Search

Power production by conversion of salt gradient energy (osmotic power production) has the potential for global commercialization. Research on the net-power output and osmotic power plant configurations could result in viable methods for improvement of plant efficiency. In this paper, a novel equivalent electric-circuit model of the pressure-retarded osmosis (PRO) process is described and is used to develop a power-hardware-in-the-loop (PHIL) emulator to represent the osmotic power plant. The model considers many dynamics involved with PRO including reverse salt leakage, concentration polarization, and the salt storage capacity of water. The proposed model facilitates real-time dynamic simulation and analysis of the PRO power plant, and its interaction with the rest of the PRO power system, namely the impulse turbine and the synchronous generator supplying power to off-grid or isolated loads. The response of the multidomain system including hydraulic, mechanical, and electrical components of the system is observed, given changes in the input parameters such as source flow rate. The proposed PHIL emulator provides insight into the operational dynamics and behavior of the PRO system. The proposed real-time emulator serves as a powerful tool that can advance research and development of PRO power generation systems. Simulation and experimental results are presented in this paper to validate the PRO plant model and the operation of the proposed real-time PHIL PRO emulator. [ABSTRACT FROM PUBLISHER]

Energy insufficiency is obstructing the socio-economic and industrial improvement of Bangladesh. Renewable energy contributes about 560 Megawatt (MW) of the total electricity production of 20,430 MW, which can be a sustainable solution to the demand-supply crisis. This paper, summarises the current energy situation of Bangladesh and examines the available renewable energy resources and their future prospect. It has been revealed that Bangladesh is heavily (62%) relying on natural gas although government has already taken steps to generate electricity from renewable energy sources. Current policies and legislations related to generation of renewable energy in Bangladesh have been discussed explicitly. Finally, some suggestions have been made to tackle the ongoing energy crisis in the country, in addition to the renewable energy.Abbreviations: GDP: Gross domestic product; RNPP: Rooppur Nuclear Power Plant; Tcf: Trillion cubic feet; IDCOL: Infrastructure development company limited; BPDB: Bangladesh Power Development Board: GS: Grameen Shakti; BWDB: Bangladesh Water Development Board: USD: United States Dollar; IPP: Independent power producer: BCAS: Bangladesh center for advanced studies; NWPGCL: North West Power Generation Company Limited: BCSIR: Bangladesh Council of Scientific and Industrial Research; EGCB: Electricity Generation Company of Bangladesh: WRA: Wind Resource Assessment; REB: Rural Electrification Board: BRAC: Bangladesh Rural Advancement Committee; kW: Kilowatt: PJ: Petajoules; MW: Megawatt: IFRAD: Institute for fuel research and Development; GWh: Gigawatt hours: ICS: Improved Cooking Stoves; MWh: Megawatt hours: DoE: Department of Environment; TWh: Trillion-watt hour: DLS: Department of Livestock Services; RPCL: Rural Power Company Limited: mmcfd: million cubic feet per day; APSCL: Ashugang Power Station Company Limited: BSCIC: Bangladesh Small & Cottage Industries Corporation (BSCIC); GOB: Government of Bangladesh: BADC: Bangladesh Agricultural Development Corporation; SREDA: Sustainable and Renewable Energy Development Authority: DIDA: Danish International Development Agency; LGED: Local Government Engineering Directorate: BAU: Bangladesh Agricultural University; NGO: Non-Governmental Organization: HBRI: Housing & Building Research Institute; IRENA: International Renewable energy Agency: : BARD: Bangladesh Academy for Rural Development; ETP: Electronic Traffic Pricing: BCCD: Bangladesh Commission for Christian Development; PV: Photovoltaic: BRRI: Bangladesh Rice Research Institute; SHS: Solar Home Systems: NDBMP: National Domestic Biogas and Manure Program; TOE: Tonne of oil equivalent: K/km: Kelvin/kilometer; LEAP: Long range Energy Alternative Planning [ABSTRACT FROM AUTHOR]

Growth of electricity generation from variable renewable resources like wind and solar has raised questions about future grid stability. This paper used several renewable energy penetration scenarios to determine when an electric grid might be more vulnerable to frequency contingencies, such as a generator outage. Unit commitment and dispatch modeling was used to quantify system inertia, an established proxy for grid stability. A case study of the Electric Reliability Council of Texas grid was used to illustrate the method. Results from the modeled scenarios showed that the Texas grid is resilient to major grid changes, even with relatively high penetrations (∼ 30% of annual energy generation compared to 18% in 2017) of renewable energy. However, retiring nuclear power plants and private-use networks in the model led to unstable inertia levels in our results. When the system inertia was constrained to meet a minimum threshold in our model, multiple coal and natural gas combined-cycle plants were dispatched at part-load or at their minimum operating level to maintain stable system inertia levels. This behavior is expected to expand with higher renewable energy penetrations and could occur on other electric grids that are reliant on synchronous generators for inertia support. [ABSTRACT FROM AUTHOR]

This paper aims to apply a multiobjective optimization modeling technique to a power expansion problem evaluating two objectives functions: minimizing the power generating cost and minimizing CO2 emissions, between which there is a tradeoff. A convex curve is obtained representing the relationship between the generating cost (Rp=kWh) and CO2 emissions (ton). This represents a bad-luck curve where there is an increasing marginal cost to reduce 1 t of CO2 emissions. This is because most of the less-carbon-intensive power plants consume oil, which has the highest fuel cost. Instead of simply minimizing CO2 emissions, this paper argues that Indonesia needs to pursue technology to switch from steam coal subcritical technology to supercritical and ultra-supercritical technology to reduce CO2 emissions. It is further found that the generating cost will increase by less than 1.6% and yearly CO2 emissions can be reduced by about 6.9% by adopting supercritical technology. This implies that adopting ultra-supercritical technology can cut CO2 emissions by more than half. A squeezing effect is also found by adopting more-advanced steam coal technology. Thus, promoting renewable energy and gas utilization also should be enhanced. The green path power system allows both CO2 emissions and the generating cost to increase gradually, but with lower CO2 emissions than by minimizing the generating cost alone. It is thereby proposed that the current feed-in tariff for renewable energy also needs to be supported with an emissions reduction target. [ABSTRACT FROM AUTHOR]

