Electrical Energy Demand Research Articles

Multi-Phase Power System Simulation

Abstract: Six Phase Transmission System has the capacity to increase the transmission capacity by 1.732 times the existing Three Phase System. It is possible to convert existing Three Phase Double circuit transmission line into compact Six Phase transmission line within the existing Right-of-way. Forecasting the demand and supply of Electrical energy gives the alternative solution is Six Phase Transmission system in addition to its several advantages like reduced phase voltage, less corona, declined magnetic field etc. This paper presents the study and analysis of design of transformer for six phase system. Comparison by system count per unit use MATLAB and PSCAD/ EMTDC simulation implemented for both system. Analysis of data carried out for parameters as value phase difference, voltage, current and power in transmission line. Apart from that assessment choosing the best transformer design for six phase system also implemented. From the analysis data performed found line system six phase have successfully produced ascendant as many as 73% in the division transmission line over system double three phase circuit. Apart from obtain that the best connection six phase system to acquire stated ascendant is delta Star delta inverted Star connection and diametrical connection

Factors affecting electric vehicle acceptance, energy demand and CO2 emissions in Pakistan

This work aims to investigate the factors accelerating electric vehicle (EV) acceptance at the consumer end in Pakistan and analyzes the implications for policymakers for a fast-track EV transition. The study further investigates the high EV penetration scenario resulting from the technology acceptance model (TAM's 80% EV) and its impact on energy demand and CO2 emissions. The study design used a quantitative analysis method with the survey as an instrument for data collection regarding EV acceptance. The model under investigation was adapted from the famous Technology-Acceptance Models (TAMs) and modified with other significant predictors evidenced in the literature. Correlation and stepwise regression were performed with a multicollinearity check for model hypothesis testing. Out of six predictors, only four factors were significant in accelerating the EV transition. Financial policies were found to be highly significant, followed by environmental concern, facilitating conditions and perceived ease of use. The research then used exponential smoothing forecasts for transport demand and developed an EV penetration scenario based on modified TAM results. The results highlight the significant increase in transport demand and the opportunity for Pakistan to limit passenger transport emissions to 36.6 ​MT instead of 61.6 ​MT by 2040.

KAJIAN BAHAN BAKAR HSD, MFO, LNG TERHADAP BIAYA DAN DAYA LISTRIK YANG DIHASILKAN DI PLTG PEMARON

With the increasing demand for electrical energy, steps are needed to increase the production of electrical energy and one of them is the study of PLTG fuel. The PLTG fuel study aims to analyze the ratio of the generated electric power and fuel costs to the power generated by the PLTG. The benefit of this study is to know how much the ratio of power and fuel costs to the power produced, so that it can be used as a reference to determine which fuel is suitable for use. With a quantitative descriptive analysis method where the qualitative data from the calculation results will be described descriptively so that the advantages, disadvantages and differences of the three fuels can be identified. Through SFC calculations the results of this study show that LNG fuel has the lowest SFC value of 0.13 kg/kWh while for HSD it is 0.33 kg/kWh and MFO is 0.43 kg/kWh. With the same amount of fuel, the power produced by LNG is still higher than the other two fuels, which is 40.48 kWh, followed by HSD, which is 25.77 kWh, and MFO, which is 22.63 kWh. When viewed from an economic perspective, LNG is also the cheapest fuel, with a price of IDR 33,639.02, -, while MFO is slightly cheaper than HSD, which is IDR 194,000.00 and for HSD fuel, which is IDR 223,500.00,-.

