Feasibility, Design and authorization of a zero-emission Geothermal Power Plant in Italy; Case Study: “Montenero” Project

Author(s):  
Paolo Basile ◽  
Roberto Brogi ◽  
Favaro Lorenzo ◽  
Tiziana Mazzoni

<p><span><span>Social consensus is a </span><span>condition precedent for any intervention having an impact on the territory, such as geothermal power plants. Therefore, private investors studied and proposed innovative solution for the exploitation of the medium enthalpy geothermal resource, with “zero emissions” in atmosphere, with the target of minimizing its environmental impact. “Montenero” project, developed by GESTO Italia, complies with this precondition.</span></span></p><p><span><span>The area covered b</span><span>y the exploration and exploitation permit is located on the northern edge of the great geothermal anomaly of Mt. Amiata (Tuscany), about 10 km north of the geothermal field of Bagnore, included in the homonymous Concession of Enel Green Power.</span></span></p><p><span><span>The geological - structural setting of the area around the inactive volc</span><span>ano of Mt. Amiata has been characterized by researches for the geothermal field of Bagnore, carried out by Enel Green Power over the years. The geothermal reservoir is present in the limestone and evaporitic rocks of the “Falda Toscana”, below which stands the Metamorphic Basement, as testified by the wells of geothermal field of Bagnore. The foreseen reservoir temperature at the target depth of 1.800 m is 140 °C, with an incondensable gas content of 1,8% by weight.</span></span></p><p><span><span>The project was presented to the authorities in 2013 and it is </span><span>now undergoing exploitation authorization and features the construction of a 5 MW ORC (Organic Ranking Circle) binary power plant. The plant is fed by three production wells for a total mass flow rate of 700 t/h. The geothermal fluid is pumped by three ESPs (Electrical Submersible Pump) keeping the geothermal fluid in liquid state from the extraction through the heat exchangers to its final reinjection three wells.</span></span></p><p><span><span>The reinjection temperature is 70 °C and the circuit pressure is maintained above the </span><span>incondensable gas bubble pressure, i.e. 40 bar, condition which prevents also the formation of calcium carbonate scaling. The confinement of the geothermal fluid in a “closed loop system” is an important advantage from the environmental point of view: possible pollutants presented inside the geothermal fluid are not released into the environment and are directly reinjected in geothermal reservoir.</span></span></p><p><span><span>The </span><span>environmental authorization procedure (obtained) has taken into account all the environmental aspects concerning the natural matrices (air, water, ground, ...) potentially affected by the activities needed for the development, construction and operation of “Montenero” ORC geothermal power plant. A numerical modeling was designed and applied in order to estimate the effect of the cultivation activity and to assess the reinjection overpressure (seismic effect evaluation). The project also follows the “best practices” implemented in Italy by the “Guidelines for the usage of medium and high enthalpy geothermal resources” prepared in cooperation between the Ministry of Economic Development and the Ministry of the Environment.</span></span></p>

Tatapani Geothermal field is one of the most promising low-enthalpy geothermal fields in central India, located on Son-Narmada lineament in the state of Chhattisgarh, India. The Tatapani geothermal field geological, geo-chemical & reservoir data has been compiled and analysed for evaluating true power potential & better understanding of the field. The low enthalpy geothermal reservoirs can be utilized for power production using Organic Rankine Cycle (ORC) or binary power cycle. Based on previous research works done, the Tatapani geothermal field has been found to be very prospective and has got huge potential for power generation. The binary power cycle has been studied in detail along with thermodynamic concepts. In addition, similar low enthalpy geothermal power plants (conceptual & existing both) have been thoroughly studied in order to understand the concepts and methodology to perform technical feasibility based on thermodynamic and exergy analysis. The literature review covers the previous works done on Tatapani geothermal field including works on other geothermal fields in India along with previous research works for Thermodynamic & Exergy Analysis carried-out for binary geothermal power plants across the world for similar low enthalpy prospects. The methods of performing thermodynamic and exergy analysis for a potential geothermal power plant has been studied and compared. Exergy analysis highlights the areas of primary exergy destruction at various plant components and can be illustrated in the form of exergy flow diagram. The loss of exergy indicates the potential reasons for the inefficiencies within a process and exergic efficiency as conversion of input heat energy from the brine in to useful work output. The exergic efficiencies can be calculated for each component along with exergy destruction. The detailed study has been conducted in order to gather the knowledge regarding conducting the feasibility of setting up binary geothermal power plant at Tatapani from technical point of view using thermodynamic concepts.


