| Abstract |
We propose that Figure 1 be called the Lindal diagram, to recognize the contribution of the Icelandic engineer Baldur Lindal, in furthering direct uses of geothermal energy worldwide. The diagram depicts the application temperature of several current and potential uses of geothermal energy, ranging from fish farming and soil heating at low temperatures, through space heating and drying at intermediate temperatures, to electric power generation and industrial processing at high temperatures. In this paper, examples of direct used in Iceland, New Zealand, and the United States, serve to illustrate the range of temperatures used in established applications. |