scholarly journals AKUMULIACINĖS TALPYKLOS DINAMINIO VEIKIMO EKSPERIMENTINIS IR SKAITINIS TYRIMAS / EXPERIMENTAL AND NUMERICAL RESEARCH OF DYNAMIC OPERATION OF HEAT STORAGE TANK

2019 ◽  
Vol 11 (0) ◽  
pp. 1-5 ◽  
Author(s):  
Tomas Kropask ◽  
Giedrė Streckienė ◽  
Anton Frik
Keyword(s):  
Renewable Energy ◽  
Energy Demand ◽  
Storage Tank ◽  
Discharge Rate ◽  
Renewable Energy Sources ◽  
Operation Mode ◽  
Hot Water ◽  
Dynamic Mode ◽  
Ansys Fluent ◽  
Development And Validation

Renewable energy sources (RES) and their transformation technologies become more attractive in building sector as energy demand and emissions to the environment increase. Along with renewable energy transformation technologies, the importance of energy storage also arises as these RES are characterized by volatility and energy mismatch over time. For this reason, engineering systems which use RES are becoming increasingly dynamic. This study examines ongoing processes in a vertical cylindrical storage tank designed to cover domestic hot water demand in a building. Simultaneous dynamic mode of operation when the energy is being charged and at the same time discharged from the storage tank is analysed. Experiments are performed and stratification number describing thermal stratification is calculated. The obtained data are used for the development and validation of the numerical model. Using Ansys Fluent software, the influence of different discharge rate on operation mode of the storage tank is investigated. Graphical and numerical interpretation of results is performed.

scholarly journals Estimation of Energy Activity and Flexibility Range in Smart Active Residential Building

Smart Cities ◽  
2019 ◽  
Vol 2 (4) ◽  
pp. 471-495
Author(s):  
Viktor Stepaniuk ◽  
Jayakrishnan Pillai ◽  
Birgitte Bak-Jensen ◽  
Sanjeevikumar Padmanaban
Keyword(s):  
Renewable Energy ◽  
Energy Management ◽  
Storage Tank ◽  
Residential Buildings ◽  
Renewable Energy Sources ◽  
Hot Water ◽  
Active Management ◽  
Worst Case ◽  
And Storage ◽  
Storage Units

The smart active residential buildings play a vital role to realize intelligent energy systems by harnessing energy flexibility from loads and storage units. This is imperative to integrate higher proportions of variable renewable energy generation and implement economically attractive demand-side participation schemes. The purpose of this paper is to develop an energy management scheme for smart sustainable buildings and analyze its efficacy when subjected to variable generation, energy storage management, and flexible demand control. This work estimate the flexibility range that can be reached utilizing deferrable/controllable energy system units such as heat pump (HP) in combination with on-site renewable energy sources (RESs), namely photovoltaic (PV) panels and wind turbine (WT), and in-house thermal and electric energy storages, namely hot water storage tank (HWST) and electric battery as back up units. A detailed HP model in combination with the storage tank is developed that accounts for thermal comforts and requirements, and defrost mode. Data analytics is applied to generate demand and generation profiles, and a hybrid energy management and a HP control algorithm is developed in this work. This is to integrate all active components of a building within a single complex-set of energy management solution to be able to apply demand response (DR) signals, as well as to execute all necessary computation and evaluation. Different capacity scenarios of the HWST and battery are used to prioritize the maximum use of renewable energy and consumer comfort preferences. A flexibility range of 22.3% is achieved for the scenario with the largest HWST considered without a battery, while 10.1% in the worst-case scenario with the smallest HWST considered and the largest battery. The results show that the active management and scheduling scheme developed to combine and prioritize thermal, electrical and storage units in buildings is essential to be studied to demonstrate the adequacy of sustainable energy buildings.

scholarly journals Analysis and comparison of methods for the preparation of domestic hot water from district heating system, selected renewable and non-renewable sources in low-energy buildings

2018 ◽  
Vol 30 ◽  
pp. 03001
Author(s):  
Maciej Knapik
Keyword(s):  
Renewable Energy ◽  
Energy Demand ◽  
Renewable Energy Sources ◽  
District Heating ◽  
Heating System ◽  
Hot Water ◽  
Low Energy ◽  
Energy Sources ◽  
District Heating System ◽  
Domestic Hot Water