STUDI PERENCANAAN PEMBANGKIT LISTRIK TENAGA MIKROHIDRO PADA SALURAN IRIGASI DESA ANGANTAKA ABIANSEMAL BADUNG

The utilization of renewable energy can be a solution to meet the current increasing demand for electrical energy in rural areas, one of which is the use of water energy with the development of PLTMH. In this study, the planning of a microhydro power plant was carried out in the irrigation canal of Angantaka Abiansemal Badung Village as a source of electrical energy to meet the needs of electrical energy. The Angantaka Village irrigation channel has a head 2,1 meters, a width of 1,95 meters, an average depth of 0,88 meters and a water discharge of 0,3045 m3/s. The PLTMH planning system uses a breastshot wheel type water wheel with an efficiency of 75% and TEK STC-5 kW 3 phase AC synchronous generator and a 6 kW ELC control panel. Planning for PLTMH on the irrigation canal of Angantaka Abiansemal Badung Village with a capacity of 3,76 kW / 4,70 kVA. The initial investment cost required is IDR. 72.055.375 with operational and maintenance cost of IDR. 720.553 in one year.

Pemberdayaan Masyarakat Desa Tumpak Kecamatan Pujut Lombok Tengah Melalui Pelatihan Uji Kelayakan Instalasi Listrik

The increasing demand for electrical energy, especially in the household sector, requires the use of electrical equipment with electrical installations that meet the safety standard criteria according to SNI: 0225 (PUIL 2011). Electrical energy provides great benefits for human life, but it is also a threat to human life. This can happen if you do not comply with the standards for installing and using electrical installation equipment in accordance with SNI: 0225 (PUIL 2011) and Minister of Energy and Mineral Resources No. 045 of 2005, as well as behavior that is not wise and proper in using electrical equipment. As one of the villages in the KEK Mandalika area, Tumpak village has the potential to develop eco-friendly tourism, so it is necessary to prepare human resources with knowledge of electrical installations. Through community empowerment activities there has been an increase in the ability of participants in terms of theory and practice of the electrical installation feasibility test with an average value of 58.998 to 81.98 or an average increase of 38.95%.

Techno-economic analysis of a combined heat and power system integrating hybrid photovoltaic-thermal collectors, a Stirling engine and energy storage

This paper presents a comprehensive analysis of the energetic, economic and environmental performance of a micro-combined heat and power (CHP) system that comprises 29.5 m2 of hybrid photovoltaic-thermal (PVT) collectors, a 1-kWe Stirling engine (SE) and energy storage. First, a model for the solar micro-CHP system, which includes a validated transient model for the SE micro-CHP unit, is developed. Parametric analyses are performed throughout a year to evaluate the effects of key component sizes and operating parameters, including collector flow rate, storage tank size, SE micro-CHP flow rate, and battery capacity, on the energetic, economic and environmental performance of the proposed system using real hourly weather data, and thermal and electrical energy demand profiles of a detached house located in London (UK). The optimum component sizes and operating parameters are determined accordingly. The daily and monthly operating characteristics of the system are evaluated, and its annual performance is compared to those of a reference system (gas boiler plus grid electricity), as well as of other alternative solar-CHP systems including a PVT-assisted heat pump system and a standalone PVT system. The results indicate that the installation of such a system can achieve an annual electricity self-sufficiency of 87% and an annual thermal energy demand coverage of 99%, along with annual primary energy savings and carbon emission reduction rate of 35% and 37% relative to the reference system. Over 30 years of operation, the net present value (NPV) of the proposed system is £1990 and the discounted payback period is 28 years. The economics of the proposed system is very sensitive to utility prices, especially the electricity purchase price. Relative to the alternative solar systems, the proposed system offers greater environmental benefits but has a longer payback period. This implies that although the energy saving and emission reduction potential of the proposed system is significant, the initial/capital investment, especially of the SE CHP unit and the PVT collector array, are currently high, so efforts should focus on the cost reduction of these technologies.

