Organización Latinoamericana de Energía
Latin American Energy Organization
Organização Latino-Americana de Energia
Organisation Latino-américaine D’Energie
Theoretical Fundamentals
Estimation of Wood consumption in the residential sector
It is possible to calculate it using a general equation as below:
(Population) X (% Wood consuming population) X (% population that use wood as U)
X (Specific consumption per person per meal) X (number of meals prepared per day
accordingly to U)
U= Single, primary or secondary fuel.
Single fuel means that firewood is the only fuel used, while primary and
secondary fuel mean respectively that firewood is consumed as the main
fuel with a complementary (e.g. charcoal, or LPG) or is the complementary
fuel of a primary one.
Wood consumption can be estimated starting from the demographic
characteristics of a country.
An important factor is the percentage of people and households that
consume Wood. This information can be collected in the population and
households surveys with values as shown in Table 6.
Another important factor is the specific consumption of Wood per person
or per person per meal. This specific consumption is normally known
through surveys and it tends to vary over time with the average household
size. Indeed, the specific consumption per person decreases if more
persons are living in the same household.
It is fundamental to understand how the distribution of the population
fluctuates accordingly to the number of persons per households.
In the spreadsheet, table 1 illustrates the population distribution
accordingly to the household sizes. In column A there is the number of
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Tel.(593 2) 2598-122 / 2598-280 / 2597-995 / 2599-489 Fax: 2531-691 Casilla:17 -11-6413CCNU
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Organización Latinoamericana de Energía
Latin American Energy Organization
Organização Latino-Americana de Energia
Organisation Latino-américaine D’Energie
persons per household, in column B the distribution of urban population,
in column C the one of the rural population and in the column D the
distribution of the total population. These data could be issued from the
population and household survey for one year; however, they could be
also calculated using the Poisson distribution whose equation is shown
below:
e x x x
y
x!
y is the fraction of the population living in households of dimension equal
to x, x is the average size of the households. It is possible to use the
Poisson distribution for different values of x.
Table 2 contains the Wood specific consumptions per person per meal in
kg, depending on the fact that the firewood is used as single, primary or
secondary fuel.
These specific consumptions are obtained through surveys and
measurements of wood consumption in households of different sizes.
These specific consumptions can be represented by means of the
following equation:
ce( s)  Ae Bs
In the equation above A and B are parameters of regression and s is the
size of the household. The values shown for A and B in Table 5 are typical
values that could be used when results from surveys are not available.
Table 7 shows the number of meals prepared per day for different
firewood utilisation (i.e. single, primary or secondary fuel).
The data of all these tables allow applying the first equation and obtaining
the results in Table 3.
Dir. Av Mariscal Antonio José de Sucre N 58-63 y Fernández Salvador Edif. OLADE - Sector San Carlos.
Tel.(593 2) 2598-122 / 2598-280 / 2597-995 / 2599-489 Fax: 2531-691 Casilla:17 -11-6413CCNU
Quito - Ecuador