scholarly journals Energy Flexibility as Additional Energy Source in Multi-Energy Systems with District Cooling

Energies ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 519
Author(s):  
Alice Mugnini ◽  
Gianluca Coccia ◽  
Fabio Polonara ◽  
Alessia Arteconi

The integration of multi-energy systems to meet the energy demand of buildings represents one of the most promising solutions for improving the energy performance of the sector. The energy flexibility provided by the building is paramount to allowing optimal management of the different available resources. The objective of this work is to highlight the effectiveness of exploiting building energy flexibility provided by thermostatically controlled loads (TCLs) in order to manage multi-energy systems (MES) through model predictive control (MPC), such that energy flexibility can be regarded as an additional energy source in MESs. Considering the growing demand for space cooling, a case study in which the MPC is used to satisfy the cooling demand of a reference building is tested. The multi-energy sources include electricity from the power grid and photovoltaic modules (both of which are used to feed a variable-load heat pump), and a district cooling network. To evaluate the varying contributions of energy flexibility in resource management, different objective functions—namely, the minimization of the withdrawal of energy from the grid, of the total energy cost and of the total primary energy consumption—are tested in the MPC. The results highlight that using energy flexibility as an additional energy source makes it possible to achieve improvements in the energy performance of an MES building based on the objective function implemented, i.e., a reduction of 53% for the use of electricity taken from the grid, a 43% cost reduction, and a 17% primary energy reduction. This paper also reflects on the impact that the individual optimization of a building with a multi-energy system could have on other users sharing the same energy sources.

2014 ◽  
Vol 1041 ◽  
pp. 222-225
Author(s):  
Michal Kraus ◽  
Kateřina Kubenková ◽  
Darja Kubečková

The evaluation of non-renewable primary energy expressing the impact of the environment is part of the energy performance certificate. The evaluation is based on factors of primary energy. New buildings or larger modifications of existing buildings must meet the legislative requirements in the Czech Republic, which are consistent with the requirements of the European Union. On the basis of modeling of different energy sources and different number of energy sources for the selected building are set values of non-renewable primary energy.


2020 ◽  
Vol 11 (41) ◽  
pp. 11-26
Author(s):  
Keziban Seçkin Codal ◽  
İzzet Arı ◽  
H. Kemal İlter

Climate change is an undeniable fact. Considering that two-thirds of greenhouse gas emissions originate from the energy sector, it is expected that the world's energy system will be transformed with renewable energy sources. Energy efficiency will be continuously increased. Reducing energy-related carbon dioxide emissions is the heart of the energy transition. Big data in energy systems play a crucial role in evaluating the adaptive capacity and investing more smartly to manage energy demand and supply. Indeed, the impact of the smart energy grid and meters on smart energy systems provide and assist decision-makers in transforming energy production, consumption, and communities. This study reviews the literature for aligning big data and smart energy systems and criticized according to regional perspective, period, disciplines, big data characteristics, and used data analytics. The critical review has been categorized into present themes. The results address issues, including scientific studies using data analysis techniques that take into account the characteristics of big data in the smart energy literature and the future of smart energy approaches. The manuscripts on big data in smart energy systems are a promising issue, albeit it is essential to expand subjects through comprehensive interdisciplinary studies


Proceedings ◽  
2020 ◽  
Vol 58 (1) ◽  
pp. 7
Author(s):  
Beaud Muriel ◽  
Amarasinghage Tharindu Dasun Perera ◽  
Cai Hanmin ◽  
Andrew Bollinger ◽  
Kristina Orehounig

The building sector plays a vital role in Switzerland’s climate policy. In order to support the energy transition in the building sector, Rolle, a suburban area located along the shore of Lake Geneva is considered in this study to understand the promising future scenarios for integration of renewable energy technologies. The area is clustered into 12 clusters and a distributed energy system is designed for each cluster. Subsequently, three energy systems with contrasting densities are taken for further comparison to understand the impact of urban density on the design of the distributed energy system. The study reveals that urban density will influence the peak as well as the annual energy demand of the energy hubs. The study reveals that the energy technologies used in the energy hubs are strongly influenced by the capacity of the system (peak and annual energy demand). Energy systems with higher capacities are less sensitive to the market changes when compared to the systems with lower capacities (leading to sparse suburban areas).