The article presents an economic analysis and comparison of selected (district heating, natural gas, heat pump with renewable energy sources) methods for the preparation of domestic hot water in a building with low energy demand. In buildings of this type increased demand of energy for domestic hot water preparation in relation to the total energy demand can be observed. As a result, the proposed solutions allow to further lower energy demand by using the renewable energy sources. This article presents the results of numerical analysis and calculations performed mainly in MATLAB software, based on typical meteorological years. The results showed that system with heat pump and renewable energy sources Is comparable with district heating system.

scholarly journals Impact of location characteristics on renewable energy production for a group of buildings

2019 ◽  
Vol 116 ◽  
pp. 00084
Author(s):  
Krystian Szczerbak
Keyword(s):  
Renewable Energy ◽  
Heat Pump ◽  
Energy Demand ◽  
Renewable Energy Sources ◽  
Heat Pumps ◽  
Hot Water ◽  
Energy Sources ◽  
Solar Collectors ◽  
Single Family ◽  
Northern Regions

The climate in Poland is slightly disparate in each region. The differences in temperature not always come along with the intensity of solar radiation in 5 climate zones. South of the country is colder, but well irradiated by the Sun and northern regions have milder climate, but are less irradiated. This fact alone makes people consider the suitability and safety of using renewable energy sources such as air-to-water heat pumps, solar collectors and photovoltaics instead of more traditional, fossil fuel powered sources. This paper presents a comparison analysis of energy demand and the cost for heating in a group of single-family buildings by 4 variants (gas boiler, gas boiler and solar collectors, air-to-water heat pump, air-to-water heat pump and photovoltaics) in 5 chosen cities in each polish climate zone. Calculations were done for space heating and domestic hot water energy demand, CO2 emissions and cumulative costs for all variants and locations. The results confirm the inconsistency of polish climate and have shown profitability and utility of renewable energy sources.

ENERGY AUDIT – METHOD FOR ENERGY CONSERVATION IN HOTELS

2007 ◽  
Vol 14 (2) ◽  
pp. 349-358
Author(s):  
Zeljka Hrs Borkovic ◽  
Biljana Kulisic ◽  
Margareta Zidar
Keyword(s):  
Renewable Energy ◽  
Energy Conservation ◽  
Energy Demand ◽  
Renewable Energy Sources ◽  
Hotel Industry ◽  
Hot Water ◽  
Energy Sources ◽  
Energy Audit ◽  
Increasing Demand ◽  
Near Future

: In the very near future, energy efficient hotels will cease to be the exception but will be the rule. Energy conservation and the intelligent utilization of renewable energy sources are prerequisite for sustainable development of tourism. Due to global warming and increased standards in hotel industry, there is an increasing demand for energy for cooling in general, although this is especially reflected in hotel industry peaking in summer period. Furthermore, energy demand for hot water and food and beverages preparation in a hotel increases proportionally with the number of tourists. All these energy issues are overburdening the ever competing hotel industry. Hotels, in order to optimize their energy costs and implementation of renewable energy sources utilization, have to perform energy audit - an analysis of thermal performance and energy systems of building with the purpose to determent its energy efficiency or non-efficiency. This paper combines energy audit methodology with properties of energy consumption in hotel industry with an aim to provide guidelines for modern hotel energy management.

scholarly journals Techno-Economic Analysis of a Novel Hydrogen-Based Hybrid Renewable Energy System for Both Grid-Tied and Off-Grid Power Supply in Japan: The Case of Fukushima Prefecture

2020 ◽  
Vol 10 (12) ◽  
pp. 4061 ◽  
Author(s):  
Naoto Takatsu ◽  
Hooman Farzaneh
Keyword(s):  
Renewable Energy ◽  
Energy Demand ◽  
Renewable Energy Sources ◽  
Economic Assessment ◽  
Energy System ◽  
Modeling Framework ◽  
Integrated Simulation ◽  
Hybrid Renewable Energy System ◽  
Renewable Energy System ◽  
Hybrid Renewable Energy

