Search

This paper presents a techno-economic approach to readily assess the profitability or otherwise of combined cycle power plants (CCPPs) for increased electricity production in Nigeria. As a case study for this analysis, a combined cycle gas turbine plant with 650MW installed capacity at Afam VI power station is used to evaluate the installation of a 1000MW and 1500MW CCPP economically. The results and analysis determined a Levelized cost of electricity of N41.57k/KWh and N34.09k/KWh for the 1500MW and 1000MW CCPP, respectively. It signifies an increase of 33.33% and 66.67% in the cost of electricity per kWh between the 1000MW and 1500MW plant capacities respectively, relative to the 650MW CCPP. Therefore, the low LCOE makes it economically viable to install the 1000MW CCPP for electricity production in the country. The paper also proposes upgrading existing gas-fired power plants in the country into combined cycle power plants for improved electricity supply.

Author(s): Mathew, Paul; Farmer, Alision; Werner, Jacob | Abstract: Purpose and Audience A wide spectrum of laboratory owners, ranging from universities to federal agencies, have explicit goals for energy efficiency and greenhouse gas reductions in their facilities. For example, new federal buildings and major renovations of existing buildings are to reduce fossil fuel-generated energy consumption by 90% in 2025, and 100% in 2030, compared with a 2003 baseline (FEMP n.d.). Minnesota SB2030 standard requires achieving an 80% reduction from the average building baseline for commercial, institutional, and industrial buildings (SB2030 n.d). A laboratory—new or existing—is much more likely to meet energy efficiency goals if quantitative metrics and targets are explicitly specified and tracked over the life cycle of the building, from design through construction, commissioning, operations, and renovations. If efficiency targets are not explicitly and properly defined, any additional capital costs or design time associated with attaining higher efficiencies can be difficult to justify relative to other priorities. The purpose of this guide is to provide guidance on how to specify and compute energy efficiency metrics and benchmarks for laboratories, at the whole-building as well as the system level. The information in this guide can be used to incorporate quantitative metrics and targets into new construction or retrofit of existing facilities. For information on strategies and technologies to achieve energy efficiency, the reader is referred to I2SL resources, including technology best practice guides and case studies.

Among the technologies being researched for grid-scale electricity storage, pumped thermal energy storage consists of storing electricity as thermal energy, with the conversions being done by a reversible heat pump/heat engine system. Advantages include the use of abundant and cheap materials, conventional components from the power industry, as well as full flexibility in siting. Various thermodynamic cycles can be used for the energy conversion, including the Joule-Brayton, transcritical, and glide (also known as Kalina) cycles. The latter has not been extensively studied yet for PTES and is the focus of the present work. Akin to a Rankine cycle, it differs by employing a zeotropic mixture for the working fluid. As a result, evaporation and condensation occur non-isothermally over a temperature “glide”, making this cycle a good match for sensible heat storage. The mixture used for the working fluid must be chosen carefully. Its effective heat capacity during phase change (a well defined property due to the temperature glide) can exhibit extremely high variability, which would incur substantial pinch-point problems and thus inefficiency in the heat transfer processes integral to PTES. In the present work, an alkane mixture is therefore optimised to achieve near-constant heat capacity. This alkane mixture is then used as the working fluid in a model of a low temperature glide cycle that uses water for both the hot and cold stores. Despite the low temperatures involved, the computed cycle round-trip efficiency reaches roughly 55% under realistic assumptions for isentropic efficiency and heat exchanger effectiveness. This is largely due to the efficient heat transfer enabled by optimising the working fluid. Energy density is relatively low at 2.2 kWh.m−3 compared to other PTES cycles, though still several times higher than for pumped hydro storage. Capital cost is estimated at 15-45 $/kWhe for the specific energy cost and 1300-2900 $/kW for the specific power cost, making this competitive with batteries for long duration storage even under conservative assumptions. Capital cost is then investigated further in order to analyse the physical drivers of cost in PTES systems in general, both in terms of power and energy. The nature of the working fluid influences the specific power cost via the turbomachinery as well as the heat exchangers. Operating conditions like pressure and temperature also have a major effect; in particular, increasing temperature lowers the heat-to-work ratio of the cycle and therefore lowers heat exchanger cost, although beyond a certain point material limits force a switch to more expensive materials and cause a discrete jump in cost. In order to improve efficiency, energy density, and potentially reduce cost, a higher temperature glide cycle is then modelled, after the optimisation of a new working fluid mixture. To that end, many fluids are examined according to several criteria, before deciding on a final mixture that is also based on alkanes. Pressurised water is used for the hot store at up to 180 °C while unpressurised water is again used for the cold store. Performance is characterised by parametric studies which suggest round-trip efficiency can reach 60%, with an energy density of around 5 kWh.m −3 . The specific power cost is (conservatively) estimated at 1600 $/kW, an improvement on the low-temperature cycle thanks to the lower heat-to-work ratio. However, the specific energy cost is higher at around 120 $/kWhe, due to the expense of the pressure vessel for the hot store. Consequently, the PTES plant’s storage duration determines which of the low and high temperature glide is most cost-effective.

Remote areas electrification is usually achieved through costly and eco-unfriendly diesel generator (DG) systems with additional cost-obstacles arising through diesel–fuel transportation. Hybridization of renewable energy systems (RESs) with DG units offers a dynamic approach of electrification for the remote areas. A techno-economic study is required to assess the viability of RES in such locations. This research work examines the case of Al-Shumaisi cluster, located in the west of Makkah Province, Kingdom of Saudi Arabia (KSA). This is where the Makkah transport company (MTC) is located. A techno-economic investigation is performed for a commercial load profile of MTC with a hybrid wind/DG/fuel cell/battery/electrolyzer system. In this study, two hybrid configurations are proposed: 1) wind/DG/FC/battery system; 2) wind/FC/battery system. Moreover, another configuration that uses only DG units is also investigated. A comparative study is achieved for the most optimal combination, depending on the gross present cost (GPC) and levelized cost of energy (LCOE) as the essential parameters. Furthermore, other financial parameters like operation and maintenance (O&M) costs, capital costs, and replacement costs are investigated. The well-recognized simulation tool, HOMER (Hybrid Optimization of Multiple Energy Resources) developed by the National Renewable Energy Laboratory, is used to fulfill this study. The sensitivity investigation is carried out by optimally scaling the configuration capacities as well as by monitoring the future changes like weather, load demand, and fuel price uncertainties. The results of the sensitivity investigation and HOMER simulation confirm that the wind/DG/FC/battery hybrid off-grid configuration is the most economic and eco-friendly solution with a total GPC of 7.045 million USD, COE of 0.271 USD/kWh, and CO2 emissions of 566 tons. This signifies the 13.84% reduction of net present cost compared to DG-based units, with a 64.2% decrease of pollutants and zero unmet load.

