Impacts Of Shallow Geothermal Energy On Groundwater Quality

The use of shallow geothermal energy (SGE) systems to acclimatize buildings has increased exponentially in the Netherlands and worldwide. In certain areas, SGE systems are constructed in aquifers also used for drinking water supply raising the question of potential groundwater quality impact. Impacts of Shallow Geothermal Energy on Groundwater Quality provides a hydrochemical and geomicrobial overview of the effects of ground source heat pumps and aquifer thermal energy storage. The area is investigated with field and laboratory experiments, and reactive transport models, showing that shallow geothermal energy systems can influence groundwater quality in a number of ways. Most prominent in open ground source heating systems operating at low temperature (20°C) is the physical mixing of deep and shallow groundwater of different quality distorting the natural water quality stratification in aquifers. At a temperature of 25°C and beyond certain trace elements were observed to mobilize in laboratory experiments, and beyond 40°C redox conditions change significantly while the microbial community shift towards a thermophilic community. div Based on the results of this research, guidelines are presented for monitoring and permitting of SGE systems. The book is a useful resource for regulators of these systems, water companies and installers of the SGE systems. Author: Matthijs Bonte, Amsterdam, The Netherlands

The recommendations summarise the state of the art. Their aim is the proper exploitation of the ground for geothermal purposes without adversely affecting the ground or the groundwater on the one hand and the operation of the system and nearby buildings on the other. The recommendations should be used during consulting, design, installation and operation in order to achieve optimum and sustainable use of the ground at a specific location. Authorities responsible for supervising and approving projects can use the recommendations as a guide when taking decisions and making stipulations. The Geothermal Energy Study Group was set up in Bochum in 2004 and became the joint DGGV/DGGT study group in 2007. Some 20 specialists from universities, authorities and engineering consultants are active in the group and meet two or three times a year.

This book is the outcome of more than a decade of research and technical development activities at Spain’s Geological Survey (IGME) concerning shallow geothermal energy, which were pursued in collaboration with other public bodies and European entities. It presents a compilation of papers on the theoretical foundations of, and practical aspects needed to understand the thermal regime of the topmost subsoil, up to 400 m deep, and the exceptional properties that this underground environment offers, which make it the ideal thermal reservoir for heating, ventilation, and air conditioning (HVAC). In the book’s first section, the basic theory of thermodynamics as applied to shallow geothermal energy, heat transfer and fluid mechanics in the geological porous medium is developed. The nature of the subsoil’s thermal regime in general and in the urban environment in particular is described. The second section introduces readers to the fundamental aspects of thermal installations equipped with geothermal heat pumps, describes the types of geothermal exchangers most commonly used, and reviews the techniques used to obtain the thermal parameters of the terrain. It also discusses the potential environmental impacts of shallow geothermal activity and corresponding management strategies, as well as the legal aspects of its regulation for the governance of shallow geothermal resources in the EU in general and Spain in particular. In closing, the book highlights examples of the methodologies’ applications, developed by IGME in the city of Zaragoza and the Canary Islands. The theoretical foundations, systematics and concrete applications make the book a valuable reference source for hydrogeologists, engineers and specialized technicians alike.

Wind power and solar power systems have become part of common knowledge and conversation over the past few years. While these provide excellent sustainable options of energy production, geothermal energy systems are just as efficient and economical. Shallow geothermal systems are mainly based on using low - moderate temperatures for heating and cooling. These temperatures are naturally found in the upper geological layers and will mostly be in the same order as the average outdoors temperature seen over a year. The earth has a generally constant temperature throughout the year which can be used in geothermal systems to benefit all sites. Using these temperatures in geothermal system is referred to a direct use, mainly for serving as a source of heat for heat pump applications. Geothermal systems create positive energy, meaning that they produce higher quantities of energy than they require operating. Geothermal energy has until recently had a considerable economic potential only in areas where thermal water or steam is found concentrated at depths less than 3 km in restricted volumes analogous to oil in commercial oil reservoirs. This has recently changed with developments in the application of ground-source heat pumps using the earth as a heat source for heating or as a heat sink for cooling, depending on the season. This has made it possible for all countries to use the heat of the earth for heating and/or cooling, as appropriate. Shallow Geothermal Systems is aimed at appropriate modes of development, utilization, and dividing the suitable areas of shallow geothermal energy according to the resource conditions of shallow geothermal energy. The book focuses on the proper exploitation of the ground for geothermal purposes without unfavorably affecting the ground or the groundwater on the one hand and the operation of the system and nearby buildings on the other. SGE is in many cases a financially viable and an energy efficient way of acclimatizing houses and buildings. For this reason, governments are actively stimulating the application of shallow geothermal energy which has led to a strong growth in the application of these systems.

This text combines the science and engineering of hydrogeology in an accessible, innovative style. As well as providing physical descriptions and characterisations of hydrogeological processes, it also sets out the corresponding mathematical equations for groundwater flow and solute/heat transport calculations. And, within this, the methodological and conceptual aspects for flow and contaminant transport modelling are discussed in detail. This comprehensive analysis forms the ideal textbook for graduate and undergraduate students interested in groundwater resources and engineering, and indeed its analyses can apply to researchers and professionals involved in the area.

Under the Earth’s surface is a rich array of geological resources, many with potential use to humankind. However, extracting and harnessing them comes with enormous uncertainties, high costs, and considerable risks. The valuation of subsurface resources involves assessing discordant factors to produce a decision model that is functional and sustainable. This volume provides real-world examples relating to oilfields, geothermal systems, contaminated sites, and aquifer recharge. Volume highlights include: • A multi-disciplinary treatment of uncertainty quantification • Case studies with actual data that will appeal to methodology developers • A Bayesian evidential learning framework that reduces computation and modeling time Quantifying Uncertainty in Subsurface Systems is a multidisciplinary volume that brings together five major fields: information science, decision science, geosciences, data science and computer science. It will appeal to both students and practitioners, and be a valuable resource for geoscientists, engineers and applied mathematicians. Read the Editors’ Vox: https://eos.org/editors-vox/quantifying-uncertainty-about-earths-resources