Low-cost Generation Research Articles

Characterization of artificially re-pigmented ARPE-19 retinal pigment epithelial cell model

Melanin pigment has a significant role in ocular pharmacokinetics, because many drugs bind at high extent to melanin in the retinal pigment epithelial cells. Most retinal pigment epithelial cell lines lack pigmentation and, therefore, we re-pigmented human ARPE-19 cells to generate a pigmented cell model. Melanosomes from porcine retinal pigment epithelium were isolated and co-incubated with ARPE-19 cells that spontaneously phagocytosed the melanosomes. Internalized melanosomes were functionally integrated to the cellular system as evidenced by correct translocation of cellular Rab27a protein to the melanosomal membranes. The pigmentation was retained during cell cultivation and the level of pigmentation can be controlled by altering the amount of administered melanosomes. We used these cells to study melanosomal uptake of six drugs. The uptake was negligible with low melanin-binders (methotrexate, diclofenac) whereas most of the high melanin-binders (propranolol, chloroquine) were extensively taken up by the melanosomes. This cell line can be used to model pigmentation of the retinal pigment epithelium, while maintaining the beneficial cell line characteristics, such as fast generation of cultures, low cost, long-term maintenance and good reproducibility. The model enables studies at normal and decreased levels of pigmentation to model different retinal conditions.

The Core Agenda of Public Debate on the Cigéo Project in France

원자력 발전은 상대적으로 저렴한 발전비용으로 우리나라 경제성장의 밑거름이 되었던 에너지원으 로 알려져 있으나 방사성 폐기물 처리에 대해서는 논란이 지속적으로 발생하고 있다. 본 연구에서는 프랑스의 고준위 방폐장인 Cigéo의 설치에 대한 정책 수립과정과 공론화 과정을 살펴보고, 시맨틱네트워크 분석(Semantic Network Analysis)을 통해 프랑스의 고준위 방폐장 건설과정에서 제시되었던 여러 가지 핵심적인 의제들을 파악하였다. 분석결과 연결중심성이 높은 상위 10위의 주제어는 토론사업, 폐기물, 저장, 공공의, 질문, 위험, 시민, 참여, 부지 등이다. 프랑스의 사례를 볼 때 우리나라의 고준위 방폐장 설치단계에서 다양한 정책행위자들의 참여와 토론을 유도하고, 현세대와 미래세대간의 형평성을 고려해야 하는 한편, 사전적으로 관련 법제도를 정비해야 한다는 정책적 시사점을 제시할 수 있다.Nuclear power generation has been the cornerstone of economic growth due to low generation costs in Korea, but the disposal of radioactive waste continues to be controversial. Looking back on the controversy at the time of the establishment of low-level radioactive waste disposal facilities, it is expected that the establishment of high-level radioactive waste disposal facilities will lead to enormous social conflicts, urgently seeking social consensus. In this study, we examined the process of establishing the policy and public debate on the installation of Cigeo, a high-level radioactive waste disposal facility in France. In addition, through SNA (semantic network analysis), we identified several key agenda items which had been presented during the installation process, including debate, business, waste, storage, public, question, danger, citizen, participation, and site. Based on the case of Cigeo, we suggested several policy implications that it is necessary to promote participation and discussion of various policy actors and to consider intergenerational equity as well as preemptive legal action.

A Low-Cost Generator for Testing and Calibrating Current Transformers

Current transformers for ac power systems applications are usually calibrated by applying sinusoidal currents at different frequencies. The main limitation of this approach is that it does not take into account nonlinearities that may have a significant impact on harmonic current measurement. A more accurate characterization should be based on test currents that are similar to those found in normal working conditions. However, this demands a proper current generator able to generate multitone waveforms with proper accuracy, which is seldom available in laboratories. This paper proposes a simple approach to implement a current generator, based on a waveform generator, a power amplifier, and a transformer which allows boosting the output current capability. Its uneven input-output response can be compensated through linear prefiltering of the desired current waveform. When the generator is employed to reproduce a specific class of current waveforms, such as those typically found in ac distribution grids, an optimal compensation filter can be easily designed. This approach allows canceling systematic nonlinearities introduced by the transformer and the power amplifier, thus significantly increasing accuracy with respect to a conventional frequency response compensation, as confirmed by experimental results.