Fuzzy Logic Controller Based Efficiency Power Management of Grid Operated Microgrid

The exponential increase in electrical energy demand in the current scenario makes the world to turn towards the use of renewable energy sources naturally. The best way to utilize the renewable energy sources is in the form of microgrid. Microgrids are having multiple distributed energy sources and energy storage elements located nearer to the consumer. This paper implements a Fuzzy Logic Controller that efficiently manages the loads in a grid operated Microgrid. In this paper, maximum power point tracking (MPPT) with fuzzy logic controller is used for a grid operated microgrid constituted by solar system and battery. The system consists of Photo Voltaic (PV) system with MPPT controller, Battery with Buck boost converter, Inverter, critical and non-critical loads and utility grid. The simulation results prove that the efficiency of the fuzzy logic controller for different irradiation level with different load conditions has been improved.

Potensi Pengolahan Limbah Padi Menjadi Sumber Energi Listrik Terbarukan yang Bersih dan Terjangkau

Indonesia has a level of agricultural productivity which tends to increase every year as a result of optimizing farmer performance and being supported by large and fertile agricultural land. The abundant production of agricultural products, especially rice production, provides convenience in obtaining food sources forpeople in agrarian countries. On the other hand, processing rice into rice products as the main food source produces waste products which are commonly referred to as waste. Waste has been a subject of world concern for a long time in the design of innovation and technology for its management. The management of rice waste, which is abundant in quantity, needs to be carried out optimally with the right methods and processes so as not to interfere with the sustainability of productivity in the future. Researchers examine these methods and processes in an effort to optimize the potential of rice waste by converting it into renewable electrical energy. With qualitative and quantitative approaches, this research provides solutions in the form of incineration and gasification methods as optimal handling of ricewaste and answers the increasing demand for electrical energy. A high level of production consistency and maximum waste utilization can be easily achieved with a technology that is structured, safe, easy to operate and environmentally friendly. The management of rice waste into a source of electrical energy is expected to reduce the use of fossil-fueled to the Net Zero 2060 launched by the government. That way, the environmental balance will be maintained in Era Society 5.0. in the future, where electricity is the main need for humans who live side by side with technology. The abundance of biomass in Indonesia which is managed optimally is expected to be a solution to the need for renewable energy. The results of this study are expected to be a reference in further design and development.

Water-Energy Nexus in the Antofagasta Mining District: Options for Municipal Wastewater Reuse from a Nearly Energy-Neutral WWTP

The region of Antofagasta is the mining hearth of Chile. The water requirement of the local mining sector is 65% of the total water uses, with a water consumption of approx. 9 m3/s in the year 2020. That determines an important pressure onto freshwater, which can only be alleviated by resorting to desalination or reuse of treated wastewater. At present, an amount equal to 90% of the wastewater generated in the city of Antofagasta is discharged into the ocean, after undergoing only preliminary treatments. The wastewater treatment plant (WWTP), which includes a conventional activated sludge (CAS) process, has a very low treatment capacity, insufficient to serve the whole population. A new WWTP will be built with the twofold aim of (i) purifying the totality of the wastewater generated from the city (approx. 320,000 equivalent inhabitants, e.i.), and (ii) allowing the reuse of 100% of the treated wastewater in the local mining sector, in agreement with the goals of the Chilean government. The new Antofagasta WWTP will include preliminary treatments and a conventional activated sludge (CAS) process with a higher treatment capacity. This study integrates a number of modeling tools, namely the Activated Sludge Model n.3 (ASM3), the Takacs model, and some stoichiometric and energy balances, to assess the impact that some changes, possibly introduced into the project of the new WWTP, could determine on its energy and environmental sustainability. Specifically, through an energy-economic-environmental (3-E) analysis, the original scheme of the planned WWTP was compared with three scenarios, of which Scenario 1 introduces anaerobic digestion (AD) of secondary sludge, Scenario 2 concerns primary sedimentation and AD of both primary and secondary sludge, and, finally, Scenario 3, other than primary sedimentation and AD, also includes a pre-denitrification process. The results of the study demonstrated that all the changes introduced by Scenario 3 were of capital importance to promote the transformation of the WWTP into a nearly energy-neutral water resource recovery facility (WRRF). Specifically, the processes/operations introduced with Scenario 3 can reduce the electric energy demand from external sources to only 20% of that of the original scheme, and consequently avoid the emission of 4390 tons CO2-equivalent/y.

