The fast-growing worldwide demand for energy, due to population growth and increasing standard of living, is in contrast with the limited fossil energy resources, with the political problems of nuclear fission energy, with the demand to reduce CO2 production for climate control (Kyoto protocol), and with the slow advances of renewable energy sources. It will be shown how crystal growth technology (including epitaxy technology) can contribute to reduce the energy problem. CGT is the rate-determining factor for progress in energy-saving electrical technologies with high-temperature/high-power electrical technology and illumination from GaN-based devices as examples. Progress in CGT is also essential for the development of renewable energy sources like economic high-efficiency solar cells and in future laser-fusion energy where large laser and nonlinear-optic crystals of high radiation hardness are required. Education of CGT engineers and scientific development of CGT, using normally one optimum technology for industrial fabrication of specific crystals and one technology for specific epitaxial layers "epilayers", are needed. (c) 2004 Elsevier B.V. All rights reserved.