Applied Energy 98 (2012) 301–306
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Analysis of the life-cycle costs and environmental impacts of cooking fuels used in Ghana George Afrane a,⇑, Augustine Ntiamoah b a b
University of Ghana, Department of Food Process Engineering, Legon, Accra, Ghana Koforidua Polytechnic, Department of Energy Systems Engineering, Koforidua, Ghana
h i g h l i g h t s " Environmental impact assessment and costing of six cooking fuels were undertaken. " Using traditional methods, ﬁrewood was found to be the cheapest but most polluting. " A Swedish approach to emissions monetization was used to handle the cooking stage. " Emission from ﬁrewood was found to be the highest; some fuels need more processing. " The relative ranking of various pollutants was maintained after monetization.
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Article history: Received 24 November 2011 Received in revised form 19 March 2012 Accepted 20 March 2012 Available online 21 May 2012 Keywords: Life-cycle assessment Life-cycle costing Cookstoves Woodfuels Emissions costing
a b s t r a c t This study evaluated the life-cycle costs and environmental impacts of fuels used in Ghanaian households for cooking. The analysis covered all the common cooking energy sources, namely, ﬁrewood, charcoal, kerosene, liqueﬁed petroleum gas, electricity and even biogas, whose use is not as widespread as the others. In addition to the usual costing methods, the Environmental Product Strategies approach (EPS) of Steen and co-workers, which is based on the concept of ‘willingness-to-pay’ for the restoration of degraded systems, is used to monetise the emissions from the cookstoves. The results indicate that ﬁrewood, one of the popular woodfuels in Ghana and other developing countries, with an annual environmental damage cost of US$36,497 per household, is more than one order of magnitude less desirable than charcoal, the nearest fuel on the same scale, at US$3120. This method of representing the results of environmental analysis is complementary to the usual gravimetric life-cycle assessment (LCA) representation, and brings home clearly to decision-makers, especially non-LCA practitioners, the signiﬁcance of environmental analysis results in terms that are familiar to all. Ó 2012 Elsevier Ltd. All rights reserved.
1. Introduction Most of the effects of the use of fossil fuels on the global environment are well-known and have been documented in many scientiﬁc studies in the literature. Developed countries, because of their extensive need for energy, are the most to blame for the adverse effects of the use of these fuels, such as acidiﬁcation, global warming and ozone-depletion. Not as much attention seems to have been given to the fact that less-developed countries, less dependent on fossil fuels because of the costs associated with them and their need for less energy generally, have insidiously become major contributors to the global environmental degradation while trying to satisfy one of the basic daily needs of man: cooked food [1–8]. In developing countries, where laws are not properly en⇑ Corresponding author. Tel: +233 20 744 1239; fax: +233 30 251 7741. E-mail address: [email protected]
(G. Afrane). 0306-2619/$ - see front matter Ó 2012 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.apenergy.2012.03.041
forced, forests are indiscriminately cleared for the economic sustenance of the rural dwellers, but in the process an important sink for carbon dioxide removal from the atmosphere is decimated. In addition, using the fuels produced from the forest for cooking can affect human health and global warming directly [4–8]. Foell et al.  estimate that 2.7 million people worldwide are at risk from the use of biomass for cooking in households, with 511,000 childhood deaths in 2004 attributable to soot deposits on children’s lungs. Thus the production and use of fuels for cooking in developing countries deserve serious attention. In Ghana, surveys show that woodfuels used for household cooking, mainly ﬁrewood and charcoal, account for over 60% of the total national energy consumption and constitute 2% of the Gross Domestic Product . The 2000 Housing and Population Census of Ghana, gave the breakdown of the cooking fuels as follows: ﬁrewood (53.8%), charcoal (28.9%), crop residues (7.4%), liqueﬁed petroleum gas (LPG) (5.9%), kerosene (2.9%) and electricity (1.1%) . Biogas
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is also being promoted currently as another renewable source, but this has met with limited success, except in bio-sanitation usage in a few schools, slaughterhouses and hospitals . In a study conducted in Osun State in Nigeria, Anozie et al.  found that ﬁrewood and charcoal together accounted for over 40% of the cooking fuel usage. In Nigeria, however, kerosene, perhaps because of government subsidy, accounts for 33% usage in the rural areas and 42% in the cities. The results of studies in Bangladesh  are similar to those of Nigeria, in that kerosene usage in 53% of households is quite high, and it is used alongside woodfuels. In India, a speciﬁc trend did not emerge from a similar survey; a wide variation in preferred cooking fuels was observed across cities and states . Life-cycle assessment (LCA) and life-cycle costing (LCC) are tools used to make a cradle-to-grave analysis of the environmental and economic consequences of using a product or providing services . Their application could lead, not only to a cleaner and healthier environment, but also to cost-savings in the design, production and use of manufactured products. In this study the two tools were applied to six cooking fuels used in Ghana. The life-cycle cost in such an analysis has