scholarly journals Central versus wellhead power plants in geothermal grid electricity generation

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Moses Jeremiah Barasa Kabeyi ◽  
Oludolapo A. Olanrewaju
Keyword(s):  
Return On Investment ◽  
Electricity Generation ◽  
Power Plants ◽  
Steam Pressure ◽  
Financial Risks ◽  
Steam Consumption ◽  
Lower Efficiency ◽  
Early Return ◽  
Geothermal Wells ◽  
Geothermal Power

AbstractThe long gestation period, high upfront costs and the risks in the development of central geothermal power plants are the main reasons for the slow rate of geothermal electricity growth and its contribution to the global electricity mix. The overall objective of this study was to make a comparison between central geothermal power plants and wellhead power plants in the delivery of geothermal electricity projects. The study showed that wellhead power plants are generally less efficient compared to central power plants because of higher specific steam consumption, but are financially attractive because of the quicker return on investment, early electricity generation and the lower financial risks. The study showed that permanent wellhead power plants are a better option for geothermal wells with too low or too high steam pressure compared to others in the steam field. Temporary use of wellhead power plants as opposed to their permanent use is preferred when only limited time is available between the commissioning of a wellhead plant and the commissioning of a central power plant in the same steam field. Technical, operational and environmental challenges, including higher specific steam consumption and lower efficiency than central power plants as well as absence of geothermal fluid reinjection system make wellhead plants less economical and less sustainable in resource use. It can thus be concluded that wellhead power plants can reduce the long wait to generate geothermal electricity and make an early return on investment for investors. Both central and wellhead power plants have relatively higher capacity factor than many other power plants and so can be used to supply base load electricity for the grid or off-grid power supply. This study is a review of the central and wellhead power plants and additionally provides policy guidelines in the execution of geothermal electricity projects either as central or wellhead power plants for grid electricity generation.

scholarly journals Estimating the Geothermal Electricity Generation Potential of Sedimentary Basins Using genGEO (The Generalizable GEOthermal Techno-Economic Simulator)

2021 ◽  
Author(s):  
Benjamin Adams ◽  
Jonathan Ogland-Hand ◽  
Jeffrey M. Bielicki ◽  
Philipp Schädle ◽  
Martin Saar
Keyword(s):  
Electricity Generation ◽  
Power Plants ◽  
Sedimentary Basin ◽  
Sedimentary Basins ◽  
Heat Extraction ◽  
Subsurface Water ◽  
Geothermal Heat ◽  
Geothermal Resources ◽  
Geothermal Power ◽  
Economic Tools

<p><b>Abstract</b></p><p>Sedimentary basins are ubiquitous, naturally porous and permeable, and the geothermal heat in these basins can be extracted with geologic water or CO<sub>2</sub> and used to generate electricity. Despite this, the broad potential that these formations may have for electricity generation is unknown. Here we investigate this potential, which required the creation of the <u>gen</u>eralizable <u>GEO</u>thermal techno-economic simulator (genGEO). genGEO is built with only publicly available data and uses five standalone, but integrated, models that directly simulate all components of geothermal power plants to estimate electricity generation and cost. As a result of this structure, genGEO, or a portion of it, can be applied or extended to study any geothermal power technology. In contrast, the current techno-economic tools for geothermal power plants rely on characterizations of unpublished ASPEN results and are thus not generalizable enough to be applied to sedimentary basin geothermal power plants which use subsurface CO<sub>2</sub>.</p> <p>In this study, we present genGEO as open-source software, validate it with industry data, and compare its estimates to other geothermal techno-economic tools. We then apply genGEO to sedimentary basin geothermal resources and find that using CO<sub>2</sub> as a subsurface heat extraction fluid compared to water decreases the cost of geothermal electricity across most geologic conditions that are representative of sedimentary basins. Using genGEO results and p50 geologic data, we produce supply curves for sedimentary basin geothermal power plants in the U.S., which suggests that there is present-day potential to profitably increase the capacity of geothermal power by ~10% using water as the subsurface heat extraction fluid. More capacity is available at lower cost when CO<sub>2</sub> is used as the subsurface fluid, but realizing this capacity requires geologically storing between ~2 and ~7 MtCO<sub>2</sub>/MW<sub>e</sub>. But developing sedimentary basin resources in the short-term using subsurface water may not eliminate options for CO₂-based power plants in the long-term because the least-cost order of sedimentary basins is not the same for both CO<sub>2</sub> and water. With sufficient geologic CO<sub>2</sub> storage, developing sedimentary basins using CO<sub>2</sub>- and water-based power plants may be able to proceed in parallel.</p>