Electrification of road transportation with utility controlled charging: A case study for British Columbia with a 93% renewable electricity target

To mitigate emissions from the electricity and transportation sectors, large scale deployment of renewable energy generators and battery electric vehicles are expected in the coming decades. However, adoption of these technologies may exacerbate issues related to mismatch of electricity supply and demand. In this study, we utilize a hybrid capacity expansion and dispatch model to quantify grid impacts of the conversion of the entire road vehicle fleet to electric vehicles by 2050. We examine impacts of policies, such as targeting a renewable energy penetration of 93%, using British Columbia as a case study. Scenarios making use of utility controlled charging of vehicles to balance supply and demand are further analyzed. Results show that although electrifying the entire road vehicle fleet will require generation capacity to increase by up to 60%, relative to a scenario without electrification, levelized cost of electricity only increases by 9% in the same scenario due to availability of low cost generation options such as wind and solar. We also find that a 93% renewable energy target leads to carbon abatement costs 30% lower than a scenario where this policy is removed. Further use of utility controlled charging reduces total system capacity up to 7%.

Setting cost targets for zero-emission electricity generation technologies

Clean energy deployment scenarios typically assume a diverse mix of low-emission generation. However, because of historically low natural gas prices and cost reductions for onshore wind and photovoltaic technologies, recent new capacity deployment, especially in the United States, has come largely from these three generation sources. Here, we quantify competitive cost targets for three less-common zero-emission generation technologies—nuclear, concentrating solar, and offshore wind—under a range of future conditions. We determine the cost targets based on the technologies’ system value, such that technology value equals or exceeds its cost. Using a capacity expansion model that develops system-wide, economically optimal generation scenarios of the United States power sector, we find that nuclear, concentrating solar, and offshore wind would need to attain levelized cost ranges of $53–84/MWh, $65–91/MWh, and $39–77/MWh, respectively, to achieve 1% additional grid penetration. We refer to this metric as the “required cost,” which is a technology’s levelized cost of energy needed to achieve a specific penetration level. Higher penetrations lead to lower required costs as lower-cost generation is displaced. We estimate that to reach 10% penetration, the required cost for nuclear declines to $45–76/MWh. Because of resource variability and increased transmission needs for concentrating solar power and offshore wind, even lower costs are needed to reach higher penetrations: required cost ranges to achieve 10% penetration are estimated to be $30–56/MWh and $18–40/MWh for these two technologies respectively. Our analysis informs research and development priorities and the design of policies supporting clean technologies.

Economics of stationary electricity storage with various charge and discharge durations

Abstract Electricity storage encompasses a disparate list of technologies such as pumped-storage hydroelectricity, compressed-air energy storage, chemical batteries and flywheels. These technologies can provide the electricity system with heterogeneous services of energy transfers across months, weeks, days or intra-days, power transfers for an hour, a few minutes or seconds, and can assist operators in load following, frequency control, and uninterrupted power supply. The paper presents a unified economic analysis of these technologies and services. We underline the role of charge and discharge durations as a criterion for economic segmentation of technologies and services. We highlight the complementary value of storage in electricity systems with a high share of low variable cost and low carbon generation (nuclear, hydro, wind power, solar photovoltaic). We also underline the limited substitution value of storage for generation with high variable cost (gas combustion-turbines or gas-oil motor engines), given the high cost of state-of-the-art storage technologies, the current low cost of fossil fuels and low price of carbon emissions.

