Energies

Research

41 pages, 62894 KiB

Open AccessArticle

Evaluation of the Cost-Optimal Method Applied to Existing Schools Considering PV System Optimization

by Cecilia Ciacci, Neri Banti, Vincenzo Di Naso and Frida Bazzocchi

Energies 2022, 15(2), 611; https://doi.org/10.3390/en15020611 - 15 Jan 2022

Cited by 5 | Viewed by 2225

In Italy in 2020, only 15.5% of school building heritage was retrofitted from an energy and environmental point of view. In this paper, the cost-optimal method was applied to two different school buildings belonging to the same Italian cold climate zone but characterized [...] Read more.

In Italy in 2020, only 15.5% of school building heritage was retrofitted from an energy and environmental point of view. In this paper, the cost-optimal method was applied to two different school buildings belonging to the same Italian cold climate zone but characterized by different structural and technological solutions. The research aims at defining the cost-effective redevelopment solution among several ones proposed to apply to this building type. At the same time, this paper provides a critical analysis of the methodology applied, highlighting deficiencies related to a not proper evaluation of environmentally friendly retrofitting measures. In a cost-effective context, the main results show that the intervention on the heating system is more convenient than the retrofitting of the envelope. The energy saving is equal to about 35% for both considered schools. Among the different proposed requalification configurations, the adoption of PV (photovoltaic) electric generation is included. In this regard, an optimization procedure was implemented in a generative design environment to maximize energy production with reference to different design parameters. As a result, a solution with south oriented PV modules with a tilt angle of 42° and arranged in 0.7 m spaced rows proved to be the most effective. Full article

(This article belongs to the Special Issue Innovations-Sustainability-Modernity-Openness in Energy Research 2021)

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15 pages, 5108 KiB

Open AccessArticle

Optimization of Energy Consumption in the Pumping Station Supplying Two Zones of the Water Supply System

by Martyna Świętochowska and Izabela Bartkowska

Energies 2022, 15(1), 310; https://doi.org/10.3390/en15010310 - 3 Jan 2022

Cited by 12 | Viewed by 2934

Abstract

Water supply pumping stations are among the main energy-consuming elements in the water supply system. The energy optimization of a pumping station can significantly affect the energy consumption of a water utility. This article deals with the energy optimization of water pumping stations. [...] Read more.

Water supply pumping stations are among the main energy-consuming elements in the water supply system. The energy optimization of a pumping station can significantly affect the energy consumption of a water utility. This article deals with the energy optimization of water pumping stations. The work assumes several variants of optimization of water supply pumping stations through changes in the water supply system, pressure changes in the pumping station, and modification of the number of pumps. After analyzing the network, conducting field tests, and creating a model of the water supply network, the network was calibrated in order to reproduce the existing water network as accurately as possible. Then, a variant analysis was performed, and the best optimization method for the pumping station was selected. In two variants, there was a decrease in electricity consumption; in three there, was an increase; in one, there was no change. By connecting the DMA zones and modifying the pressure in the pumping station, the energy consumption of the pumping stations was reduced. On this basis, it was found that it is possible to optimize the water pumping station by modifying the pumping station and work related to the network layout. Full article

(This article belongs to the Special Issue Innovations-Sustainability-Modernity-Openness in Energy Research 2021)

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24 pages, 2577 KiB

Open AccessArticle

An Environmental Assessment of Heat Pumps in Poland

by Sara Sewastianik and Andrzej Gajewski

Energies 2021, 14(23), 8104; https://doi.org/10.3390/en14238104 - 3 Dec 2021

Cited by 6 | Viewed by 2380

Abstract

Greenhouse gas emissions are regarded as the cause of the rise in mean Earth temperature, the further increase of which may cause dramatic irreversible global changes. Their levels in Poland are some of the highest in the world. In this study, to evaluate [...] Read more.

Greenhouse gas emissions are regarded as the cause of the rise in mean Earth temperature, the further increase of which may cause dramatic irreversible global changes. Their levels in Poland are some of the highest in the world. In this study, to evaluate the “Energy policy of Poland until 2040”, greenhouse gas and particulate matter emissions were compared in all Polish climatic zones using a typical meteorological year. A comparison was made between air-to-water, brine-to-water, and water-to-water devices. The electrical energy consumption and coefficient of performance were determined hourly in the heating season. The determining algorithm took a buffer tank or separating heat exchanger into consideration, when they were required, and electricity transmission efficiency. Subsequently the emissions were estimated for the present Polish energy mix and a mix proposed in the “Energy policy of Poland until 2040”. After implementing this policy all heat pumps will be energetically viable devices. However, only in one location will water-to-water heat pumps cause less emissions than a condensing gas boiler. In other cases, condensing gas boilers will be significantly less emissive devices. Therefore, this policy is insufficient for reducing emissions. Hence, it is necessary to replace almost all coal-fired power plants with natural gas-fired gas turbines in a transitional period. Full article