Author(s):  
Omar Othman Badran ◽  
Ghazi Salem Al-Marahleh ◽  
Al- Faroq Omar AlKhawaldeh ◽  
Izzeldeen Abed Aldabaibeh

Jordan is a developing non-producing oil country; a major part of its needed energy is imported from the neighboring countries in the forms of oil and gas, the cost of this imported energy creates a heavy financial burden on the national economy which reflects on the development plans and the standard living of the people. Jordan has good potential of geothermal energy at different places. Therefore, several applications are suggested to be utilized in the agricultural and industrial fields. In this study the binary thermodynamic cycle is suggested to utilize the geothermal source into the form of power plant for generating electricity for heating and cooling system of a health resort in the nearby region of the geothermal field. Also in this study, the air- conditioning and heating loads for a health resort are calculated and the underground thermal power plant is designed to provide the suitable power supply to the health resort. It is concluded that the geothermal resources of energy is proved to be one of the good options of renewable energy sectors in Jordan. Therefore the geothermal power plant can be an option for electrical production of the Jordanian volcanic mountains resorts.


Author(s):  
Obumneme Oken

Nigeria has some surface phenomena that indicate the presence of viable geothermal energy. None of these locations have been explored extensively to determine the feasibility of sustainable geothermal energy development for electricity generation or direct heating. In this context, the present study aims to provide insight into the energy potential of such development based on the enthalpy estimation of geothermal reservoirs. This particular project was conducted to determine the amount of energy that can be gotten from a geothermal reservoir for electricity generation and direct heating based on the estimated enthalpy of the geothermal fluid. The process route chosen for this project is the single-flash geothermal power plant because of the temperature (180℃) and unique property of the geothermal fluid (a mixture of hot water and steam that exists as a liquid under high pressure). The Ikogosi warm spring in Ekiti State, Nigeria was chosen as the site location for this power plant. To support food security efforts in Africa, this project proposes the cascading of a hot water stream from the flash tank to serve direct heat purposes in agriculture for food preservation, before re-injection to the reservoir. The flowrate of the geothermal fluid to the flash separator was chosen as 3125 tonnes/hr. The power output from a single well using a single flash geothermal plant was evaluated to be 11.3 MW*. This result was obtained by applying basic thermodynamic principles, including material balance, energy balance, and enthalpy calculations. This particular project is a prelude to a robust model that will accurately determine the power capacity of geothermal power plants based on the enthalpy of fluid and different plant designs.


2006 ◽  
Vol 129 (2) ◽  
pp. 125-133 ◽  
Author(s):  
Ahmet Dagdas

One of the most important cycles for electricity generation from geothermal energy is the double-flash cycle. Approximately 25% of the total geothermal based electricity generation all over the world comes from double-flash geothermal power plants. In this paper, performance analysis of a hypothetical double-flash geothermal power plant is performed and variations of fundamental characteristics of the plant are examined. In the performance analysis, initially, optimum flashing pressures are determined, and energy and exergy values of the base points of the plant are calculated. In addition, first and second law efficiencies of the power plant are calculated. Main exergy destruction locations are determined and these losses are illustrated in an exergy flow diagram. For these purposes, it is assumed that a hypothetical double-flash geothermal power plant is constructed in the conditions of western Turkey. The geothermal field where the power plant will be built produces geofluid at a temperature of 210°C and a mass flow rate of 200kg∕s. According to simulation results, it is possible to produce 11,488kWe electrical power output in this field. Optimum first and second flashing pressures are determined to be 530kPa and 95kPa, respectively. Based on the exergy of the geothermal fluid at reservoir, overall first and second law efficiencies of the power plant are also calculated to be 6.88% and 28.55%, respectively.


1998 ◽  
Vol 120 (2) ◽  
pp. 179-184 ◽  
Author(s):  
M. Kanog˘lu ◽  
Y. A. C¸engel ◽  
R. H. Turner

Geothermal energy has been used for power generation, space and process heating, and to a lesser extent, space cooling. However, it is rarely used for cogeneration. This paper shows how a district heating/cooling system can be incorporated into an existing geothermal power plant to make the best use of extracted hot brine. In the power plant analysis, exergy destruction throughout the plant is quantified and illustrated using an exergy cascade. The primary source of exergy destruction in the plant is determined to be the reinjection of used brine into the ground, which accounts for 48.1 percent of the total exergy destruction. The overall first and the second law efficiencies of the plant are calculated to be 5.6 and 28.3 percent, respectively, based on the exergy of the geothermal fluid at downwell, and 5.7 and 28.6 percent, respectively, based on the exergy of the geothermal fluid at wellhead. A binary system is considered for the heating/cooling district to avoid corrosion and scaling problems. The heating system, as designed, has the capability to meet the entire needs of the Reno Industrial Park under peak load conditions, and has 30 percent reserve for future expansion. An absorption system will be used for the cooling of the intended 40 percent floor space of the industrial park. An economic analysis shows that the incorporation of the district heating/cooling system with 2,785,000 m2 of floor space connected to the geothermal grid appears to be feasible, and financially very attractive. Further, using the returning freshwater from the district heating/cooling system for partial cooling of the binary fluid of the power plant can save up to 15 percent of the fan work.