Dividing-wall columns (DWCs) are widely used in the separation of ternary mixtures, but rarely seen in the separation of petroleum fractions. This work develops two novel and energy-efficient designs of lubricant-type vacuum distillation process (LVDP) for the separation of hydroisomerization fractions (HIF) of a hydrocracking tail oil (HTO). First, the HTO hydroisomerization reaction is investigated in an experimental fixed-bed reactor to achieve the optimum liquid HIF by analyzing the impact of the operating conditions. A LVDP used for HIF separation is proposed and optimized. Subsequently, two thermal coupling intensified technologies, including side-stream (SC) and dividing-wall column (DWC), are combined with the LVDP to develop side-stream vacuum distillation process (SC-LVDP) and dividing-wall column vacuum distillation process (DWC-LVDP). The performance of LVDP, SC-LVDP, and DWC-LVDP are evaluated in terms of energy consumption, capital cost, total annual cost, product yields, and stripping steam consumption. The results demonstrates that the intensified processes, SC-LVDP and DWC-LVDP significantly decreases the energy consumption and capital cost compared with LVDP. DWC-LVDP further decreases in capital cost due to the removal of the side stripper and narrows the overlap between the third lube oils and fourth lube oils. This study attempts to combine DWC structure into the separation of petroleum fractions, and the proposed approach and the results presented provide an incentive for the industrial implementation of high-quality utilization of HTO through intensified LVDP.

Desiccant dehumidification systems are thermally regenerated systems that can be used either as standalone or as complementary additives for conventional cooling systems. One of their best competitive qualities is the potential to utilize low-grade heat sources for the regeneration process, thus decreasing electrical power consumption and scaling back the emissions of greenhouse gasses. However, up till now, desiccant dehumidification systems saw limited practical applications, due to their relatively high capital costs and low efficiency. To enhance the commercial competitiveness of desiccant dehumidification systems and expand their fairly tiny niche market, it was necessary to improve the system's performance and reliability and reduce their costs. A detailed discussion of the current designs configurations and the main differences between them may help future researchers to come up with novel, innovative designs, to overcome the system's drawbacks and make them actual viable alternative competitors in the dehumidification market. Consequently, this paper presents and analyzes the development of those configurations in the following three main aspects: packed bed, fluidized bed, and rotating desiccant wheel.

Al-Marj is located about 100 km from Benghazi, and it has a rugged mountainous terrain. The grid extensionmakesit impractical in some places, and off-grid electricity the best option. In this study, the feasibility of a small hybrid electrical Micro-hydro/Photovoltaic/battery supply system for road lighting was analyzed. The reservoir's water potential is analyzed as well as meteorological data collected from NASA. The initial reservoir flow data was taken for accurate hydropower modeling located at the start of the slope by measuring the total height with the help of GPS (Geographical Positioning System) and flow data obtained from the Ministry of Water and Irrigation. The average flow rate is 0.46 m3/s. HOMER software was used to model and analyze data for a hybrid power generation system. The study included the electrical load for lighting the road with 100 poles powered by solar energy with a LED lamp. From the HOMER program result, 30 KW PV and 0.9 KW Hydro was selected. It has an initial energy cost of $0.032 per kilowatt-hour, much lower than the network system capital cost for such particular site. For a distance of more than three kilometers, the government network can use no lighting.

The solar energy as renewable energy resources for desalination of water is novel, since it allows the daily use of renewable resources existed. Three phases are employed for desalination process. The first phase is preheating the pumped seawater, this is followed by steam generation phase by means of parabolic dish or trough collectors. The third phase is the condensation phase. An automatic sun tracking system is attached to parabolic dish or trough collector to increase the efficiency of solar energy collected during the day. Preliminary calculations suggest that the system could provide a temperature of 315 °C at least during the day with about 0.06 L/s of soft water, using parabolic dish of 4 m2 surface area. Solar thermal energy had previously only be used in small-scale devices in rural regions for sea water desalination. The reason for this has mainly been explained by the relatively low productivity rate compared to the high capital cost. However, the coming shortage in fossil fuel supply and the growing need for fresh water in order to support increasing water and irrigation needs, have motivated further development of water desalination and purification by renewable energies.

While hydrogen generation by alkaline water electrolysis is a well-established, mature technology and currently the lowest capital cost electrolyser option; polymer electrolyte membrane water electrolysers (PEMWEs) have made major advances in terms of cost, efficiency, and durability, and the installed capacity is growing rapidly. This makes the technology a promising candidate for large-scale hydrogen production, and especially for energy storage in conjunction with renewable energy sources – an application for which PEMWEs offer inherent advantages over alkaline electrolysis. Improvements in PEMWE technology have led to increasingly high operational current densities, which requires adequate mass transport strategies to ensure sufficient supply of reactant and removal of products. This review discusses the current knowledge related to mass transport and its characterisation/diagnosis for PEMWEs, considering the flow channels, liquid-gas diffusion layer, and polymer electrolyte membrane in particular.

There is a need to address the energy consumption of existing single family homes in the City of Toronto. This study outlines a process for developing and analyzing retrofit strategies for specific housing archetypes. The process was applied to Century, Century-Semi, and War Time Home archetypes. Housing data was collected and baseline energy models were prepared utilizing EnergyPlus software. Retrofit strategies were selected and analyzed for hygrothermal performance and cost. The process utilized a Brute Force method for retrofit selection considering the cost/benefit of each strategy and showed where in the process it was beneficial to upgrade each parameter. Furnace and air sealing parameters were typically upgraded early in the process as they showed an attractive cost/benefit. Basement walls and slab parameters were then upgraded, followed by exterior walls and roofs. Windows tended to be upgraded late in the process as they exhibited high capital costs compared to energy savings.

The introduction of modernized (improved) and new technologies is necessary to improve the quality of construction with a reasonable reduction in costs and terms of block-complete construction (BCS). There are various BCS technologies that combine known and developed methods and methods. Therefore, in order to increase the efficiency of construction, it is necessary to solve a number of tasks: to calculate the enclosing structures at BCS in accordance with their requirements for thermal protection, to determine the economic feasibility of the measures under consideration. On the example of a research object, the choice of enclosing structures is presented in order to reduce capital costs. If the tasks are successfully solved, it will be possible to offer the restoration of objects destroyed by natural disasters, BCS of new buildings, as well as during the reconstruction of objects. The article presents: the object of research "Compressor station in the area of BPS-2 X field"; block buildings located on the site of the booster pump station are considered; the characteristics of the enclosing structures of the "sandwich" type with various heaters are given; their thermal engineering calculation and comparative analysis of the efficiency of the heat-insulating material were carried out. Conclusions, methods and ways of solving BCS problems are presented; modernization of construction technologies.