Bangladesh is a hugely populated country in South Asia. The country produces its electricity mainly from natural gas followed by liquid fuels. Although the installed electricity generation capacity of the country has been increased to 12,261 MW, there is scarcity of electricity in the hot summer season which is a barrier to industrial development as well as socio-economic development. Combustion of fossil fuels releases greenhouse gases (GHGs) into the atmosphere which causes global warming. Bangladesh can be badly affected by greenhouse effect and global warming. These problems can be mitigated by incorporating renewable energy sources (e.g., solar, wind, hydro, biomass, etc.) to the country's electricity generation. Renewable energy resources are considered as clean and can serve the electricity demand in the remote areas where grid connection is not possible. The potential of solar energy and biomass is enormous in Bangladesh and people have already started to harness energy from these sources. The government and the policy makers should come forward to encourage the people of rural areas as well as urban areas to use renewable based electricity. The government of Bangladesh has set up a plan to generate 5% of the country's total electricity from renewable sources within 2015 and 10% within 2020. However, within 2015 the country has been able to generate only 3.5% of the total electricity from renewable sources. This paper presents a thorough review of the current status and future potentials of renewable energy sector in Bangladesh. In this paper the updated information is provided for the overall renewable energy sector of the country. [ABSTRACT FROM AUTHOR]

Unit Commitment (UC) is an optimization problem used to determine the operation schedule of the generating units at every hour interval with varying loads and generations under different generational, environmental and technical constraints. With the significant increase of Renewable Energy Sources (RES) integration into the power networks, effects posed by these system changes to the UC are actively being studied and investigated by global researchers and operation engineers. To this end, this paper firstly provides a literature survey of UC concept, objectives and constraints. Different UC models developed for addressing RES impacts are also reviewed. Moreover, many algorithms have been proposed in the past few decades to optimize the UC problem. This work explores the necessity for alternative optimization approaches for UC solution. In doing that, the work uncovers the advantages and disadvantages of the existing methodologies so that future algorithms could be designed in retaining the advantages of the existing methodologies while avoiding the presented weaknesses. In addition, installation of energy storage devices to balance the fluctuation in power generation and their associated impacts on UC models are reviewed. The contents of this paper provide ready-to-refer and ready-to-use information for the researchers working in the field of UC. [ABSTRACT FROM AUTHOR]

In the present context, energy access to remote rural households through local energy generating systems has been recognized as a cost effective and extent efficient option. With increased emphasis on eco-friendly technologies and high fuel cost associated with conventional energy generation, the use of renewable energy resources (small hydro, biomass, solar, wind energy etc.) are being explored. The present paper is focused on the optimal sizing of a stand-alone Integrated Renewable Energy System (IRES) which comprises the resources of micro hydro power (MHP), biogas, biomass, solar and wind energy. Initially, a demand response (DR) strategy based on energy consumption scheduling of appliances has been suggested and modelled in the paper. This strategy aims to minimize the peak hourly energy consumption of the study area. Further, different combinations of system components without and with DR strategy were considered and optimized for power reliability criteria of 0% and 5% unmet load. It has been found that significant amount of savings in system sizes and costs are obtained with DR strategy compared to system without DR. [ABSTRACT FROM AUTHOR]

Solar pond undoubtedly has been a reliable source of low grade heat supply by acting as both collector and storage for the incoming solar radiation. The thermal efficiency of the solar ponds is between 15 and 25% of the incoming horizontal solar radiation. Meanwhile, the thermoelectric technology enables the conversion of heat into electricity using thermoelectric modules. In this paper, the feasibility of the system by combining solar pond and thermoelectric modules is presented. This system can be achieved by using a thermoelectric modules-embedded heat exchanger module that will able to extract the heat available from the lower convective zone of the solar pond. The analysis in this paper was conducted by investigating the solar ponds operating in different climate conditions, which are Group A (Kuala Lumpur), Group B (Riyadh) and Group C (Melbourne and Granada) base on Köppen climate classification. The theoretical feasibility draws the limit on the performance and cost of the solar pond-thermoelectric system under commercially available thermoelectric technology at the present state. Later, the result was contrasted against the performance of the power generation units operate under realisable operating condition with solar pond. The result in this study revealed that, under ideal condition, the system is at least 10 times costly compared to other renewable energy sources like off-grid solar photovoltaic system with storage. Meanwhile, at its best operating climate, this system will be able to achieve annual carbon dioxide reduction of 2.38 kg/m 2 -year in a practical case. [ABSTRACT FROM AUTHOR]

The use of renewable energy sources is one of the most relevant goals to be achieved in order to match the climate protection targets. As a case study, the paper shows the current electrical energy production by sources in the Sicilian context. Among the renewable energy sources, the paper investigates the wave energy potential along the Sicilian coasts, because of the favorable climate around the island. A point absorber is present in order to exploit this source. Two scenarios are presented, with two different levels of energy production. [ABSTRACT FROM AUTHOR]

The centralised power grid bears a heavy burden in a time when consumers expect an uninterrupted reliable power supply, a reduction in carbon emissions, increased efficiency within the national grid and power supplied to remote communities. As expectations increase, it becomes the task of power systems research and design to develop new structures to meet these demands. This has led to alternatives being sought for centralised power generation, which is prone to outages (due to long distance transmission), is a substantial contributor to global carbon emissions, has large transmission losses and is often not a practical solution when supplying remote communities. Distributed generation (DG) looks to remedy these inadequacies by producing power close to its point of consumption, often utilising carbon neutral, renewable energy (RE) sources (sun, wind). To maximise the efficient use of DG, control structures are used to balance the intermittent RE power production with consumer power consumption. One such structure is used to implement control of small scale DG, at a single house/small building level: the nanogrid. This paper explores the current nanogrid research, it collates the existing definitions and uses the knowledge to give a concise definition of a nanogrid. It then discusses the control topologies and techniques which enable the intelligent control of the nanogrid, before presenting the hardware platform used to ensure the efficient operation of a small scale DG system. The paper then considers the interconnection of multiple nanogrids forming a network (microgrid), facilitating the sharing of power between individual nanogrids. The future developments are then explored before the paper's conclusions are presented. [ABSTRACT FROM AUTHOR]

Contingent valuation is widely used due to its flexibility in valuing a wide variety of non-market goods. Although this method has important benefits, its validity and reliability are often criticised. This paper reviews the literature on the use of contingent valuation for measuring willingness to pay (WTP) for electricity generated from renewable energy sources (green electricity). A literature review, conducted on a sample of 57 peer-reviewed studies, shows that the vast majority of contingent evaluation studies stems from developed economies. Furthermore, most frequently used WTP elicitation techniques are open-ended and dichotomous choice approaches, which tend to produce varying levels of WTP. Studies dealing with the antecedents of WTP are predominantly inspired by the theory of reasoned action or by its extension, the theory of planned behaviour. This paper identifies six common errors in contingent valuation methods and discusses a number of remedies to deal with these errors in WTP research. [ABSTRACT FROM AUTHOR]