scholarly journals A Project To Estimate The Power Capacity Of Geothermal Power Plants Based On The Enthalpy Of Geothermal Fluid And Plant Design

2021 ◽  
Author(s):  
Obumneme Oken
Keyword(s):  
Power Plant ◽  
Geothermal Energy ◽  
Electricity Generation ◽  
Power Plants ◽  
Hot Water ◽  
Power Capacity ◽  
Geothermal Fluid ◽  
Direct Heating ◽  
Single Flash ◽  
Geothermal Power

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.

Performance Analysis and Optimization of Double-Flash Geothermal Power Plants

2006 ◽  
Vol 129 (2) ◽  
pp. 125-133 ◽  
Author(s):  
Ahmet Dagdas
Keyword(s):  
Power Plant ◽  
Performance Analysis ◽  
Electricity Generation ◽  
Power Plants ◽  
Second Law ◽  
Western Turkey ◽  
Geothermal Power Plant ◽  
Base Points ◽  
Geothermal Power ◽  
Double Flash

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.

scholarly journals Geological and Thermodynamic Analysis of Low Enthalpy Geothermal Resources to Electricity Generation Using ORC and Kalina Cycle Technology

Energies ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1335 ◽  
Author(s):  
Michał Kaczmarczyk ◽  
Barbara Tomaszewska ◽  
Leszek Pająk
Keyword(s):  
Power Output ◽  
Electricity Generation ◽  
Power Plants ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Total Production ◽  
Geothermal Resources ◽  
Geothermal Waters ◽  
Kalina Cycle ◽  
Geothermal Wells

The article presents an assessment of the potential for using low enthalpy geothermal resources for electricity generation on the basis of the Małopolskie Voivodeship (southern Poland). Identification the locations providing the best prospects with the highest efficiency and possible gross power output. Thermodynamic calculations of power plants were based on data from several geothermal wells: the Bańska PGP-1, Bańska IG-1, Bańska PGP-3 and Chochołów PIG-1 which are working wells located in one of the best geothermal reservoirs in Poland. As the temperature of geothermal waters from the wells does not exceed 86 °C, considerations include the use of binary technologies—the Organic Rankine Cycle (ORC) and Kalina Cycle. The potential gross capacity calculated for existing geothermal wells will not exceed 900 kW for ORC and 1.6 MW for Kalina Cycle. In the case of gross electricity, the total production will not exceed 3.3 GWh/year using the ORC, and will not exceed 6.3 GWh/year for the Kalina Cycle.

scholarly journals Estimating the Geothermal Electricity Generation Potential of Sedimentary Basins Using genGEO (The Generalizable GEOthermal Techno-Economic Simulator)

2021 ◽  
Author(s):  
Benjamin Adams ◽  
Jonathan Ogland-Hand ◽  
Jeffrey M. Bielicki ◽  
Philipp Schädle ◽  
Martin Saar
Keyword(s):  
Electricity Generation ◽  
Power Plants ◽  
Sedimentary Basin ◽  
Sedimentary Basins ◽  
Heat Extraction ◽  
Subsurface Water ◽  
Geothermal Heat ◽  
Geothermal Resources ◽  
Geothermal Power ◽  
Economic Tools