Energies ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2555
Author(s):  
Joanna Rucińska ◽  
Adrian Trząski

This paper deals with the impact of the use of daylight on the overall energy demand for heating, cooling, and lighting in educational buildings. The energy performance of buildings is currently of the utmost importance as current European regulations, starting from 31st December 2020 impose that all new buildings must meet nearly zero-energy building requirements. This paper presents a study of the illuminance distribution in an educational room obtained from measurements and simulation results using two different models. One of the models, integrated with a thermal simulation software, was used to estimate the impact of daylight on the energy demand. The analysis included the use of various window types, lighting control system, reference point location, and daylight calculation model for a sample room in an educational building. Results of the analysis indicate that, due to the high share of lighting demand (reaching up to 78% of the primary energy balance), there is a need to take into account the efficiency of lighting systems during the design process to correctly determine the actual energy balance of a building, increase the quality of the design of lighting systems, as well as to select the optimal parameters of windows.


2017 ◽  
Vol 26 (3) ◽  
pp. 31-41
Author(s):  
Marta Skiba ◽  
Natalia Rzeszowska

Abstract One of the five far-reaching goals of the European Union is climate change and sustainable energy use. The first step in the implementation of this task is to reduce energy demand in buildings to a minimum by 2021, and in the case of public buildings by 2019. This article analyses the possibility of improving energy efficiency in public buildings, the relationship between particular indicators of the demand for usable energy (UE), final energy (FE) and primary energy (PE) in buildings and the impact of these indicators on the assessment of energy efficiency in public buildings, based on 5 variants of extensive thermal renovation of a school building. The analysis of the abovementioned variants confirms that the thermal renovation of merely the outer envelope of the building is insufficient and requires the use of additional energy sources, for example RES. Moreover, each indicator of energy demand in the building plays a key role in assessing the energy efficiency of the building. For this reason it is important to analyze each of them individually, as well as the dependencies between them.


Author(s):  
Antonio Piacentino ◽  
Fabio Cardona

The many comprehensive approaches formulated for the optimization of large industrial energy systems have been rarely applied to small and medium scale units, because of the difficulties in handling a continuously variable energy demand and of the lower margins for energy and emissions saving. Today, the growing interest for decentralised energy systems in the civil sector stimulates major efforts for the optimization of such plants, with a particular focus on the control system and on a management strategy able to exploit the opportunities existing in the free energy market. In this paper a methodology is proposed for the optimization of design and operation of variable demand systems supplying different non-storable products. In such systems, efficiency penalty due to off-design operation is usually assumed as a key issue; the proposed method, however, introduces an original and meaningful interpretation of the capital depreciation cost and keeps into account the possibility for grid connected power systems to produce surplus electricity to be sold. The proposed optimization process, based on the Lagrange multipliers method, assumes either an economic indicator (the Net Present Value, NPV or the Net Cash Flow, NCF) or a function depending only on fuel consumption (as usually proposed in literature) as objective function. Main advantages of the proposed method are the high level of integration between the optimization of design and operation and the possibility to automate the algorithm in order to drive a real-time optimized control system aiming to achieve the maximum profitability or the maximum primary energy saving.


2017 ◽  
Vol 65 (6) ◽  
pp. 859-869 ◽  
Author(s):  
J. Jurasz ◽  
J. Mikulik

AbstractThis paper introduces a mixed integer non-linear mathematical model for a simulation of a hybrid energy source consisting of photovoltaics (PV), wind turbines (WT) and pumped storage hydroelectricity (PSH). The concept of PV–WT–PSH has been well described and evaluated for sparsely populated or remote areas such as islands. Here, due to the rapid development of renewable energy sources and most importantly the variable (non-dispatchable) energy sources such as wind and solar, the idea of wind and solar powered PSHs has been investigated in the context of the national energy system. The economic and environmental impact of the proposed hybrid has been assessed. The results reveal that to cover almost 40% of the energy demand one should expect the energy cost to increase by 25%.