The penetration of photovoltaics (PV’s) in electric power generation is continually increasing. Tracking maximum power point in PV systems is an important task and represents a challenging problem. In maximum power point tracking (MPPT), the duty cycle of DC-DC converter is adjusted in a way that maximum achievable power is extracted from PV system. In this paper, the existing MPPT strategies are classified into two main categories and the strategies of each category are reviewed. Based on the conducted review, some directions for future research are recommended. The author strongly believes that this paper will be helpful for researchers and engineers in the field of PV systems. [ABSTRACT FROM AUTHOR]

Majority of the power generation in India is carried out by conventional energy sources, coal and fossil fuels being the primary ones, which contribute heavily to greenhouse gas emission and global warming. The Indian power sector is witnessing a revolution as excitement grips the nation about harnessing electricity from various renewable energy sources. Electricity generation from renewable sources is increasingly recognized to play an important role for the achievement of a variety of primary and secondary energy policy goals, such as improved diversity and security of energy supply, reduction of local pollutant and global greenhouse gas emissions, regional and rural development, and exploitation of opportunities for fostering social cohesion, value addition and employment generation at the local and regional level. This focuses the solution of the energy crisis on judicious utilization of abundant the renewable energy resources, such as biomass, solar, wind, geothermal and ocean tidal energy. This paper reviews the renewable energy scenario of India as well as extrapolates the future developments keeping in view the consumption, production and supply of power. Research, development, production and demonstration have been carried out enthusiastically in India to find a feasible solution to the perennial problem of power shortage for the past three decades. India has obtained application of a variety of renewable energy technologies for use in different sectors too. There are ample opportunities with favorable geology and geography with huge customer base and widening gap between demand and supply. Technological advancement, suitable regulatory policies, tax rebates, efficiency improvement in consequence to R&D efforts are the few pathways to energy and environment conservation and it will ensure that these large, clean resource bases are exploited as quickly and cost effectively as possible. This paper gives an overview of the potential renewable energy resources in Indian context while evaluating the present status, the energy demand of the country and forecast consumption and production, with the objective to evaluate and assess whether India can sustain its growth and its society with renewable resources. [ABSTRACT FROM AUTHOR]

Variability and intermittency are some of the main features that characterize renewable energy sources. Intermittency usually includes both predictable and unpredictable variations. The many drawbacks of intermittency of renewable sources can be overcome by considering some special design considerations. Integrating more than one renewable energy source and including backup sources and storage systems are among the few measures to overcome these drawbacks. These additional design considerations usually increase the overall cost of the renewable system. Furthermore, the presence of more than one energy supply/storage system requires the control of energy flow among the various sources. Therefore, optimizing the size of the components and adopting an energy management strategy (EMS) are essential to decreasing the cost of the system and limiting its negative effects. The energy management strategy is commonly integrated with optimization to ensure the continuity of load supply and to decrease the cost of energy production. Therefore, energy management is a term that collects all the systematic procedures to control and minimize the quantity and the cost of energy used to provide a certain application with its requirements. The energy management strategy usually depends on the type of energy system and its components. Various approaches and techniques have been used to develop a successful energy management strategy. In this paper, a comprehensive review of the approaches proposed and used by authors of many papers is conducted. These approaches include both the standalone hybrid renewable energy systems and the grid-connected hybrid renewable systems. More attention is focused on popularly used techniques to address the features of each system. The selected papers in this review cover the various configurations of the hybrid renewable energy systems for electric power generation only. [ABSTRACT FROM AUTHOR]

Renewables around the globe, provide fuel diversification, energy security and produce little or no emissions during the electricity generation. The unavailability of rotating masses prohibits on-grid renewable energy generation systems from providing inertia during a frequency disruption. This would be extremely unsettling and impactful when the proportion of energy in the grid due to renewables is high. India currently, has a 28.04% share of on-grid renewable energy. The grid infrastructure systems of India would face severe challenges when the share of on-grid renewables leaps past 50% in the future. Thus, this paper primarily addresses the repercussions of increasing share of on-grid renewables in terms of inertia and frequency response in India. The energy scenario of 2040 in India under 80% proliferation of on-grid renewables has been well reviewed in this paper. The novelty of this paper is the narrative literature review of the Indian Electricity Grid Code (IEGC) on frequency response which is unique and exclusive to this manuscript. It demonstrates the current strategies prevalent in the grid system of India towards frequency response and inertia support. This paper also explains the diverse control strategies and energy storage technologies required for adoption with the on-grid renewables in India for frequency response. The other novelty in this paper is the insight about the inertia lost due to an on-grid 100-kW p solar photovoltaic system to explain the readers about the impact when the integration is hundreds to thousands of kilowatts. • Share of renewables in the Indian grid network is 28.04% (113.226 GW) as of 2022. • India aspires to achieve 54% share of on-grid renewables by 2030 and 80% by 2040. • Indian Electricity Grid Code indicates need for expansion in active power reserves. • India requires diverse control strategies and energy storages for inertia support. • On-grid 100-kW p solar photovoltaic system loses inertia of 100-kW for 4.44 s. [ABSTRACT FROM AUTHOR]

Concerns over environmental impact and high infrastructure cost heavily influence the uptake of wind turbine technology. Recently, researchers have started to look into small wind turbines, which are much smaller in size and capacity. Small wind turbines have less environmental impact and low infrastructure cost. These small turbines have limited power generation capacity, requiring multiple turbines to be connected together to produce useful power. In order to capture power from multiple wind turbines, researchers have proposed numerous topologies in the literature. However, these traditional topologies were designed for high-power wind turbines and cannot be used to connect very small wind turbines since a significant amount of the generated power would be lost in driving the complex electronic circuits used in traditional topologies. In this paper, we present a multiple-input nonisolated dc–dc converter design that collects the output power from series-connected very small wind turbines. The proposed system was implemented in our smart energy laboratory and experimental results were gathered, showing a significant improvement over existing converters. [ABSTRACT FROM AUTHOR]

