Environmental Engineering Reference
In-Depth Information
Extending the
electrons
New things in electricity
Electricity is not a fuel or a primary energy source (except in the
uncontrollable form of lightning, that is). But its role in the energy
infrastructure is crucial, as it is the most convenient means of trans-
mitting energy.
The basics
Primary fuels (oil, gas, coal, nuclear and wood, for example) can heat
up water, turning it into steam, which can then rotate the blades of a
turbine, which in turn can spin a generator. In that generator the relative
rotary motion of magnets and windings of wire (usually made of copper)
produce electricity. This electricity can then be used to power motorized
appliances simply by reversing the process - turning electricity back into
mechanical energy. In the case of solar photovoltaics, sunlight is con-
verted directly into electricity.
A constant theme in energy history has been the steady advance of
electricity into new uses. In the nineteenth century, electricity began to
displace gas and candles in lighting, and created entirely new communica-
tions services with the invention of the electric telegraph and telephone.
In the twentieth century, it has replaced human muscle power in wash-
ing clothes and dishes, and provided new services in refrigerating food.
And in the twenty-first century, it is powering electronic devices such as
computers, which hold open the possibility of rationalizing supply and
demand better than ever via smart grids.
