2.5.1. Estimation of the carbon dioxide (CO2) emission reduction
Estimate of the carbon dioxide (CO2) reduction is calculated using the AMS-II G methodology [50]. Emission reduction from the use of efficient cooking stoves will be calculated as a product of the amount of woody biomass saved, i.e. fuel consumption, the fraction that is considered non-renewable biomass (fNRB), the emission factor for fossil fuel and the net calorific value (NCV) of biomass [30].
\({\text{E}\text{R}}_{\text{y},} ={\text{B}}_{\text{y},}\times {\text{f}}_{\text{N}\text{R}\text{B},\text{y} }\times {NCV}_{Biomass}\times \text{E}\text{F}\dots \dots \dots \dots \dots \dots \dots \dots \dots \dots \dots \dots \dots\) 1
Where:
$${\text{E}\text{R}}_{\text{y}}=\text{E}\text{m}\text{i}\text{s}\text{s}\text{i}\text{o}\text{n} \text{r}\text{e}\text{d}\text{u}\text{c}\text{t}\text{i}\text{o}\text{n} \text{d}\text{u}\text{r}\text{i}\text{n}\text{g} \text{y}\text{e}\text{a}\text{r} \text{y} \text{i}\text{n} \text{t}\text{C}\text{O}2\text{e}$$
$${\text{B}}_{\text{y},}=\text{Q}\text{u}\text{a}\text{n}\text{t}\text{i}\text{t}\text{y} \text{o}\text{f} \text{f}\text{u}\text{e}\text{l}\text{w}\text{o}\text{o}\text{d} \text{s}\text{a}\text{v}\text{e}\text{d} \left(\text{s}\text{u}\text{b}\text{s}\text{t}\text{i}\text{t}\text{u}\text{t}\text{e} \text{o}\text{r} \text{d}\text{i}\text{s}\text{p}\text{l}\text{a}\text{y}\text{e}\text{d}\right) \text{i}\text{n} \text{t}\text{o}\text{n}\text{e}$$
\({\text{f}}_{\text{N}\text{R}\text{B},\text{y} }=\) Fraction of non-renewable woody biomass saved by the project activity in year y (UNFCCC, [50] default value for Ethiopia is 88%)
\({\text{N}\text{C}\text{V}}_{\text{B}\text{i}\text{o}\text{m}\text{a}\text{s}\text{s}}=\) Net calorific value of the non-renewable woody biomass that is substituted (IPCC Change default for wood fuel is 0.015 TJ/ton or 15 MJ/kg)
\(\text{E}\text{F}=\) default emission factor (per unit of energy) which is 81.6 tCO2/TJ or 112 g CO2/MJ
\({\text{B}}_{\text{y}}={\text{B}}_{\text{o}\text{l}\text{d}, \text{c}\text{o}\text{o}\text{k}\text{i}\text{n}\text{g} \text{s}\text{t}\text{o}\text{v}\text{e}}\times (1-\frac{{\text{ƞ}}_{\text{o}\text{l}\text{d}}}{{\text{ƞ}}_{\text{n}\text{e}\text{w} \text{I}\text{C}\text{S}}})\) ---------------------------------------------------------2
Where,
$${\text{ƞ}}_{\text{n}\text{e}\text{w} \text{I}\text{C}\text{S}}=\text{t}\text{h}\text{e} \text{e}\text{f}\text{f}\text{i}\text{c}\text{i}\text{e}\text{n}\text{c}\text{y} \text{o}\text{f} \text{I}\text{C}\text{S} \text{i}\text{n} \text{t}\text{h}\text{e} \text{s}\text{t}\text{u}\text{d}\text{y}$$
\({\text{ƞ}}_{\text{o}\text{l}\text{d}}=\) 10% [The default value of 10% will be applied as the systems to be replaced are three stone fires
\({\text{B}}_{\text{o}\text{l}\text{d} , \text{c}\text{o}\text{o}\text{k}\text{i}\text{n}\text{g} \text{s}\text{t}\text{o}\text{v}\text{e}}={\text{B}}_{\text{y},\text{d}\text{e}\text{i}\text{v}\text{c}\text{e} }\times {\text{L}}_{\text{y}}\) --------------------------------------------------------------3
Where,
\({\text{L}}_{\text{y}}=\) The default net to gross adjustment factor of 0.95 was applied to account for leakages