Highlights • Some Grid Codes impose restrictions on the ramp rate of PV plants. • Hybrid energy storage systems can be more cost efficient for ramp-rate control. • Hybridizing batteries with ultracapacitors expands their lifetime. • The proposed methodology can be used to size the components of the storage. • The total Net Present Cost of controlling ramp rate in a PV plant is optimized. Abstract This paper proposes a methodology for optimal sizing of a Hybrid (battery and ultracapacitors) Energy Storage system for ramp-rate control in PV plants. Frequency stability events can appear in power systems high non-dispatchable renewable energy generation due to sharp power output fluctuations. This has caused TSOs in several countries to require PV and wind plants to implement some method for limiting the pace at which the power injection to the grid is allowed to vary (ramp-rate control). Due to its quick response, properly controlled energy storage consisting of batteries and ultracapacitors can perform this task by dampening quick increases/decreases in the power injection to the grid by absorbing/injecting power at the point of common coupling. In this work, a techno-economic model is presented that can be used to calculate the Net Present Cost over the project life of different energy storage devices used for ramp-rate control by simulating their operation. A real case is studied for a PV power plant is presented. Results are reported comparing different configurations of the energy storage system. [ABSTRACT FROM AUTHOR]

This paper focuses on a review of the state of the art of future power grids, where new and modern technologies will be integrated into the power distribution grid, and will become the future key players for electricity generation, transmission, and distribution. The current power grids are undergoing an unprecedented transformation from the original design, changing the way how energy has been produced, delivered, and consumed over the past century. This new energy era includes the integration of renewable sources such as wind and solar, supported by the distributed or community energy storage, to power distribution grids through innovative high-frequency magnetic links and power-electronic converters. The use of emission free transportation, such as electric vehicles, and energy efficient technologies, such as superconducting generators and storage systems, are also rapidly emerging and will be integrated into the power grids in the foreseeable future. However, it is necessary to reconsider the current paradigms of system analysis and plan with a focus on how to achieve the most flexible, efficient, and reliable power grid for the future––the one that enables operation in a domain which is very different than the current one to deliver the services to consumers at an affordable cost. [ABSTRACT FROM AUTHOR]

Oman, like other Arabian Gulf countries, depends on oil and gas to produce electricity. However, these resources are not guaranteed to last forever and constitute one of the energy security issues in the country. This paper explores the potential of using biomass energy resources for electricity generation in Oman. Energy from biomass resources is counted as a type of renewable energy, which means that its availability is not affected by the lack of sources and the increasing price of fossil oil. The review of biomass energy shows that waste from different sources such as wood and woody plants and their wastes, agricultural crops and residues, municipal solid organic wastes, animal wastes, sewage, waste from organic industrial processing and food processing, and aquatic plants and algae can be used for electricity generation. Biomass from animal manure and waste water are reported as having potential for electricity generation. The results show that a total of 2651·81 GWh/year electricity can be produced from animal manure and waste water, which corresponds to 10% of the total electricity consumption in Oman. Although there is potential to use biomass for sustainable electricity generation, several environmental, social and technological factors associated with biomass energy need to be considered before adopting such resources. [ABSTRACT FROM AUTHOR]

This paper presents an investigation of a 111 MWe linear Fresnel reflector (LFR) plant integrated direct contact membrane distillation (DCMD) system. Both the technologies are synergized by using seawater as cooling fluid in the condenser, and then utilizing heated seawater from the condenser into the DCMD unit. The performance analysis of the LFR plant and DCMD unit has been conducted mainly in regard to direct normal irradiance (DNI) and feed water temperature, respectively. For the LFR plant, electricity generation increased with increasing DNI. The highest and the lowest energy production was 38.33 GWh and 14.08 GWh in June and December, respectively. The real levelized cost of energy was found to be 0.34 ¢/kWh. For DCMD unit, the evaporation efficiency increased from 39.13% to 50.01% corresponding to a feed temperature increase from 30 °C to 45 °C. The average freshwater production capacity of the DCMD unit was found to be 31,844.6 L/day with a water production cost $0.425/m 3 . The investigations revealed that the performance of the proposed system is quite satisfactory, and the low unit production cost of electricity and freshwater make it competitive to eradicate energy and freshwater crises. [ABSTRACT FROM AUTHOR]

Abstract The Brazilian electricity system is an important example of a large country relying on a high renewable energy matrix with a major focus on hydropower, which has historically allowed for low carbon electricity production. However, the increase in the demand and climate change impacts on the availability of these renewable resources represent important challenges for long-term power planning. The contribution of this paper is twofold: Firstly, a first attempt to use the EnergyPLAN model for the analysis of the Brazilian electricity sector and in particular to study future scenarios is presented. Secondly, the possibility of achieving a 100% RES system is also addressed. The 100% RES scenario is found to be theoretically possible but a substantial increase in the overall installed capacity would be required, to support the grid mainly during the spring and summer season. The results underline the importance of seasonal complementarity of hydro and wind power and reveal how an increase in RES would add exportation potential, reducing also the Brazilian external energy dependency. The study identifies risk factors for these high RES scenarios and outlines several avenues for future research to address cost, environmental and technical uncertainties of the system. Highlights • The Brazilian power sector is analysed with EnergyPLAN computer model. • Renewable scenarios are compared for technical, cost, emissions and risk parameters. • The importance of seasonal complementarity of hydro and wind power is outlined. • The 100% RES scenario results in full decarbonization of the system at higher cost. • The 100% RES scenario results in higher exportation and lower importation potential. [ABSTRACT FROM AUTHOR]

This paper proposes a real‐time generation regulation system named as "on‐demand generation regulation control" system, which is suitable for small independent power grids with unstable renewable energy generators. It has been developed as a part of "robust demand and supply control manager" and plays an important role of flexible frequency control that includes vehicle to grid and generation restriction when necessary. The main feature of the system is the integrated framework to effectively deal with hard‐to‐predict control options in a flexible way by observing the unstable generator outputs and all generators/batteries status including electric vehicles. In addition, a feedback system is also proposed to flexibly adjust the regulation capacity in case unexpected disturbances occur. The performance of the proposed system is verified through numerical simulations based on an actual test site with successful results. [ABSTRACT FROM AUTHOR]

