ABSTRACT
The capitalist economic system is inherently built to pursue endless economic growth. Historically, when global economic growth rates fell below a certain level, the capitalist system tended to suffer from major crises and instabilities. Beyond the twenty-first century, with the depletion of nonrenewable energy resources, eventually both electricity and the liquid fuels have provide entirely from renewable energy resources. Currently, a solar thermal electric power plant typically has a capacity utilization rate of 25 percent. Suppose that, in the future, the solar thermal electricity will serve as the main source of electricity generation. World primary energy consumption is the sum of oil consumption, natural gas consumption, coal consumption, nuclear energy consumption, and the consumption of renewable energies. The renewable energies include renewable electricity and biofuels. Nuclear and renewable electricity is measured by electrical energy content. Energy efficiency is the ratio of economic output over energy consumption. The inverse of energy efficiency is known as the 'energy intensity'.
