Background to Sustainable Cities - Theme Cities: Solutions for Urban Problems - page 188

Table 5﻽3 (contin ued)

Source Specific problems to be overcome

Solar a) Photo-voltaic (PV) panels. Can be applied at individual house, community

level, or in large industrial scale with fields of panels on large sites. Cur-
rent panels are only 15 % efficient in capturing potential sunlight energy of
1,366 W/m 2 , but research has now developed second generation panels which
achieve 25 % efficiency, with greater prospects for the future.
b) Solar Thermal Power plants. Focuses sunlight from 'fields' of mirrors that
track sunlight either upon a tower or pipe that heats up water or oil to power
a turbine. High start-up costs. Still expensive, but new technologies promise
cost reductions. Both these approaches need sunny areas or south exposures,
otherwise generation is less efficient. But large scale batteries to store energy
generated in daylight are not yet available, so part of the utility of this source
is lost.

Batteries Electric batteries are viable for cars but have limited capacity and range

(approximately 150 km) and continued higher relative costs. Few plug-in
renewal outlets exist in cities, although some countries are rapidly adding
them. Recent technological progress is reducing battery size and increasing
energy generation. The problem of range is being reduced with the grow-
ing use of hybrid cars, and the prospect of easier night-time recharging of
batteries.

dies for vehicle gas. The IEA ( 2013 ) estimated that these fossil fuel subsidies have
grown substantially in recent years and reached $ 544 billion a year in 2012, over
five times the subsidies to renewables at $ 101 billion, although the later need to
double to $ 220 billion if the New Policy Scenario in Table 5.1 is to be achieved.
In addition, lobbyists for the fossil fuel industries spend large amounts in advertis-
ing, persuading politicians to maintain these subsidies and often finance negative
opinions about renewal sources and sponsor climate change deniers. Moreover, the
externalised costs of fossil fuel use—whether problems from global warming or the
pollution effect on human health—are rarely considered in the cost comparisons
between fossil and renewable energy sources (IEA 2012 ). The case of the large
numbers of premature deaths due to the free coal policy in north China has already
been described. A report on the effects of coal mining in Kentucky is also salutary. It
showed an increase in mountaintop mining which involves stripping off the tops of
mountains to get at the coal beneath, then dumping the fill into the valleys (Palmer
et al 2010 ). Apart from the loss of forest and biodiversity that this development
creates, the water that emerges from the buried streams is full of toxic materials,
leading to the poisoning of fish and humans. In addition, the extra dust in the air has
been shown to increase rates of lung cancer and other related respiratory diseases.
Clearly the damage to ecosystems, threats to human health and the lack of effective
mitigation require new approaches to mining regulation.
Even in cities the externalities associated with vehicle use are obvious but vary
with the density and sprawl of settlements. In a study of large American cities Glae-
ser and Kahn ( 2010 ) calculated that the cost of greenhouse emissions varied from
$ 1150 per household in San Diego to $ 2015 in Memphis, and suggested that land
use regulations should take into account these externalized costs, since the price of