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Renewable energy is one of environmentally friendly strategies to reduce the environmental pollution caused by energy generation from fossil fuels and reach sustainable development. In this current study, a geothermal driven multi-generation system to provide power, heating, freshwater, hydrogen and oxygen demands is investigated. The main components are encompassed single-pressure organic Rankine cycle, reverse osmosis desalination unit, domestic water heater and proton exchange membrane electrolyzer. For this purpose, energy, exergy, economic and exergoenvironmental (4E) evaluations are accomplished upon proposed system. Non-dominant sorting genetic algorithm has been considered as optimization method that leads to reveal the maximum and minimum of exergy efficiency and total annual cost (TAC) rate as two objective functions. In addition, sensitivity analysis is performed to reveal the roles of design parameters on the system performance and productivity from different standpoints. The optimal results showed that exergy efficiency and TAC increased, as operating temperature of PEM electrolyzer enhances. In terms of economic analysis, the most percentage of total investment cost is pertained to RO unit which was 58.05%. In addition, exergy efficiency and TAC of the proposed system were 30.42% and 255.96 $/h, respectively. As well, the mass flow rate of freshwater, hydrogen, oxygen, net power output and heating production were obtained 3146.7 m3/day, 0.42 m3/day, 3.35 m3/day, 1556.2 kW and 18,586 kW, respectively. Furthermore, by taking into account exergoenvironmental analysis, the environmental impact rate of power, heating, freshwater and hydrogen–oxygen production 2.331 × 10−5 pts/kJh, 3.668 × 10−3 pts/kJh, 1.45 pts/m3h and 11.42 pts/kgh, respectively. Eventually, the optimal outcomes from various perspectives were compared and argued. [ABSTRACT FROM AUTHOR]

This study provides a comprehensive exploration of ground motions associated with micro-earthquakes induced by geothermal power plants (GPP) in Southern Germany and proposes corresponding ground motion prediction equations (GMPE). Initiating with a statistical analysis of recorded seismic data from the GPP in Insheim, the study is extended to the greater Munich area. For the latter, the scarce recorded data are merged with physics-based simulation data. The recorded data in Insheim, Poing, Unterhaching and the simulated data in Munich are compared to existing GMPEs for GPP-induced events, highlighting the need of new region-specific prediction equations. The proposed GMPEs are expressed in terms of peak quantities, spectral accelerations and velocities, separating the horizontal and vertical direction. The regression curves exhibit a good alignment with both recorded and simulated data, within an acceptable range. Notably, the results reveal higher spectral quantities at shorter periods ( < 0.1 s), underscoring the importance of this characteristic in seismic assessment. The article shows an exemplary application for a low-rise residential building, located at a hypocentral distance of 3 km. While the building meets serviceability standards for an M W up to 2.5, the verification fails at M W = 3 , emphasizing the need for robust risk assessment. These findings contribute to the understanding of ground motions of GPP-induced events, offering practical implications for serviceability verifications and aiding informed decision-making in geothermal energy projects. [ABSTRACT FROM AUTHOR]

Qualtra, an innovative 10 MW geothermal power plant proposal, employs a closed-loop design to mitigate emissions, ensuring no direct release into the atmosphere. A thorough assessment utilizing energy and exergy analysis, life cycle assessment (LCA), exergo-economic analysis, and exergo environmental analysis (EevA) was conducted. The LCA results, utilizing the ReCiPe 2016 midpoint methodology, encompass all the spectrum of environmental indicators provided. The technology implemented makes it possible to avoid direct atmospheric emissions from the Qualtra plant, so the environmental impact is mainly due to indirect emissions over the life cycle. The result obtained for the global warming potential indicator is about 6.6 g CO2 eq/kWh, notably lower compared to other conventional systems. Contribution analysis reveals that the construction phase dominates, accounting for over 90% of the impact for almost all LCA midpoint categories, excluding stratospheric ozone depletion, which is dominated by the impact from the operation and maintenance phase, at about 87%. Endpoint indicators were assessed to estimate the single score value using normalization and weighting at the component level. The resulting single score is then used in an Exergo-Environmental Analysis (EEvA), highlighting the well system as the most impactful contributor, constituting approximately 45% of the total impact. Other substantial contributions to the environmental impact include the condenser (21%), the turbine (17%), and the HEGeo (14%). The exergo-economic analysis assesses cost distribution across major plant components, projecting an electricity cost of about 9.4 c€/kWh. [ABSTRACT FROM AUTHOR]

The article is devoted to the actual problem of handling the natural coolant used in geothermal energy systems. The choice of the optimal method of disposing of the spent coolant in advance allows to establish environmentally safe operation of power plants, affects the design features of energy systems, and also determines the productivity of the energy system, its service life and technical and economic indicators. Based on the analysis of natural geothermal conditions of domestic geothermal deposits, depending on the location of the static level of the productive horizon, two types of hydrothermal deposits are distinguished. For each type, the mode of operation of the wells is given, the general principles of calculating the water extraction system are defined, and an effective method of disposal of the spent natural heat carrier is also proposed. [ABSTRACT FROM AUTHOR]

Structural modifications play a crucial role in enhancing the sustainability of natural gas power plants owing to their significant contribution to greenhouse gas emissions and irreversibility factors. One primary solution is using waste heat recovery systems integrated with these power plants, producing different products. Furthermore, integrating renewable energy resources into the entire system within a co-feed framework may be a viable method for further enhancements. The current study focuses on a novel heat integration process combined with a natural gas power plant, which uses geothermal energy as an auxiliary energy source. The newly designed system encompasses a gas turbine cycle, two modified geothermal power plants, a water electrolyzer unit, and a methanol synthesis unit. The process is simulated utilizing the Aspen HYSYS software, and to evaluate its viability, analyses are performed pertaining to energy, exergy, environment, and economics. Furthermore, a comprehensive parametric analysis is conducted on the primary performance indicators. The simulation results show that the process's energy, exergy, and electrical efficiencies equal 53.85%, 47.30%, and 40.26%, respectively. The environmental evaluation demonstrates that the specific carbon dioxide emissions associated with the total energy produced and the sum of power and heating are 0.27 kg/kWh and 0.294 kg/kWh, respectively. From the economic aspect, the total unit cost of the products and the cost of energy of the system are 20.69 $/GJ and 0.086 $/kWh, respectively. Also, total annual cost, investment cost, and net present value of 222.81 M$, 1010.64 M$, and 1220.57 M$, respectively. • Proposal of a novel polygeneration system using natural gas and geothermal energy. • Producing electricity, hot water, fresh water, and methanol simultaneously. • Use of Aspen HYSYS for simulation and multi-aspect study from 4E perspective. • Total exergy efficiency and total unit cost of the product are 47.3% and 20.69 /GJ. • The CO 2 emission based on the total energy produced equals 0.27 kg CO 2 / kWh. [ABSTRACT FROM AUTHOR]