Variability of renewables like solar and wind remains a major concern, despite a substantial decrease in the capital cost of their power conversion devices. One of the methods to improve the reliability of power is to combine more than one renewable power sources and storage systems together, as per the local renewable potential, is called a hybrid renewable energy system (HRES). The exact sizing of individual sources and storage systems to fulfill the respective load demand for the renewable potential of the site is not a straightforward task. Different sizing and optimization methodologies are developed by the research community. A comprehensive overview of the literature of these methodologies is carried out in this paper. Classical techniques were being applied to the HRES sizing, but their limitations led researchers to increasingly look for multi-objective heuristic techniques. This has led to a range of evolutionary algorithms being employed lately. The robustness of these techniques made them an effective tool for the search of global optimum, but their convergence speed may well be slower in comparison to gradient-based methods in the vicinity of the optimum point. It is needed to come up with novel hybrid techniques, which can carefully combine the conventional and evolutionary techniques by augmenting their advantages and at the same time avoiding their shortcomings. The literature survey proves that HRES from very small capacity of a few watts to many megawatts have been proposed for a variety of different locations throughout the world with varying degrees of cost of energy.

Obtaining maximum power output even under adverse contributing factors is the main aim of all reconfiguration techniques that have been reported in literature. Although various attempt has been made to harness maximum energy via physical or electrical PV panel reconfiguration techniques. All these reconfiguration techniques increase the value of output power either by physical or electrical relocation of panel within a column or by placing it at a suitable position in the entire PV array. The placement of PV panel or reconnection of the PV panel at a new location is inspired by some optimization algorithm or by some pattern. This paper proposes a new reconfiguration scheme for maximum power output along with effective shade dispersion, lower voltage drops and lesser cost of cables. Paper also attempted to analyse the pragmatic aspect of PV modules connected under different reconfiguration schemes namely Series Parallel (SP), Total Cross Tied (TCT), Odd-Even (OE), Odd-Even-Prime (OEP), LU SHO, Sudoku etc. and evaluates the consequences of its applicability at field. Although the various reconfiguration scheme has reported to increase the output current and thereby the output power but the increase in capital cost of cables, voltage drop and power losses outweighs the increase in output current and power. Also, if the distance between the rooftop PV array and the location of the String Combiner Unit (SCU) is large, then loses will even be more. A comparative analysis of different reconfiguration techniques under various parameters is performed.

As one of the main engines driving economic growth, investment has made an important contribution to China’s economy. However, in recent years, the growth rate of China’s fixed asset investment has shown a downward trend. Therefore, it is vital to determine the main influencing factors of China’s investment for formulating stable investment policies. Using the nonlinear autoregressive distributed lag (NARDL) model, this study finds that economic policy uncertainty, capital cost, and raw material cost have asymmetrical impacts on China’s fixed asset investment. Further research finds that the above variables have asymmetrical impacts on the two major components of aggregate investment, private investment and public investment, but the impact mechanism for each is completely different. When facing the positive or negative impacts from different factors, different investment entities will adopt different directions and magnitudes of investment decisions, ultimately leading to asymmetric relationships between various variables and aggregate investment.

Renewable energy technologies (RETs), particularly solar and wind energy technologies, have experienced a rapid decline in their costs over the last two decades. Several studies claim that RETs are cost-competitive with fossil fuel technologies based on their levelized costs of electricity (LCOE), the most common indicator used to compare the cost competitiveness of electricity-generating technologies. However, no consensus exists due to the wide variations in factors influencing the LCOEs across countries and technologies. This study calculates more than 4000 LCOEs for 11 technologies, varying all input variables. It shows that the LCOEs for RETs, except concentrated solar and offshore wind, are lower than those for fossil fuel technologies at the lower range of capital costs and discount rates of 10% or lower. However, for a reasonable range of input variables, the study cannot justify the low auction prices for solar power, below US$20/MWh, recently observed in some parts of the world. The study illustrates how various factors influence the cost of electricity generation across technologies. It also compares the trends in electricity generation costs between RETs and fossil fuels over the last two decades.

On-grid and off-grid renewable energy sources have emerged as a more efficient way to meet large-scale urban and rural needs. The integration of renewables into the utilities/island mode as well as into the techno-economic feasibility studies determines the financial viability, technical and operational viability of the project. This study was conducted to integrate renewables and techno-economic feasibility analysis using the utility grid-connected and islanded mode to meet the demand for community and commercial loads with these strategic objectives. Three main analytical tasks have been performed, including: optimization, simulation, and sensitivity analysis. We selected four sensitivity cases and further divided each sensitivity case into four sensitivity loops, including different combinations of renewable energy sources, e.g., photovoltaics, wind turbines, battery banks, power grids, converters, and diesel generators. The following parameters were used to conduct a techno-economic feasibility analysis: capital costs, replacement costs, operating and maintenance costs, salvage costs, fuel costs, real-time commercial/community load, and climate data. The best results of sensitivity case-2 were selected for the techno-economic feasibility analysis of the remaining four sensitivity cases. The islanded mode net present and annualized sensitivity loop-1 costs in sensitivity case-2 were noted at $1381080.42 and $106832.62, respectively. Net present and annualized sensitivity loop-1 costs in sensitivity case-2 of the grid-connected utility mode were noted at $512792.1 and $39,666.71, respectively. The proposed utility grid-connected mode cost is two times lower than that of the islanded mode, so we have chosen sensitive case-2 for hourly, seasonal, and annual electrical load flow and techno-economic feasibility analysis to meet the community and commercial load demand.

Despite the higher capital costs of tunnels and supplementary cost of maintenance, fewer deterioration models have been built compared with other highway components. Most of these models were limited to structural defects, not operational conditions. Moreover, there are inherent subjectivity and inaccuracy of the developed models, which may affect the maintenance process. The aim of this research and proposed contribution are investigating and modeling the impact of explanatory variables and non-periodic maintenance effect on highway tunnel condition. The stochastic regression analysis has been conducted to come out with a realistic tunnel condition through the Monte Carlo simulation methodology. The research methodology consists of three phases: cluster analysis, regression modeling, and stochastic analysis. A dataset of 473 highway tunnels along 41 American states from the National Tunnels Inventory (NTI) has been used. Nine models have been developed with a high coefficient of determination (R2 = 90.8%). The obtained results and the models could help advance the development of tunnel deterioration models from a management perspective, not only from the structural view. The developed models help highway authorities to prioritize the maintenance and objectively make informed investment decisions based on the historical data. This research has come as a response to the significant problems facing the highway authorities regarding tunnels and asset management.