Abstract Fuel cells and solar energy are promising candidates for electricity generation. It is forecast that fuel cells and solar power systems will play an important role in reducing the greenhouse gas footprint and replacing fossil fuels. Therefore, the limitations of fuel cells and solar power systems, such as low efficiency, high cost, and low reliability, must be addressed appropriately to enable their full potentials. Metal foam is a new class of material that has gained immense attention due to its excellent properties suitable for a wide range of applications. Its unique characteristics distinguish it from typical solid metals. The properties of metal foam can be modified during the fabrication stage by manipulating its physical structure. The goal of this paper is to review the application of metal foam in fuel cells and solar power systems. Besides, the performance of metal foam in fuel cells and solar systems is also discussed. Metal foam has been applied to the electrodes, gas diffusion layer and flow field of fuel cells to enhance performance, especially in regard to current density and flow distribution. Furthermore, metal foam is a heat exchanger for the solar energy harvesting system to improve its efficiency. Superior performances in experimental testing allows the possibility of commercialization of metal foam products in the renewable energy field. Highlights • This article reviews the past research on metal foam in fuel cell and solar power systems. • Metal foam applications on bipolar plates, electrodes and the gas diffusion layer in a fuel cell. • Metal foam as a thermal management system in solar power systems. • Barriers and future perspectives of metal foam applications in fuel cells and solar power systems. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Use of solar chimney can reduce the semi-transparent PV temperature by up to 38 °C. • Use of solar chimney results enhances the PV generated power by around 30%. • There is an optimum packing factor that maximizes the power generation. • There is an optimal chimney height at which the best cooling effect is achieved. Abstract Semi-transparent photovoltaic (STPV) system’s performance strongly depends on its surface temperature. To provide a mechanism that decrease the temperature of STPV can improve the power generation significantly. This cooling mechanism will be more interesting if it needs no additional energy. In this paper a novel solar chimney system is proposed to cool a STPV system. The STPV is employed as a roof for the solar chimney and an air flow generated by the solar chimney cools the STPV. Based on the energy balance for three main components: STPV, air and ground, a theoretical model is developed for the proposed system. Convection heat transfer coefficients are calculated precisely for the heat transfers taking place in the system and the obtained results for the solar chimney are compared with the existing experimental data in literature. Results of proposed model have a good agreement with the previous data. It’s shown that there is an optimum packing factor that maximizes the generated power for each radiation intensity. It is observed that the proposed system effectiveness depends on the radiation intensity as well as on the structural parameters. The proposed system can reduce the average temperature of the STPV up to 15 °C. It is concluded that, by cooling the STPV power plant with the solar chimney for a solar radiation of 500 W/m2, an enhancement of about 29% in power generation is gained. [ABSTRACT FROM AUTHOR]

Distributed generation (DG) has been rapidly integrated into microgrids. However, uncertain power generation of intermittent DG such as wind turbines brings challenges to the DG planning problem. This paper proposes a novel probability-weighted robust optimization (PRO) method to allocate DG units including microturbines and wind turbines in microgrids, aiming to maximize the total profit over a long-term planning horizon. First, probability-weighted uncertainty sets are proposed to model uncertainties including wind turbine output and load demand during a long-term planning horizon which can fully cover the uncertainty spectrum and accurately represent the uncertainty probability distribution. Then, the PRO method optimizes DG sizing and locating under the worst uncertainty cases considering their occurrence probabilities. Therefore, the planning decision is robust against any possible uncertainty realization. Besides, a modified column-and-constraint generation algorithm is developed to solve the PRO problem. Simulation results show that the DG planning obtained by the proposed method can achieve full operating robustness. [ABSTRACT FROM AUTHOR]

This paper aims to relate total greenhouse gas emissions footprint with Energy Return on Energy Invested for Coal, Natural Gas, Hydro, Geothermal, Wind and Solar PV electricity generation methods. Emissions from construction, decommissioning, operations and maintenance, and fuel, are all included in the analysis. Often the generation equipment is imported so much of the emissions associated with construction are “virtual” emissions (i.e. imported). These virtual emissions contribute to a peak emission as renewable generation is installed at the start to ultimately lead to a lower emissions factor for a countries’ electricity system over time. The peak occurs due to the short-term emissions resulting from construction and a long-term emissions reduction due to the low/zero carbon renewable generation installed. The electricity sector in New Zealand is used as a case study for projected new generation through to 2050 for four scenarios (a) Global Low Carbon, (b) Mixed Renewables, (c) High Grid and (d) High Solar. The study demonstrates that as total greenhouse gas footprints are included an emissions peak occurs due to new construction, mainly because of renewable generation, especially solar and high energy emissions factors in countries manufacturing generation equipment. [ABSTRACT FROM AUTHOR]

Despite the positive momentum achieved by the renewable energy sector in recent years, there are substantial challenges that need the attention of the global community, and one of the more pressing issues is dealing with the deleterious external costs of power generation. One of the parameters to compare costs of energy across various technologies is levelised cost of energy (LCOE), but it has been conventional practice to neglect the external costs in estimating the LCOE of power generation technologies. Furthermore, as LCOE is a critical indicator for policy and decision makers, there is a need to juxtapose actual costs of renewable and conventional power generation technologies. This research paper attempts to internalise some of these external and GHG emission costs across various power generation and storage technologies in all the G20 countries, as they account for 85% of global power consumption. As future investment decisions are largely influenced by costs, estimates in this research prove renewables and storage to be far cheaper than fossil and nuclear sources by 2030, even without considering external costs. The myth that renewables are ‘way too expensive’ has been debunked repeatedly, and the cost decline of wind and solar photovoltaic (PV) technologies have outpaced most industry expectations. The results of this research not only substantiate this trend, but also statistically display that all the G20 countries have the opportunity to decrease their energy costs significantly, between now and 2030. Renewable energy technologies offer the lowest LCOE ranges across G20 countries in 2030. Utility-scale solar PV generally shows the lowest values ranging from 16 to 117 €/MWh el and onshore wind LCOE range is from 16 to 90 €/MWh el . Rooftop solar PV generally offers the next lowest LCOE ranging from 31 to 126 €/MWh el , followed by LCOE of offshore wind power ranging from 64 to 135 €/MWh el . Solar PV and battery systems are highly competitive on an LCOE basis at utility-scale ranging from 21 to 165 €/MWh el and at residential scale from 40 to 204 €/MWh el . The G20, as well as other countries, can continue to develop their economies in a sustainable manner, along with substantial co-benefits in adjacent policy fields such as higher national welfare, better health of citizens, lower respective health costs and improved energy security. [ABSTRACT FROM AUTHOR]