Indonesia has enormous geothermal potential, but it only contributes 5% to Indonesia's energy matrix. During 37 years of operation, PT. Pertamina Geothermal Energy Kamojang area has been operating to produce electricity and is currently capable of supplying and distributing electricity to the Java-Bali area with a capacity of 60 MWe. However, this can run into a decrease in the efficiency and effectiveness of system performance due to energy losses in several geothermal power plant components during energy conversion. In this case, exergy analysis at PT. Pertamina Geothermal Energy Kamojang area Unit 4 direct-dry steam cycle was done on each component and state. This aims to know the energy and exergy stream and where it happened irreversibly at the component. The biggest irreversibility value occurred at the turbine and main condenser, with a value of 21,693.890 kW and 21,688.148 kW. The total irreversibility of all systems is 58,326.201 kW, while the total exergy inlet systems is 119,308.457 kW, so the value efficiency exergy obtained is 51.13%. Based on the environment as dead state analysis, an efficiency exergy value is inversely proportional to the irreversibility value and ascending environment temperature. System optimization was done with the genetic algorithm method, with variable values at the pressure wellhead and inlet turbine for the overall exergy efficiency value. The value obtained from optimization is 11.98 bar at the wellhead and 10.023 bar at the inlet turbine, and the overall efficiency exergy increased by 51.22%.

Japanese geothermal power plants are expected to be significant renewable energy sources owing to the abundance of geothermal sources in Japan. The plant capacity factor in geothermal power plants is low. One reason is frequent sudden pressure drops in production well corresponding to the change of subsurface condition. To obtain a stable steam quantity, it is necessary to observe the subsurface conditions in real-time and perform appropriate operations. The use of a model to predict steam enthalpy in real-time has potential to monitor changes in subsurface conditions and contribute to the composition of plant operational strategies. However, training a model requires a large amount of data. The purpose of this study is to evaluate the effectiveness of transferring the knowledge of a pretrained model for predicting steam enthalpy in one plant to another plant with limited data. This study proposes a methodology based on the combination of the temporal fusion transformer (TFT) architecture and transfer learning (TL). This approach represents a novel way to share knowledge from a pretrained model based on historical data from a plant, which helps reduce the need for large amounts of data when dealing with a new plant. A pretrained TFT model (PM) enables the prediction of rapid steam enthalpy decreases in the source plant. Transfer learning using a PM was confirmed to enhance the performance of steam enthalpy prediction in another plant compared to using a model without pretraining. The effectiveness of transfer techniques has the potential to contribute to improving the operational efficiency of geothermal power plants. The transfer learning strategies proposed in this study heavily rely on the similarity of the source data. In the future, we aim to compute data correlations between plants and the effectiveness of transfer learning.

In the field of electricity production, factors such as the restricted availability of investment resources and the state of the surrounding environment are among the most significant factors that influence this process. Minimizing the cost and the harmful effects of the environment has always been and will be the concern of experts. The method of generating electricity using geothermal power plants is being highlighted due to the gravity of the issue of environmental protection as well as the security of electricity. Obviously, the resources necessary for investment in our country are overshadowed by environmental issues. Now, the main question is whether it is possible to replace fossil power plants with geothermal ones, or at least in the future? Given the high cost of electricity production by geothermal power plants and the state of electricity production costs in the country, this study tried to do an economic study of the aforementioned issue, taking into account the social costs. In this study, the total cost of electricity generation per kilowatt hour (kWh) in each of the power plants has been calculated. Then, a necessary evaluation has been made taking into account the pollution and greenhouse gas emissions from fossil fuel power plants along with the imposed external costs. At the end, it was found that the production of electricity by geothermal power plants is not economically justified, compared to fossil power plants in scenarios 1 and 2. However, this can be taken into consideration in scenario 3, and it is economic in scenarios 4 and 5. Finally, it seems using energy from fossil power plants based on scenarios 1 and 2 will not be economically justified in the not-too-distant future given the rise in electricity demand, the scarcity of fossil resources, and the high level of pollution from these sources.

The fuzzy proposed system is a multigeneration system capable of producing different multi-products including power, cooling, heating, and fresh water. The energy required for the operation of the system is geothermal renewable energy, which is a very serious issue in the green transient. To analyze the function of the suggested subsystems, such thermodynamic rules have been considered as an important tool. Another important parameter that is evaluated is the entransy parameter that evaluates the function of thermodynamic cycles. In this study, the rate of G ˙ l o s s is achieved at 699699 KW.K. The results of the suggested system demonstrate the rate of electrical power is 226.1 KW, the rate of cooling load is 24.5 KW, freshwater production is 0.235 kg/s, and the heating load is 418.5 KW of the system output products. In addition, energy efficiency and exergy are calculated as 59.51% and 51.5%, respectively. To provide an optimal performance state of the system, a multi-objective optimization method with a genetic algorithm method is used to optimize the objective functions ( G ˙ l o s s and η I I ) of Matlab software. In this research, it has been attempted to reduce entransy and increase exergy efficiency using algorithm genetic (GA). [ABSTRACT FROM AUTHOR]

This article presents a novel and comprehensive approach for the thermoeconomic evaluation of subcritical and supercritical isobutane cycles for geothermal temperatures of Tgeo = 100–200 °C. The isobutane cycles are optimized with respect to the maximum net power or minimum levelized cost of electricity (LCOE). Cycle optimization is also included, using a minimum superheat temperature to avoid turbine erosion, which is usually neglected in the literature. The results show that economic optimums are found in the far superheated region, while thermal optimums are obtained with dry saturated or with slightly superheated vapor at the turbine inlet (ΔTsup < 5 °C). Supercritical cycles achieve better thermal performance than subcritical cycles for Tgeo = 179–200 °C. Internal heat recuperation improves the cycle performance: the net power output increases and the LCOE decreases, but specific installation costs (SICs) increase due to the additional heat exchanger. For geothermal temperatures of Tgeo = 120 → 150 °C, the costs are LCOE = 100 → 80 USD2022/MWh and SIC = 7000 → 5250 USD2022/kW, while for geothermal temperatures of Tgeo = 150 → 200 °C, the estimated costs are LCOE = 80 → 70 USD2022/MWh and SIC = 5250 → 4600 USD2022/kW. [ABSTRACT FROM AUTHOR]

