1.2 World Energy Demand
The use of fossil fuels increased rapidly during the twentieth century and continues to grow: it has quadrupled since the 1970s. The global population consumes petroleum products at a rate 100,000 times greater than the rate that they are formed [1, 2]. China is currently the third largest consumer of oil in the world. However, if a Chinese citizen consumed oil at the same rate as an American citizen, China alone would need 90 million barrels of oil per day to sustain its needs [1, 2]. According to the Energy Information Administration, the typical amount of oil produced in one day by the whole world is only 80 million barrels. Obviously there is something wrong with this equation!
Figure 1-3 shows the current and projected energy consumption from 1980–2030 . International energy consumption is estimated to increase by just 2% per year from 2003 to 2030. It doesn’t sound like much, but that means total worldwide energy use would grow from 421 quadrillion British thermal units (BTU) in 2003 to 563 quadrillion BTU in 2015 and 722 quadrillion BTU in 2030 .
The British thermal unit (BTU)
A unit of energy used in power, steam generation and heating and air conditioning industries. The BTU has largely been replaced by the SI unit of energy, the joule (J), although it is still used in countries such as the United Kingdom, New Zealand, Canada and the United States.
World energy demand by region is shown in Figure 1-4. As you can see, China and India have energy demands that are growing at a much faster rate than the rest of the world. They’re only two countries, but together they make up more than 36% of the world’s population, so it’s likely that their energy demands will continue to grow for a long time.
In every country, there are groups that support fossil-fuel taxes in order to reduce the consumption of fossil fuels. There are also groups that are advocates of alternative energy technologies. Many experts are encouraging the reduction of fossil fuel use for industrialized countries, and are promoting the building of their infrastructure to adopt sustainable, renewable sources of power.
Approximately 43% of the global population use oil as their primary means of obtaining energy. Natural gas follows with 15%, waste and combustible renewables account for 13%, coal has 8%, and alternative sources of energy (including geothermal, hydro and solar) the remaining 3% as illustrated in Figure 1-5 [1, 2].
During the 18th and 19th century, coal was the primary fuel used during the Industrial Revolution. After automobiles and household electricity became popular, oil became the primary fuel of the 20th century. However, during the last few years, coal has become the fastest growing fossil fuel due to the increased consumption of fossil fuels in China. If we’re going to have enough energy for the 22nd century, we need to find renewable sources of energy here in the 21st. Although the renewable forms of energy currently have a small percentage of the total energy consumption, they have the highest average annual growth rate (AAGR) compared with all other energy forms as shown in Figure 1-6.
Average annual growth rate (% AAGR)
The average increase in growth over the period of one year. It is calculated by taking the arithmetic mean of the growth rate per year. For example, if the energy demand for a region is predicted to be 10% one year, and 20% the next, the AAGR for the two year period would be 15%.