Small Scale Geothermal Projects for Island Operation

Abstract

The correlation between volcanic islands and the existence of available geothermal energy has been known for a long time. In big islands like New Zealand, Iceland, Philippines, Japan and others, geothermal power plants for electricity generation are in operation and contribute significantly to the electrical grid, as they do on the mainland.
The development of geothermal power plants in small and medium size islands raises design requirements and issues that are not common to plants on the mainland or big islands. This includes control problems resulting from the size of the electrical grid, changes in the load, transportation difficulties, operation problems and more. Specially designed modular type binary plants can address and solve most of the islands’ challenges and supply reliable and low cost electrical energy which can compete successfully with other alternatives such as diesel engine or gas turbine plants.
This paper will illustrate the geothermal modular plant solution for island operation using two power plants that have been built on the big island of Hawaii and in Sao Miguel in the Azores islands as test cases.