282 Energy andtransport for thefuture
7.56420
0 200 400
Electricity savings (TWh year−^1 )Cost of conserved electricity (US cents per kWh)
600 8001234 5 6789 101112Figure 11.8Cost of various options (at 1989 prices) for saving electricity in
buildings. If the cost of conservation is less than the cost of the electricity saved
over the lifetime of the application, a net saving results. The various options are:
(1) use of white surfaces to reduce the need for air conditioning; (2) residential
lighting; (3) residential water heating; (4) commercial water heating; (5)
commercial lighting; (6) commercial cooking; (7) commercial cooling; (8)
commercial refrigeration; (9) residential appliances; (10) residential space
heating; (11) commercial and industrial space heating; (12) commercial
ventilation. The shaded areas are all below 7.5 cents per kWh (the all-sector
average electricity price) and 3.5 cents per kWh (typical operating cost of US
electricity generation). The total savings in the figure add up to about forty-five
per cent of the electricity use.more acceptable and user-friendly than those that have been designed in
more traditional ways.^15 Some recent examples demonstrate the possi-
bility of more radical building designs that aim at Zero Emission (fossil-
fuel) Developments (ZED). The box illustrates a recent development in
the UK along these lines.
Recentstudies^17 suggest that withaggressive implementation of
energy-efficient policies and measures, carbon dioxide emissions from
buildings in both developed and developing countries could be reduced
by about twenty-five per cent in 2010 and about fifty per cent in 2050. If
however growth in energy demand in the buildings sector continues to
increase at the current rate, these savings in emissions due to increased ef-
ficiency will mostly go to compensate for the growth in demand. Further
increases in efficiency, however, could be achieved by new technolo-
gies that are in prospect such as the use of LEDs for lighting (see box
above on appliances). What is clearly necessary also is a switch to non-
fossil-fuel energy sources to which we shall be turning in later sections.