Trees may represent useful long-term monitors of historical trends of atmospheric pollution due to the trace elements stored along the tree rings caused by modifications in the environment during a tree's life. Chestnut (Castanea sativa Mill.) tree trunk sections were used to document the yearly evolution of atmospheric Hg in the world-class mining district of Monte Amiata (MAMD; Central Italy) and were exploited until 1982. An additional source of Hg emissions in the area have been the active geothermal power plants. A marked decrease (from >200 µg/kg to <100 µg/kg) in Hg contents in heartwood tree rings is recorded, likely because of mine closure; the average contents (tens of µg/kg) in recent years remain higher than in a reference area ~150 km away from the district (average 4.6 µg/kg). Chestnut barks, recording present-day Hg pollution, systematically show higher Hg concentrations than sapwood (up to 394 µg/kg in the mining area). This study shows that tree rings may be a good record of the atmospheric Hg changes in areas affected by mining activity and geothermal plants and can be used as a low-cost biomonitoring method for impact minimization and optimal resource and land management. [ABSTRACT FROM AUTHOR]

Performance data from a geothermal power plant that uses a dry-type working fluid (n-Pentane) was evaluated. The experimental working conditions of the geothermal power plant were recorded. By using these recorded data the structural and parametrical optimisation of the plant was applied. As a structural modification, the probable performance of the plant was scrutinised by considering the integration of a superheater into the plant. For both present and structurally optimised cases, parametric optimisations were made as an operational modification. During the analyses, the high and low pressure Organic Rankine Cycles (ORCs) of the energy converter plant were optimised for varying turbine inlet temperatures and pressures. After comprehensive analyses, it was concluded that superheating the working fluid by structural modification (superheater integration) had a negative effect on the system performance. On the other hand, together with parametric analyses, a considerable improvement in system performance was obtained. For all cases and parametric values, the system was also evaluated in terms of environmental effect. [ABSTRACT FROM AUTHOR]

Different studies highlighted the environmental impacts of geothermal power plants (GPPs), especially in the operational phase. Primary data are essential for reliable environmental assessments, but these are not available when considering alternative configurations. Rigorous simulation can offer such a degree of information, representing also a tool for a digital twin technology transition. Considering a GPP in Tuscany, Italy, four alternatives configurations are simulated in UniSim Design®, performing accurate refinements to the thermodynamic model to properly estimate the behavior of different pollutants (Hg, H 2 S, NH 3 , and SO 2) among the various unit operations. The configurations alternate direct-contact and surface condensers as well as wet and dry towers as cooling systems, while a fifth one adopts an organic Rankine cycle. The actual plant model has been reconciliated with data collected during two different monitoring campaigns. Performance analysis shows a trade-off: the lowest pollutant emissions are obtained using the dry tower generating less net energy (20.17 MWe and 20.83 MWe), instead, adopting surface condenser and wet tower, 22.26 MWe are produced with NH 3 emissions almost 3 times the measured ones. The CO 2 and CH 4 amount in the well fluid is not abated in any configurations and therefore their emissions are the same among them. • Operational environmental assessments of geothermal power plants need primary data. • Modeling a geothermal power plant with UniSim Design® and custom thermodynamic package. • Data reconciliation with a power plant in Italy under different seasonal conditions. • Use of direct-contact or surface condensers and wet or dry towers for cooling or ORC. • Net power production and pollutants emissions compared for the various plant set-ups. [ABSTRACT FROM AUTHOR]

Binary geothermal power plants (GPPs) are mostly encountered in geothermal fields with medium and low temperatures. The design and operation of dual binary GPPs can be difficult due to the geothermal fluid properties. This affects their performance and feasibility. Thermoeconomics are essential elements for the design and operation of the GPPs. In this study, advanced exergoeconomic analysis is applied to a true dual binary GPP (as a case study) to further evaluate it from performance and economic perspectives. In analysis, the specific exergy cost (SPECO) method is used. Then, some specific indicators are presented to evaluate the performance and economics of the GPP. Thus, technical and economic solutions have been developed in the design and operation stages through the analysis. The results of the study indicated that the total operating cost of 1218 USD/h could be reduced to 186 USD/h by improving the operating conditions. This corresponds to an 85% decrease. The cost per electricity generated, cost per geothermal energy input, and cost per CO2 emission of the GPP are determined as 0.049 USD/kWh, 5.3 USD/GJ, and 0.13 USD/kg, respectively. As a result, while the savings potential of the GPP is 15%, it can result in a 15% reduction in CO2 emission cost. [ABSTRACT FROM AUTHOR]

The article presents data on the resource base of Russia's geothermal steam–water fields located in the Kamchatka Peninsula and Kuril Islands with the approved reserves of 285.5 kg/s and production in 2020 amounting to 13 million t. The prospective steam–water mixture reserves are estimated at up to 1100 MW according to the volume method and with the natural discharge of steam-hydrotherms. The results of studies accomplished by the Institute of Volcanology and Seismology, Russian Academy of Sciences and the Institute of Geothermy and Renewable Energy Problems of the Joint Institute for High Temperatures, Russian Academy of Sciences, are given. The prospects of explorations on drilling wells at the foot of volcanoes in the Kamchatka Peninsula for obtaining fluids with supercritical parameters (above 450°С and 25 MPa) are estimated. The activity conducted by AO Teplo Zemli (Heat of the Earth) on producing a steam–water mixture in the Kamchatka Peninsula is described. The chronology and description of technical solutions on geothermal power plants in Russia are given. The key technical characteristics, thermal process cycle diagrams, and operation results of the Pauzhetka, Verhkne-Mutnovsky, and Mutnovsky geothermal power plants (GeoPPs) with the total installed capacity equal to 74 MW and amount of electricity production in 2020 equal to 428 GW h are presented. The article analyzes the results of modern studies carried out in Russia on binary geothermal power units with a geothermal fluid having a temperature from 120 to 180°С, on combining binary power units with hydrogen-assisted geothermal steam superheating and expanding the Mutnovsky GeoPP with direct-cycle and combined cycle power units with increasing the plant capacity by 50–63 MW. Proposals on increasing the target financial support, constructing experimental installations and demonstration facilities, and establishing a center for geothermal power engineering competences are suggested. [ABSTRACT FROM AUTHOR]

Geothermal energy is one of the strategies employed by the Indonesian government to meet rising electricity demand. Developing geothermal energy is often characterized by uncertainties and requires sequential decision-making which is divided into four development phases: 1) identification, 2) exploration, 3) exploitation, and 4) engineering, procurement, construction, and commissioning (EPPC) before it can be commercialized. Traditional valuation techniques often produce a negative net present value (NPV), suggesting decision to reject the project's investment plan. This paper investigates the economic viability of a geothermal power generation project using both NPV and real options analysis (ROA). Costs and uncertainties associated with the various development phases as well as the investment structure of geothermal projects are studied. We develop a framework for assessing the impact of four uncertainties using a binomial lattice: capacity factor, electricity price, make-up well-drilling costs, and operation and maintenance (O&M) costs. Secondary data from an Indonesian context geothermal power plant was used. Positive option values were found for the lattice approach compared to negative values found for the common NPV calculation. The result of this study showed the successful outcome of the exploration stage is very critical to determining the continuation of the project. The framework supports decision-makers in evaluating the impact of geothermal power generation projects in the face of uncertainty by providing a rigorous analysis. The movement of the underlying asset's value in the whole project's lifetime will assist the management in deciding on whether to exit or continue.