two components, namely, the direct monetary costs associated with the equipment themselves, and the indirect costs linked to the pollutants emitted by the equipment. Conventionally, direct equipment-related life-cycle costs are calculated by summing all the charges related to the initial purchase, installation, operation and maintenance of a system throughout its operational lifetime . These costs are of course given in a speciﬁc currency, as one component of the life-cycle cost of the product. The other component is the environmental burden associated with the emissions from the stoves over a speciﬁed period of time. The usual LCA analysis gives the pollution results in gravimetric units, e.g. kg-CO2 equivalent. How to handle the second component, as well as the social and socio-economic aspects in a consistent and objective fashion continues to engage the attention of workers in this ﬁeld. While there is a standardized method for conducting LCA in the International Organization for Standardization (ISO) 14040-14043 series, LCC and other methods do not yet have an agreed international framework or methodology. Efforts have been made by various workers in this direction, and these have led to progressive improvements in life-cycle methods over the years [14,16–19]. A guideline (LCA type) for economic, social and socio-economic is being developed by the United Nations Environmental Programme (UNEP), along with the Society for Environmental Toxicology and Chemistry (SETAC) under the UNEP/SETAC Life Cycle Initiative as a basis for future standardization . While Wiedema  balks at the monetisation of environmental loads from the various impact categories, this approach, in principle, enables the additivity of the results of the two cost components (although the direct-cost component is normally negligible). The emissions from the cookstoves during the cooking process are handled using the monetisation model of Steen [18,19]. Various studies have been conducted to estimate pollutant levels in cookstove emissions and their health impacts particularly in developing countries. However, the results usually differ widely due to variations in the cooking environment, assumptions made in the studies and the measuring devices and techniques used [20–23]. This work uses theoretical analytical techniques with measured and estimated emissions and costs data obtained from surveys and other sources.
determined by surveying the market. The Centre for Environmental Assessment of Product and Material Systems (CPM) at Chalmers University has developed a systematic method for the incorporation of environmental aspects into product development. With their Environmental Product Strategies (EPS) approach, undesirable environmental impact categories like global-warming and acidiﬁcation are classiﬁed as ‘threats’, while desirable circumstances like good human health and bio-diversity, which need to be preserved, are classiﬁed as ‘safeguards’. A ‘willingness-to-pay’ (WTP) concept is based on an objective and realistic determination of the amount of money one would be prepared to pay to restore a degraded safeguard entity back to a chosen reference point. This monetary value is known as the environmental load unit, ELU. Steen and co-workers  have compiled environmental load units, for most of the common emission compounds using this concept. 2.2. LCA of ﬁrewood, kerosene and electricity as cooking fuels 2.2.1. Goal and scope of the LCA study The goal of the current LCA study was to determine the life-cycle environmental impacts of ﬁrewood, kerosene and electricity, which are used for cooking in Ghana, and to add the results to those of an earlier work by the authors, which was done with biogas, charcoal and LPG . This is meant to provide a complete assessment and comparison of the environmental impacts of all the major fuels used for cooking in the country. Another goal was to estimate the life-cycle costs of the cooking-fuel systems, which was not done in the earlier work. Where it was not possible to ﬁnd the needed information locally, results of similar studies conducted in other developing countries were substituted, as is normally done in LCA studies. As in the previous study, a functional unit of 1 MJ of energy delivered to the cooking pot was used as basis for comparison. 2.2.2. Boundaries of the LCA study Firewood. Ninety percent of woodfuels used in Ghana are obtained directly from the natural forests and the remaining ten percent from wood waste, such as logging and sawmill residues, and planted forests. In this study, it is assumed that the ﬁrewood used for cooking is deadwood or dead branches broken from live trees or wood obtained from land cleared for farming. Firewood is normally transported to rural households by human beings who carry them on their heads. Thus no environmental impacts were assigned to their production and transportation. The traditional three-point mud-stove was chosen as the representative ﬁrewood cookstove, since it is still the most commonly used type in rural households. The production of these stoves does not cause any signiﬁcant environmental damage. Electricity. Hydropower constitutes about 70% of Ghana’s grid electricity supply and hence electricity obtained from this source was assumed for the study. The dams were built too many decades ago for their construction per se to have any signiﬁcant effect on the current environment. Standard LCA databases were however used to estimate the impacts of electricity production from these plants. Environmental impacts from the transmission and distribution of power to households could not be assessed due to lack of relevant data. In any case, these are deemed not to have a signiﬁcant effect on the results.
