Sustainability evaluation of geothermal systems in Iceland. Indicators for sustainable production

• Main Author: Rut Bjarnadóttir 1983-
• Other Authors: Háskóli Íslands
• Format: Thesis
• Language: English
• Published: 2010
• Subjects: Vélaverkfræði; Sjálfbær orka og verkfræði; Jarðhiti; Jarðhitanýting; Sjálfbærni; Krafla; Iceland
• Online Access: http://hdl.handle.net/1946/4383

There is an increasing demand from the society to utilize resources in a sustainable way. Utilization of geothermal resources are no exception from that and as the demand for renewable energy sources increase as does the stress on existing resources. This calls for a policy in the sustainable management for resources but no such policy exists for geothermal development in Iceland. Ruth Shortall, a master student at the University of Iceland has developed a Geothermal Sustainability Assessment Protocol (GSAP) which takes into consideration all aspects of geothermal development, the environment, the economy and the society. The GSAP is a set of sustainability indicators that measure sustainable development. In this thesis the indicators that have to do with the geothermal production and the influence it has on the resource itself are developed. Seven indicators were developed and they capture some of the most important properties affected during geothermal utilization. The indicators developed and the method used to evaluate them are: 1) Utilization efficiency, using exergy analysis 2) Productive lifetime, using existing reservoir models 3) Reserve capacity ratio, using definitions of probable and proven reserves 4) Reclamation time, using existing reservoir models 5) Change in dissolved chemicals, using geothermometers and relative changes 6) Ground subsidence, evaluating impacts on the surroundings and 7) Micro seismic activity, evaluating impacts on the surroundings. To test the effectiveness of these indicators they are applied to the Krafla geothermal field in Iceland. The grading of the indicators is in some cases based on relative comparison to other geothermal fields and in other cases a benchmark is set. The results for the Krafla field indicate the production is sustainable under current conditions. The overall result is that sustainability indicators are a good way to measure sustainability of geothermal production because they take into consideration many properties and can quantify the sustainability ...