After the Great East Japan Earthquake, energy security and vulnerability have become critical issues facing the Japanese energy system. The integration of renewable energy sources to meet specific regional energy demand is a promising scenario to overcome these challenges. To this aim, this paper proposes a novel hydrogen-based hybrid renewable energy system (HRES), in which hydrogen fuel can be produced using both the methods of solar electrolysis and supercritical water gasification (SCWG) of biomass feedstock. The produced hydrogen is considered to function as an energy storage medium by storing renewable energy until the fuel cell converts it to electricity. The proposed HRES is used to meet the electricity demand load requirements for a typical household in a selected residential area located in Shinchi-machi in Fukuoka prefecture, Japan. The techno-economic assessment of deploying the proposed systems was conducted, using an integrated simulation-optimization modeling framework, considering two scenarios: (1) minimization of the total cost of the system in an off-grid mode and (2) maximization of the total profit obtained from using renewable electricity and selling surplus solar electricity to the grid, considering the feed-in-tariff (FiT) scheme in a grid-tied mode. As indicated by the model results, the proposed HRES can generate about 47.3 MWh of electricity in all scenarios, which is needed to meet the external load requirement in the selected study area. The levelized cost of energy (LCOE) of the system in scenarios 1 and 2 was estimated at 55.92 JPY/kWh and 56.47 JPY/kWh, respectively.

scholarly journals A Sizing Method for PV–Battery–Generator Systems for Off-Grid Applications Based on the LCOE

Energies ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1988
Author(s):  
Ioannis E. Kosmadakis ◽  
Costas Elmasides
Keyword(s):  
Renewable Energy ◽  
Energy Demand ◽  
Renewable Energy Sources ◽  
Temporal Distribution ◽  
Electrical Energy ◽  
Optimal Number ◽  
Diesel Generator ◽  
Levelized Cost Of Electricity ◽  
Sufficient Power ◽  
Battery Energy

Electricity supply in nonelectrified areas can be covered by distributed renewable energy systems. The main disadvantage of these systems is the intermittent and often unpredictable nature of renewable energy sources. Moreover, the temporal distribution of renewable energy may not match that of energy demand. Systems that combine photovoltaic modules with electrical energy storage (EES) can eliminate the above disadvantages. However, the adoption of such solutions is often financially prohibitive. Therefore, all parameters that lead to a functionally reliable and self-sufficient power generation system should be carefully considered during the design phase of such systems. This study proposes a sizing method for off-grid electrification systems consisting of photovoltaics (PV), batteries, and a diesel generator set. The method is based on the optimal number of PV panels and battery energy capacity whilst minimizing the levelized cost of electricity (LCOE) for a period of 25 years. Validations against a synthesized load profile produced grid-independent systems backed by different accumulator technologies, with LCOEs ranging from 0.34 EUR/kWh to 0.46 EUR/kWh. The applied algorithm emphasizes a parameter of useful energy as a key output parameter for which the solar harvest is maximized in parallel with the minimization of the LCOE.

scholarly journals Optimal Planning and Operation of a Residential Energy Community under Shared Electricity Incentives

Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2045
Author(s):  
Pierpaolo Garavaso ◽  
Fabio Bignucolo ◽  
Jacopo Vivian ◽  
Giulia Alessio ◽  
Michele De Carli
Keyword(s):  
Renewable Energy ◽  
Power Distribution ◽  
Energy Demand ◽  
Renewable Energy Sources ◽  
Energy System ◽  
Distribution Networks ◽  
Building Envelope ◽  
Net Energy ◽  
Technical Equipment ◽  
Optimal Planning

Energy communities (ECs) are becoming increasingly common entities in power distribution networks. To promote local consumption of renewable energy sources, governments are supporting members of ECs with strong incentives on shared electricity. This policy encourages investments in the residential sector for building retrofit interventions and technical equipment renovations. In this paper, a general EC is modeled as an energy hub, which is deemed as a multi-energy system where different energy carriers are converted or stored to meet the building energy needs. Following the standardized matrix modeling approach, this paper introduces a novel methodology that aims at jointly identifying both optimal investments (planning) and optimal management strategies (operation) to supply the EC’s energy demand in the most convenient way under the current economic framework and policies. Optimal planning and operating results of five refurbishment cases for a real multi-family building are found and discussed, both in terms of overall cost and environmental impact. Simulation results verify that investing in building thermal efficiency leads to progressive electrification of end uses. It is demonstrated that the combination of improvements on building envelope thermal performances, photovoltaic (PV) generation, and heat pump results to be the most convenient refurbishment investment, allowing a 28% overall cost reduction compared to the benchmark scenario. Furthermore, incentives on shared electricity prove to stimulate higher renewable energy source (RES) penetration, reaching a significant reduction of emissions due to decreased net energy import.