<p><b>Abstract</b></p><p>Sedimentary basins are ubiquitous, naturally porous and permeable, and the geothermal heat in these basins can be extracted with geologic water or CO<sub>2</sub> and used to generate electricity. Despite this, the broad potential that these formations may have for electricity generation is unknown. Here we investigate this potential, which required the creation of the <u>gen</u>eralizable <u>GEO</u>thermal techno-economic simulator (genGEO). genGEO is built with only publicly available data and uses five standalone, but integrated, models that directly simulate all components of geothermal power plants to estimate electricity generation and cost. As a result of this structure, genGEO, or a portion of it, can be applied or extended to study any geothermal power technology. In contrast, the current techno-economic tools for geothermal power plants rely on characterizations of unpublished ASPEN results and are thus not generalizable enough to be applied to sedimentary basin geothermal power plants which use subsurface CO<sub>2</sub>.</p> <p>In this study, we present genGEO as open-source software, validate it with industry data, and compare its estimates to other geothermal techno-economic tools. We then apply genGEO to sedimentary basin geothermal resources and find that using CO<sub>2</sub> as a subsurface heat extraction fluid compared to water decreases the cost of geothermal electricity across most geologic conditions that are representative of sedimentary basins. Using genGEO results and p50 geologic data, we produce supply curves for sedimentary basin geothermal power plants in the U.S., which suggests that there is present-day potential to profitably increase the capacity of geothermal power by ~10% using water as the subsurface heat extraction fluid. More capacity is available at lower cost when CO<sub>2</sub> is used as the subsurface fluid, but realizing this capacity requires geologically storing between ~2 and ~7 MtCO<sub>2</sub>/MW<sub>e</sub>. But developing sedimentary basin resources in the short-term using subsurface water may not eliminate options for CO₂-based power plants in the long-term because the least-cost order of sedimentary basins is not the same for both CO<sub>2</sub> and water. With sufficient geologic CO<sub>2</sub> storage, developing sedimentary basins using CO<sub>2</sub>- and water-based power plants may be able to proceed in parallel.</p>

A Review on Utilization of Fly- Ash and Pond-Ash as a Partial Replacement of Cement in Concrete Mix Design

2018 ◽  
pp. 413-418
Author(s):  
Harshkumar Patel ◽  
Yogesh Patel
Keyword(s):  
Fly Ash ◽  
Electricity Generation ◽  
Power Plants ◽  
Renewable Energy Sources ◽  
Thermal Power ◽  
Strength Test ◽  
Partial Replacement ◽  
Pond Ash ◽  
Research Activities ◽  
Ash Disposal

Now-a-days energy planners are aiming to increase the use of renewable energy sources and nuclear to meet the electricity generation. But till now coal-based power plants are the major source of electricity generation. Disadvantages of coal-based thermal power plants is disposal problem of fly ash and pond ash. It was earlier considered as a total waste and environmental hazard thus its use was limited, but now its useful properties have been known as raw material for various application in construction field. Fly ash from the thermal plants is available in large quantities in fine and coarse form. Fine fly ash is used in construction industry in some amount and coarse fly ash is subsequently disposed over land in slurry forms. In India around 180 MT fly is produced and only around 45% of that is being utilized in different sectors. Balance fly ash is being disposed over land. It needs one acre of land for ash disposal to produce 1MW electricity from coal. Fly ash and pond ash utilization helps to reduce the consumption of natural resources. The fly ash became available in coal based thermal power station in the year 1930 in USA. For its gainful utilization, scientist started research activities and in the year 1937, R.E. Davis and his associates at university of California published research details on use of fly ash in cement concrete. This research had laid foundation for its specification, testing & usages. This study reports the potential use of pond-ash and fly-ash as cement in concrete mixes. In this present study of concrete produced using fly ash, pond ash and OPC 53 grade will be carried. An attempt will be made to investigate characteristics of OPC concrete with combined fly ash and pond ash mixed concrete for Compressive Strength test, Split Tensile Strength test, Flexural Strength test and Durability tests. This paper deals with the review of literature for fly-ash and pond-ash as partial replacement of cement in concrete.

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