2. Methodology 2.1. Life-cycle cost analysis of the cooking fuels For the conventional cost-summing method, the actual costs of the cooking fuels and their corresponding cookstoves were
Kerosene. In Ghana kerosene, whether imported or produced locally, comes from the Tema Oil Reﬁnery. Crude oil, the raw material, is imported from Nigeria. Data on both upstream and downstream processes are required. The upstream processes include exploration, production, and transportation to reﬁnery, while
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the downstream processes include reﬁning the oil into kerosene and other by-products. Data on both upstream and downstream production processes were taken from the Ecoinvent database. The database also takes into account inputs and outputs for the construction, maintenance and operation of the production equipments. The ﬁnished product is lifted to ﬁlling stations scattered across the country before dispensing to the general public. An average travelling distance of 250 km was assumed. 3. Life cycle inventory data Inventory data on crude oil and electricity production were taken from the Ecoinvent LCA database. Emission factors due to the transportation of kerosene from the reﬁnery to ﬁlling stations came from the GaBi 4 database, while those resulting from the burning of kerosene and ﬁrewood in cookstoves came from the work of Jungbluth [1,20]. These data have been compiled in Table 1. Cooking with electricity does not cause any direct emissions . The pollutants from cookstoves mainly arise from incomplete combustion processes [20–23]. They include particulate matter (PM), carbon monoxide (CO) oxides of nitrogen (NOx), methane (CH4), non-methane volatile organic compounds (NMVOC) such as methane, benzene, toluene, xylene and sulfur dioxide (SO2). These pollutants are of great concern due to their harmful effects on human health. (The LCI data for the manufacture of the cookstoves themselves were not included in the analysis for both the current and previous studies because either they are not signiﬁcant – as in using mud-stoves for ﬁrewood – or accurate and consistent data are not available). Due to their adverse effects on human health during the cooking stage, efforts must be made to reduce cookstove emissions. The emissions at the cooking stage and their ELU values in US$/kg are given in Table 1. 4. Results of life-cycle costs and impact assessment analyses 4.1. Results of life-cycle cost analysis The life-cycle costs of cookstoves were calculated by summing the costs of the cooking devices, their replacement and annual fuel consumption costs, and discounting them at a rate of 10% using the following equation :
ð1 þ iÞn 1 ið1 þ iÞn
where P is the present worth, A the amount in dollars, i the discount rate, and n the number of interest periods, in this case ten. The discount rate of 10% was chosen to approximate the prevailing annual rate of inﬂation in the country. The market prices of the various cost components were obtained from direct and indirect sources like
ﬁeld/market survey, reports and expert opinions. Table 2 gives the initial capital and replacement costs of the devices. Ahiataku-Togobo  has estimated the amount of energy that a given Ghanaian household would consume in a year while using the various types of cookstoves. These results are given in Table 3, along with the stove efﬁciencies and the caloriﬁc values of the fuels. Table 4 gives the life-cycle costs of the cooking fuel systems, excluding the effect of their emissions. Not surprisingly ﬁrewood is the cheapest among the fuels, since they do not undergo any processing before usage. In the urban areas, where it is sold, the cost of ﬁrewood is mainly due to the transportation from the hinterland. The