[en] Expansion of a large commercial geothermally-heated greenhouse is underway and requires additional geothermal fluid production. This report discusses the results of a cost-shared U.S. Department of Energy (DOE) and A.R. Masson, Inc. drilling project designed to construct a highly productive geothermal production well for expansion of the large commercial greenhouse at Radium Springs. The well should eliminate the potential for future thermal breakthrough from existing injection wells and the inducement of inflow from shallow cold water aquifers by geothermal production drawdown in the shallow reservoir. An 800 feet deep production well, Masson 36, was drilled on a US Bureau of Land Management (BLM) Geothermal Lease NM-3479 at Radium Springs adjacent to the A. R. Masson Radium Springs Farm commercial greenhouse 15 miles north of Las Cruces in Dona Ana County, New Mexico just west of Interstate 25 near the east bank of the Rio Grande. The area is in the Rio Grande rift, a tectonically-active region with high heat flow, and is one of the major geothermal provinces in the western United State

[en] This study deals with an exergetic performance evaluation of a geothermally heated building. This building used in the analysis has a volume of 1147.03 m³ and a net floor area of 95.59 m², while indoor and exterior air temperatures are 20 and 0 deg. C, respectively. The geothermal heating system used for the heat production was constructed in the Ozkilcik heating center, Izmir, Turkey. Thermal water has a pressure of 6.8 bar, a temperature of 122 deg. C and a mass flow rate of 54.73 kg/s, while it is reinjected at 3.2 bar and 72 deg. C. The system investigated feeds three regions. Among these, the Ozkanlar region has supply/return pressure and temperature values of 4.6/3 bar and 80/60 deg. C, respectively. Energy and exergy flows are studied to quantify and illustrate exergy destructions in the overall system. Total exergy input rate to the system is found to be 9.92 kW and the largest exergy destruction rate occurs in the primary energy transformation at 3.85 kW

[en] In recent years, for several types of buildings and users, the choice of conditioning by heat pump and low enthalpy geothermal reservoir has been increasing in the Italian market. In fact, such systems are efficient in terms of energy and consumption, they can perform, even at the same time, both functions, heating and cooling and they are environmentally friendly, because they do not produce local emissions. This article will introduce the technology and will focus on critical points of a geothermal field design, from actual practice, to future perspectives for the geo exchanger improvement. Finally, the article presents a best practice case in Bologna district, with an economic analysis showing the convenience of a geothermal heat pump. Conclusions of the real benefits of these plants can be drawn: compared to a non-negligible initial cost, the investment has a pay-back period almost always acceptable, usually less than 10 years.

[en] Bulgarian territory is rich in thermal water of temperature in the range of 20 - 100^oC. The highest water temperature (98^oC) is measured in Sapareva banya geothermal reservoir. Electricity generation from geothermal water is not currently available in the country. The major direct thermal water use nowadays covers: balneology, space heating and air-conditioning, domestic hot water supply, greenhouses, swimming pools, bottling of potable water and geothermal ground source heat pumps (GSHP). The total installed capacity amounts to about 77.67 MW (excl. GSHP) and the produced energy is 1083.89 TJ/year. Two applications - balneology and geothermal ground source heat pumps show more stable development during the period of 2005 - 2010. The update information on the state-owned hydrothermal fields is based on issued permits and concessions by the state.

[en] Reducing energy consumption and greenhouse gases emissions is a constant and major challenge. The valorization of low-depth subsurface energy resources has been considered for the last few years as an efficient alternative to traditional heating methods. This is called near surface geothermal science. Many devices are currently available in order to extract and use the heat contained in soils. This article thus offers to review the current devises and assess the techniques. The principle and functioning of heat pumps in surface geothermal science are notably described as well as the performances observed

[en] As part of its support for the decarbonization of heating systems, ACTEE is highlighting geothermal energy with this new guide which provides the technical and financial keys to projects that combine the decarbonization of heating systems through geothermal energy with work on building energy efficiency.

[en] Highlights: • A 3D model couples flow and heat transfer processes of DHE, wellbore and reservoir. • The model is validated against experimental data with a maximum error of 8.3%. • The entire temperature and flow fields of DHE system is analyzed comprehensively. • Performances of single U-tube, double U-tube and spiral tube are compared. • Effects of key factors on heat extraction performance of DHE system are studied. - Abstract: The downhole heat exchanger (DHE) geothermal system is commonly used to exploit geothermal energy for space heating. In this paper, a 3D unsteady state numerical model is established to couple fluid flow and heat transfer processes of DHE system. The model is validated by field experimental data. Temperature and velocity fields are analyzed to understand thermal process of DHE system. Heat extraction performances of three different DHE structures, including single U-tube, double U-tube and spiral tube, are compared. Subsequently, cases are studied to investigate how key parameters affect DHE performance. Simulation results depict that spiral-tube has the best heat extraction performance. As working fluid mass flow rate rises, outlet temperature declines and thermal power increases. When inlet temperature ascends, outlet temperature rises while thermal power decreases. Effects of reservoir porosity and tube wall heat conductivity on DHE performance are minor. Higher subsurface water velocity and larger rock heat conductivity can improve DHE performance, but the former has a more significant influence. Besides, subsurface water flow direction has neglected influence on performances of single and double U-tube, but appreciable impact on that of spiral tube. Key findings of this work are beneficial for optimal design and optimization of DHE geothermal system.

[en] This publication is an updated version of a brochure initially published in December 2018 about surface geothermal energy. Illustrated by examples of application and their characteristics, it proposes an overview of surface geothermal energy through six good reasons to choose it: a well controlled bill, an environmental exemplary way, a promotion of local resources, an energy which is adaptable to anticipate future challenges, an energy which is harmoniously integrated into its environment, and a proven technology

[en] The atlas of Limousin's very-low-energy geothermal potential includes exploitable deposits for geothermal installations on vertical probes outside the water table (potential throughout the region) and those for geothermal drilling on aquifers in areas where the latter are potentially developed (sedimentary formations). Within the framework of this study, the resource/use match was approached by comparing: - the geothermal capacity that can be exploited by vertical geothermal probes, based on the thermal properties of the geological formations in question; - the geothermal capacity that would have to be installed locally to meet the thermal needs of the built environment. The methodology used consisted in reducing all expressions of power to the unit of floor area (W/calculation grid). Demand calculations are carried out building by building, dwelling by dwelling, and the results are presented in 250 m square grids. The specific geothermal capacity represents the geothermal capacity to be installed. It has been estimated for the coldest month of the year (January), which represents energy consumption equal to around 18% of annual consumption. The vertical geothermal probes solution is able to cover the expressed geothermal power requirements of almost 100% of the territory's built areas. This atlas should be seen first and foremost as an information tool designed to help and guide decisions concerning the adoption of geothermal energy as a source of heating and/or cooling for buildings

[en] This publication, illustrated by examples of application and their characteristics, proposes an overview of surface geothermal energy through six good reasons to choose it: a well controlled bill, an environmental exemplary way, a promotion of local resources, an energy which is adaptable to anticipate future challenges, an energy which is harmoniously integrated into its environment, and a proven technology.