Abstract The problem of optimal power management for uncertain off-grid hybrid systems is studied in this paper. A suitable parametrization of the energy sources and sinks is used to obtain a graphical representation of the feasible set along with a direct observation of the solution and its piecewise description. The proposed approach pretends to clarify how the optimal solution migrates from the use of one source to another as the solar radiation changes and how the dynamic response of the sources restrict the feasible set. A power generation system (PGS) is used to study the limitations that the sun power variability and the parametric uncertainty impose on the optimality; being the PGS constituted by photovoltaic (PV) panels, a fuel cell (FC), an electrolyzer (E) and a battery bank. A simple optimal Power Management Strategy (PMS) is proposed as a result of the analysis and its performance is illustrated in a telecom facility for three different locations in Mexico. Results are shown indicating the viability of the strategy for highly variable environments. Highlights • A graphical approach for optimal power management is proposed. • A parametrization is used to allow simplification of the optimization problem. • The case of parameter uncertainty in the power hybrid system is analyzed. • Results demonstrate that optimal operation is possible in presence of uncertainty. [ABSTRACT FROM AUTHOR]

Malaysia's framework for energy development was established in the early 1970s. Henceforth, many successive policies were introduced as potential resources for electricity generation and utilization. Currently, as a signatory to the United Nations Framework Convention on Climate Change, Malaysia is sparing a number of effort to comply with the policy to meet the challenges of mitigating over-dependence on fossil fuels, reducing carbon levels, and achieving sustainable national development. This paper reviews the baseline studies on electrical energy policies and the measurement indicators used in Malaysia's electric power system. This research involves a comprehensive survey of electrical energy policies in Malaysia that focus on issues pertaining to energy supply, utilization, its environmental impact and considerations, renewable energy (RE) policies, production and consumption, energy efficiency, and feed-in tariffs. Fourteen energy indicators for sustainable development in Malaysia were investigated through the identification of energy policies in significant areas, such as reliability, safety, adequacy and cost-effectiveness of energy supply; increasing energy efficiency; minimizing environmental impact; and enhancing quality of life in terms of social well-being. The policies and the indicators are classified into different sustainable dimensions and summarized in tables along with the corresponding key references. In this study, future energy planning and options, especially in nuclear and RE programs, as well as the conflict between them, are illustrated through the overall performance relative to targets and benchmarks for past and future projections up to the year 2030. This review seeks to examine the past, present, and future policies and indicators to provide a sufficient overview of Malaysian energy policies for optimizing sustainable development. The goal is for this review to lead to increased efforts to accommodate the increasing demand for the management and utilization of RE, promote energy efficiency, and improve performance in achieving sustainable national development. [ABSTRACT FROM AUTHOR]

Renewable Energy Sources have been growing rapidly over the last few years. The spreading of renewables has become stronger due to the increased air pollution, which is largely believed to be irreversible for the environment. On the other hand, the penetration of renewable energy technologies causes major problems to the stability of the grid. Along with the fluctuations of the renewable energy technologies production, storage is important for power and voltage smoothing. Energy storage is also important for energy management, frequency regulation, peak shaving, load leveling, seasonal storage and standby generation during a fault. Thus, storage technologies have gained an increased attention and have become more than a necessity nowadays. This paper presents an up to date comprehensive overview of energy storage technologies. It incorporates characteristics and functionalities of each storage technology, as well as their advantages and disadvantages compared with other storage technologies. Comparison tables with several characteristics of each storage method are included, while different applications of energy storage technologies are described as well. Finally, several hybrid energy storage applications are analyzed and different combinations of energy storage technologies are reviewed. [ABSTRACT FROM AUTHOR]

This paper evaluates the net effect of renewable energy policy in Spain from 2002 to 2017 and calculates its cost-effectiveness in terms of CO 2 emission reductions in the production of electricity. Our conclusions indicate that although the phasing out of Feed-in Tariffs reduced the regulatory costs, it also limited renewable participation in the electricity market, leading to an increased electricity price and higher emissions. According to our results, the joint effect of (i) the value of avoided emissions due to renewable energy participation and (ii) the merit order effect was able to compensate for the regulatory costs (subsidies) up until 2010, while the sign of the net effect was reversed from 2011 to 2017. Finally, we find that the economic implications of emission reductions are highly dependent on how the social cost of carbon is measured. [ABSTRACT FROM AUTHOR]

Abstract Hydrogen is a flexible energy carrier that can be produced in various ways and support a variety of applications including industrial processes, energy storage and electricity production, and can serve as an alternative transportation fuel. Hydrogen can be integrated in multiple energy sectors and has the potential to increase overall energy system flexibility, improve energy security, and reduce environmental impact. In this paper, the interactions between fuel cell electric vehicles (FCEVs), hydrogen production facilities, and the electric power grid are explored. The flexibility of hydrogen production systems can create synergistic opportunities to better integrate renewable sources into the electricity system. To quantify this potential, we project the hourly system-wide balancing challenges in California out to 2025 as more renewables are deployed and electricity demand continues to grow. Passenger FCEV adoption and refueling behavior are modeled in detail to spatially and temporally resolve the hydrogen demand. We then quantify the system-wide balancing benefits of controlling hydrogen production from water electrolysis to mitigate renewable intermittency, without compromising the mobility needs of FCEV drivers. Finally, a control algorithm that can achieve different objectives, including peak shaving, valley filling, and ramping mitigation is proposed. Our results show that oversizing electrolyzers can provide considerable benefits to mitigate renewable intermittency, while also supporting the deployment of hydrogen vehicles to help decarbonize the transportation sector. Highlights • Interactions between FCEVs and electric power systems are studied. • FCEV powertrain, adoption and refueling behavior are modeled. • Two controllers are designed to mitigate California “Duck Curve” problems. • Controllable H 2 production systems can facilitate renewable energy deployment. [ABSTRACT FROM AUTHOR]

After years of dormant scenarios, the Brazilian industry of photovoltaic (PV) energy systems is now growing fast. Therefore, improving interconnection and certification codes, as well as standards, has become undeniably important to establish a well-regulated market under concern of businesses, equipment, and power quality matters. Thus, considering international standards and world-recognized scenarios for distributed PV systems, this paper aims to discuss the existing local energy regulations, grid connection codes, and other related limitations that restrain a faster market and technology development in Brazil. Special attention is given to the certification requirements for grid-connected inverters and other PV equipment, along with the new trends in energy policies, focusing on their impacts on Brazilian PV industry. In the end, it demonstrates that despite its current underdeveloped status, the Brazilian scenario is expected to be quite enthusiastic in the following years and may represent an attractive and dynamic market for professionals, companies, and energy investors. [ABSTRACT FROM AUTHOR]