table clearly shows that a shift from ﬁrewood to kerosene (to save the forests, for example) would be the worst option, in terms of cost. For the majority of ﬁrewood users who earn less than US$2 a day, this would not be possible, regardless of its environmental implications. Due to the obvious deleterious effect of using ﬁrewood and charcoal on human health and the environment, government has sought to replace them with LPG. Once again monetary considerations, both on the part of the users and also on the part of government (need for subsidies) have not made this option sustainable. Estimates by the Energy Commission of Ghana also indicate that the demand for LPG, if it were to replace charcoal and ﬁrewood completely, could not be met . 4.2. Results of life-cycle impact assessment analysis The results of the impact assessment for ﬁrewood, kerosene and electricity have been added to those from the earlier study by the authors and summarized in Table 5. In Table 6, the contributions of the various fuels types to a particular impact category, as given by the LCA results of Table 5, are converted into percentages. These results show, ﬁrstly, that electricity, ﬁrewood and biogas are not the leading contributors in any category. Secondly, kerosene and LPG, which are fossil-based fuels, lead in ﬁve out of the seven selected impact categories, while charcoal contributes the most to global warming (GWP) and photochemical ozone creation (POCP). The results of Table 6, while informative, unfortunately, mask the environmental importance of local cooking fuels, especially ﬁrewood, which does not make the highest contribution in any of the categories indicated. Because petroleum fuels are often explored, extracted and transported for use in places far from where they are produced, their effect on the environment is more global in nature. Locally-derived fuels, such as ﬁrewood and charcoal, tend to have a localized environmental impact. The impacts of ﬁrewood and charcoal can be properly appreciated by isolating the cooking stage for consideration. This has been done and presented in Fig. 1; it shows clearly the dominance of ﬁrewood at the cooking stage. Firewood is the highest contributor in almost all the categories under consideration at this stage.
Table 1 Inventory data for cook-stove emissions (kg/MJ fuel). Item
CO2 CO NOx N2O SO2 NMVOC CH4 PM a b
5.20E01 6.00E02 5.19E05 0.00E+00 0.00E+00 2.00E03 2.00E03 1.00E03
1.47E01 2.03E04 9.15E06 0.00E+00 1.02E05 6.10E05 1.02E04 4.82E06
1.20E01 1.00E03 5.74E06 0.00E+00 0.00E+00 1.00E03 1.91E06 0.00E+00
9.59E01 8.00E02 1.04E04 1.00E05 2.10E05 3.00E03 3.04E03 3.00E02
1.40E01 1.23E02 7.17E05 1.00E06 9.30E05 1.43E04 1.34E05 9.00E06
Afrane and Ntiamoah . Jungbluth ; Smith et al. .
ELU  (US$/kg) 0.14 0.42 2.72 48.97 4.18 2.74 3.48 46.03
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Table 2 Costs of cooking appliances (based on a 10-year lifetime). Fuel
Type of cooking appliance
Cost of appliance (US$)
Life time (year)
Replacement cost (US$)
Firewood Charcoal Kerosene LPG
3-stone mud stove Improved stove (1–2) Burner stove (1–2) Burner stove Gas storage vessel (1–2) Burner stove (1–2) Burner stove
0 10.34 20.69 25.00 41.38 34.48 48.28
3 5 3 5 10 5 5
3 times 1 time 1 time 1 time None 1 time 1 time
0 10.34 20.69 25.00 None 34.48 48.28
Table 3 Cost of cooking fuels consumed, 2005. Fuel
Stove efﬁciency (%)
Caloriﬁc value (kW h/kg)
Consumption/HHD (kW h/year)a
Cost of fuel (US¢/kW h)a
Cost of fuel consumption/HHD/year (US $/kW h)
Firewood Charcoal Kerosene LPG Electricity Biogas
14 18 35 45 65 55
3.9 8.5 12.7 13.0 1.0 6.7
7143 5556 2857 2222 1538 –
1.2 1.9 6.6 5.5 7.3 –
85.72 105.56 188.56 122.21 112.27 80.00b
Avg. size of household = 4.3; HHD – Household. a Source . b Estimated.