Domestic refrigeration appliances are ubiquitous consuming roughly 14% of the global residential electrical consumption. It is estimated that the global installed stock of domestic refrigerators is between 2 and 2.3 billion units. Furthermore, domestic refrigerators employ high global warming potential (GWP) refrigerants (e.g., R-134a). The global goal to limit the global warming to 1.5°C requires rapid reduction in CO2 emissions and other greenhouse gases (GHGs). Transition towards cost-effective, efficient, and environmentally friendly refrigeration technologies is considered one of the most effective measures to reduce GHG emissions. In this paper, we worked with 5 manufacturers in 4 developing countries to study energy efficiency design options and the associated incremental capital cost and incremental recurring cost (IRC). In our study, we have accounted for their product development capabilities, their productions volume, their relationship with original equipment manufacturers (OEMs), and the local product competition in their markets. Our detailed study showed that cost effective energy savings of 9.5 to 19.2% can be achieved while the maximum energy efficiency upgrades varied between 30.2 to 50%. Furthermore, the corresponding indirect emissions reduction varied by the local electricity production mix and the baseline technology. The cost-effective energy efficiency upgrades result in emission reduction of 65,145 to 612,959 metric tons of CO2eq while the maximum energy efficiency upgrades result in emission reduction of 157,675 to 1,077,005 metric tons of CO2eq.

PurposeIn many countries, innovation in building design for improving energy performance, reducing CO2 emissions and minimizing life cycle cost has received much attention for sustainable development. This paper investigates the importance of optimization tools for enhancing the design performance in the early stages of Vietnam's cooling-dominated buildings in hot and humid climates using an integrated building design approach.Design/methodology/approachThe methodology of this study exploits the non-dominated sorting genetic algorithm (NSGA-II) optimization algorithm coupled with building simulation to research a trade-off between the optimization of investment cost and energy consumption. Our approach focuses on the whole optimization problem of thermal envelope, glazing and energy systems from preliminary design phases. The methodology is then tested for a case study of a non-residential building located in Hanoi.FindingsThe results show a considerable improvement in design performance by our method compared to current building design. The optimal solutions present the trade-off between energy consumption and capital cost in the form of a Pareto front. This helps architects, engineers and investors make important decisions in the early design stages with a large view of impacts of all factors on energy performance and cost.Originality/valueThis is one of the original research to study integrated building design applying the simulation-based genetic optimization algorithm for cooling-dominated buildings in Vietnam. The case study in this article is for a non-residential building in the north of Vietnam but the methodology can also be applied to residential buildings and other regions.

The choice of condenser cooling option for concentrating solar power (CSP) plants is likely to affect their techno-economic feasibility. In view of this, an attempt has been made to assess relative techno-economics and net life cycle CO2-eq emissions mitigation (LCCM) potential for 50 MW nominal capacity wet-cooled and dry-cooled parabolic trough solar collector (PTSC) and dry-cooled solar power tower (SPT) based CSP plants with 6.0 h of thermal energy storage for two potential locations in India. It was observed that though dry cooling is likely to save significant amount of water (∼92%) in PTSC based plants, the same shall result in higher capital cost, higher performance penalty and higher parasitic power requirements leading to around 20% higher levelized cost of electricity (LCOE) as compared to wet-cooled PTSC based plants. It was also observed that the dry-cooled SPT based plants shall be able to deliver up to 4.5% higher annual electricity output and LCOE is also likely to be lowered by 13% than wet-cooled PTSC based plants. Considering emissions embodied and emissions associated with water transport/extraction from the source and water treatment, the estimation of LCCM from the PTSC and SPT based CSP plants have also been undertaken.

Phase-change solvents (PCSs) is a class of chemicals that promises significant cost reductions in post-combustion CO2 capture. However, their use in the design of efficient absorption/desorption processes is challenged by their non-ideal behavior. A generic and flexible model is proposed for the design of phase-change CO2 capture process systems, that enables the effective identification of highly performing flowsheet configurations and recycle stream redistribution policies. The validation of the model using experimental data for the PCS mixture of MAPA/DEEA (3-(Methylamino)-Propylamine/2-(Diethylamino)-Ethanol) indicates only 4% and 0.5% differences in the reboiler duty and in the absorption and desorption temperatures. The novel PCS mixture of S1N/DMCA (N-Cyclohexyl-1,3-Propanediamine/N,N-Dimethylcyclohexylamine) and the PCS MCA (N-methylcyclohexylamine) are used in the optimum design of CO2 capture process units in two industrial cases; a quicklime production plant and a gas-fired power plant. The reboiler duty of S1N/DMCA reaches 2.1 GJ/ton CO2 and the solvent exhibits up to 47% lower operating costs than the conventional MEA (Monoethanolamine), with only 1.7% higher capital costs. The loading of S1N/DMCA reaches up to 1.35 mol CO2/mol of solvent at the exit stream of the phase-separator, whereas this solvent exhibits up to 181% higher CO2 release efficiency than MEA in the desorber. S1N/DMCA is an excellent option for plants with flue gas CO2 concentration as low as 3.5 mol%.

Capital cost limitation is a practical problem in a system installation and single optimal rating may lead to requirement of high capital cost investment. This calls for a need a need to develop a framework which provides alternate system ratings when confronted with capital cost limitation. A framework for sizing microgrid distributed energy resources (DER) considering capital cost limit and inclusion of manufacturer catalog ratings is introduced in this paper. This framework uses a system composite cost metric which combines system capital cost and operating cost and is calculated on monthly basis. The monthly optimization results are transformed to evaluate the feasible DER ratings and annual savings possible. The framework is demonstrated using a case study of sizing microgrid to perform peak shaving at industrial facilities located in the UK and USA. This paper also introduces development of Hardware-in-Loop (HiL) system as a tool to validate microgrid sizing results. The HiL simulation verifies the estimated annual savings possible through the installation of microgrid and verifies no violation of state of charge limits of battery energy storage system in the microgrid operation simulation, thus validating the sizing framework.

The Scripps Institution of Oceanography (SIO) current coastal/local research vessel, the R/V Robert Gordon Sproul, is nearing the end of its service life and will soon require replacement. This study compares three potential variants for an R/V Sproul replacement vessel (SRV): a Baseline SRV consisting of a traditional diesel-electric powertrain, a Battery Hybrid SRV (battery/diesel-electric) and a Hydrogen Hybrid SRV (hydrogen fuel cell/diesel-electric). All three variants meet the science mission requirements of the SRV but with varying levels of zero-emission runtime, energy efficiency and emissions. The Battery Hybrid SRV can provide 2.5 h of zero emissions (battery only) operation, but could not complete any of the identified SRV science missions without also engaging the diesel generators. In contrast, the Hydrogen Hybrid SRV can provide 23.4 h of zero emission (hydrogen only) runtime, and can complete 74% of the SRV science missions solely with zero-emission operation. The superior performance of the Hydrogen Hybrid SRV is attributable to the higher volumetric energy storage density of the LH2/fuel cell combination. The capital costs of these vessels are estimated to be: ∼ $21.4 M for the diesel-electric Baseline SRV, ∼ $26.0 M for the Battery Hybrid SRV vessel and ∼ $34.4 M for the Hydrogen Hybrid SRV. The “well-to-waves” (WTW) greenhouse gas (GHG) and criteria pollutant emissions were estimated using various sourcings for the diesel fuel, electricity and hydrogen fuel. The lowest emission levels are achieved with the Hydrogen Hybrid variant using 100% renewable hydrogen. The annual WTW GHG emissions from the Hydrogen Hybrid using renewable LH2 in combination with fossil diesel in the hybrid arrangement yields a 26.7% GHG emissions reduction from the Baseline vessel using fossil-derived diesel fuel. The Battery Hybrid vessel with 100% renewable electricity combined with diesel fuel provides a 6.9% reduction in GHG emissions. Similar results are seen for the criteria pollutant emissions. The hybrid vessels are also compared with regard to operational safety. The study reveals that hydrogen fuel-cell technology provides an effective hybrid supplement to diesel power for a coastal/local research vessel.