In the field of electricity production, factors such as the restricted availability of investment resources and the state of the surrounding environment are among the most significant factors that influence this process. Minimizing the cost and the harmful effects of the environment has always been and will be the concern of experts. The method of generating electricity using geothermal power plants is being highlighted due to the gravity of the issue of environmental protection as well as the security of electricity. Obviously, the resources necessary for investment in our country are overshadowed by environmental issues. Now, the main question is whether it is possible to replace fossil power plants with geothermal ones, or at least in the future? Given the high cost of electricity production by geothermal power plants and the state of electricity production costs in the country, this study tried to do an economic study of the aforementioned issue, taking into account the social costs. In this study, the total cost of electricity generation per kilowatt hour (kWh) in each of the power plants has been calculated. Then, a necessary evaluation has been made taking into account the pollution and greenhouse gas emissions from fossil fuel power plants along with the imposed external costs. At the end, it was found that the production of electricity by geothermal power plants is not economically justified, compared to fossil power plants in scenarios 1 and 2. However, this can be taken into consideration in scenario 3, and it is economic in scenarios 4 and 5. Finally, it seems using energy from fossil power plants based on scenarios 1 and 2 will not be economically justified in the not-too-distant future given the rise in electricity demand, the scarcity of fossil resources, and the high level of pollution from these sources. [ABSTRACT FROM AUTHOR]

The perception of automatic generation control (AGC) has a massive part in delivering eminence power in an interrelated structure. To acquire eminence power by monitoring the fluctuations of frequency and tie-link power, an appropriate controller strategy is essential. This work explores AGC learning under the traditional situation. In this study, we employ a cascade controller with proportional amalgamation with a tilt-integral-derivative with a filter (TIDN) and fractional order integral-derivative (FOID), named TIDN-FOID. In order to acquire the controller's attributes, a meta-heuristic optimization algorithm spotted hyena optimizer (SHO) is employed. Several investigations express the excellency of the TIDN-FOID controller over other controllers from outlook regarding the lessened level of peak_overshoot, peak_undershoot, and settling_time for the considered structure. The structure comprises thermal, biodiesel units in area 1, thermal, and geothermal units in area-2, and hydrothermal units in area-3. Both biodiesel and GPP have a better effect on system dynamics even in the presence of time delay. Action in the redox flow battery is also examined, providing a noteworthy outcome. Eigenvalue assessment is carried out to comment on the stability of the system. TIDN-FOID parameter values at nominal conditions are appropriate for a higher disturbance value without the need for optimization. [ABSTRACT FROM AUTHOR]

The concept of automatic generation control has an immense role in providing quality power in an interconnected system. To obtain quality power by controlling the oscillations of frequency and tie-line power, a proper controller design is necessary. So, an innovative endeavor has been undertaken to enforce a two-stage controller with the amalgamation of a proportional-derivative with filter (PDN) (integer-order) and a fractional order integral-derivative (FOID), i.e., PDN(FOID). In an effort to acquire the controller's gains and parameters, a bio-inspired meta-heuristic spotted hyena optimizer is applied. Various examinations manifest the excellence of PDN(FOID) over other controllers such as integral, proportional–integral, proportional–integral-derivative filter, and fractional order PID from perspectives concerning the diminished amount of peak anomaly oscillations, and the instant of settling for a three-area system. The system includes thermal–bio-diesel in area-1; a thermal–geothermal power plant in area-2; and a thermal–split-shaft gas turbine in area-3. It is also observed that the presence of renewable sources such as wave power plants and photovoltaics makes the system significantly better compared to the base system, when assessed individually or both together. Action in a combination of capacitive energy storage with duple compensation is also examined using the PDN(FOID) controller, which provides a noteworthy outcome in dynamic performance. Moreover, PDN(FOID) parameter values at a nominal condition are appropriate for the random patterns of disturbance needed for optimization. [ABSTRACT FROM AUTHOR]

The purpose of this study will analyze noise intensity at a geothermal power plant and its association with employees’ blood pressure and risk of hypertension. A cross-sectional survey using questionnaire as primary data; noise dosimeter, body mass index and blood pressure measurement records as secondary data. Total 101 workers participated by purposive sampling based on a similar exposure group (SEG). Mann-Whitney & χ2 test analysis was applied to examine the association of dependent variables and independent variables. Noise intensity was measured from the noise dose result during 8 working hours. Subjects with noise dose >80 dBA had higher levels of SBP / systolic blood pressure (119.1±11.2 mmHg) and DBP / diastolic blood pressure (75.6±5.3) than subjects with noise dose ≤80 dBA (SBP: 117.9±6.6 mmHg, DBP: 75.0±5.1). The hypertension prevalence was 7.9% at participants with noise dose >80 dBA and 2.6% in noise dose ≤80 dBA. The odds ratio (OR) of noise dose >80 dBA (OR = 3.190, 95% CI = 0.358-28.394), and smoking (OR = 2.469, 95% CI = 0.416-14.645). Noise intensity was not associated with SBP (p-value = 0.664), DBP (p-value = 0.538), and hypertension (p-value = 0.405). This study was the pioneer in the geothermal industry with noise dosimetry measurement. Further comprehensive studies need to be conducted to confirm the association between noise intensity and blood pressure and the risk of hypertension.

Abstract This research is proposed to fully investigate the performance of a single‐effect water/lithium bromide absorption chiller driven by geothermal energy. Since absorption cycles are considered as low‐grade energy cycles, this innovative idea of rejecting fluid from a single‐flash geothermal power plant with low‐grade energy would serve as efficient, economical, and promising technology. In order to examine the feasibility of this approach, a residential building which is located in Sharjah, UAE, considered to evaluate its cooling capacity of 39 kW which is calculated using MATLAB software. Based on the obtained cooling load, modeling of the required water/lithium bromide single‐effect absorption chiller machine is implemented and discussed. A detailed performance analysis of the proposed model under different conditions is performed using Engineering Equation Solver software (EES). Based on the obtained results, the major factors in the design of the proposed system are the size of the heat exchangers and the input heat source temperature. The results are presented graphically to find out the geofluid temperature and mass flow and solution heat exchanger effectiveness effects on the chiller thermal performance. Moreover, the effects of the size of all components of the absorption chiller on the cooling load to meet the space heating are presented. The thermal efficiency of the single‐flash geothermal power plant is about 13% when the power plant is at production well temperature 250℃, separator pressure 0.24 MPa, and condenser pressure 7.5 kPa. The results show that the coefficient of performance (COP) reaches about 0.87 at solution heat exchanger effectiveness of 0.9, when the geofluid temperature is 120℃.