Table 4 Results of life cycle cost calculations. Item
Analysis period Cost of cooking devices (USD) Replacement cost (USD) Annual fuel cost (USD) Discount rate Residual costs (USD) Life cycle cost (USD)
10 years 10.34 10.34 105.56 10% 0 669.35
10 years 48.28 48.28 80.00 10% 0 588.16
10 years 111.38 25.00 750.98 10% 0 862.36
10 years 0.00 0.00 85.72 10% 0 526.75
10 years 20.69 20.69 188.56 10% 0 1200.08
10 years 34.48 34.48 112.27 10% 0 758.86
Table 5 Characterization results of cooking fuel systems based on the CML 2001 environmental impact assessment method. Impact category
FAETP GWP HTP POCP TETP
3.02E06 1.63E01 1.68E05 3.22E05 3.44E07
1.13E03 1.45E+00 1.64E03 1.19E02 1.29E04
4.95E02 1.20E01 3.71E+01 2.83E04 2.13E+00
1.4861E04 1.0319E+00 2.4902E02 3.2742E03 1.6917E05
3.0071E02 2.2220E01 1.5001E+01 4.7900E04 1.0000E+00
7.1472E04 4.4254E03 2.3298E03 1.8676E06 8.5388E05
Unit kg SO2 kg PO3 4 kg DCB kg CO2 kg DCB kg C2H4 kg DCB
AP = Acidiﬁcation Potential; EP = Eutrophication Potential; FAETP = Freshwater Aquatic Ecotoxicity Potential; GWP = Global Warming Potential; HTP = Human Toxicity Potential; POCP = Photochemical Ozone Creation Potential; TETP = Terrestial Ecotoxicity Potential; DCB = 1,4-dichlorobenzene. a Source .
Table 6 Percentage contributions to overall characterization results. Impact category
AP EP FAETP GWP HTP POCP TETP
17.92 0.00 0.18 34.48 0.05 20.02 0.00
37.86 17.70 36.86 7.42 28.80 2.93 31.92
2.81 0.00 0.88 0.15 0.00 0.01 0.00
4.91 0.00 0.00 5.45 0.00 0.20 0.00
32.19 0.00 1.38 48.50 0.00 72.89 0.00
4.30 82.29 60.69 4.00 71.14 3.96 68.07
5. Discussion A comparison of the impact assessment results shows an advantage in biogas and electricity usage in nearly all the investigated
indicators. It must be noted that electric stoves are reported to emit no pollutants and hence no environmental impacts were attributed to electricity at the cooking stage. The low impact scores for electricity could also be partly due to the non-inclusion of the
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Fig. 1. Relative impact category contributions at the cooking stage of the various fuels.
Table 7 Annual environmental damage cost of cookstove emissions. Fuel
Environmental damage cost (MJ)
Consumption per HHD/year (MJ)
Total damage cost (US$)
Kerosene Firewood LPG Charcoal Biogas Electricity
2.04E02 1.11E00 1.53E02 1.22E01 1.65E02 0.00E00
10285.2 25714.8 7999.2 20001.6 – 5536.8
268.3 36496.9 156.5 3120.3 – 0.0
dam construction stage. The construction of dams for electricity generation in general can interfere extensively with the environment. The amount of building materials used and their sources, also accounts for some environmental impacts. However, these impacts are difﬁcult to quantify decades after the construction of such structures, as is the case in Ghana. A major concern has been the direct impact of cookstove emissions on women and children during cooking . At this stage, the study shows that ﬁrewood emits the most gaseous pollutants followed by charcoal, kerosene, biogas, LPG and electricity in that order. Indeed ﬁrewood emissions lead in all the potentials considered in Fig. 1, except acidiﬁcation. Cooking with ﬁrewood contributes most to human toxicity (about 78%), followed by charcoal (20%). Thus for households where it is used, substituting ﬁrewood with charcoal could improve on their respiratory health situation. While most of the emissions associated with ﬁrewood occurs at the cooking stage, charcoal, emits most pollutants at the production stage. The impact of crude oil extraction and transportation from Nigeria to Ghana contributed signiﬁcantly to LPG and kerosene’s overall higher scores in most of the categories. Taking both health and costs concerns into consideration therefore, an obvious option may be to ﬁrst promote a shift from ﬁrewood to charcoal. Using the caloriﬁc value of these fuels and estimates of total annual energy consumption (Table 3), along with the ELU cost factors given in Table 1, the total environmental damage cost of the fuel consumed by a household in a year can be estimated. These results are summarized in Table 7. The life-cycle costs of the various indigenous fuels are easy to rank, even without the analysis of Table 4. Firewood is virtually free, (at least for rural dwellers) since it costs nothing to collect them from the forest; then comes charcoal, which requires little processing and hence comes in relatively cheaply. Biogas is not yet popular in Ghana, but where they are used, they are normally not for sale. It is the petroleum products, kerosene, LPG, and electricity that have signiﬁcant costs. However their ranking, in terms of cost, depends largely on prevailing government policy; no elaborate calculations