Modelling of an Optimized Microgrid Model by Integrating DG Distributed Generation Sources to IEEE 13 Bus System

2021 ◽  
Vol 5 (2) ◽  
pp. 18-25
Author(s):  
Bisma Imtiaz ◽  
Imran Zafar ◽  
Cui Yuanhui
Keyword(s):  
Renewable Energy ◽  
Distributed Generation ◽  
Energy Demand ◽  
High Reliability ◽  
Renewable Energy Sources ◽  
Energy Sources ◽  
Efficient Manner ◽  
Matlab Simulink ◽  
Control Scheme ◽  
Power Quality Improvement

Due to the rapid increase in energy demand with depleting conventional sources, the world’s interest is moving towards renewable energy sources. Microgrid provides easy and reliable integration of distributed generation (DG) units based on renewable energy sources to the grid. The DG’s are usually integrated to microgrid through inverters. For a reliable operation of microgrid, it must have to operate in grid connected as well as isolated mode. Due to sudden mode change, performance of the DG inverter system will be compromised. Design and simulation of an optimized microgrid model in MATLAB/Simulink is presented in this work. The goal of the designed model is to integrate the inverter-interfaced DG’s to the microgrid in an efficient manner. The IEEE 13 bus test feeder has been converted to a microgrid by integration of DG’s including diesel engine generator, photovoltaic (PV) block and battery. The main feature of the designed MG model is its optimization in both operated modes to ensure the high reliability. For reliable interconnection of designed MG model to the power grid, a control scheme for DG inverter system based on PI controllers and DQ-PLL (phase-locked loop) has been designed. This designed scheme provides constant voltage in isolated mode and constant currents in grid connected mode. For power quality improvement, the regulation of harmonic current insertion has been performed using LCL filter. The performance of the designed MG model has been evaluated from the simulation results in MATLAB/ Simulink.

scholarly journals Conversion of Biomass of Bagasse to Syngas Through Downdraft Gasification

2018 ◽  
Vol 7 (1) ◽  
pp. 28-33 ◽  
Author(s):  
Maryudi Maryudi ◽  
Agus Aktawan ◽  
Siti Salamah
Keyword(s):  
Energy Source ◽  
Renewable Energy ◽  
Energy Demand ◽  
Alternative Energy ◽  
Renewable Energy Sources ◽  
Energy Reserves ◽  
Gasification Process ◽  
Gas Fuel ◽  
Gasification Products ◽  
Gasification Technology

National energy demand has been fulfilled by non-renewable energy sources, such as natural gas, petroleum, coal and so on. However, non-renewable energy reserves deplete increasingly which can cause an energy crisis. Conversion of biomass into energy becomes one of the solutions to overcome it. Indonesia has an enormous biomass potential especially from sugarcane plantation. Sugarcane plantations produce waste of bagasse abundantly. Commonly bagasse is utilized as energy source by conventional combustion.  This research studies the utilization of bagasse as energy source by gasification technology to produce gas fuel. The gasification model used in this research is downdraft gasifier equipped with cyclone to separate gas with solid or liquid gasification products. The result has shown  that gasification of bagasse has produced flammable syngas. The increase of bagasse weight increases the amount of syngas of gasification process. Carbon monoxide is the greatest content of syngas, while a few amount of H2, CH4 are also detected. Bagasse through gasification process is very potential source of alternative energy, since it is derived from waste and a cheap material.

Selection of Renewable Energy Sources for Buildings

2018 ◽  
pp. 69-97
Author(s):  
Hanna Irena Jędrzejuk
Keyword(s):  
Renewable Energy ◽  
Energy Demand ◽  
Renewable Energy Sources ◽  
Short Review ◽  
Biomass Energy ◽  
Energy Sources ◽  
Legal Regulations ◽  
Zero Energy Building ◽  
Standard Application ◽  
Technical Systems

This chapter describes a general issue of selecting renewable energy sources (RES) and technical systems. To achieve the nearly zero-energy building (nZEB) standard, application of an RES (e.g., solar, wind, geothermal, hydropower, and biomass energy) is necessary. Each type of RES has specific characteristics and can be used to produce electricity and/or heat in certain systems. A short review of various systems using renewable energy sources is presented. To find the required and satisfactory solution that guaranties meeting the nZEB standard, an analysis must be carried out considering a number of aspects: local availability, structure and time-dependence of energy demand, building construction, economic conditions, legal regulations, and specific requirements. Finally, two examples of modernisation towards the nZEB standard are included.

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