Using hybrid renewable energy systems is a smart choice for reducing the carbon emitted by power plants. It also helps climate change mitigation and global warming, leading to universal health for humans and the environment. The efficiency of these systems depends on choosing the right combination of renewable sources, their sizes, and proper scheduling of the generating units. This paper suggests an optimisation method for sizing a geothermal/PV/wind/diesel system, both in off-grid and grid-connected configurations. In the grid-connected mode, the possibility of selling surplus energy generated by renewable resources to the network is considered. Investigations reveal that without accurate control of geothermal reservoirs, they may become depleted. In this study, a strategy is suggested for unit commitment; moreover, the harmony search algorithm is used to find the optimal size of the hybrid system in both configurations. The effectiveness of the proposed approach is represented by simulating an HRES for Ferdows/Iran.

This paper introduces an innovative integration of geothermal and solar energies to assess the production of power, cooling, and freshwater. These products are achieved through a modified absorption refrigeration cycle, a modified organic Rankine cycle, and humidification-dehumidification subsystems driven by a flash-binary configuration. The performance of the setup is evaluated using both thermodynamic and economic approaches. Additionally, three multi-objective optimizations are applied to determine a suitable optimal state. The approaches reveal net power, cooling, and freshwater production rates of 807.3 kW, 1345 kW, and 7.96 kg/s, respectively. The designed setup requires a total capital investment cost of $2,490,310 and has a payback period of 5.76 years in the base mode. The study highlights that the temperature difference of superheating significantly impacts the total capital investment cost and exergy efficiency, while the cooling production is mainly influenced by the evaporator temperature. The final optimal state achieved an exergy efficiency of 15.98 % and a net present value of $1,999,864. Overall, this innovative hybrid geothermal-solar setup demonstrates a viable solution for sustainable energy production, combining power generation, cooling, and freshwater production in a single integrated system. The findings support the system's potential for real-world applications, particularly in regions with suitable geothermal and solar resources. • Designing a novel multi-generation driven by solar and geothermal energies. • Considering the energy, exergy, and economic analyses for the performance evaluation. • Producing 807.7 kW net power, 1592 kW cooling, and 8.8 kg/s freshwater. • Achieving 15.98 % of exergy efficiency with a payback period of 5.36 years. [ABSTRACT FROM AUTHOR]

• CO 2 is the dominant gas in the gas phase of geothermal fluids. However, after a geothermal power plant is commissioned, reservoir pressure and CO 2 gas concentration tend to decrease. • In most geothermal power plants, hydrogen sulfide gas is more remarkable than carbon dioxide gas because of its impact on human and environmental health. • Although there is a high amount of CO 2 (99.8–9 %) in Kızıldere geothermal system, the amount of H 2 S (0.02–0.04 %) is relatively lower than other geothermal power plants in Türkiye. • The main focal points of this study are the reduction of H 2 S and CO 2 gasses. • A test study is conducted to reduce the amount of H 2 S in the non-condensable gas in the geothermal fluid using chemical washing methods. Geothermal power plants are among the most important renewable energy power plants owing to their high-capacity factors and integrated utilization possibilities. Currently, these power plants utilize geothermal fluid to generate electricity. Although their emissions are lower than those of conventional power plants, gasses such as CO 2 and H 2 S are released into the air from the cooling towers, particularly in flash-type geothermal power plants To reduce the emission of CO 2 gas released from geothermal power plants, reinjection studies have mainly been carried out around the world. These types of studies require extensive analysis of underground fracture systems, detailed geosciences, and the reservoir studies. However, these studies are considered risky and expensive for most plant operators because possible changes in underground fracture systems may affect the productivity of geothermal production zones. In terms of the environmental impact, hydrogen sulfide is a more harmful gas than CO 2. Effective H 2 S removal methods cannot be widely used, except in areas with extremely high concentrations, because they commonly incur significant costs for plant operators. Effective H 2 S removal methods are not widely available except for geothermal sites with high concentrations. The fact that local limit values can be exceeded in geothermal power plants with relatively low H 2 S concentrations, such as geothermal power plants in Türkiye, pushes plant operators to find new low-cost solutions due to high operation costs. For this reason, a treatment method that can be applied at every site and whose cost is not too high has not yet been put forward. However, NaOH is used for this purpose in geothermal fields such as steam-dominated Geyser field to increase the pH values in geothermal wells, which has been producing for a long time. In this study, field tests were carried out with five different chemicals and pure water to examine the reduction of non-condensable gasses in a geothermal power plant located in the Kızıldere (Denizli, Türkiye) geothermal field, one of the most important geothermal fields in the world. According to this, the capture of these gasses is technically possible using chemical methods, with a performance of up to 70 % observed in CO 2 gas capture. However, although it is possible to capture 70 % of non-condensable gasses with such chemical methods, the consumable cost of the operation is quite high. [ABSTRACT FROM AUTHOR]

Geothermal energy is one of the strategies employed by the Indonesian government to meet rising electricity demand. Developing geothermal energy is often characterized by uncertainties and requires sequential decision-making which is divided into four development phases: 1) identification, 2) exploration, 3) exploitation, and 4) engineering, procurement, construction, and commissioning (EPPC) before it can be commercialized. Traditional valuation techniques often produce a negative net present value (NPV), suggesting decision to reject the project's investment plan. This paper investigates the economic viability of a geothermal power generation project using both NPV and real options analysis (ROA). Costs and uncertainties associated with the various development phases as well as the investment structure of geothermal projects are studied. We develop a framework for assessing the impact of four uncertainties using a binomial lattice: capacity factor, electricity price, make-up welldrilling costs, and operation and maintenance (O&M) costs. Secondary data from an Indonesian context geothermal power plant was used. Positive option values were found for the lattice approach compared to negative values found for the common NPV calculation. The result of this study showed the successful outcome of the exploration stage is very critical to determining the continuation of the project. The framework supports decision-makers in evaluating the impact of geothermal power generation projects in the face of uncertainty by providing a rigorous analysis. The movement of the underlying asset's value in the whole project's lifetime will assist the management in deciding on whether to exit or continue. [ABSTRACT FROM AUTHOR]

Act No. 21/2014 on Geothermal Energy is considered a solution to the slow development of geothermal energy utilization for power plants by opening the way for exploitation in conservation forest areas. However, in practice, such exploitation is still constrained because it often clashes with the conservation interest. This study aims to review: (1) the role of Act No. 21/2014 as a legal justification to conduct geothermal power plant exploitation in Gunung Kembar and Gunung Waihlup within the core zone of Gunung Leuser National Park (GLNP), and (2) the potential impact of such exploitation on the international recognition of Tropical Rainforest Heritage of Sumatra (TRHS) as a world heritage. This research is normative legal research, using secondary data consisting of primary and secondary legal materials, and employs a qualitative method to analyze the data. The results showed that Act No. 21/2014 could not justify geothermal exploitation activity within the core zone of GLNP. The study also concluded that the geothermal power plant activity is projected to have the potential to compromise TRHS recognition as a world heritage site.