In this work optimization of the parabolic trough (PT) based concentrated solar power (CSP) system is analyzed for solar energy export from Saudi Arabia to European and Asian countries based on their peak load hours. Initially, Al-Ahsa, in east, and Tabuk, in the west, are compared for a PT based CSP plant for electrical energy generation as these locations are used to export solar energy from Saudi Arabia to Pakistan, India, and China in east and Greece, Germany and UK in the west. The analysis is performed to sell electrical energy generated by the CSP plant to the customers in their peak load hours to reduce their load factor and keep the capital cost minimum. A high voltage direct current (HVDC) transmission system is employed for this study as an undersea cable for Asian or European countries. The feasibility of 2 GW solar energy export by PT based CSP system transmitted by 2 GW bipolar 660 kV HVDC transmission line is based on the net present value of the project (NPV), real levelized cost of energy (LCOE), and the payback period of the project where Karachi, Pakistan has the highest NPV of 1866 MUSD with LCOE of 10.76 cents/kWh and a payback period of 12.7 years.

Several companies are developing enabling elements of urban air mobility (UAM) for air taxis, including prototypes of electric vertical take-off and landing (eVTOL) vehicles. These prototypes incorporate electric and hybrid powertrains for multi-rotor and tilt-rotor crafts. Many eVTOLS are using batteries for propulsion and charging them rapidly between the flights or swapping them for slow charging overnight. Rapid charging degrades the battery cycle life while swapping requires multiple batteries and charging stations. This study has conducted a technoeconomic evaluation of the eVTOL air taxis with alternate powertrains using hydrogen fuel cell systems being developed for light-duty and heavy-duty vehicles. We consider performance metrics such as fuel cell engine power, weight, and durability; hydrogen consumption and weight of storage system; and maximum take-off weight. The metrics for economic evaluation are capital cost, operating and maintenance cost, fuel cost, and the total cost of ownership (TCO). We compare the performance and TCO of battery, fuel cell and fuel cell – battery hybrid powertrains for multi-rotor and tilt-rotor crafts. We show that fuel cells are the only viable concept for powering multi-rotor eVTOLs on an urban scenario that requires 60-mile range, and hybrid fuel cells are superior to batteries as powertrains for tiltrotor eVTOLs.

Canada’s access to neutron beams for neutron scattering was significantly curtailed in 2018 with the closure of the National Research Universal (NRU) reactor in Chalk River, Ontario, Canada. New sources are needed for the long-term; otherwise, access will only become harder as the global supply shrinks. Compact Accelerator-based Neutron Sources (CANS) offer the possibility of an intense source of neutrons with a capital cost significantly lower than spallation sources. In this paper, we propose a CANS for Canada. The proposal is staged with the first stage offering a medium neutron flux, linear accelerator-based approach for neutron scattering that is also coupled with a boron neutron capture therapy (BNCT) station and a positron emission tomography (PET) isotope production station. The first stage will serve as a prototype for a second stage: a higher brightness, higher cost facility that could be viewed as a national centre for neutron applications.

Robotic-assisted total knee arthroplasty (TKA) may improve the precision of bone preparation and component alignment when compared to the conventional surgical approach; however, the detailed cost analysis of robotic-assisted TKA is lacking. This study aims to compare in-hospital costs between robotic-assisted and computer-navigated TKA. Patients undergoing primary TKA at a public hospital in Sydney between October 2018 and June 2019 were included. Patient demographics, surgical outcomes and in-hospital cost variables including, staff, critical care, emergency department, diagnostic, prosthesis, operating room, ward and other related costs until the discharge to the community were collected. Differences across in-hospital costs between robotic-assisted and computer-navigated TKA were compared using independent Student’s t-tests. Of the 258 primary TKAs, 181 (70.2%) were computer-navigated and 77 (29.8%) robotic-assisted. Surgical time (p

Congestion in power flow, voltage fluctuation occurs if electricity production and consumption are not balanced. Application of some electrical energy storage (EES) devices can control this problem. Pumped hydroelectricity storage (PHS), electro-chemical batteries, compressed air energy storage, flywheel, etc. are such EES. Considering the technical maturity level, storage time, capital cost, life cycle, potential etc., in India, PHS is found to be the best possible option with no additional fuel needs. In India, the Central Electricity Authority (CEA) has identified 63 sites where 96,524 MW PHS can be installed but at present 9 PHS with a total installed capacity of 4785.6 MW are in operation and 1205 MW is under construction [February 2021, CEA]. Therefore, India has wide scope to enhance its hydropower generation along with PHS. Generally, the lifespan of a PHS project is at least 50 years and these hydro projects help in reducing carbon footprint of Indian power sector as well as conserving scarce fossil fuels. So, in this paper, all the technical views related to PHS are discussed along with total PHS scenario of India as well as the constraints and policies are summarized.

This study assessed the environmental impacts and economic feasibility of generating heat using wood-briquettes (WBs), and heat and electricity using torrefied-wood-briquettes (TWBs). WBs and TWBs were manufactured from forest residues using portable systems and delivered to either residential consumers or power plants in the United States. An integrated cradle-to-grave life-cycle assessment (LCA) and techno-economic analysis (TEA) approach was used to quantify environmental impacts and minimum-selling prices (MSPs) of heat and electricity, respectively. Results illustrated that 82% and 59% of the cradle-to-grave global warming (GW) impact of producing heat resulted from the feedstock preparation in WBs and torrefaction in TWBs, respectively. About 46–54% of total cost in the production of heat were from labor and capital costs only. The GW impact of electricity production with TWBs was dominated by the torrefaction process (48% contribution). Capital cost (50%) was a major contributor to the total cost of electricity production using TWBs. The GW impacts of producing heat were 7–37 gCO₂eq/MJ for WBs, and 14–51 gCO₂eq/MJ for TWBs, whereas producing electricity using TWBs was 146–443 gCO₂eq/kWhe. MSPs of generating heat from WBs and TWBs were €1.09–€1.73 and €1.60–€2.26/MJ, respectively, whereas the MSP of electricity from TWBs was €20–€25/kWhe. Considering carbon and pile-burn credits, MSPs of heat and electricity were reduced by 60–90% compared to the base-case.