A New Communication-Efficient Privacy-Preserving Range Query Scheme in Fog-Enhanced IoT

Fog-enhanced Internet of Things (IoT) has received considerable attention in recent years, as fog devices deployed at the network edge can not only improve the performance of IoT applications but also enhance the security and privacy of IoT. In this paper, we present a new communication-efficient privacy-preserving range query scheme in Fog-enhanced IoT. With the proposed scheme, both the query range and individual IoT device's data can be privacy-preserved by using BGN homomorphic encryption technique. In addition, the proposed scheme employs a range query expression, decomposition, and composition technique to reorganize the range query, which can achieve O(√n) communication efficiency. Detailed security analysis shows that the proposed scheme is really a privacy-preserving range query scheme. Extensive experiments are conducted, and the results indicate that the proposed scheme is also efficient in terms of low range query generation cost and low communication overhead.

Scalable and robust bilayer polymer foams for highly efficient and stable solar desalination

Solar-driven vaporization devices are often hindered by complex fabrication process, low efficiency, poor durability, and non-reusability. Herein, based on the pre-pressed melamine foam (MF), we have fabricated a scalable, low cost, and durable bilayer polymer foam for efficient and stable solar steam generation. Making use of the bilayer structure, different functions are assigned to different layers, with polypyrrole (PPy) coating pre-pressed MF (PPy layer) for light absorption and water evaporation, and bottom pre-pressed MF layer for water transport and thermal insulation. A high average evaporation rate of 1.574 kg m−2 h−1 and a superb steam generation efficiency of 90.4% under 1 sun are achieved. Bilayer foam demonstrates remarkable robustness and stability under a series of severe conditions. Bilayer foam can keep its structural stability and evaporation performance in durability tests (over 30 days, with 60 min each day), exhibiting the long-term durability, excellent antifouling property, and good reusability. We have also demonstrated the potential practicability of two simple prototype devices for solar steam generation on land and water. The low cost, large-scale, and durable solar steam generation device is promising for highly efficient and stable generating fresh water under natural sunlight conditions, which is especially attractive for remote areas that lack of fresh water supply.

Economic assessment of nuclear electricity from VVER-1000 reactor deployment in a developing country

The decision of policymakers in developing countries to introduce nuclear power to their energy mix has been mainly conversant with the low generation cost of nuclear electricity and its competitiveness with alternative conventional and renewable sources. This paper presents an economic assessment of the levelized cost of VVER-1000 reactors deployment in a newcomer developing country, taking Jordan as an example. This paper applies recent engineering procurement and construction (EPC) cost; observed construction time and plant performance, cost escalation rates, owner cost, and real discount rates in developing countries to calculate the levelized cost of electricity. The obtained results estimate the levelized cost of nuclear generation to be between $212.32 and $277.56 per MWh. However, evidence and sensitivity analysis presented in this paper suggest that the levelized cost vary considerably and may endup being as high as $610.09 per MWh or as low as $144.81 per MWh, this is mainly due to its sensitivity to unpredictable input parameters, which in turn has significant policy implications.

Tubular nitrogen-doped carbon materials derived from green foxtail as a metal-free electrocatalyst in microbial fuel cells for efficient electron generation

Oxygen reduction reaction (ORR) on a cathode is a key factor that limits the power generation and application of air-cathode microbial fuel cells. Tubular nitrogen-doped carbon materials synthesized by thermally annealing green foxtail with melamine were investigated as a metal-free electrocatalyst for efficient cathode ORR. Owing to the high specific surface area, tubular and porous structure, and abundant active centers of the pyridinic and graphite nitrogen incorporated carbon matrix, the nitrogen-doped carbon materials showed excellent activity toward ORR in a neutral electrolyte. Oxygen was reduced to water in a four electron reaction on the three-phase boundary of the as-prepared materials. The microbial fuel cell with the nitrogen-doped carbon electrocatalyst prepared at 800 °C had a satisfactory power density and better stability than commercial Pt/C due to its metal-free property and porous structure. Thus, nitrogen-doped carbon materials derived from economical and sustainable biomass could be a potential alternative for the metal-free ORR catalyst in microbial fuel cells with low cost and high electricity generation efficiency.