Geothermal as one of renewable resources, provide alternative to address the ever-increasing energy demand. Most of the sources are located in forest ecosystem, on which ecological impact took place. PT Supreme Energi Rantau Dedap (SERD) is geothermal power plant project located in protected forest of Bukit Jambul Gunung Patah, South Sumatera. To investigate the large mammal’s species richness and its occupancy, the research observe data from SERD camera trap data installed during exploration and construction phases. Data are then analyzed with single season occupancy modelling with habitat changes (distance), light and elevation as the impact parameters. There are 13, out of 14, large mammals that captured by the camera trap and one was identified on direct encounter. Mostly, the best occupancy model is with constants covariate. Hog badger and muntjac constantly apparent as high occupancy both in naïve occupancy and model result. Four species occupancies are affected by geothermal power plant activity, they are: surili, forest pig, tapir and hog badger. The result showed that during the development phase, large mammals still inhabited the powerplant area despite the fact that some species responded negatively against the impact. Meanwhile, during the construction phase the species richness is tend to be higher but the detection level is lower with varied occupancy level for each large mammals’ species.

This research aims to analyze the student community's resistance to developing geothermal power plants (in Indonesia, referred to as Pembangkit Listrik Tenaga Panas Bumi, abbreviated as PLTP), analyze movement patterns, and assess the resistance movement's challenges. This study used qualitative research methods. Data were collected by interview, observation, and document study. According to the study's findings, the rejection movement began with local media coverage of police of icers' coercive tactics to secure the activities of corporations conducting preliminary research at the project site. The student community perceives PLTP development activities as environmental injustice, even though the projects are ostensibly environmentally friendly. Patterns of rejection movements are carried out in three ways: 1) Disseminating information; 2) Employing provocative tactics (delivering criticism of environmental injustice and police repression through performing arts such as theatre, murals, short monologues, and poetry readings); and 3) Mobilizing public support (through campaigns in public spaces and using social media, to campaign for the potential impact of PLTP development). The roots of rejection are typically minimal because there is no apparent conflict of interest between students and the PLTP development business (in contrast to the local community as the affected party. [ABSTRACT FROM AUTHOR]

The use of renewable energy is critical to the long-term development of global energy. Geothermal power plants (GPPs) differ in the technology they use to convert the source to electricity (dual, single flash, double flash, back pressure, and dry steam) as well as the cooling technology they use (water-cooled and air-cooled). The environmental consequences vary depending on the conversion and cooling technology used. Environmental consequences of geothermal exploration, development, and energy generation include land use and visual impacts, microclimatic impacts, impacts on flora-fauna and biodiversity, air emissions, water quality, soil pollution, noise, micro-earthquakes, induced seismicity, and subsidence. It can also have an impact on social and economic communities. As geothermal activity progresses from exploration to development and production, these effects become more significant. Before beginning geothermal energy activity, the positive and negative aspects of these effects should be considered. The number of GPPs in the Büyük Menderes Graben (BMG) geothermal area is increasing rapidly. According to the findings, in order to reduce the environmental and social impacts of the GPPs in the BMG, resource conservation and development, production sustainability, and operational problems should be continuously monitored. [ABSTRACT FROM AUTHOR]

Waste Heat Recovery System (WHRS) technology, e.g., Organic Rankine Cycle (ORC) has been explored as a solution to the increase in geothermal potential, possibly applied in binary or combined form, as a single-flash plant. This approach utilizes waste brine obtained from the separator. The purpose of this study, therefore, was to determine the performance of R134a refrigerant on ORC systems, using scroll-expander. The experiment was conducted with motor different frequency, at 7.5 Hz, 10 Hz, 12.5 Hz, 15 Hz, 17.5 Hz, and 20 Hz, evaporator temperature regulation of 95 °C, condenser at 10 °C, and an initial working fluid pressure of 5 bar. The results showed modifications in the ORC system performance with scroll-expander, alongside the motor frequency, which influenced the net power and energy efficiency. In addition, the maximum speed produced by the expander was 505.8 rpm, while the highest for energy efficiency achieved from the system was 3.17%, at a motor frequency of 7.5 Hz, with a resulting net power of 584.5 Watt.

Today, due to the challenges of fossil fuels and environmental crises, the use of geothermal energy as a renewable energy source can be useful. Since the two wells used for Sabalan geothermal power plant have different thermodynamic, in the present article, a new combined layout based on two flash cycles is proposed and investigated. In the introduced energy cycle, the transcritical Rankin and Kalina cycles are also used as downstream cycles to generate more power. In addition, heat exchangers are used to transfer heat to the liquefied natural gas (LNG) cycle to prevent energy and exergy losses in the downstream cycles. Relying on the proposed layout can prevent heat loss of downstream cycle's condensers. LNG cycle, in addition to generating more power by using heat losses, can supply natural gas to the system and suburban villages. It was determined that the proposed energy cycle is able to produce a net power of ~27.8 MW with a thermal efficiency of ~26%. In addition, the total exergy destruction and exergy efficiency of the cycle are 29.9 MW and 52.6%, respectively. The proposed energy cycle is evaluated from the energy and exergy points of view. In addition, a parametric evaluation is presented to assess the effect of various factors on the performance of the proposed energy cycle. Moreover, the net power and performance of the energy cycle have been optimized subject to various input variables using a genetic algorithm. [ABSTRACT FROM AUTHOR]