This work presents a novel renewable trigeneration plant powered by solar, geothermal and biomass energy, producing simultaneously electricity, heat and cool. The developed system includes a 193 m2 photovoltaic field, a 159 kWh lithium-ion battery, a 30 kWe organic Rankine cycle, a 350 kWth biomass auxiliary heater, a geothermal well at 96 °C and a 80 kW single stage H2O/LiBr absorption chiller. The Organic Rankine Cycle is mainly supplied by the geothermal well, producing electricity. An additional amount of electricity is produced by the photovoltaic panels. A detailed dynamic simulation model was developed in TRNSYS environment in order to calculate both energy and economic performance of the plant. The model includes algorithms validated versus literature and experimental data. The model of the renewable trigeneration plant is used for a suitable case study, a residential building in the Campi Flegrei (Naples, South Italy) area, a well-known location for its geothermal sources and good solar availability. The proposed plant exhibits promising energy performance achieving a primary energy saving of 139%, mainly due to the obtained excess energy. From the economic point of view, the proposed plant gets a limited profitability, showing a payback period of about 19 years, mainly due to the high capital cost of the employed technologies. A thermo-economic optimization is also implemented, considering photovoltaic field and battery capacities as independent variables. The results of the optimization suggest increasing the area of the photovoltaic field and to limit the capacity of electric energy storage system, due to the high specific capital cost of the lithium-ion battery. Finally, a multi-objective optimization is also carried out, aiming at calculating the set of the optimal design variables of the proposed trigeneration plant.

Background Even though raw and processed crops are consumed as food worldwide, one-third of these agricultural produces go as waste or by-products. These by-products contain several valuable components, such as pectin, that can be valorized in the food processing industry through waste recycling to improve resource efficiency. However, the conventional methods (e.g., acid extraction of pectin) have limitations, such as low yield, and are energy-intensive and associated with environmental problems. Therefore, the possibility of using emerging processing technologies for pectin extraction has attracted wider attention. Scope and approach This paper aims to describe the status of the valorization of food and agricultural by-products through the application of emerging processing methodologies with specific attention to pectin extraction. In this regard, papers published in this area of research during the past decade were retrieved from scientific databases and their findings were analyzed. Key findings and conclusions Emerging thermal (e.g., microwave and ohmic heating) and non-thermal (e.g., moderate electric field, pulsed electric field, high-pressure processing, and ultrasound), as well as combinations of these technologies (e.g., a combined effect of microwave and ultrasound) are among the innovative approaches that have been used for pectin extraction. These methodologies can result in higher extraction yields and produce pectin with a desirable degree of esterification. However, the industrial application of these technologies can be challenging at this moment due to relatively high capital costs, limited professional expertise, and inadequate data on process upscaling. Therefore, research on up-scaled versions and further training in this area of food processing are recommended.

Parking lots (PLs) equipped with electric vehicle (EV) chargers will be the most convenient places for EV users to charge their cars. However, there is a high degree of unpredictability around how car parks are used, especially shopping center parking lots (SCPLs). Moreover, the cluster charging of EVs in PLs may destabilise the grid. The application of a battery energy storage system (BESS) in PLs is a potential way to reduce the impact of EV charging on the grid. This article proposes an approach for estimating the size of a stationary BESS for PLs in a constrained grid. At first, the intermittent charging demand of EVs is determined by considering the travel patterns, charging needs, and driver behavior of EVs. Then, a region reduction method combined with nonlinear optimization is proposed to estimate the optimal size of the BESS such that the capital cost and operational cost of the SCPL are minimized. The proposed sizing method 1) ensures the maximum utilization of the stationary BESS; 2) avoids over/undersizing; 3) reduces operational costs; and 4) maintains; the reliability of the system. The applicability of the proposed method is shown by simulating different cases, characterized by real household travel survey data and shopping center car park occupancy data.

Accurate estimation of the static and dynamic wind loads on heliostats based on detailed measurement and characterisation of turbulence is crucial to avoid structural failure and reduce the cost of the structural heliostat components. Wind load predictions for heliostats are not specified in design standards for buildings because of a heliostat’s non-standard shape and the variations of wind velocity and turbulence in the lowest 10 m of the atmospheric boundary layer (ABL). This paper reviews the static and dynamic wind loads on heliostats in the most unfavourable operating and stow positions, with a focus on the aerodynamic effects related to the heliostat structural component geometry, turbulence parameters in the ABL and field spacing. An increased resolution of field-scale wind measurements at heliostat field sites is recommended to fully characterise the ABL turbulence, as the high-intensity gusts over shorter durations at heights below 10 m lead to high-amplitude displacements with larger frequencies than observed in standard building structures. Increased understanding and development of aerodynamic wind load predictions for heliostats, based on their critical scaling parameters and local wind conditions, would increase the accuracy of annual field efficiency models through an improved resolution of operating load data and reduce the capital cost of structural components in power tower plants.

Gas to liquid (GTL) is one of the main processes that liquefied natural gas through chemical conversion into synthetic crude that can be upgraded and separated into different useful hydrocarbons. The present study has been carried out to optimize the distillation column configuration and applied it to the GTL distillation unit. The distillation simulation code has been developed in two main parts, shortcut and rigorous based on inside–out algorithm. A modular design approach is presented in which the code is developed in only one computational environment. Compared to the existing methods, the uniform code avoids time-wasting data transmission between different commercial software. Therefore, the developed code includes all three main steps, generation, simulation and optimization, which are interconnected to achieve the best sequence according to the objective function. The genetic algorithm is utilized to minimize the hybrid TAC function that checks products specifications simultaneously. The results demonstrate the capacity of direct configuration that performances the best overall evaluation parts of TAC, operating costs, capital costs, and exergy losses, therefore it reduces up to 26% in operating cost compared with indirect configuration which is the most commonly used sequence in GTL plant.

Hydrogen network management has economic appeal due to its importance in oil refineries. It has become genuinely relevant due to the restrictions of sulfur content in fuels, which need hydrogen to be removed. Mathematical programming can be used as a tool for optimizing hydrogen networks, and the efficient management of hydrogen within the refineries can be achieved through a material balance of the units that make up the hydrogen network. In this work, an optimization model Mixed-Integer Linear Programming (MILP) and Mixed-Integer Nonlinear Programming (MINLP) for hydrogen networks was applied to minimize the operating costs. The optimization model was developed in GAMS, and it was validated using a literature case study and a real case study from a Brazilian Refinery. The operation cost was reduced by 10% and 19.6% with MILP and 9.7% and 31.5% with MINLP, for example 1 and 2, respectively. Comparing the results, both achieve significant savings in operating costs. The MILP model, which is easier to solve, has proved to be an efficient tool for optimizing hydrogen networks. However, optimization via MINLP, although not guaranteeing the optimal solution, resulted in lower operating and capital costs. The design of the optimized hydrogen networks was also detailed, and other extra restrictions were imposed on the problem.

Seismic analysis, design, and qualification of systems, structures, and components (SSCs) is a significant contributor to the capital cost of a nuclear power plant. To reduce capital costs of advan...

