation work should involve communities and households, giving women a role in decision-making to ensure community investment in water access.",
keywords = "biogas, pyrolysis, composting, people-centred discourse approaches, local and national governance, sustainable organic waste practices",
author = "Smith, {Jo U.} and Anke Fischer and Hallett, {Paul D.} and Homans, {Hilary Y.} and Pete Smith and Yakubu Abdul-Salam and Emmerling, {Hanna H.} and Phimister, {Euan C}",
note = "Acknowledgements We are grateful to the United Kingdom Economic and Social Research Council Nexus Network for funding this work.",
year = "2015",
month = "10",
doi = "10.1016/j.rser.2015.04.071",
language = "English",
volume = "50",
pages = "903--917",
journal = "Renewable and Sustainable Energy Reviews",
issn = "1364-0321",
publisher = "PERGAMON-ELSEVIER SCIENCE LTD",

}

TY - JOUR

T1 - Sustainable use of organic resources for bioenergy, food and water provision in rural Sub-Saharan Africa

AU - Smith, Jo U.

AU - Fischer, Anke

AU - Hallett, Paul D.

AU - Homans, Hilary Y.

AU - Smith, Pete

AU - Abdul-Salam, Yakubu

AU - Emmerling, Hanna H.

AU - Phimister, Euan C

N1 - Acknowledgements We are grateful to the United Kingdom Economic and Social Research Council Nexus Network for funding this work.

PY - 2015/10

Y1 - 2015/10

N2 - This paper reviews use of organic resources in rural Sub-Saharan Africa (SSA), impacts on household energy, and interactions with provision of food and water. Wood, charcoal and dung supply over 70% of household energy in SSA, but with improvements in energy technologies, crop-residues and human excreta could also contribute. Improving cookstoves is not enough to make woodfuel use sustainable, reducing deforestation due to woodfuel demand by only 41-50%. Further reductions of 21% are achieved by using crop-residues and 23% by anaerobic digestion of cattle manure. Taken together, these measures could reduce deforestation due to woodfuel demand by 70-100%. Burning crop-residues loses a large proportion of nitrogen needed for crop production, which could be partially counteracted by applying biochar from pyrolysis cookstoves to improve retention of soil nitrogen. Better nutrient recycling would be achieved by composting, but this precludes energy provision. Both energy and efficient nutrient recycling are provided by anaerobic digestion, but carbon sequestration is reduced compared to composting or pyrolysis. Nevertheless, a wider range of waste materials may be recycled in the closed digester system, so pyrolysis of dry crop-residues together with anaerobic digestion of wet wastes is likely to provide the best solution for both food and energy. However, anaerobic digestion may demand more water than pyrolysis and, if soil carbon is reduced, may also increase the need for irrigation. Therefore, in water limited areas, biogas digesters should only be installed if integrated with water harvesting systems. Governments can encourage adoption of sustainable technologies by providing subsidies to cover fixed costs, facilitating credit and complementary infrastructure investments, and improving standardization and quality control in cookstove and digester markets. Implementation work should involve communities and households, giving women a role in decision-making to ensure community investment in water access.

AB - This paper reviews use of organic resources in rural Sub-Saharan Africa (SSA), impacts on household energy, and interactions with provision of food and water. Wood, charcoal and dung supply over 70% of household energy in SSA, but with improvements in energy technologies, crop-residues and human excreta could also contribute. Improving cookstoves is not enough to make woodfuel use sustainable, reducing deforestation due to woodfuel demand by only 41-50%. Further reductions of 21% are achieved by using crop-residues and 23% by anaerobic digestion of cattle manure. Taken together, these measures could reduce deforestation due to woodfuel demand by 70-100%. Burning crop-residues loses a large proportion of nitrogen needed for crop production, which could be partially counteracted by applying biochar from pyrolysis cookstoves to improve retention of soil nitrogen. Better nutrient recycling would be achieved by composting, but this precludes energy provision. Both energy and efficient nutrient recycling are provided by anaerobic digestion, but carbon sequestration is reduced compared to composting or pyrolysis. Nevertheless, a wider range of waste materials may be recycled in the closed digester system, so pyrolysis of dry crop-residues together with anaerobic digestion of wet wastes is likely to provide the best solution for both food and energy. However, anaerobic digestion may demand more water than pyrolysis and, if soil carbon is reduced, may also increase the need for irrigation. Therefore, in water limited areas, biogas digesters should only be installed if integrated with water harvesting systems. Governments can encourage adoption of sustainable technologies by providing subsidies to cover fixed costs, facilitating credit and complementary infrastructure investments, and improving standardization and quality control in cookstove and digester markets. Implementation work should involve communities and households, giving women a role in decision-making to ensure community investment in water access.

KW - biogas

KW - pyrolysis

KW - composting

KW - people-centred discourse approaches

KW - local and national governance

KW - sustainable organic waste practices

U2 - 10.1016/j.rser.2015.04.071

DO - 10.1016/j.rser.2015.04.071

M3 - Article

VL - 50

SP - 903

EP - 917

JO - Renewable and Sustainable Energy Reviews

JF - Renewable and Sustainable Energy Reviews

SN - 1364-0321

ER -