Environmental Engineering Reference
In-Depth Information
remained about level with 2011, even as the share of modern renewables
increased. This is because the rapid growth in modern renewable energy is
tempered by a slow migration away from traditional biomass and a contin-
ued rise in total global energy demand [80].
It is useful to codify all aspects of sustainability, thus ensuring that all
factors are taken into account for each and every development proposal.
Therefore, with the intention of promoting debate, the following consider-
ations are proposed [67]:
1. Long-term availability of the energy source or fuel
2. Price stability of energy source or fuel
3. Acceptability or otherwise of by-products of the generation process
4. Grid services, particularly controllability of real and reactive power
output
5. Technological stability, likelihood of rapid technical obsolescence
6. Knowledge base of applying the technology
7. Life of the installation—a dam may last more than 100 years, but a
gas turbine probably will not
8. Maintenance requirement of the plant
However, the improved energy performance of cities from these kinds of
initiatives is usually being outweighed by the increases in the use of fossil
fuels by private transports that have occurred in recent years. This is the
case all over the developed world, and particularly in the United States
and Australia, where low-density urban sprawl has made it very difficult
to introduce energy-efficient public transport systems. In cities with low-
density sprawl where most people rely on private cars, it will be particularly
important to introduce new transport propulsion such as fuel cell technol-
ogy to make private transport and public transport less polluting and more
energy efficient [81].
Really significant breakthroughs in urban EE and introduction of sustain-
able energy systems in cities will emerge only as a result of major changes
in national energy policy. We have seen some significant breakthroughs in
some countries, but far more needs to be done to transform our cities from
fossil fuel junkies to sustainable, future-proof systems [81].
Thus, in order to reach a sustainable environment, a combination of poli-
cies and actions is essential (as proposed in Figure 2.3). These policies
include sustainable energy production and renewable energy production
as considerations for city planning regarding EE. When these policies are
combined with trends in users' consumption patterns, a sustainable envi-
ronment can be reached.
It is important to note that the know-how exists to decrease urban energy
use by 50% or more without significantly affecting living standards, while