Рассмотрены вопросы оптимальной организации системы теплообмена установки первичной перегонки нефти ЭЛОУ АВТ. Для этого с целью выявления экономической целесообразности функционирующей системы теплообмена проведен пинч-анализ. В результате пинч-анализа были построены композитные кривые горячих и холодных потоков и большая составная кривая, позволившие определить предельно возможное количество рекуперируемой энергии технологическими потоками, тип энергоносителей по энергетическому уровню и значение оптимальной движущей силы, при которой обеспечивается минимум критерия оптимальности — суммарных приведенных и капитальных затрат. Результаты пинч-анализа показали наличие около 30 % полезной энергии для рекуперации технологическими потоками установки. Анализ методов синтеза оптимальных систем теплообмена показал, что одним из наиболее эффективных методов решения крупномасштабных задач является декомпозиционный подход, который подразумевает разбиение задачи синтеза на несколько подзадач меньшей размерности: задачи линейного программирования для минимизации энергетических затрат, задачи дискретно-непрерывного линейного программирования для минимизации числа теплообменного оборудования, задачи нелинейного программирования для определения минимальных суммарных приведённых затрат. В результате использования алгоритма декомпозиционного синтеза, были найдены оптимальные структуры системы теплообмена, режимы работы входящих в их состав теплообменников и даны экономические оценки найденным структурам. Результаты синтеза оптимальных систем теплообмена показали возможность для снижения суммарных приведенных затрат на 40 % при реорганизации функционирующей системы теплообмена. Анализ результатов синтеза схем с возможностью регенерации тепловой энергии показал возможность дополнительной экономии до 6377 тыс. у.е./г, что стало возможным вследствие использования излишков энергии для подогрева технологических потоков близлежащих установок.

A hybrid renewable energy system offers a significant cost and environmental benefits over the conventional sources due to the constant reduction in the capital costs and increase in the efficiency of renewable energy generators. The major challenge is to properly size the hybrid system components for supplying a stable and cost-effective power with lower environmental emissions. This study analyses a photovoltaic-PV and wind-based hybrid system using different storage technologies based on the technical and economic indicators while satisfying the load requirements of a remote community in an Australian state, Western Australia. For optimizing the system configurations, the effects of temporal resolutions, different storage technologies, PV tracking systems, and lifetime of the battery are comprehensively investigated in conjunction with a sensitivity analysis. Results indicate that the PV/Wind-based hybrid system with vanadium redox flow battery has a lower cost of energy-COE (0.229$/kWh) and net present cost-NPC ($558,118) than those of the PV/Wind/Li-ion (COE: 0.323$/kWh; NPC: $787,464) and PV/Wind/Zinc-Bromide (COE: 0.270$/kWh; NPC: $658,326) ones, but comparable with the PV/Wind/Lead acid (COE: 0.231$/kWh; NPC: $564,002). However, the PV/Wind with a pump-hydro storage option offers the lowest COE of 0.177$/kWh and the NPC of $431,818..

This work provides a comparative technical assessment of three technologies for CO2 removal from air: two aqueous-scrubbing processes and one solid sorbent process. We compute productivity and exergy and energy consumption using process simulations and mathematical optimization. Moreover, we evaluate the cost range and discuss the challenges for large-scale deployment. We show that all technologies can provide high-purity CO2 and that the solid-based process has the potential to offer the best performance, owing to an exergy demand of 1.4–3.7 MJ.kgCO2−1 and a productivity of 3.8–10.6 kgCO2.m−3.h−1. Translating productivity and energy into cost of CO2 capture via a simple model, we show that the capital cost is the main cost driver. All technologies have the potential to operate below 200 $.tonCO2−1 under favorable, yet realistic, energy and reactor costs. The solid-sorbent process achieves this under a broader range of conditions and is less dependent on the installation cost when a high mass transfer is achieved.

In the world and domestic practices of technical maintenance and repair (TMR) of locomotives there exists a tendency for the expanded use of technical diagnostics systems, the transition to predictive repair to reduce the costs of their life cycle. Modern hardware and software tools make it possible to create automated technical diagnostics systems (ATDS) for all types of locomotive equipment but equipping service repair locomotive depots with them requires significant capital costs with an unacceptably long payback period. The objective of the work is to develop a method and a corresponding simulation modelling software program to determine technical and economic feasibility of using certain means of technical diagnostics.Diagnostic systems reduce waiting time for repairs, the volume and cost of scheduled and unscheduled TMR, which makes it possible to reduce the operating fleet of locomotives.In modern economic calculations, to assess the success of an investment project, the indicator «Net present value (NPV)» of the project is used. Based on this principle, in relation to ATDS, a method for determining feasibility of introducing various types of ATDS and the corresponding methodology and software made with the algorithmic language VBA (Visual BASIC for Applications) in the MS Excel environment has been developed.The work carried out simulation modelling for Russian conditions of the payback of main types of diagnostic systems comprising on-board based microprocessor control systems, rheostat testing stations for diesel locomotives, diagnostics of traction motors, etc. The economic feasibility of introducing these systems has been proved. Also, economically inexpedient diagnostic systems have been identified, f o r example, automatic measurement of the profile of a wheel set tire.

The phenomenon of false financial statements still exists. However, in addition to the risk of being punished, what kind of price do companies have to pay? In recent decades, with China's rapid progress in economic, the relevant accounting system and corporate governance standards are actively improving, and the earnings quality is improving. This paper takes China's listed companies from 2015 to 2019 as samples, and adopts quantile regression supplemented by ordinary least square method to explore the relationship between earnings quality and capital cost. The research findings show that the higher the earnings management, the higher the capital cost, especially for the company with low capital cost. Nevertheless, for the extremely company with high capital cost, earnings management can reduce the capital cost. The research results can provide the focus of regulators of listed companies and reference for the revision of relevant accounting system.

In this paper, we examine the effect of relative/absolute firm efficiency on weighted average cost of capital (WACC). Using a sample of Korean listed firms, we find that WACC is negatively associated with relative firm efficiency (operational performance) suggesting that firms with higher (lower) relatively efficiency are expected to pay lower (higher) capital costs. When we repeat our analysis using absolute firm efficiency (ROA), we do not find a statistically significant relationship. Our results suggest relative efficiency which is estimated as output (sales) divided by the resources that are directly under the control of management is assessed by capital providers and impounded into a firm’s capital costs. Absolute efficiency (ROA) which is estimated as sales divided by total assets is not. Our results suggest that simple accounting ratios used in the accounting literature are not considered as informative to explain borrowing costs compared to relative efficiency that captures managerial operational performance.