Towards the Decarbonization of Industrial Districts through Renewable Energy Communities: Techno-Economic Feasibility of an Italian Case Study

In Europe, the recast of Directive 2018/2001 defined Renewable Energy Communities as innovative configurations for renewable energy sharing between different end user types. In this regard, this work aims to assess the benefits following the constitution of a Renewable Energy Community in the industrial area of Benevento (South of Italy), involving a mixed-use building and an industrial wastewater treatment plant. The alternative single end users’ configuration has been also examined, and both solutions have been compared with the current state where the users’ electric energy requests are fully met by the power grid. The users have been equipped with a 466 kWp photovoltaic plant, modelled in HOMER Pro®, providing in input experimental meteorological data (global solar radiation and air temperature) collected by one of the weather control units in Benevento. Real data about users’ electric energy demand have been gathered from their electricity bills, and when unavailable their electric load profiles on an hourly basis have been reconstructed based on the aggregated monthly data. Energy sharing has been proven to increase energy self-consumption and the users’ self-sufficiency. Annually, the primary energy demand is reduced by 577 MWh (1.2 MWh/kWp), carbon dioxide emissions by 84 tCO2 and operative costs by 101 kEUR.

Climate impact of diverting residual biomass to cement production

AbstractCo‐firing residual lignocellulosic biomass with fossil fuels is often used to reduce greenhouse gas (GHG) emissions, especially in processes like cement production where fuel costs are critical and residual biomass can be obtained at a low cost. Since plants remove CO2 from the atmosphere, CO2 emissions from biomass combustion are often assumed to have zero global warming potential (= 0) and do not contribute to climate forcing. However, diverting residual biomass to energy use has recently been shown to increase the atmospheric CO2 load when compared to business‐as‐usual (BAU) practices, resulting in values between 0 and 1. A detailed process model for a natural gas‐fired cement plant producing 4200 megagrams of clinker per day was used to calculate the material and energy flows, as well as the lifecycle emissions associated with cement production without and with diverted biomass (supplying 50% of precalciner energy demand) from forestry and landfill sources. Biomass co‐firing reduced natural gas demand in the precalciner of the cement plant by 39% relative to the reference scenario (100% natural gas), but the total demands for thermal, electrical, and diesel (transportation) energy increased by at least 14%. Assuming values of zero for biomass combustion, cement's lifecycle GHG intensity changed from the reference (natural gas only) plant by −40, −23, and − 89 kg CO2/Mg clinker for diverted biomass from slash burning, forest floor and landfill biomass, respectively. However, using the calculated values for diverted biomass from these same fuel sources, the lifecycle GHG intensities changes were −37, +20 and +28 kg CO2/Mg clinker, respectively. The switch from decreasing to increasing cement plant GHG emissions (i.e., forest floor or landfill feedstocks scenarios) highlights the importance of calculating and using the factor when quantifying lifecycle GHG impacts associated with diverting residual biomass to bioenergy use.

Impacts of Renewable Energy Generation on Greenhouse Gas Emissions in Saudi Arabia: A Comprehensive Review