An internal trading strategy for optimal energy management of combined cooling, heat and power in building microgrids

This paper proposes a three-step internal trading strategy for optimal energy sharing among building microgrids (MGs) to minimize the operation cost of the entire system. In the first step, barter trading is performed to exchange energies among building MGs of the network. Building MGs having shortage of electricity and surplus of heat can pair with buildings having surplus of electricity and shortage of heat to exchange their energies. Then, the surplus/shortage energy is updated after carrying out the barter trading. In the second step, building MGs sell their remaining surplus energy to other building MGs that have shortage energy. In the third step, building MGs, which have lower generation cost than the external system and ability to increase their power generation, increase their power generation and trade with other building MGs. These three steps can increase the power sharing among building MGs and reduce the trading with the external systems, which results in reduced operation cost of the network. An additional internal market along with price signals is also presented to carry out the proposed internal trading strategy. The internal market provides a mechanism for trading energies among the building MGs of a combined cooling, heat and power (CCHP) system. A hierarchical energy management system (EMS), including building EMSs (BEMSs) and a community EMS (C-EMS) is developed to minimize the operation cost of the CCHP system. Moreover, a heat pipeline (HPL) system is applied for storing the surplus heat energy for fulfilling the shortage heat energy in the building MGs. By using the proposed strategy, total trading cost of CCHP system is reduced by 7.43% compared with the conventional operation strategy.

Toward a new generation of low cost, efficient, and durable metal–air flow batteries

Metal–air flow batteries are promising candidates for next-generation energy storage systems because of their high performance and scale flexibility. Further development should be conducted from material to structure design and operation management.

In-Band Controllable Radio Interference Generation for Wireless Sensor Networks

Interference signals negatively impact the performance of wireless embedded systems. The increased packet losses, delays, and energy consumption experienced by devices operating in environments subject to interference are particularly critical in constrained systems such as wireless sensor networks. The need to design and test systems for mitigating the effects of interference prompts for the capability of reproducing in a controllable way suitable interference signals. Solutions have been proposed recently, which tackle the problem by making use of 802.15.4 compliant radio transceivers, like those available on board of commonly used sensor nodes, thus paving the way for low cost and repeatable generation of interference which could reliably emulate real-world scenarios, for instance densely deployed networks. In this paper, we present an investigation regarding the emulation of interference sources by means of 802.15.4 radios on novel 32-bit wireless system-on-chip. The study is based on an extensive experimental evaluation, providing novel insights into the main features of the system. In particular, the effects of interference on the communication link, measured in terms of packet reception rate, are investigated for different parameters (namely, duty cycle and power of the interference signal, communication protocols, and payload size), and results are discussed concerning the feasibility of emulating background noise by means of the analyzed techniques.

A low-cost microplasma generation unit allowing for the on-site processing of ZnO-based gas sensors.

In this study, a low-cost gas-sensing device that integrates a zinc-oxide (ZnO)-based gas sensor with a microplasma generation unit is presented. By the proper connection of different sets of electrodes to the desired power sources or the measurement circuit, the device can be operated in the microplasma mode (MPM) or the gas-sensing mode (GSM), respectively. Due to the device design, microplasma can be generated at the same location where the precursor for the sensing materials, namely Zn(NO3)2 solution, is coated. Such an arrangement allows for low temperature and the on-site conversion of the precursor materials to ZnO particles upon microplasma treatment under MPM. GSM can be used to detect ethanol vapor with a concentration between 100 and 18 000 ppm at room temperature. We observed that the sensor can be operated under a wide range of ethanol concentrations with stable sensing behavior for over 80 test cycles.