2019 ◽  
Vol 9 (22) ◽  
pp. 4778 ◽  
Author(s):  
Zhengbiao Hu ◽  
Dongfeng He ◽  
Kai Feng ◽  
Pingze Liu ◽  
Yongwei Jia

In steel enterprises, the design of energy systems mainly depends on experience and lacks systematic optimization methods. Therefore, it is of great significance to propose an overall optimization design method for the energy system of steel enterprises. In this paper, a linear model is proposed to select the energy conversion equipment types and distribute energy sources with the aim of maximizing the economic benefits of an energy system. In the model, the choice of energy conversion technology and the distribution of energy source are considered comprehensively. For the S steel plant, the case analysis results show that under the condition of keeping the original energy conversion equipment unchanged and optimizing the distribution of energy source, the economic benefits of the energy system can be increased by 15.77 CNY/t steel, and under the conditions of optimizing the distribution schemes of the energy conversion equipment types and energy sources, the economic benefits of the energy system can be increased by 180.26 CNY/t steel. In addition, the effects of different energy conversion equipment configurations, different energy sources prices and different pollution cost standards on the steel plant energy economic benefits were analyzed.


Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1226
Author(s):  
Beatriz Fraga-De Cal ◽  
Antonio Garrido-Marijuan ◽  
Olaia Eguiarte ◽  
Beñat Arregi ◽  
Ander Romero-Amorrortu ◽  
...  

Prefabricated solutions incorporating thermal insulation are increasingly adopted as an energy conservation measure for building renovation. The InnoWEE European project developed three technologies from Construction and Demolition Waste (CDW) materials through a manufacturing process that supports the circular economy strategy of the European Union. Two of them consisted of geopolymer panels incorporated into an External Thermal Insulation Composite System (ETICS) and a ventilated façade. This study evaluates their thermal performance by means of monitoring data from three pilot case studies in Greece, Italy, and Romania, and calibrated building simulation models enabling the reliable prediction of energy savings in different climates and use scenarios. Results showed a reduction in energy demand for all demo buildings, with annual energy savings up to 25% after placing the novel insulation solutions. However, savings are highly dependent on weather conditions since the panels affect cooling and heating loads differently. Finally, a parametric assessment is performed to assess the impact of insulation thickness through an energy performance prediction and a cash flow analysis.


Energies ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3640
Author(s):  
Davide Borelli ◽  
Francesco Devia ◽  
Corrado Schenone ◽  
Federico Silenzi ◽  
Luca A. Tagliafico

Liquefied Natural Gas (LNG) is a crucial resource to reduce the environmental impact of fossil-fueled vehicles, especially with regards to maritime transport, where LNG is increasingly used for ship bunkering. The present paper gives insights on how the installation of LNG tanks inside harbors can be capitalized to increase the energy efficiency of port cities and reduce GHG emissions. To this purpose, a novel integrated energy system is introduced. The Boil Off Gas (BOG) from LNG tanks is exploited in a combined plant, where heat and power are produced by a regenerated gas turbine cycle; at the same time, cold exergy from LNG regasification contributes to an increase in the efficiency of a vapor compression refrigeration cycle. In the paper, the integrated energy system is simulated by means of dynamic modeling under daily variable working conditions. Results confirm that the model is stable and able to determine the time behavior of the integrated plant. Energy saving is evaluated, and daily trends of key thermophysical parameters are reported and discussed. The analysis of thermal recovering from the flue gases shows that it is possible to recover a large energy share from the turbine exhausts. Hence, the system can generate electricity for port cold ironing and, through a secondary brine loop, cold exergy for a refrigeration plant. Overall, the proposed solution allows primary energy savings up to 22% when compared with equivalent standard technologies with the same final user needs. The exploitation of an LNG regasification process through smart integration of energy systems and implementation of efficient energy grids can contribute to greener energy management in harbors.


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