\({\text{B}}_{\text{y},\text{d}\text{e}\text{i}\text{v}\text{c}\text{e} }=\) Average annual consumption of woody biomass per appliance in tones per year
\({\text{B}}_{\text{y},\text{d}\text{e}\text{v}\text{i}\text{c}\text{e}}={\text{B}}_{\text{o}\text{l}\text{d}, \text{c}\text{a}\text{p}\text{t}\text{i}\text{o}\text{n}}\times {\text{N}}_{\text{r}\text{e}\text{s}\text{d}\text{e}\text{n}\text{t} \text{h}\text{o}\text{u}\text{s}\text{e}\text{h}\text{o}\text{l}\text{d}}\times {\text{F}\text{W}}_{\text{p}\text{r}\text{o}\text{p}\text{o}\text{r}\text{t}\text{i}\text{o}\text{n}}\) -----------------------------------4
Where,
\({\text{F}\text{W}}_{\text{p}\text{r}\text{o}\text{p}\text{o}\text{r}\text{t}\text{i}\text{o}\text{n}}=\text{P}\text{r}\text{o}\text{p}\text{o}\text{r}\text{t}\text{i}\text{o}\text{n} \text{o}\text{f} \text{H}\text{H} \text{f}\text{u}\text{e}\text{l} \text{w}\text{o}\text{o}\text{d} \text{c}\text{o}\text{n}\text{s}\text{u}\text{m}\text{e}\text{d} \text{b}\text{y} \text{c}\text{o}\text{o}\text{k}\text{i}\text{n}\text{g} \text{s}\text{t}\text{o}\text{v}\text{e}\) . Use 41.50% for cooking application
\({\text{B}}_{\text{o}\text{l}\text{d}, \text{c}\text{a}\text{p}\text{t}\text{i}\text{o}\text{n}}=\) Average baseline fuel wood consumption in tones per capita per year
\({\text{B}}_{\text{o}\text{l}\text{d}, \text{c}\text{a}\text{p}\text{i}\text{o}\text{n}}=\frac{{\text{H}\text{C}}_{\text{f}\text{u}\text{e}\text{l} \text{w}\text{o}\text{o}\text{d},\text{u}\text{s}\text{a}\text{g}\text{e},\text{y}}}{{\text{H}\text{C}}_{\text{p}\text{o}\text{p}\text{u}\text{l}\text{a}\text{t}\text{i}\text{o}\text{n} ,\text{y}}}\) -----------------------------------------------------------------5
Where, \({\text{H}\text{C}}_{\text{f}\text{u}\text{e}\text{l} \text{w}\text{o}\text{o}\text{d},\text{u}\text{s}\text{a}\text{g}\text{e},\text{y}}=\text{58,134,125}\text{t}/\text{y}\text{e}\text{a}\text{r}\)
$${\text{H}\text{C}}_{\text{p}\text{o}\text{p}\text{u}\text{l}\text{a}\text{t}\text{i}\text{o}\text{n},\text{y}}=\text{84,320,987}(\text{E}\text{t}\text{h}\text{i}\text{o}\text{p}\text{i}\text{a} \text{C}\text{S}\text{A}, 2012)$$
$${\text{B}}_{\text{o}\text{l}\text{d}, \text{c}\text{a}\text{p}\text{i}\text{o}\text{n}}=0.689\text{t}/\text{y}\text{e}\text{a}\text{r} \text{f}\text{o}\text{r} \text{f}\text{u}\text{e}\text{l} \text{w}\text{o}\text{o}\text{d}$$
\({\text{H}\text{C}}_{\text{f}\text{u}\text{e}\text{l} \text{w}\text{o}\text{o}\text{d},\text{u}\text{s}\text{a}\text{g}\text{e},\text{y}}=\text{f}\text{u}\text{e}\text{l} \text{w}\text{o}\text{o}\text{d} \text{c}\text{o}\text{n}\text{s}\text{u}\text{m}\text{t}\text{i}\text{o}\text{n} \text{i}\text{n}\text{c}\text{u}\text{b}\text{i}\text{c} \text{m}\text{e}\text{t}\text{e}\text{r} \times \text{w}\text{o}\text{o}\text{d} \text{d}\text{e}\text{n}\text{s}\text{i}\text{t}\text{y}\) ------------6
\(\text{f}\text{u}\text{e}\text{l}\text{w}\text{o}\text{o}\text{d} \text{c}\text{o}\text{n}\text{s}\text{u}\text{m}\text{p}\text{t}\text{i}\text{o}\text{n} \text{i}\text{n} \text{c}\text{u}\text{b}\text{i}\text{c} \text{m}\text{e}\text{t}\text{e}\text{r} =\text{80,185,000}{\text{m}}^{3}\) [51]
$$\text{w}\text{o}\text{o}\text{d} \text{d}\text{e}\text{n}\text{s}\text{i}\text{t}\text{y}=\frac{0.727\text{t}}{{\text{m}}^{3}} \left(\text{F}\text{A}\text{O},2004\right)$$