| Abstract |
In 1985 a countrywide assessment of the geothermal resources of Iceland was published by the National Energy Authority. It emphasized estimating the thermal energy content (stored heat) of the island’s crust. Consequently, the technically harnessable geothermal energy was estimated based on the expectation that hot dry rock technology would soon become feasible. In addition, the heat flow through the crust was estimated (heat conduction and hot springs), reflecting the double nature of geothermal. The proportion of geothermal in the primary energy mix of Iceland is now about 2/3 and it is envisioned that it will continue to increase. The 1985 assessment is therefore being updated based on a vast and comprehensive database compiled during the last 40 years, including exploration data, information on nearly 3000 exploration and production wells as well as monitoring and evaluation data for numerous geothermal systems utilized. The present assessment emphasizes the heat flow aspect even though the stored crustal energy is also estimated. The energy flow is assessed for four energy streams: 1) Crustal heat conduction, 2) natural state flow through hot springs and geysers, 3) estimated capacity of drilled wells and 4) present geothermal energy production. The results indicate that geothermal use in Iceland can continue to grow in the future, partly through utilization of unconventional resources (deep drilling, EGS development and ocean floor utilization) but also through more efficient utilization of conventional resources. The present assessment will serve as basis and motivation for innovation and technological advances needed for future development. |