Hybrid peeling for fast and accurate calling, phasing, and imputation with sequence data of any coverage in pedigrees

BackgroundIn this paper, we extend multi-locus iterative peeling to provide a computationally efficient method for calling, phasing, and imputing sequence data of any coverage in small or large pedigrees. Our method, called hybrid peeling, uses multi-locus iterative peeling to estimate shared chromosome segments between parents and their offspring at a subset of loci, and then uses single-locus iterative peeling to aggregate genomic information across multiple generations at the remaining loci.ResultsUsing a synthetic dataset, we first analysed the performance of hybrid peeling for calling and phasing genotypes in disconnected families, which contained only a focal individual and its parents and grandparents. Second, we analysed the performance of hybrid peeling for calling and phasing genotypes in the context of a full general pedigree. Third, we analysed the performance of hybrid peeling for imputing whole-genome sequence data to non-sequenced individuals in the population. We found that hybrid peeling substantially increased the number of called and phased genotypes by leveraging sequence information on related individuals. The calling rate and accuracy increased when the full pedigree was used compared to a reduced pedigree of just parents and grandparents. Finally, hybrid peeling imputed accurately whole-genome sequence to non-sequenced individuals.ConclusionsWe believe that this algorithm will enable the generation of low cost and high accuracy whole-genome sequence data in many pedigreed populations. We make this algorithm available as a standalone program called AlphaPeel.

Analysis of power plants in China Pakistan economic corridor (CPEC): An application of analytic network process (ANP)

The availability of consistent and cheap energy is key to a sustainable economy. The challenge of cheap, clean, and sustainable energy supply is faced by all countries. Pakistan is an energy starved country and is trying to overcome its energy woes by installing different types of energy plants under the massive investment of China Pakistan Economic Corridor (CPEC). This paper attempts to determine the suitability of existing power plants installed under the umbrella of CPEC in Pakistan. By considering four different types of power plants, i.e., Coal, Hydro, Solar, and wind, with four essential criteria of Technical, Economic, Life Quality, and Socioeconomic and 11 sub-criterias, the appropriate model has been formulated consisting of goals, criteria, sub-criteria, and alternatives. The analytical network process approach has been applied that uses the principle of multi-criteria decision making to rank and evaluate the four alternatives of electricity generation. The quantitative secondary data were collected from the governmental organizations and international research publications. The results show that hydro power plants are the best source of electricity generation followed by wind, solar, and coal. The proposed decision framework can be used for formulating policies aiming at low cost, clean, and secure energy generation.

Highly efficient solar steam generation of low cost TiN/bio-carbon foam

The use of solar energy to produce steam is an effective method to purify sewage or seawater. Herein, we deposited TiN nanoparticles (NPs) on a piece of carbonized wood as a new type of double layer material for solar water evaporation. TiN NPs possess better stability, lower cost, lower toxicity and wider and stronger optical absorption than the previously reported photo-thermal conversion (PTC) materials, such as plasmonic metals, carbon-based materials and semiconductor nanomaterials. The amounts of TiN NPs and the thicknesses and types of the substrates have important influences on water evaporation rates and solar-vapor conversion efficiency. A solar-vapor conversion efficiency of 92.5%, the highest efficiency in the reported wood-based PTC materials, is obtained under 1-sun simulated solar irradiation. In addition, the TBCF hybrid materials (TiN NPs on bio-carbon foam) exhibit good reusability.