Over the last few years, the electric energy demand in the Kingdom of Saudi Arabia (KSA) has increased many folds due to several factors including increased population, industrialization, economic activities, and urbanization. The main source of electric power generation in KSA is the burning of petroleum products. Almost one third of greenhouse gas (GHG) emissions are contributed from the electric power generation sector, mainly, by burning diesel and natural gas. As a result, it makes it necessary to consider alternate forms of electricity generation in order to cut down emissions and to keep sustainable growth alive. The government has planned to diversify energy sources and suppliers. In recent years, energy generation from renewable sources including solar photovoltaic (PV), wind, concentrated solar power (CSP), biomass, geothermal, and tidal, has been given more importance. The ambitious Saudi Vision 2030 targets of 58.7 GW of power generation from renewable energy sources will cause a significant reduction in GHG emissions from the energy sector. This article systematically reviews the impact of renewable energy generation on GHG emissions. The detailed breakdown of GHG emission is discussed. Then, the status of renewable energy generation is investigated, focusing on the technical and economic potentials. The correlation of renewable energy generation and GHG emissions is then explained. The most distinguishing feature of this review is that it provides a comprehensive list of recommendations to reduce GHG emissions. The discussions and recommendations of this article will support decision makers, system planners, industry personnel, researchers, and academics to develop sustainable energy pathways for the Kingdom.

Hospital energy demand forecasting for prioritisation during periods of constrained supply

Purpose: Sustaining healthcare operations without adequate energy capacity creates significant challenges, especially during periods of constrained energy supply. This research develops a clinical and non-clinical activity-based hospital energy model for electrical load prioritization during periods of constrained energy supply.Design/methodology/approach: Discrete event modelling is adopted for development of the hospital energy model (HEM). The basis of the HEM is business process mapping of the hospitals clinical and non-clinical activities. The model prioritizes the electrical load demand as Priority 1, 2 and 3; with Priority 1 activities essential to the survival of patients, Priority 2 activities are critical activities that are required after one to four hours, and Priority 3 activities can run for several hours without electricity.Findings: The model was applied to a small, medium, and large hospital. The results demonstrate that Priority 2 activities have the highest energy demand, followed by Priority 1 and Priority 3 activities, respectively for all hospital sizes. For the medium and large hospitals, the top three contributors to energy demand are lighting, HVAC, and patient services. For the small hospital, it is patient services, lighting, and HVAC, respectively.Research limitations/implications: The model is specific to hospitals but can be modified for other healthcare facilities.Practical implications: The resolution of the electrical energy demand down to the business activity level, enables hospitals to evaluate current practices for optimization. It facilitates multiple energy supply scenarios, enabling hospital management to conduct feasibility studies based on available power supply optionsSocial implications: Improved planning of capital expenditure and operational budgets and during constrained energy supply. This reduces risk to hospitals and ensures consistent quality of service. Originality/value: Current hospital energy models are limited, especially for operations management under constrained energy supply. A simple to use model is proposed to assist in planning of activities based on available supply.

ANALISA LAJU KOROSI KETEBALAN PIPA BAJA KARBON PADA PROSES PEMBAKARAN DI UNIT BOILER

The demand for electrical energy continues to increase along with the increase in economic growth in Indonesia, where currently almost all equipment used by humans depends on electrical energy. The steam power generation system is one of the power generation systems that are commonly used in industries and other power plants. In general, a steam power generation system consists of several main components, namely: pumps, steam turbines, boilers, generators and condensers. Boilers are composed of several components such as pipes, chimneys, superheaters, steam drums, economizers, and other important components. One of the most important components in the boiler system is the boiler pipe which plays a role in helping the combustion process to be used in the boiler. Loss of boiler pipe thickness due to corrosion is one of the important factors that really need to be considered in the boiler combustion process at PLTU. Loss of thickness of the boiler pipe in the combustion process that is too large can cause pipe leakage which results in the interruption of the combustion process in the boiler pipe. So to overcome this problem, checks are carried out to carry out maintenance on the boiler pipe to avoid leaks in the boiler pipe. After the calculation, the average reduction in pipe thickness due to corrosion is 0.1465 mm/yr

Energy impact of heat pipe-assisted microencapsulated phase change material heat sink for photovoltaic and thermoelectric generator hybrid panel

