Environmental Engineering Reference
In-Depth Information
•
By reducing demand on gas and electricity distribution networks, energy effi ciency will
improve the security and resilience of these networks and reduce dependence on imported
fuels.
•
By reducing energy bills, energy effi ciency will help businesses to be more productive and
competitive.
•
Improving the energy standards of homes has an important role in reducing spending on
fuel by those in fuel poverty.
Increasing energy end use effi ciency is unattractive for energy companies driven by com-
mercial imperatives to increase sales and profi ts. It thus falls to governments to implement
policies that change these drivers. Regulations can be put in place for example that require
utilities to encourage customers to use electricity effi ciently. A more revolutionary approach
envisages the utility being transformed into a supplier of energy services, owning appliances
in people's homes and thus being motivated to maximize the effi ciency of these appliances.
Whatever approach is fi nally adopted, the importance of reducing energy consumption should
be the cornerstone of any CO
2
mitigation programme.
1.2.6 The Electricity Sector
Figure 1.7 shows the percentage of fuels used in the generation of electricity. Fossil fuels
account for 64% of the fuels used in this sector with coal being the dominant source at
approximately 40% and contributing nearly three quarters of CO
2
emissions. At present, large
hydropower plants account for the major part of the renewables sector. Under half of the
electricity produced is used in buildings, about a third in industry, under one-tenth in energy
production (e.g. refi neries) and less than one-tenth in transmission and distribution.
The world annual generation of electricity is in the region of 18 000 TW h representing an
average rate of consumption of around 2000 GW. This electrical energy is generated in a very
large collection of power stations driven mostly by fossil fuels. The electricity sector is the
fastest growing source of emissions and estimated to increase fourfold between now and
2050. According to Stern this sector would need to be at least 60% decarbonized by 2050
1
1. Oil 10%
2
5
2. Nuclear 16%
3. Gas 15%
4. Hydro 19%
5. Coal 39%
3
4
Figure 1.7
Contributions in the generation of electricity. (Data from Boyle, G.,
Renewable Energy
,
Oxford University Press, 2004)
