1. Radu Zmeureanu Demba Ndiaye Michel Bernier
EVALUATION OF THE EMBODIED ENERGY IN BUILDING MATERIALS AND RELATED CARBON DIOXIDE EMISSIONS IN SENEGAL
Radu Zmeureanu
Demba Ndiaye
Michel Bernier

2. CONTENTS Introduction The context of Senegal Methodology Application
Results
Comparison
Conclusion

3. INTRODUCTION (1/2)
Design and evaluate buildings’ performance on the basis of:
life-cycle energy use (LCE)
life-cycle cost
life-cycle CO2 emissions
LCE = (Initial (embodied) energy) +
N x (Annual operating energy use)
N  life duration of the building

4. INTRODUCTION (2/2)
Difficulties in the estimation of embodied energy and related CO2 emissions
Energy used in manufacturing/installation processes
Wide variation in published values
Few data for developing countries such as Senegal

5. THE CONTEXT OF SENEGAL (1/4)

6. THE CONTEXT OF SENEGAL (2/4)

7. THE CONTEXT OF SENEGAL (3/4)
Building materials: imported and locally produced
Reinforced concrete for columns, beams & floors
Exterior walls: reinforced concrete or concrete blocks
Thermal insulation & special types of glass rare

8. THE CONTEXT OF SENEGAL (4/4)

9. METHODOLOGY (1/2) ENERGY ANALYSIS
“Process of evaluation of the energy used, directly or indirectly, by a system to produce goods or services”
a coefficient called Energy content or Embodied energy: MJ/unit (litre, kg, m2, m3, …)
3 methods: process analysis, input-output analysis, hybrid analysis

10. Proposed by IPCC  6-step process
METHODOLOGY (2/2)
CO2 EMISSIONS
Proposed by IPCC  6-step process
Product
Fuel consumption
(kg)
Energy equivalent
(GJ/kg)
Emission
(kgC/GJ)
Carbon content
(kgC/kg)
Carbon oxidized
(%)
Emission factor
(kgCO2/kg)
Gas-oil 1
19.95
0.848
0.990
3.08
Fuel-oil
21.10
0.876
3.18
Natural gas
15.3
0.793
0.995
2.89

11. APPLICATION (1/1) Process analysis used
Construction activities accounted for
Data collected from Senegalese enterprises and the Statistics Bureau of Senegal

12. 4 resources: electricity, water, fuel-oil, gas-oil
RESULTS (1/5)
4 resources: electricity, water, fuel-oil, gas-oil

13. RESULTS (2/5) EXAMPLE: GRAVEL FROM BASALT
Ndiack quarry at 105 km from Dakar
Input
Unit
Quantity EE
(MJ/Unit)
Total EE
(MJ)
CO2
(kgCO2/Unit)
Total CO2
(kgCO2)
Gas-oil kg
1.128
46.01
51.90
3.08
3.47
Electricity
kWh
0.012
16.07
0.19
1.10
0.01
Transport to Dakar
unit 1
108.08
7.23
Water m3
0.008
11.25
0.09
0.75
Total by metric ton of gravel
160.26
10.72

14. Published data of embodied energy
RESULTS (3/5)
RESOURCES
PRODUCT
UNIT
Senegal
Published data of embodied energy
CO2
(kg/Unit) EE
(MJ/Unit)
Number of values
Minimum value
Maximum value
Median value
Gas-oil kg
3.08 46
Fuel-oil
3.18 45 2
45.7
46.5
46.1
Electricity
kWh
1.10
16.07 9
9.88
11.67
10.60
Water m3
0.75
11.25

15. Published data of embodied energy
RESULTS (4/5)
MATERIALS
PRODUCT
UNIT
Senegal
Published data of embodied energy
CO2
(kg/Unit) EE
(MJ/Unit)
Number of values
Minimum value
Maximum value
Median value
Conc. bar kg
1.06
15.97 9
10.1 32
17.90
Sand
0.004
0.06 3
0.04
0.10
0.05
Gravel
0.01
0.16 4
0.051
0.3
0.12
Cement
0.73
3.32 8
0.078
9.4
6.85
Cem. block
unit
1.55
7.96
7.13
23.29
8.9
Mortar m3
298
1418
1682
5980
3200
Concrete
272
1404 13
1242
4600
2348
Rein. conc.
477
4416 1
5040

16. Published data of embodied energy
RESULTS (5/5)
COMPONENTS
PRODUCT
UNIT
Senegal
Published data of embodied energy
CO2
(kg/Unit) EE
(MJ/Unit)
Number of values
Minimum value
Maximum value
Median value
Block wall m2 38
247
Concrete wall
372
1974
Slab
(16 cm) 85
749

17. COMPARISON WITH PUBLISHED DATA (1/1)
EE of all selected local materials (except sand and gravel) is lower than the median values of published data
EE of mortar & reinforced concrete produced in Senegal is below the minimum value of published data
EE of local materials is not higher than those of similar materials produced in industrialized countries

18. CONCLUSION
Process analysis is a suitable tool for EE figures computation
Comparison between data for Senegal and those for industrialized countries  only minor differences
In developing countries, extensive use of human energy counterbalances low energy efficiency of manufacturing processes

19. The End
Questions ???