As the importance of energy saving continues to increase owing to climate change, various Internet of Things sensors, related to building temperatures, humidity, and energy usage, are being employed in buildings, such as in building energy management systems. Aiming to satisfy the rapidly increasing electric energy demands of buildings, studies have combined various building-integrated photovoltaic (BIPV) and thermoelectric generators (TEGs) to recover sunlight and heat wasted from building envelopes. However, in most previous studies, active methods for heat rejection were applied to increase the temperature difference between both ends of the TEG and cooling of the solar panel. The actual constructability problems, such as leakage problems, were insufficiently addressed. Therefore, this study proposed a BIPV-TEG system with increased constructability and heat dissipation efficiency using a heat pipe and microencapsulated phase change material (mPCM). In addition, this study analyzed the thermal behaviors and improvements in power generation efficiency through field tests by manufacturing a prototype. The results of the outdoor experiment indicated that the BIPV-TEG-PCM prototype improved power generation efficiency by approximately 2% in the intermediate season and 2.5% in the summer relative to the efficiency of a general PV panel. Moreover, using a single TEG, approximately 3.06 Wh of the heat wasted in the building envelope can be recovered as a form of electricity annually.

Accurate Key Parameters Estimation of PEMFCs’ Models Based on Dandelion Optimization Algorithm

With the increasing demand for electrical energy and the challenges related to its production, along with the need to be environmentally friendly to achieve sustainability for future generations, proton exchange membrane fuel cells (PEMFCs) are emerging as a clean energy source that can effectively replace conventional energy sources, in various fields of application and especially in the field of transportation exploiting electric vehicles (EVs). To improve the development and control of the PEMFCs, the precise determination of its mathematical model remains an essential task. Indeed, the accuracy of such a model depends on the ability to overcome the constraints associated with the nonlinearity and the numerous involved unknown parameters. The present paper proposes a new Dandelion Optimizer (DO) to accurately identify, for the first time, the parameters of the PEMFC model. The DO addresses the weaknesses of the majority of metaheuristic algorithms related to the self-adaptation of parameters, the stagnation of convergence to local minima, and the ability to refer to the whole population. The high ability of the proposed method is investigated using both steady-state and dynamic situations. The DO-based parameters estimation approach has been assessed through a specific comparative study with the most recently published techniques including GWO, GBO, HHO, IAEO, VSDE, and ABCDESC is performed using two typical PEMFC modules, namely 250 W PEMFC and NedStack PS6. The results obtained proved that the proposed approach obtained promising achievements and better performances comparatively with well-recognized and competitive methods.

An Examination of Modelling, Simulation and Detection of Fault Behaviours in HVDC Monopolar System

Purpose: Some previous researchers work on the HVDC Monopolar systems using Matlab/Simulink environment to carry out their analyses. We continue this discussion of Monopolar HVDC systems.
 Methodology: The analyses that are carried out include double phase-to-ground fault, single phase-to-ground fault and three phase-to-ground fault at the AC side of the rectifier and the DC line to ground fault. 
 Findings: It is discovered, among others, that for three phase-to-ground fault, the voltages at the AC side of the rectifier, the DC line voltage and the voltage at the inverter side of the load are completely zero but that the current in the rectifier will increase from its standard value though will be less harmful and the current of the inverter side will decrease from its original value. It is further discovered that the fastest transient will be the case when fault is applied to the DC transmission system and that transmission network is of critical importance in high voltage transmission lines and engineers can also use this result to identify different faults in the transmission lines and the care of power quality is highly important because of electrical energy demand.
 Unique Contribution to Theory, Practice and Policy: The current in the rectifier decreases from its standard value but will be less harmful. The causes of decrease in DC transmission line depend on severity of the fault such as single phase to ground, double line to ground and three phase-to ground at the rectifier side.

