Geothermal Energy: Delivering on the Global Potential

After decades of being largely the preserve of countries in volcanic regions, the use of geothermal energy—for both heat and power applications—is now expanding worldwide. This reflects its excellent low-carbon credentials and its ability to offer baseload and dispatchable output - rare amongst the mainstream renewables. Yet uptake of geothermal still lags behind that of solar and wind, principally because of (i) uncertainties over resource availability in poorly-explored reservoirs and (ii) the concentration of full-lifetime costs into early-stage capital expenditure (capex). Recent advances in reservoir characterization techniques are beginning to narrow the bounds of exploration uncertainty, both by improving estimates of reservoir geometry and properties, and by providing pre-drilling estimates of temperature at depth. Advances in drilling technologies and management have potential to significantly lower initial capex, while operating expenditure is being further reduced by more effective reservoir management — supported by robust mathematical models — and increasingly efficient energy conversion systems (flash, binary and combined-heat-and-power). Advances in characterization and modelling are also improving management of shallow low-enthalpy resources that can only be exploited using heat-pump technology. Taken together with increased public appreciation of the benefits of geothermal, the technology is finally ready to take its place as a mainstream renewable technology, This book draws together some of the latest developments in concepts and technology that are enabling the growing realisation of the global potential of geothermal energy in all its manifestations.After decades of being largely the preserve of countries in volcanic regions, the use of geothermal energy—for both heat and power applications—is now expanding worldwide. This reflects its excellent low-carbon credentials and its ability to offer baseload and dispatchable output - rare amongst the mainstream renewables. Yet uptake of geothermal still lags behind that of solar and wind, principally because of (i) uncertainties over resource availability in poorly-explored reservoirs and (ii) the concentration of full-lifetime costs into early-stage capital expenditure (capex). Recent advances in reservoir characterization techniques are beginning to narrow the bounds of exploration uncertainty, both by improving estimates of reservoir geometry and properties, and by providing pre-drilling estimates of temperature at depth. Advances in drilling technologies and management have potential to significantly lower initial capex, while operating expenditure is being further reduced by more effective reservoir management — supported by robust mathematical models — and increasingly efficient energy conversion systems (flash, binary and combined-heat-and-power). Advances in characterization and modelling are also improving management of shallow low-enthalpy resources that can only be exploited using heat-pump technology. Taken together with increased public appreciation of the benefits of geothermal, the technology is finally ready to take its place as a mainstream renewable technology

Oceanus.

v. 26, no. 3 (1983

Integrated governance of the urban subsurface - a systems-based approach

The ground our cities are built on has always been a constitutive part of urban life, but is only in recent decades starting to become recognised by built environment professionals and academics as an area that might require more intentional governance. While the task of doing so is usually assigned to the realm of urban planning, a major body of literature engaging with this stems from the engineering discipline. This thesis draws on systems thinking and uses London as a case study to bridge these two disciplines and confront currently engineering-centred ideas of urban underground governance. Applying a mixed methods strategy, the thesis presents a review of planning legislation, affirming the central position of engineers and Local Planning Authorities in the current governance arrangement around London’s subsurface. Overarching theoretical and strategic suggestions are drawn from a thematic analysis of interviews with tunnelling and planning professionals, designed to provide insights into discipline specific perceptions of the urban underground, with additional insights provided by a questionnaire with a broader group of practitioners. The research shows that the spatio-material context of the ground is underrecognised when specific functions are managed within it and that despite growing engagement in the field, governance of the subsurface remains fragmented across sectors as well as temporal scales. The findings indicate that (a) an integrated data format and repository and (b) an integrated evaluation of priority for interventions in the subsurface could serve as enabling mechanisms towards a more holistic understanding of subsurface value that extends beyond purely financial assessments, and moves towards more integrated overall strategies. Reflection on ownership models, specific local contexts, early citizen engagement, and consideration of pathways are shown to be key elements of a potentially broader conversation about the role of the subsurface in cities like London today and in the future

Early growth technology analysis : case studies in solar energy and geothermal energy

Thesis (S.M. in Technology and Policy)--Massachusetts Institute of Technology, Engineering Systems Division, Technology and Policy Program, 2010.Cataloged from PDF version of thesis.Includes bibliographical references (p. 85-87).Public and private organizations try to forecast the future of technological developments and allocate funds accordingly. Based on our interviews with experts from MIT's Entrepreneurship Center, Sloan School of Management, and IBM, and review of literature, we found out that this important fund allocation process is dominated by reliance on expert opinions, which has important drawbacks alongside its advantages. In this Thesis, we introduce a data-driven approach, called early growth technology analysis, to technology forecasting that utilizes diverse information sources to analyze the evolution of promising new technologies. Our approach is based on bibliometric analysis, consisting of three key steps: extraction of related keywords from online publication databases, determining the occurrence frequencies of these keywords, and identifying those exhibiting rapid growth. Our proposal goes beyond the theoretical level, and is embodied in software that collects the required inputs from the user through a visual interface, extracts data from web sites on the fly, performs an analysis on the collected data, and displays the results. Compared to earlier software within our group, the new interface offers a much improved user experience in performing the analysis. Although these methods are applicable to any domain of study, this Thesis presents results from case studies on the fields of solar and geothermal energy. We identified emerging technologies in these specific fields to test the viability of our results. We believe that data-driven approaches, such as the one proposed in this Thesis, will increasingly be used by policy makers to complement, verify, and validate expert opinions in mapping practical goals into basic/applied research areas and coming up with technology investment decisions.by Ayse Kaya Firat.S.M.in Technology and Polic