Energy from My Backyard - The Renaissance of Renewable Energy - page 227

7 Energy from My Backyard
7.1 The Insatiable Demand for Energy
Around the turn of the nineteenth century, the human population of this planet topped
one billion for the first time. A century later, it had increased by roughly 600,000 people.
Two centuries later (in October 2011), it already reached 7 billion. Clearly, something
extraordinary has happened in the last hundred years. Despite two world wars and numerous
smaller conflicts that cumulatively claimed 231 million lives during the twentieth century
(Leitenberg 2006 ), population has grown exponentially. So too has human demand for
the finite resources of the global ecosystem. In the last forty years, world population has
doubled, the global economy has grown fifteen times, the number of cars sixteen times, and
fertilizer use sixfold. This has resulted in shrinking forests and more land for food, 1 vast
mines defacing landscapes, and vastly increased water consumption (Biello 2011b ) .
Primary energy production provides a useful indicator of the impact of human population
growth and economic development on the Earth's resources. Energy production increased
more than tenfold during the last century, and since the first oil crisis in 1973 it has doubled
from 255 to more than 530 exajoules per year (IEA 2012a ) . Global electricity generation
currently stands at roughly 190 exajoules per year (38 per cent of primary production). Most
of this energy (62 per cent) is lost in conversion as heat.
Coal is the dominant primary source for power production, accounting for 40 per cent of
all electricity generated. Oil is of minor importance for electricity generation (6 per cent) but
dominatesthetransportsector.Aconsiderable amountofoilisalsousedtoproduceproducts
such as plastics, lubricants, chemicals, and fertilizers. Natural gas, currently at 21 per cent,
is rapidly increasing its share in power production and is likely to overtake coal in the next
decade. Renewables also play a significant role (19 per cent), the most important by far
being hydroelectricity (16 per cent). Despite its abiding unpopularity, nuclear power retains
an important share (13 per cent) of the global power mix. 'New renewables', although
rapidly expanding, still account for only 3 per cent of global electricity generation.
The most energy-hungry sector of human activity is industry, which consumes 105
exajoules per year, though transport (93 EJ per year) and domestic consumption (85 EJ per
year) are not far behind. Someone living in a highly developed country may be surprised to
read that the largest domestic energy sources are biomass and (mostly agricultural) waste,