Design of International Airport Hybrid Renewable Energy System

This paper presents the design and simulation of a hybrid renewable energy system utilizing solar and wind energy sources with a backup generator. The demand for reliable electric energy in support of investments in large social and economic development activities such as airport operations has been an agenda worldwide. In Tanzania, Mwanza International Airport (MIA) expects to consume about 18 MVA of electric power annually to support its operations for the next 25 years. About 78-80% of the world's commercial energy comes from fossil fuels. Non-renewable fuels and other negative effects contribute to global warming through greenhouse gas emissions and carbon dioxide emissions. Additionally, most centralized conventional power generation methods require transmission systems, adding complexity and poor power quality. Therefore, the proposal to use a mixed-coupled hybrid renewable energy source to power the airport is necessary. The energy mix considered is solar photovoltaic (PV), wind, diesel generator and a battery. There is an average solar irradiation of 5.38 kWh/m2 and a wind speed average of 4.20 m/s that could be converted to electricity by installing a 10-kW wind turbine (this is enough to generate power for MIA). The diesel generator and the battery designed at 140 kVA and 400 Ah, respectively, take the intermittency. The project will be in operation for 25 years; hence its costs are reasonable, and the justification is the potentiality of harvesting that estimated energy output of 18 MVA, which will meet the load for MIA. Some mathematical computations were performed, and, in the end, simulation results displayed different techno-economic Hybrid Renewable Energy Source (HRSE) configurations. The selected system's complete design would include a 78.48 kW PV system comprising 314 pieces of 200 W poly-crystalline modules, 608 batteries of 83.4 Ah, 12 V rating, 140 kVA diesel generator, and 41.64 kVA bidirectional converter. The net present cost of the selected design is US$357,780.8, the energy cost is 0.93US$/kW, and the minimum renewable fraction is 40.2%.

Experimental validation of a state-of-the-art model predictive control approach for demand side management with a hot water heat pump

Hot water heat pumps are well suited for demand side management, as the heat pump market faced a rapid growth in the past years with the trend to decentralized domestic hot water use. Sales were accelerated through wants and needs of energy conservation, energy efficiency, and less restrictive rules regarding Legionella. While in literature the model predictive control potential for heat pumps is commonly shown in simulations, the share of experimental studies is relatively low. To this day, experimental studies considering solely domestic hot water use are not available. In this paper, the realistic achievable model predictive control potential of a hot water heat pump is compared to the standard hysteresis control, to provide an experimental proof. We show for the first time, how state-of-the-art approaches (model predictive control, system identification, live state estimation, and demand prediction) can be transferred from electric hot water heaters to hot water heat pumps, combined, and implemented into a real-world hot water heat pump setup. The optimization approach, embedded in a realistic experimental setting, leads to a decrease in electric energy demand and cost per unit electricity by approximately 12% and 14%, respectively. Further, an increase in efficiency by approximately 13% has been achieved.

Optimisation of multi-period renewable energy systems with hydrogen and battery energy storage: A P-graph approach

Renewable energy systems play an important role in alleviating environmental pollution, and their characteristics, including low emissions and recyclability, are highly favourable. At present renewable energy can be costly and renewable energy systems have room for optimization, particularly systems which cater to remote and island areas. This paper develops a P-graph-based multi-period energy model, using hydrogen for energy storage to satisfy the fluctuating electrical and thermal energy demand of an island. Hydrogen can be generated from renewable energy sources during off-peak periods and can be used to serve as an energy carrier. An economic and carbon footprint analysis of the system is performed, which compares a pure renewable energy system, with hydrogen storage, and with battery storage. Within the same scenario, the results show that the renewable energy systems with hydrogen storage and battery storage are 21.5 % and 5.3 % cheaper than the renewable energy system without energy storage, with CO2eq emissions of 1,717 t/y and 1,680 t/y. These findings show that the inclusion of energy storage systems has great potential to reduce costs within renewable energy systems. Changes in the supply of biomass were investigated (which had the greatest impact in the study area), as well as changes in the cost of hydrogen storage. In addition to the optimal solution, near-optimal solutions were also suggested to provide well-rounded guidance for implementation.