Introduction and context: global biomass resources - Biomass as Energy Source: Resources, Systems and Applications - page 24

We also can make another calculation to estimate the bioenergy potential in the US.
From World Bank indicators (World Bank, 2011) we see that the average cereal yield is 7.2
tonnes/ha in the US. The agricultural area is 58,001,425 ha, giving 4.4 × 10 8 tonne/year, or with
5.4MWh/tonne = 2270TWh/y additional as cereals. This is 14% of the total agricultural land,
411,200,000 ha. If we assume the same amount of straw is produced, that is 2270TWh/y, we get
4540TWh/y from cereals including straw, and if we get the same amount of production on the
rest of the land with energy crops, it would be 4540/0.14 = 32,430TWh/y.
The most widely grown crop in the US is Corn with 332 million tonnes per year. From these
130 million tonnes or 40% is used for production of ethanol fuel. The reason for this is that the
US government wanted to decrease the political risks with oil import and thus stimulated ethanol
production by paying a guaranteed price per liter ethanol. There is no request on how the ethanol
is produced, and thus oil and coal is often used to produce and distil the ethanol, giving poor ratio
between the heating values of ethanol produced in relation to fossil fuels used for the production.
This is the major reason for claims that ethanol is bad for the environment heard especially in
European mass media.
The forestland area is 304,022,000 ha. If we assume an average of 3 tonne/ha/per y or
16MWh/ha, we should produce some 4900TWh/y from this as well. A total production then
would be approximately 37,350TWh/y in the US. In Zalesny et al . (2009), the growth rate of
different clones of hybrid poplar was evaluated. The average of 10 clones at 10 sites was approx-
imately 11 tonne DS/ha/per y. If we assume 30% of the US forestland area is planted with this it
would mean 304,022,000 ha × 0.3 × 5.4MWh/tonne × 11 tonne/ha/y = 5420TWh/y and a total

of 5420 8850TWh/y.

If we compare this to the total use of energy in the US, this is 4160TWh/y electricity and
2,172,107 ktonne of oil equivalents/y or with 10MWh/tonne o.e. 21,720TWh/y totally (from
which fossil fuels 84% today). These figures show that the available biomass resources should
be enough to cover all energy needs if used efficiently. US government has stated that by 2030
bio-fuel will have replaced 30% of fossil fuels.
The conditions in Canada are even better than in the US, while Mexico has more limitations
for biomass production due to drier climate.

+ 4900 × 0.7 =

1.5.5 Brazil
Brazil is generally a very “green” country with a lot of forests and farmland areas. Since the
1980s Brazil has been a leading country with respect to produce bio-ethanol for vehicles. First,
there were many cars running on ethanol during the 1980s. Then oil became more favorable due
to new political decisions. Since the beginning of the new millennium, ethanol has taken back its
position and now Brazil is the major producer of ethanol globally.
There have been a lot of discussions about environmental issues around the ethanol production
in among others Brazil. It has been claimed that rain forests have been cut down to plant sugar
cane, where the sugar is fermented to ethanol, and the bagasse use for the distillation of the
ethanol. In reality, this is not correct generally, as sugar cane normally is grown at land areas with
a different climate, further to the south of the Amazonas. Instead soya beans are planted where
rain forest are cut down. The soya beans powder then is exported to a large extent to western
animal farms for production of the meat we eat.
According to Brito Cruz (2008), 15% of all energy used in Brazil is from sugar cane.1988, 50%
of vehicle fuels was ethanol. 2004 it was 30%. Sugar cane gives 6m 3 /ha. The total arable land
in Brazil was 354.8 million ha (year 2007). From this, 76.7 million ha were used for crops, 20.6
for soybean, 14.0 for corn, 7.8 for sugar cane, from which 3.4 million ha were used for ethanol
production. This corresponds to 1%of the arable land area, but replaces 30%of the fossil fuel used
for vehicles. 172.3 million ha are pastures and thus we have 105.8 million ha left for e.g. additional
ethanol production. If we triple the production 11.3 million ha would be needed, or 7.9 million
aside of what is already utilized. This would mean 7.5% of the available arable land not used