We have developed some alternate sources of energy. But these sources have drawbacks. For example, hydroelectric power, or energy from running water, affects the ecology of surrounding areas. Nuclear power, another alternate source, presents the threat of nuclear accidents. There are also problems related to the storage of nuclear wastes. Solar and wind energies aren’t consistent. We can’t rely on them. Geothermal energy, caused by heat from inside the earth, is tapped by drawing steam and hot water from pools and geysers. This energy source, like most others, isn’t fully developed.