The geothermal resources of Russia have been studied since 1956. Three versions of the country's geothermal maps and estimation of geothermal field reserves with a total design yield of 218 m3/s have been developed. The largest reserves are available in Kamchatka krai, the Kuril Islands, the Republic of Dagestan, Krasnodar krai, Stavropol krai, and the Republic of Adygea. Steam-hydrothermal fields are located mainly in Kamchatka and the Kunashir Island (the Kuril Islands). In Russia, a total of 26 geothermal fields were in operation in 2019, including 11 fields in Kamchatka, four in Dagestan, and 11 in Krasnodar krai, Stavropol krai, and the Republic of Adygea. In 2019, 743 500 t of geothermal steam (without the Mutnovsky and Verkhne-Mutnovsky fields) and 20.2 million m3 of geothermal water were produced, including 13.9 million m3 in Kamchatka, 4.3 million m3, in Dagestan, and 2.0 million m3 in Krasnodar krai, Stavropol krai, and the Republic of Adygea. In 2019, 161 geothermal wells were in operation in Russia, including 84 wells in Kamchatka, 42 in Dagestan, and 35 in Krasnodar krai, Stavropol krai, and the Republic of Adygea. The Russian geothermal electric power facilities with a total capacity equal to 83.9 MW, which produced 428 million kW h of electric energy in 2019, are reviewed. The main technical characteristics and basic thermal cycle circuits of the Pauzhetka and Mutnovsky geothermal power plants (GeoPPs) are considered, and the problems connected with their operation and the prospects for their future development are pointed out. In 2019, 23 heat distribution stations (HDS) and central heat-supply stations (CHSS) with the total thermal power capacity equal to 82.5 MW and the thermal energy output equal to 282 000 (MW h)/year supplied geothermal heat for regions in Russia. The total length of geothermal heat networks in the two-pipe equivalent was equal to 172 km. The specific features relating to the operation of HDSs and CHSSs are pointed out, and prospects for the future development of geothermal heat supply are determined. [ABSTRACT FROM AUTHOR]

This study investigates the integration of thermoelectric generators (TEGs) into geothermal power plants to harvest energy from the waste heat and possibly, as a result, to increase the electrical energy generation of geothermal power plants. For this purpose, a model of a geothermal power plant-TEG hybrid system has been designed and implemented as an experimental setup. In addition, the optimized layout configuration of TEGs is obtained by using Matlab & Simulink for 48 pieces of the TEGs. A parametric energy analysis is conducted by varying the temperature of the reinjected geothermal brine and the inlet temperature of the cooling water, since TEGs are planned, so they can be employed between the pipelines of the cooling water and the reinjected geothermal brine. The effects that this has on the performance of the organic Rankine cycle (ORC) and the TEGs are then determined. It was found that the power output of the TEGs increases with the rise in temperature of the reinjected geothermal brine, but the net power of the ORC decreases. For the maximum net power output of the ORC, which is 217.6 kW, TEGs are able to produce 43.42 W for the temperature difference of 41.98°C that corresponds to this status. Therefore, TEGs must be used with lower power outputs to achieve more energy production from this hybrid energy system. For the high inlet temperature values of cooling water, the net power of the ORC decreases, and the power output of the TEGs also goes down. TEGs are able to produce 84.29 W for the temperature difference of 60.6°C for the ORC's maximum net power output of 260 kW. Therefore, it is clear that using TEGs in the power plant for low inlet temperature values of cooling water can be considered. In conclusion, this study demonstrates that waste thermal energy in reinjected geothermal brine can be harvested through TEGs, and this energy could be used to feed the electrical equipment of the power plant with low energy consumptions such as lighting, sensors, instrumentation, and control systems. However, TEGs should be used carefully, since they may affect the overall performance of the geothermal power plant. [ABSTRACT FROM AUTHOR]

China has been the leading country worldwide in direct geothermal utilization for a rather long time, which has contributed significantly to reducing carbon emissions. But the installed capacity of geothermal power generation in China is very small, and there are only a few geothermal power plants in China, specifically in Tibet, including the well‐known Yangbajing geothermal power plant. Therefore, it is anticipated that more high‐temperature geothermal resources will be discovered in order to promote China's power generation. There is potential for high‐enthalpy geothermal in the Eastern Linqing Depression in Shandong Province, where geothermal energy is stored in Ordovician and Cambrian carbonate strata. Based on the geothermal gradient in Cenozoic strata and the depth of the target geothermal reservoir, the temperature distribution pattern of the reservoir was analyzed, and two "sweet points" were identified in the Yucheng geothermal field and the Guanxian geothermal field, where the reservoir temperature is predicted to be higher than 200°C at a depth of less than 8000 m. Due to the low karst fissure ratio and the insufficient geothermal fluid in the geothermal reservoir, it is recommended that an enhanced geothermal system be set up, to increase the permeability of the natural fracture system in the carbonate formations and provide sufficient fluid for power generation through reinjection of used geothermal fluid. The power generation capacity of the two geothermal fields was estimated using a volumetric method, revealing a power generation capacity of 1621.02 MWe for the Yucheng geothermal field, and 1287.19 MWe for the Guanxian geothermal field. [ABSTRACT FROM AUTHOR]

Improving energy efficiency and reducing carbon emissions are crucial for the technological advancement of power systems. Various carbon dioxide (CO2) power cycles have been proposed for various applications. For high-temperature heat sources, the CO2 power system is more efficient than the ultra-supercritical steam Rankine cycle. As a working fluid, CO2 exhibits environmentally friendly properties. CO2 can be used as an alternative to organic working fluids in small- and medium-sized power systems for low-grade heat sources. In this paper, the main configurations and performance characteristics of CO2 power systems are reviewed. Furthermore, recent system improvements of CO2 power cycles, including supercritical Brayton cycles and transcritical Rankine cycles, are presented. Applications of combined systems and their economic performance are discussed. Finally, the challenges and potential future developments of CO2 power cycles are discussed. CO2 power cycles have their advantages in various applications. As working fluids must exhibit environmentally-friendly properties, CO2 power cycles provide an alternative for power generation, especially for low-grade heat sources.

This research is proposed to fully investigate the performance of a single‐effect water/lithium bromide absorption chiller driven by geothermal energy. Since absorption cycles are considered as low‐grade energy cycles, this innovative idea of rejecting fluid from a single‐flash geothermal power plant with low‐grade energy would serve as efficient, economical, and promising technology. In order to examine the feasibility of this approach, a residential building which is located in Sharjah, UAE, considered to evaluate its cooling capacity of 39 kW which is calculated using MATLAB software. Based on the obtained cooling load, modeling of the required water/lithium bromide single‐effect absorption chiller machine is implemented and discussed. A detailed performance analysis of the proposed model under different conditions is performed using Engineering Equation Solver software (EES). Based on the obtained results, the major factors in the design of the proposed system are the size of the heat exchangers and the input heat source temperature. The results are presented graphically to find out the geofluid temperature and mass flow and solution heat exchanger effectiveness effects on the chiller thermal performance. Moreover, the effects of the size of all components of the absorption chiller on the cooling load to meet the space heating are presented. The thermal efficiency of the single‐flash geothermal power plant is about 13% when the power plant is at production well temperature 250℃, separator pressure 0.24 MPa, and condenser pressure 7.5 kPa. The results show that the coefficient of performance (COP) reaches about 0.87 at solution heat exchanger effectiveness of 0.9, when the geofluid temperature is 120℃. [ABSTRACT FROM AUTHOR]