Concentrating solar power (CSP) has received significant attention among researchers, power-producing companies and state policymakers for its bulk electricity generation capability, overcoming the intermittency of solar resources. The parabolic trough collector (PTC) and solar power tower (SPT) are the two dominant CSP systems that are either operational or in the construction stage. The USA and Spain are global leaders in CSP electricity generation, whereas developing countries such as China and India are emerging by aggressive investment. Each year, hundreds of articles have been published on CSP. However, there is a need to observe the overall research development of this field which is missing in the current body of literature. To bridge this gap, this study 1) provides a most up-to-date overview of the CSP technologies implemented across the globe, 2) reviews previously published review articles on this issue to highlight major findings and 3) analyzes future research trends in the CSP research. Text mining approach is utilized to analyze and visualize the scientific landscape of the research. Thermal energy storage, solar collector and policy-level analysis are found as core topics of discussion in the previous studies. With a holistic analysis, it is found that direct steam generation (DSG) is a promising innovation which is reviewed in this study. This paper provides a comprehensive outlook on the CSP technologies and its research which offers practical help to the future researchers who start to research on this topic. [ABSTRACT FROM AUTHOR]

This paper presents a set of policy recommendations for the market design of a future European electricity system characterized by a dominant share of renewable energy supply (RES), in line with the stated targets of European governments. We discuss the market failures that need to be addressed to accommodate RES in liberalized electricity markets, review the evolution of the EU's RES policy mechanisms, and summarize the key market impacts of variable RES to date. We then set out economic principles for wholesale market design and use these to develop our policy recommendations. Our analysis covers the value of interconnection and market integration, electricity storage, the design of RES support mechanisms, distributed generation and network tariffs, the pricing of electricity and flexibility as well as long-term contracting and risk management. [ABSTRACT FROM AUTHOR]

Abstract Three models for the projection of long-term electricity generation for Pakistan are developed in this paper. Baseline (BL), Coal and Renewable Energy (RE) scenarios are used to analyze current and future electricity generation. From an environmental perspective, both the BL and RE scenarios are found to be superior to the Coal scenario, but a cost-benefit analysis indicates that the RE scenario is most expensive though it brings the benefit of effectively reducing dependence on imports of primary fuel. [ABSTRACT FROM AUTHOR]

Biofuels productions from microalgae received wide attention recently and have high potential to replace fossil fuels. This paper served as a platform to critically review current production technologies of microalgae, ranging from cultivation, harvesting, extraction and several biofuels conversion processes. In addition, due to the high photosynthetic efficiency of microalgae, mass cultivation of microalgae is believed to be able to efficiently reduce the carbon dioxide emission to atmosphere and thus, reducing the impact of global warming. This is because microalgae have high growth rate and is able to develop maximum of 70% of lipid content within their cells depending on species. Apart from that, microalgae have the ability to survive under harsh condition and occupied smaller cultivation land area than other land crops. The harvested microalgae biomass can be used for electrical generation, while its crude lipid can be used as transportation fuel as it has 80% average energy content of petroleum. In the present paper, a detailed discussion to produce biodiesel, fuel gas, bio-oil, methane, hydrogen and alcohol from microalgae biomass are also included. Besides, updated research, challenges and the way forward of microalgae biofuels are also presented. In future, biofuels production from microalgae can be economical viable at some scale, which is then profitable in terms of economics and also environment. [ABSTRACT FROM AUTHOR]

The inertia of today׳s power system decreases as more and more converter connected generation units and load are integrated in the power system. This results in a power system which behaves differently from before which causes concerns for many grid operators. Therefore, a detailed study is needed to investigate the relevance of this inertia in the operation, control and stability of the system. Moreover, a new definition of the term system inertia is necessary since is it expected that in the future also the renewable electricity generation units will deliver the so-called virtual (synthetic) inertia. In this paper a review of the research related to inertia in a power system is given. Both the challenges as the solutions from an operator point of view to control a system with low inertia are discussed. Also a new definition of inertia is proposed to incorporate the different forms of inertia which are each described in more detail. From recent studies, it can be concluded that the influence of reduced inertia on frequency stability is generally considered as the main challenge for system operators, but with the additional measures listed in this paper, this impact can be mitigated. [ABSTRACT FROM AUTHOR]

In recent decades, renewable energies have become increasingly important at the global level, with a significant impact on the sustainable development of various nations. Although multiple papers have examined the efficiency of policies and instruments to promote renewable energy sources, the majority have disregarded the fact that the context in which policies are implemented determines how well they perform. This paper analyzes renewable energy development in the electricity market in Argentina, paying special mind to the contextual conditions in which the policies were designed and finding that in recent history, it is precisely these conditions that constitute the main reason why renewable energies have such a low degree of penetration in the electrical power system in Argentina. [ABSTRACT FROM AUTHOR]

A widespread adoption of distributed generation (DG) technologies in energy systems can play a key role in creating clean, reliable energy and support the targets of emission reduction. A transition from current modes of production to a significant deployment of renewable energy technologies can fundamentally affect the structure of the industry and change the way energy is produced, transmitted and sold. The current paper provides an extended review of the socio-technical configurations of micro-generation based on journal publications and reports during the 21st century. The paper analyses currently existing and missing configurations and discusses technology and policy implications to support proliferation of micro-generation technology and local energy production from renewable sources. The potential for new configurations can be found particularly in heat producing micro-generation with solar heat, heat pumps, and biomass. Developing further the operations and maintenance of distributed generation technologies and business models appears an area that calls for further innovation, and corresponding innovation policy measures. Third party service and community-driven deployment models can aide the proliferation of distributed generation and further innovation therein, justifying the introduction of feed-in-tariffs to attract such models during their early diffusion. [ABSTRACT FROM AUTHOR]

The Canary Island of Tenerife is supplied by an insular power system which relies mainly on conventional thermal power plants. However Tenerife has reached grid parity in photovoltaics (PV) and wind energy. The Spanish government has just approved a new legislation to stimulate the deployment of new PV and wind energy systems in all Spanish insular systems mainly to reduce the cost of these systems. This paper analyses the current electric power system and energy production in Tenerife, especially PV and wind energy, and investigates the consequences of this new legislation and the planning initially approved by the government of the Canary Islands to substantially increase the share of both technologies in the horizon 2020. This paper shows that the Tenerife power system is technically capable of managing the ramps expected to occur in the defined near term scenarios. However, the cost per MWh will increase because of the curtailment of renewable energy generation and the operation of the thermal power system in suboptimal conditions. Some regulatory recommendations are included as conclusions. [ABSTRACT FROM AUTHOR]

