Search results for "Geothermal Energy"

Long-term performance and life cycle assessment of energy piles in three different climatic conditions

2020

Abstract The main purpose behind the use of energy piles is to enable the exploitation of geothermal energy for meeting the heating/cooling demands of buildings in an efficient and environment-friendly manner. However, the long-term performance of energy piles in different climatic conditions, along with their actual environmental impacts, has not been fully assessed. In this paper, the results of a finite element model taking into consideration the heating and cooling demands of a reference building, and the intermittent operation of a ground source heat pump, are revealed to examine the long-term performance of energy piles. Furthermore, a life cycle assessment model is implemented to com…

Early-stage thermal performance design of thermo-active walls implemented in underground infrastructures

2022

Abstract Energy geostructures (EGs) represent an innovative technology in the sustainable energy agenda and are useful for satisfying the energy needs of the built environment. They are usually involving geostructures such as piles, walls, tunnels, shafts, and sewers. The application of such technology to infrastructure projects may have considerable thermal potential because of the large surfaces that can be thermally activated. This study focuses on thermo-active walls (energy walls, EWs), which are retaining structures used to sustain the sides of excavations. Key features related to their thermal design are examined, and a design methodology is proposed. The heat-exchange modes involvin…

A novel renewable polygeneration system for a small Mediterranean volcanic island for the combined production of energy and water: Dynamic simulation…

2014

Abstract This paper investigates the integration of solar and geothermal energy in a novel polygeneration system producing simultaneously: electricity, thermal energy, cooling energy and fresh water. The polygeneration system under analysis includes concentrating photovoltaic/thermal solar collectors (CPVT), a Geothermal Well (GW) a multi-effect distillation (MED) system for seawater desalination, a single-stage LiBr–H2O absorption chiller and additional components, such as: storage tanks, heat exchangers and balance of plant devices. The CPVT produces simultaneously electrical energy and thermal energy, at a maximum temperature of about 100 °C. The electrical energy is delivered to the gri…

Fatigue crack growth behaviour of four structural steels in air and in a geothermal fluid environment

1992

Abstract In recent years the exploitation of geothermal energy has expanded rapidly in Italy. This has created a requirement for improved drilling technology, to reduce the number of failures occuring in the drills, which is more frequent than in oil wells. This paper deals with the results obtained in FCCR tests of four materials both in air and in two types of aggressive environments. Deterioration takes place by fatigue, corrosion fatigue and hydrogen embrittlement. It is concluded that the steel G105 is a suitable substitute for S135 in drill pipes, and inspections between drillings may be adequate to prevent failure for small-curvature wells.

A novel solar-geothermal trigeneration system integrating water desalination: Design, dynamic simulation and economic assessment

2016

Abstract In this paper, an innovative solar-geothermal polygeneration system is investigated. The system supplies a small community with electricity, desalinated water and space heating and cooling through a district network. The hybrid multi-purpose plant, based on an Organic Rankine Cycle (ORC) supplied by medium-enthalpy geothermal energy and by solar energy; this latter is provided by Parabolic Trough Collectors (PTC). The geothermal brine is first used to drive the ORC loop, then to provide space heating at around 85÷90 °C (in the winter), or cooling (in the summer, by means of a single-effect absorption chiller). Finally, the geothermal brine drives a Multi-Effect Distillation (MED) s…

So close, so different: geothermal flux shapes divergent soil microbial communities at neighbouring sites

2016

This study is focused on the (micro)biogeochemical features of two close geothermal sites (FAV1 and FAV2), both selected at the main exhalative area of Pantelleria Island, Italy. A previous biogeochemical survey revealed high CH4 consumption and the presence of a diverse community of methanotrophs at FAV2 site, whereas the close site FAV1 was apparently devoid of methanotrophs and recorded no CH4 consumption. Next-Generation Sequencing (NGS) techniques were applied to describe the bacterial and archaeal communities which have been linked to the physicochemical conditions and the geothermal sources of energy available at the two sites. Both sites are dominated by Bacteria and host a negligib…

Multidisciplinary characterization and modelling of the medium enthalpy geothermal reservoir of the Western Sicily: results from the VIGOR Project

2013

Assessment of the Geochemical Potential in a Complex Tectonic Environment of South-East Sicily: New Insights From Hydrochemical Data

2019

We analyzed a large dataset (143 water sampling sites, 22 variables) of chemical parameters in local groundwaters from the south-east sector of Sicily, namely the Hyblean plateau, in order to set an original evaluation of its geothermal potential using applied geochemistry. The area was affected by volcanism until about 1.4 Ma. Today, though no active volcanism occurs, it is site of surface gas manifestations of focused degassing to which a mantle source has been attributed. We identified and thence selected the most promising sites (water springs and wells) based both on their main geochemical characteristics and on their calculated equilibrium temperature (resulting in the range between 5…

A tool for evaluating geothermal power exploitability and its application to Ischia, Southern Italy

2015

Abstract The paper proposes a method to evaluate the potential for electric power production at any site of possible geothermal interest. Accounting for geological data of the reservoirs, the method allows the computation of the available electrical power of the investigated site. Electrical energy production from geothermal sources is realized through different techniques, such as single flash and double flash, dry steam, and binary ORC plants. The technique chosen to be the most productive is determined by analyzing a specific range of geofluid properties, mainly temperature and pressure. Moreover, each plant typology has a global efficiency that may be correlated to geofluid enthalpy by …

Novel Wireless Sensor System for Dynamic Characterization of Borehole Heat Exchangers

2011

The design and field test of a novel sensor system based in autonomous wireless sensors to measure the temperature of the heat transfer fluid along a borehole heat exchanger (BHE) is presented. The system, by means of two specials valves, inserts and extracts miniaturized wireless sensors inside the pipes of the borehole, which are carried by the thermal fluid. Each sensor is embedded in a small sphere of just 25 mm diameter and 8 gr weight, containing a transceiver, a microcontroller, a temperature sensor and a power supply. A wireless data processing unit transmits to the sensors the acquisition configuration before the measurements, and also downloads the temperature data measured by the…