This paper presents the simultaneous optimization of the design and operation in nominal conditions of a geothermal plant where the geothermal fluid is split into two streams to feed an Organic Rankine Cycle (ORC) and a District Heating Network (DHN). The topology of the DHN is also investigated. A Mixed Integer Non-Linear Programming (MINLP) optimization problem is formulated and solved using the GAMS software in order to determine the ORC sizing and the DHN topology. In this study, only R-245fa is used as ORC working fluid, an optional Internal Heat Exchanger (IHE) is considered in the ORC and consumers in DHN can be definite or optional. A multi-objective optimization is performed by maximizing the annual net profit and minimizing the total exergy losses in the plant. The weighted sum of objective functions is used to solve the problem. By varying the weight factor, a Pareto front is obtained and the distance to the ideal, but infeasible, solution enabled to choose the best compromise. Four different DHN topologies are observed depending on the weight factor. Using a suitable criterion to make a decision, the selected configuration corresponds to the most expanded DHN with the smallest value of profit. A sensitive analysis shows that, in case of lower geothermal temperature, it is possible to obtain a unique DHN topology whatever the weight factor. [ABSTRACT FROM AUTHOR]

An assessment of the energy efficiency of a hybrid solar-geothermal power plant is performed taking into account the geothermal resource of one of the productive well (TD4) and the direct normal irradiance at Tendaho geothermal site in Ethiopia. A thermodynamic model of a single-flash geothermal plant integrated with a parabolic trough concentrated solar power system is developed to estimate the energy production in a hybrid solar-geothermal power plant. In the hybrid power plant, the parabolic trough concentrated solar power system is employed to superheat the geothermal steam in order to gain more energy before it expands in the turbine. Thermodynamic analysis, based on the principles of mass and energy conservation, was performed to assess the efficiency of the hybrid power plant at the given conditions of Tendaho geothermal site. A figure of merit analysis was also employed to evaluate whether a hybrid power plant could produce more power than two stand-alone power plants namely the solar and geothermal power plants that constitute the hybrid power plant. Results showed that the hybrid power plant technically outperformed the two stand-alone power plants. By integrating the two energy resources, the hybrid power plant proved to generate 7158 kW of electricity which is larger than the sum of the two stand-alone power plants (geothermal and solar).

Binary geothermal power plants (GPP) always attract researchers' attention as they are renewable-energy operated, low-temperature, high-performance, environmentally-friendly, and baseload power plants. In addition, they need to be monitored, controlled and optimized due to their complex structure and functioning. This article presents the application of the Simulated Annealing (SA) algorithm for the thermodynamic performance optimization on the verified thermodynamic model of the SINEM GPP operating in Aydın, Turkey. This algorithm is also compared to the Gravitational Search Algorithm (GSA). By using these methods, 17 optimization parameters in the plant model are simultaneously optimized for maximum exergy efficiency. Study results show that the exergy analysis, gravitational search algorithm and simulated annealing algorithm respectively determined the exergy efficiency of the plant as 14.48%, 30.62%, and 38.49%. The SA algorithm has a better performance compared to the other two methods. System components such as condensers, vaporizers, and pumps are made more efficient using the SA algorithm. In addition, the most effective parameters of the plant are evaporator pressure differences and the mass flow of ORC's working fluid. By using GSA and SA algorithm, the gross electricity generation in the power plant can be increased by 2.11 MW and 3.15 MW, respectively. While GSA uses the procedure of reducing the amount of component exergy destruction, the SA algorithm uses the procedure of reducing the amount of electricity spent in the operation of the plant equipment. The rate of non-condensing gas (NCG) outlet, which is harmful to the environment, can be reduced by using SA algorithm. In this way, a power plant can be operated more economically and in a more environmentally friendly manner. • It is used a simulated annealing (SA) algorithm for maximizing performance of a real GPP. • A comprehensive research and real-world constraints are conducted for design and off-design. • Simulation programs (SA and GSA) are compared with each other for a parametric study. • The gross electricity generation in GPP is increased by 2.11 MW and 3.15 MW with GSA and SA. • The release of non-condensing gas (NCG) can be reduced by using SA algorithm. [ABSTRACT FROM AUTHOR]

Using hybrid renewable energy systems is a smart choice for reducing the carbon emitted by power plants. It also helps climate change mitigation and global warming, leading to universal health for humans and the environment. The efficiency of these systems depends on choosing the right combination of renewable sources, their sizes, and proper scheduling of the generating units. This paper suggests an optimisation method for sizing a geothermal/PV/wind/diesel system, both in off-grid and grid-connected configurations. In the grid-connected mode, the possibility of selling surplus energy generated by renewable resources to the network is considered. Investigations reveal that without accurate control of geothermal reservoirs, they may become depleted. In this study, a strategy is suggested for unit commitment; moreover, the harmony search algorithm is used to find the optimal size of the hybrid system in both configurations. The effectiveness of the proposed approach is represented by simulating an HRES for Ferdows/Iran. [ABSTRACT FROM AUTHOR]

The vision of the community around geothermal power plants and the development of the power plants should be based on sustainable development principles, without jeopardizing the quality of life and justice for communities surrounding the power plant. This research aims to: (i) identify issues that arise as an result of the development of geothermal power plants in rural Tompaso, and (ii) find solutions to the issues to minimize the conflicts that arises from further geothermal power plant development in rural Tompaso and its surroundings. This study is based on the competitive intelligence research method. The results show that the development of geothermal power plants in Tompaso has a negative impact on the natural and social environment. The technical solutions offered include: (i) bioremediation by cultivating plants that absorb arsenic; (ii) biosulfurization and desulfurization for reducing air pollution, especially sulfur; (iii) floods and extreme drought managed by improving infrastructure and reforestation; (iv) social conflicts (land acquisition, working days, labor recruitment and settlement security) are solved by intensifying program dissemination to the community and involving local communities in decision making. The recommended policy provides incentives to the local community through strategic programs for the development of human and natural resources. [ABSTRACT FROM AUTHOR]

Today, there is a growing awareness of the need for environmental protection and a healthy ecological environment. Given the growing popularity of renewable energy sources, they should be familiar with their environmental impact. Each renewable energy source has more or less environmental impacts that are most often compared to the influence of conventional fuels on the environment. The aim of this article is to show the potential impacts of geothermal power plants on the environment both in the construction phase and in the phase of regular work. Environmental impacts may be temporary or irreversible and include changes in habitats and land use, atmospheric emissions, increased noise, impact on surface and groundwater, land subsidence, occurrence of seismicity and solid waste disposal. The magnitude of the influence depends on the characteristics of the geothermal source, the applied thermodynamic cycle, and the applied abatement systems.