Renewable energy sources have a critical role to play in contributing to the diversity, sustainability and security of energy supplies. The main objective of the paper is to gain an understanding of the support mechanism of renewable energy sources most preferred by households in the United Kingdom. This paper analyses households' preferences and willingness to pay under a mandatory scheme where all households contribute compared to a voluntary scheme where only those who wish to pay to support renewables do so (such as the green tariffs offered by electricity suppliers in the UK). Two contingent valuation method (CVM) surveys are used to explore whether the type of payment option has an impact on households' willingness to pay (WTP) for increasing share of renewable energy in electricity generation. The paper also investigates whether the type of payment mode affects respondents' self-reported certainty of paying their stated valuations. The results indicate that the likelihood of paying a positive amount for supporting renewable energy is higher under a mandatory scheme compared to a voluntary payment option in the UK. Respondents have a higher level of certainty in paying their stated WTP under a mandatory payment scheme. [ABSTRACT FROM AUTHOR]

Capacity expansion models for the power sector are used to project future decisions over the coming decades by simulating investment and operation decisions for the use of electricity. Due to model performance constraints, these models typically do not explicitly simulate every hour within a year, but instead simulate representative time segments (groups of hours). This paper evaluates different approaches for selecting time segments across three methods: sequential, categorical, and clustering, across a wide range of time-segment quantities, for a total of 204 temporal profiles. To measure the performance of each profile's ability to accurately represent data, the root-mean-square-error of each profile's time segments are compared to the data's original hourly data. The temporal alignment across regions is also measured (i.e., how often windy days align across regions). Different spatial resolutions were applied for a subset of the temporal selection methods to investigate the impact spatial resolution has on performance. This paper provides a framework for measuring the value of different temporal selection methods and of adding more granular data to energy system models. Overall, multi-criteria clustering yields the lowest root-mean-square-error across all datasets evaluated and provides a holistic view of the intertwined relationships between renewable generation and electricity demand. • Temporal selection methods analyzed across three commonly used techniques. • Measured performance of representing model data within representative hours. • Measured temporal performance across electric load and wind and solar generation. • Clustering techniques performed better than sequential or categorical techniques. [ABSTRACT FROM AUTHOR]

Although microbial fuel cells are potential candidates for electricity generation with concomitant treatment of wastewater, operational and technological improvements are still required to make them a cost effective process. In this paper, a full factorial design in combination with a central composite design were employed to probe the effects of pH and buffer concentration of catholyte on the performance of a two chamber microbial fuel cell. It was observed that at high level of buffer concentration (150 mM) varying the pH between 5.8 and 7.4 did not markedly influence the maximum power density and columbic efficiency. However, at a low level of buffer concentration (25 mM) reducing the pH led to higher power density. Furthermore, it was observed that higher concentrations of buffer were beneficial to power generation when pH was at its high level, but negatively impacted the cell performance at low pH levels. The highest maximum power was predicted to be 461 mW m −2 (at a pH of 6.3 and a buffer concentration of 82 mM) and this was confirmed by experimental results. The findings of this paper highlight the importance of the joint effect of pH and buffer concentration, which is even more influential than their main individual effects. [ABSTRACT FROM AUTHOR]

In this paper, essential statistics demonstrating the increasing role of renewable energy generation are firstly discussed. A state of the art review section covers fundamentals of wind turbines and PV systems. Included are schematic diagrams illustrating the main components and system topologies and the fundamental and increasing role of power electronics as an enabler for renewable energy integration, and for the future power system and smart grid. Recent examples of research and development, including new devices and system installations for utility power plants, as well for as residential and commercial applications are provided. Fuel cells, solar thermal, wave generators, and energy storage systems are also briefly presented and illustrated. Challenges and future trends for 2025 are summarized in a table for on-shore and off-shore wind energy, solar power, including photovoltaic and concentering, wave energy, fuel cells, and storage with batteries and hydrogen, respectively. Recommended further readings on topics of electric power engineering for renewable energy are included in a final section. This paper also represents an editorial introduction for two special issues of the Electric Power Component and Systems Journal, 43(8–10) and 43(12), respectively. [ABSTRACT FROM PUBLISHER]

Recent improvements in computer processing power have enabled the development of intelligent electronic devices (IEDs) to be capable of interpreting a substantial quantity of data at high speeds. The distribution industry is one of the largest users of real-time data during the operation of their energy distribution network and as such, has an inherent need for data processing technology. The development of intelligent devices and communication protocols has given rise to the concept of distribution system automation (DSA). In this paper the major features of DSA development are discussed. A method of communication along with the integration of wired and wireless communication solutions with IED and Mote technology is described. Protection scheme automation is investigated, showing that automated response to network fault conditions is possible. Network reconfiguration is another key aspect of DSA research and two distinct calculation techniques are discussed. The current index (CI) and the load balance index (LBI) calculation methods are presented and the benefits of LBI are highlighted. Distributed generation (DG) is addressed in the context of automation with a demand side management (DSM) program proposed to manage load during peak and off-peak periods. The paper discusses switching DG sources, load deferral strategies and direct load control to effect a reduction in load during peak periods. The paper furthers this load management by load filling during off-peak periods. Finally, conclusions on the effectiveness of the proposed method are drawn and recommendations are made for further research. [ABSTRACT FROM AUTHOR]

The planning and design of an electric power system, including high-voltage direct-current transmission, is a complex optimization problem. The optimization must integrate and model the engineering requirements and limitations of the generation, while simultaneously balancing the system electric load at all times. The problem is made more difficult with the introduction of variable generators, such as wind and solar photovoltaics. In the present paper, we introduce two comprehensive linear programming techniques to solve these problems. Linear programming is intentionally chosen to keep the problems tractable in terms of time and computational resources. The first is an optimization that minimizes the deviation from the electric load requirements. The procedure includes variable generators, conventional generators, transmission, and storage, along with their most salient engineering requirements. In addition, the optimization includes some basic electric power system requirements. The second optimization is one that minimizes the overall system costs per annum while taking into consideration all the aspects of the first optimization. We discuss the benefits and disadvantages of the proposed approaches. We show that the cost optimization, although computationally more expensive, is superior in terms of optimizing a real-world electric power system. The present paper shows that linear programming techniques can represent an electrical power system from a high-level without undue complication brought on by moving to mixed integer or nonlinear programming. In addition, the optimizations can be implemented in the future in planning tools. [ABSTRACT FROM AUTHOR]