Humic acid nanosheets decorated by tin oxide nanoparticles and there humidity sensing behavior

A novel resistive type humidity sensor based on humic acid nanosheets decorated by tin oxide nanoparticles is reported in the present work. The humic acid nanosheets have been extracted from Leonardite via acid base treatment followed by centrifugation. The SnO2 nanoparticles were incorporated in humic acid nanosheets using SnCl2. The microstructure and morphology of the as prepared samples were investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), transmission electron microscopy (TEM) and Fourier-transform infrared spectroscopy (FTIR). The results confirm the successful formation of tin oxide nanoparticles anchored and uniformly distributed over humic acid nanosheets. The surface investigations showed a crumpled, fluffy and wrinkled morphology. Humidity sensing properties of the as prepared nanocomposite has been studied. Saturated salt solutions were used to control the relative humidity. The sensing response has been measured in the relative humidity range 12.4 up to 97.1% at the room temperature. It has been found that the sensor impedance decreases as the relative humidity increases with good linearity (−0.19319 ± 0.01264). The prepared sensor exhibited a fast response and recovery time. The present type of humidity sensor opens a new generation of low cost, fast response and environmentally friend humidity sensors.

ВИБІР КРИТЕРІЇВ ОЦІНКИ ЕФЕКТИВНОСТІ ПОЛІТИКИ ПІДТРИМКИ ВІДНОВЛЮВАНИХ ДЖЕРЕЛ ЕНЕРГІЇ

At the moment, Ukraine has set targets for expanding the use of renewable energy sources (RES), while one of the key tasks is to substantiate and accurately assess the economic efficiency of using RES with the use of various criteria and indicators. The purpose of the article is to research and develop scientific and economic decisions on the assessment of the efficiency of the use of renewable energy sources, and to justify the selection of criteria for assessing renewable energy support policies. Renewable energy policy is a matter of ongoing assessment, because it implies significant financial support that should be monitored continuously and thoroughly. The article highlights five criteria for assessing renewable energy support policies: efficiency, efficiency, equity, institutional feasibility, reproducibility (long-term functioning). The article substantiates the choice of criteria for assessing the effectiveness of the policy of supporting renewable energy sources, namely the criterion of economic efficiency, which includes static and dynamic efficiency. Effectiveness shows the ratio of realizing the goals of developing RES to the cost of resources that have been spent to achieve these goals. The article presents the calculation and justification of the use of indemnification indicators that characterize the criterion of economic efficiency. The criterion of justice and its estimation are analyzed. Comparison of the use of the provided indicators of political support for renewable energy sources has been com pared. The parameters of dependence of dynamic efficiency are determined. Advantages of RES technologies relative to traditional generation depend to a large extent on local conditions: where there are favorable conditions for implementation of RES technologies, it is possible to achieve lower generation costs based on RES, rather than fossil fuels. In most cases, generation costs based on RES are higher than in traditional generation. Over time, these costs will fall, but by the time that renewable energy reaches the parity with traditional generation, the state will have to bear additional support for the industry with appropriate political support using a variety of criteria with the appropriate set of indicators.

Optimal Scheduling of Microgrid with Distributed Power Based on Water Cycle Algorithm

Microgrid, taking advantage of distributed power generation technology, plays an important role in maximizing the utilization of renewable energy. Based on the problems of the energy crisis, environmental contamination and the high operating cost of the microgrid, the microgrid model can effectively ease energy pressure. We can dispatch the output of each part in the microgrid to obtain the optimal economy. Since many traditional optimization algorithms have limitations of local optimization, multiple iterations, and slow convergence speed, this paper proposes a method that applies the Water Cycle Algorithm (WCA) to optimize the dispatch of the microgrid to minimize the operating cost. The mathematical model of each distributed power is established. The interactive power between the microgrid and large grid is also considered. The lowest generation cost considering environmental benefits is taken as the objective function. Water cycle algorithm is implemented to obtain the optimal solution under various constraints. Some optimization algorithms such as Genetic Algorithm (GA), Interior Search Algorithm (ISA), and Differential Search Algorithm (DSA) were used for results evaluation. By comparing the results obtained from four different algorithms, a case study shows the WCA possesses the advancements of better convergence performance, faster calculation and higher precision compared to the other algorithms. The results demonstrate that the WCA applied to determine the optimal scheduling of the microgrid can achieve a better result than some other algorithms with an acceptable accuracy and efficiency.