Economic growth is distinguished from commercial growth and is defined in this article as the growth of the value a society puts in monetary terms on all commercial and non-commercial goods and values it possesses during a certain period. A computable general equilibrium model is used to show the impact of changes in the endowments, preferences and production possibilities on economic income, which in the model comprises all wealth. Besides land with its natural resources and labor, energy is the key endowment to drive an economy, The model leads in an intuitive way to the following conclusions: (1) Societies should start to use appropriate indicators for true economic growth, rather than just for commercial growth as measured by gross national product. (2) All types of economic growth are limited, no matter if based on endowment growth, production efficiency growth, or changes in preferences, (3) Economic growth should be oriented more towards increasing production efficiency and less towards using more natural resources, (4) Human population growth puts at risk the possibilities for average economic growth per person. (5) We should get better prepared to use solar energy in the future. (6) Besides economic growth, there exists pure utility growth, which is not measurable in monetary terms; it includes much of scientific progress in the long run and is of great importance even though it cannot be included in an indicator of economic growth.