Environmental Engineering Reference
In-Depth Information
tion do not work effi ciently. More than 60% of the primary energy used in these
facilities is lost as power plant waste heat (Figure 3.2). If the electricity used to boil
a litre of water comes from a coal-fi red power plant, it is releasing 156 g of carbon
dioxide. In contrast, burning natural gas on a gas stove releases about 56 g of carbon
dioxide. However, the losses that occur when gas is transported from the place of
extraction to the end consumer are also a problem. Natural gas essentially consists
of methane, which is considerably more damaging to the environment than carbon
dioxide. Therefore, even the loss of a few grams can be harmful. If transport losses
are at the rate of about 10%, a gas stove is still causing a lower rate of greenhouse
gas emissions than an electric stove using coal-generated electricity. However, the
pipelines in the areas where natural gas is exploited are sometimes in very poor
condition. The use of natural gas from these sources can completely cancel out the
advantages of gas stoves.
Figure 3.2
Energy and environmental effects from boiling water using an electric versus
gas stove.
A gas stove should normally be a better alternative than an electric one - as long
as the energy used is not supplied by fossil power plants. 'Green' electricity sup-
pliers offer carbon-free electricity from renewable energy plants. Using this kind of
electricity may make an electric stove more environmently friendly than a gas stove.
In Norway all electricity is supplied by renewable energy plants. In this case, electric
stoves are generally preferred. Finally, the use of an electric kettle to boil water is
