6.5 Changing patterns of energy use
Before considering the feasibility, and the plausibility, of radical changes in patterns of energy production and consumption, of the kind that will be needed during the first half of the twenty-first century if we are to progress towards sustainability, it is useful to recall the profound changes that have already occurred in our energy systems during the latter half of the twentieth century.
In Britain just after World War II most homes and other buildings were heated by coal. Most electricity generation was coal-fired, and most rail transport was propelled by coal-burning steam engines. Coal combustion caused major pollution problems, including the notorious London 'smogs' which in most winters caused the premature deaths of hundreds (and occasionally thousands) of people until the introduction of the Clean Air Act in 1956.
Coal miners perished in their dozens, and sometimes hundreds, in mining accidents every year, and many others died slowly of lung diseases caused by inhaling coal dust. Open coal fires in most houses were so inefficient that, despite consuming large quantities of energy, they only heated a few rooms effectively whilst the rest remained cold.
Motor cars were still owned only by a minority and air travel was confined to a small elite. Most people travelled by bus, train, cycle or on foot. Journeys were relatively few, compared with today, and usually over quite short distances.
Since the late 1940s, the UK's energy systems have been transformed. Natural gas, which burns much more cleanly and efficiently, was introduced very rapidly to British homes and buildings from the 1970s, after its discovery beneath the North Sea, and has now replaced coal as the main heating fuel for buildings. Most homes now have gas-fired central heating systems which ensure that the whole house is maintained at a comfortable temperature.
Coal is still used for electricity generation, but flue gas desulphurisation and electrostatic precipitators now greatly reduce emissions of sulphur dioxide and particulates. In new power stations, coal is increasingly being replaced by gas, which can be burned very cleanly and efficiently using combined cycle gas turbines. Nuclear power, since its modest beginnings at Calder Hall in 1956, now contributes around one-quarter of UK electricity.
Cars are now owned by the majority, air travel overseas has become a mass market, railways are powered mainly by electricity, and travel overall, measured in passenger-kilometres, has tripled since the 1950s (Figure 51). Britain is currently a net exporter of oil, thanks to its large North Sea reserves, whereas before the 1970s all our oil was imported.
The dramatic changes that have occurred in Britain's energy systems during the past 50 years have, broadly, been paralleled in most 'developed' countries over the same period.
Given the scale and profundity of the changes over the past half-century, it does not seem unrealistic to suggest that equally profound changes could well occur over the next 50 to 100 years, as we attempt to improve the sustainability of our energy systems, nationally and globally.