Author(s):  
S. Barsin ◽  
K. Aung

The present work investigates thermodynamic optimum conditions with respect to resource utilization by varying the operating pressure of flash drum for an existing geothermal power plant. The main focus of the study is to maximize the power output by minimizing the waste of liquid geothermal fluid re-injected to the well. For this purpose a double-flash system has been incorporated and the effect of operating at optimum flash pressures for both primary and secondary flash units is studied. An economic model is developed that calculates the total capital investment based on the cost of major equipments including pumps, flash drums, turbine generators, and condensers. From the results obtained it can be concluded that the plant at Svartsengi currently is working close to the optimum flashing pressure for the single-flash geothermal power plant. Providing an additional flash unit to convert the high temperature liquid coming from primary flash for Svartsengi and Nevada power plants increases the net power output by 12.7% and 28.9% respectively.


2019 ◽  
Vol 2 (3) ◽  
pp. 525-531
Author(s):  
Mahmut Hekim ◽  
Engin Cetin

Geothermal power plants are the plants that provide the conversion of thermal energy in geothermal fluid to electrical energy as a result of the extraction of underground hot water resources to the earth by drilling. The total installed power of geothermal power plants in the field of geothermal resources in Turkey has reached 1,336 MW. The geothermal fluid, which is used for electric power generation in geothermal power plants, is re-injected into the underground wells after electrical energy production. For efficient generation of electrical energy in geothermal power plants, it is aimed to reuse the waste heat energy within the geothermal fluid before it is sent to the re-injection well. To achieve this aim, thermoelectric generator modules which convert waste heat energy to electrical energy can be used. In this study, a thermoelectric generator-based geothermal power plant simulator that converts geothermal fluid waste heat into electrical energy is installed and commissioned in the laboratory conditions.


2021 ◽  
pp. 575-590
Author(s):  
Dhifa Qorizki ◽  
Dwiko B. Permadi ◽  
Teguh Yuwono ◽  
Rohman Rohman

Geothermal is one of the new renewable energy, which is more environmentally friendly than the existing fossil energy and has great potential to become an alternative source of energy in the future. However, the level of social acceptance of geothermal power plants operating in forest areas has not been widely studied. This study aims to reveal the social acceptance of affected residents toward the exploration of Baturaden geothermal power plant, operating in the protection forest area of ​​Mount Slamet. The survey was conducted online  to indirectly affected residents living mostly in Banyumas urban areas, while the offline face-to-face survey was administered to the directly affected residents in Sambirata and Karang Tengah villages. A total of 286 samples were analyzed. It was found that the majority of respondents preferred not to continue the establishment of the geothermal power plant, but both rural and urban dwellers have distinctive responses and reasonings. The rural tended to have stronger rejection compared to the urban residents. The acceptance of the project in both groups combined was motivated mainly by the prospect of electricity from more environmentally friendly energy sources and compliance to government policy. Those who refused tend to see from the negative impacts on the disruptions of the daily livelihood in rural areas and environmental damages. Three attitude factors significantly affect the continuation of drilling operation of GPP, namely: economic prospects of geothermal utilization in protection forests, technological optimism to migate the engative impacts, and perceived environmental concerns. To increase the social acceptance, it is suggested that policy makers and energy industry players should integrate the mitigation measures by using more proper technology within the project budget and act harmoniously to increase public awareness of the use of renewable and cleaner energy as well as pay attention to the health, welfare and culture of the local community


Author(s):  
Kevin R. Anderson ◽  
Wael Yassine

Abstract This paper presents modeling of the Puna Geothermal Venture as a case study in understanding how the technology of geothermal can by successfully implemented. The paper presents a review of the Puna Geothermal Venture specifications, followed by simulation results carried out using NREL SAM and RETSCREEN analysis tools in order to quantify the pertinent metrics associated with the geothermal powerplant by retrofitting its current capacity of 30 MW to 60 MW. The paper closes with a review of current state-of-the art H2S abatement strategies for geothermal power plants, and presents an outline of how these technologies can be implemented at the Puna Geothermal Venture.


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