or survey are required. Similar cost ranking can be done for the cookstoves that go with these fuels. The study by Anozie et al.  in Nigeria yielded similar results with ﬁrewood coming out as the least expensive cooking fuel, and LPG the most expensive. The real interest in these fuels, therefore, lies in the determination of their impact on the environment as a result of cooking, and how this could be mitigated. The results of Table 7 are signiﬁcant because they clearly quantify these impacts in terms that are familiar and comprehensible to all. The single-score representation clearly indicates the relative magnitudes of the potential effects of the emissions on the environment and humans. Although cookfuel emissions are difﬁcult to characterize because of their dependence on the fuel type as well as the stove design, the results for work done by Smith et al.  in the Philippines may be used as representative of conditions in developing countries. The relativity of the environmental damage costs between ﬁrewood and charcoal indicated in the table is similar to the relativity of their gravimetric environmental impacts reported by Smith and others [6,7]. Specifically the impact of ﬁrewood is over ten times greater than that of the nearest ‘worse’ fuel, charcoal. These results could help focus the attention of decision-makers. With the rising demand for woodfuels amid dwindling forest reserves, alternative sources of energy for cooking must be developed in order to slow down, and possibly reverse, the rate of deforestation. Solar energy provides an alternative sustainable option, since the country receives a high level of solar radiation (4.5– 6.5 kW h/m2/day . It is estimated that 36% of the woodfuel needs of developing countries could be met by the use of solar stoves . Several initiatives aimed at promoting solar cooking have been carried out in Niger, Mali and Burkina Faso by non-governmental organizations (NGOs). Success has however been limited by cultural barriers, relatively high start-up costs and inadequate post-inception support . Technical improvements in the quality of cookstoves, promoting dedicated energy forest cultivation, processing forest products, promoting the use of biogas are all measures which could help reduce the dependence on woodfuels. Other measures may be economic in nature, such as subsidies and price control. This study has shown clearly that adding some value to the raw forest resources can help reduce their impact on the environment and human health.
6. Conclusion This paper concludes a two-part life-cycle study of the environmental impacts and costs of cooking fuels used in Ghana. Using conventional life-cycle costing methods, cookstoves and their corresponding fuels were ranked as ﬁrewood, biogas, charcoal, electricity, LPG and kerosene. Two approaches were used with the emissions related to the production and use of these fuels: ﬁrst, the standardized ISO LCA method was used to determine the environmental impacts of the cooking devices and their fuels from cradleto-grave; and second, the EPS method, which assigned monetary weights to the emissions, was used for the cooking stage. By using the monetary environmental load units, the impact of the systems involving woodfuels, especially ﬁrewood, is brought forcefully home even to lay decision-makers. While woodfuels can affect the global environment and the health of those who use them for cooking at home, it is the latter effect which is more relevant to developing countries. This is because these countries have little inﬂuence on the global environmental outlook but the human health aspects affect their economies directly in terms of the pressure on their health facilities and reduced national productivity. The work of Boadi and Kuitunen  has demonstrated a positive correlation between the use of woodfuels and respiratory health problems in Ghana, especially among children of low-income families.
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