Environmental and Social Aspects of Domestic Bathing - Ethical Engineering for International Development and Environmental Sustainability - page 203

source energy consumption as opposed to site energy consumption that refers to fi nal
consumption'. The energy data are presented in EJ per annum (EJ = exa-Joule = 10 18 J).
On p 1397 of the same paper, Fig. 11 shows the estimates of annual global primary
energy to have risen from about 220 EJ in 1970 to about 400 EJ in 2000, having risen
fairly steadily by 2.0% per annum. The projections to 2030 of two of the SRES sce-
narios, A1 (a 'baseline' scenario) and B2 (a 'mitigation' scenario), are shown.
According to projection A1, the global primary energy will rise linearly from the
2000 value to 900 EJ per annum in 2030, that is, with an increase of 2.7% pa, and
according to projection B2, the global primary energy will rise approximately lin-
early to 650 EJ per annum in 2030, that is, with an average increase of 1.6% pa.

Testing the Projections How have these projections fared in the light of knowl-
edge of subsequent years? Global energy use for 2005 is reported on p 110 of
Johansson et al. ( 2012 ). The corresponding fi gure (primary energy) is 496 EJ. This
is slightly larger than the interpolated value, 483 EJ, of the worse scenario (A1). The
less bad scenario (B2) was far from the mark, predicting only 442 EJ.

Average Global Energy Use per Person EJ per annum is hardly a unit of power
congenial to all engineers, and the fi gures are more intuitive if expressed in GW
(gigawatts), as in Table 7.1 , since the electrical power output of a large power sta-
tion is typically of this order. One EJ per annum is equal to a continuous power
output, 32 GW.

'Population is forecast to grow by 34% in the A1 scenario and 37% in B2 sce-
nario, lower than the 65% growth experienced during the past 30 years' (de la Rue
du Can and Price 2008 , pp 1395-1396). Using the fi gure of 6.1 billion for the global
population in 2000 (United Nations Department of Economic and Social Affairs,
Population Division 2004 , p 4), we fi nd the results in Table 7.1 .
Following this summary of the global energy situation, aimed at reinforcing the
proposition that profound change, for good or ill, is inevitable, I turn to the bathing-
related aspects of energy.

Energy Use in the Water Sector In their Abstract, Rothausen and Conway ( 2011 )
state 'Energy use in the water sector is growing, yet its importance is under- recognized,
and gaps remain in our knowledge'. On p 1 of the online PDF document, they say
'Water and energy are inextricably linked within what is often referred to as the
water-energy nexus'. And on p 2 of the same document, 'in the UK the water indus-
try uses around 3% of total national electricity consumption. Its energy use has

Table 7.1 Global energy use and population

Global primary
energy use (GW)

Population
(billions)

Average continuous power
per person (kW per person) Year

1970 7,000 3.7 1.9

2000 13,000 6.1 2.1

2030 (scenario A1) 29,000 8.2 3.5

2030 (scenario B2) 21,000 8.4 2.5