It is shown that lowering area specific resistance (ASR) or Rt (total resistance) should lead to lower capital cost, CAPEX, and also to the lowest possible electrical power consumption per hydrogen produced, OPEX. Many researchers have focused for many years on thinning component layers and developing new higher-performance materials. Thinning of components to lower RT is widely researched. Based on simple correlations, the CAPEX of the solid oxide electrolysis cell (SOEC) stack cost could expect to be lowered by 25 percent by thinning components. In terms of size this low- Rt SOEC stack has the potential to be significantly smaller. Building off the DOE’s progress with SOFC, even lower Rt SOEC and SOFC’s are possible with techniques such as sputtering and Atomic Layer Deposition (ALD) which produce better conducting materials. This is truly remarkable in that the low per kilowatt SOEC stack cost and low power consumption may make the SOEC a truly realizable economically viable SO manifestation.

Although a thermoelectric device (TED) sub-cooler can improve the trans-critical carbon dioxide (TCO2) cycle, the maximum heating capacity by a single TED is limited by its internal properties. This paper integrates two serially connected and independently powered TED sub-cooler devices into the trans-critical carbon dioxide (TCO2) cycle to achieve a better share of the total heating capacity amongst the TED sub-coolers. A multi-objective optimization approach is used to further optimize this new TCO2+2-TED cycle in terms of coefficient of performance (COP) and system size. A capital cost analysis is also conducted to prove that this implementation is economically feasible. In the analysis, the effect of the number of thermoelectric modules, the heating capacity ratio between the two TED sub-coolers, and the type of thermoelectric module have been studied. Furthermore, both the water heating and refrigeration case studies have been separately studied by using the NSGA-II algorithm. Results show that, in both cases, only one unique solution out of 50 in the Pareto front registered the TCO2+2-TED cycle, which offered a further 6.24% COP improvement for water heating over the common TCO2+TED cycle solutions. The TED sub-cooler costs 20% of the compressor, so the solution is reasonably economical.

Although biodiesel synthesis has been widely studied, the use of wet microalgal feedstock for biodiesel synthesis using ionic liquid catalyst and ultrasonication is scarce to find, especially pertaining to economic viability and environmental impact. In this study, new processes are designed based on the experimental results for ultrasound assisted in situ algal biodiesel production using an ionic liquid catalyst. Process retrofitting is then conducted using a divided-wall column (DWC) and multistage vapor recompression (MVR). Later, comparative analyses in terms of capital cost, cost of manufacturing (COM), cost of biodiesel, specific energy consumption (SEC) and carbon emission is presented. The process with DWC and MVR resulted in a significant saving in COM (13.84%), biodiesel cost (18.24%), utility cost (45.44%), SEC (29.15%) and carbon emissions (38.15%) than those in its counterpart. This study shows that the biodiesel cost is linearly dependent on the cost of feedstock and process economics can be improved by converting glycerol to triacetin. Major contributions of this work are (1) experimental and process design for a novel ultrasound assisted and ionic liquid catalyzed algal biodiesel production, (2) retrofitting using DWC and MVR and (3) investigation of the uncertainty in the thermodynamic property. This study is significant as it designs processes based on the experimental outcomes and investigates designs for their economic as well as environmental merits.

A comprehensive thermo-economic model combining a geothermal heat mining system and a direct supercritical CO2 turbine expansion electric power generation system was proposed in this paper. Assisted by this integrated model, thermo-economic and optimization analyses for the key design parameters of the whole system including the geothermal well pattern and operational conditions were performed to obtain a minimal levelized cost of electricity (LCOE). Specifically, in geothermal heat extraction simulation, an integrated well-bore-reservoir system model (T2Well/ECO2N) was used to generate a database for creating a fast, predictive, and compatible geothermal heat mining model by employing a response surface methodology. A parametric study was conducted to demonstrate the impact of turbine discharge pressure, injection and production well distance, CO2 injection flowrate, CO2 injection temperature, and monitored production well bottom pressure on LCOE, system thermal efficiency, and capital cost. It was found that for a 100 MWe power plant, a minimal LCOE of $0.177/kWh was achieved for a 20-year steady operation without considering CO2 sequestration credit. In addition, when CO2 sequestration credit is $1.00/t, an LCOE breakeven point compared to a conventional geothermal power plant is achieved and a breakpoint for generating electric power generation at no cost was achieved for a sequestration credit of $2.05/t.

The levelized cost of energy is commonly used in both policymaking and capital investment decisions. It unitizes capital costs by amortizing them over an assumed asset life. The life of the asset i...

The object of the research is the development of optimal conditions for the creation of the ozone elements. He provides decontamination of warehouse air. The aim of the work is the safety of food and non-food products when treated with ozone. This article presents the calculations and development of a mathematical model of the optimal characteristics of innovative technical means for producing ozone. Ozone is designed to neutralize mold fungi, harmful and toxic waste in various industries of the Republic of Kazakhstan. All over the world, both in the near and far abroad, aconsumeruse of the ozone elements for cleaning and decontamination air, water and food products. Ozone has an oxide ability, a powerful bactericidal effect, neutralizes various types of mold fungi and yeast, toxic components, etc. This article discusses the optimal conditions for the production of ozone in ozone devices. The authors develop small-sized ozone devices that will reduce energy and capital costs for the technological lain by 5-10 times compared to foreign analogues. The creation of small-sized ozone devices is achieved due to the production of ozone as a result of a corona discharge from a micro wire whose diameter does not exceed 100 microns. The material for the article on the use of ozone in the agricultural sector, light industry and other industries that ensure the safety of food and non-food products was the research of scientists from near and far abroad, as the work of the authors. The article includes the results of calculations for obtaining the optimal dimensions of corona wires. Depending on the demand for ozone, not only the size, but also the number of ozone cells devices calculated. To vary the size and other parameters of the ozone cells, a mathematical modeling technique was used, which allowed us to obtain the current-voltage characteristics of the ozone cell. To control the mode of the ozonator, a circuit with a control unit is developed.

The Kazakhstani economy has a significant emission potential. The study reveals the issues of the restraining influence on the development of Kazakhstani companies' emission activity. Among them are the role of bank lending in financing the national economy; government discouragement of economic development; weak efficiency of administrative and tax preferences for issuers. An important factor is the doubt of Kazakhstani companies on their capital fair evaluation in the market. In particular, the study noted that over the past five years, there has been a stable trend towards a decrease in bank lending as for large, the same is for small and medium-sized businesses. Basing on the continuing low number of new registrations of prospectuses for the issue of shares, there arises an issue of finding ways to meet the needs of business entities in financing. The findings from the analysis of sources of financing the State programs in the Republic of Kazakhstan showed the amount of possible funding from the stock market instruments. The study of data over the past few years made it possible to conclude that the methods and ways of using funds allocated under these state programs actually discourage business and local governments to use the emission potential that Kazakhstani market participants currently have. Administrative and tax preferences that operate in Kazakhstan for domestic participants in the stock market are either mainly aimed at investors or rather incomprehensible and imperceptible for potential issuers. Uncertainty in achieving the planned funding levels and in a fair assessment of the company's capital cost, basing on the above factors identified as a result of the study, is the main constraining reason for the low emission activity of Kazakhstani stock market participants.