(This article belongs to the Special Issue Innovations-Sustainability-Modernity-Openness in Energy Research 2021)

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15 pages, 19766 KiB

Open AccessArticle

Cash Flow Optimization for Renewable Energy Construction Projects with a New Approach to Critical Chain Scheduling

by Janusz Kulejewski, Nabi Ibadov, Jerzy Rosłon and Jacek Zawistowski

Energies 2021, 14(18), 5795; https://doi.org/10.3390/en14185795 - 14 Sep 2021

Cited by 3 | Viewed by 2271

Abstract

This study concerns the use of the critical chain method to schedule the construction of renewable energy facilities. The critical chain method is recognized as a useful project management tool, transforming a stochastic problem of uncertainty in activity durations into a deterministic one. [...] Read more.

This study concerns the use of the critical chain method to schedule the construction of renewable energy facilities. The critical chain method is recognized as a useful project management tool, transforming a stochastic problem of uncertainty in activity durations into a deterministic one. However, this method has some shortcomings. There are no clear principles of grouping non-critical activities into feeding chains. Another ambiguity is sizing the feeding buffers with regard to the topology of the network model and the resulting dependencies between activities, located in different chains. As a result, it is often necessary to arbitrarily adjust the calculated sizes of feeding buffers before inserting them into the schedule. The authors present the new approach to sizing the time buffers in the schedule, enabling a quick assessment of the quality of a given solution variant and finding a solution that best meets the established criteria, conditions, and constraints. The essence of the presented approach is the two-step sizing of time buffers with the use of deterministic optimization and stochastic optimization techniques. Taking into account construction management needs, the optimization criteria are based on the construction project cash flow analysis. The effectiveness of the presented approach is illustrated by an example of developing a wind power plant construction schedule. According to the results, the presented approach ensures the protection of the scheduled completion date of the construction and the stability of the schedule. Full article

(This article belongs to the Special Issue Innovations-Sustainability-Modernity-Openness in Energy Research 2021)

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14 pages, 621 KiB

Open AccessArticle

Analysis of the Social Aspect of Smart Cities Development for the Example of Smart Sustainable Buildings

by Aleksandra Radziejowska and Bartosz Sobotka

Energies 2021, 14(14), 4330; https://doi.org/10.3390/en14144330 - 19 Jul 2021

Cited by 22 | Viewed by 3571

Abstract

The concept of a smart city is assumed to use resources more efficiently and in an innovative, creative, and intelligent manner. Initial experience with implementing this concept relates primarily to investments in technology and infrastructure using smart solutions, particularly technical urban infrastructure. An [...] Read more.

The concept of a smart city is assumed to use resources more efficiently and in an innovative, creative, and intelligent manner. Initial experience with implementing this concept relates primarily to investments in technology and infrastructure using smart solutions, particularly technical urban infrastructure. An important social aspect of a smart city—people—cannot not go unnoticed. The inhabitants of a smart city are not only beneficiaries; they participate in its co-creation, initiate activities and are creative. This paper focuses on one of the smart city’s technical infrastructure components, which are intelligent sustainable buildings. This article aims to analyze the factors characterizing smart sustainable buildings (SSB) and the possibilities for their development. For this purpose, a SWOT matrix was developed. The factors of this matrix were subjected to a cause-effect analysis using the DEMATEL method to establish relationships between them. The results of the analysis allowed us to examine the social aspect, i.e., the impact of creators and users of sustainable, intelligent buildings on their development and possibilities for their creative and innovative use in an urban space. Full article

(This article belongs to the Special Issue Innovations-Sustainability-Modernity-Openness in Energy Research 2021)

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11 pages, 1627 KiB

Open AccessCommunication

Measurement Uncertainty Estimation for Laser Doppler Anemometer

by Karolina Weremijewicz and Andrzej Gajewski

Energies 2021, 14(13), 3847; https://doi.org/10.3390/en14133847 - 25 Jun 2021

Cited by 2 | Viewed by 1711

Abstract

Twenty percent of global electricity supplied to the buildings is used for preventing air temperature increase; its consumption for this prevention will triple by 2050 up to China’s present needs. Heat removed from the thermal power plants may drive cold generation in the [...] Read more.

Twenty percent of global electricity supplied to the buildings is used for preventing air temperature increase; its consumption for this prevention will triple by 2050 up to China’s present needs. Heat removed from the thermal power plants may drive cold generation in the absorption devices where mass and heat transfer are two-phase phenomena; hence liquid film break-up into the rivulets is extensively investigated, which needs knowledge of the velocity profiles. Laminar flow in a pipe is used in the preliminary study, velocity profile of developed flow is used as a benchmark. The study account writes the applied apparatus with their calibration procedure, and the uncertainty estimation algorithm. The calibration regression line with the slope close to one and a high Pearson’s coefficient value is the final outcome. Therefore, the apparatus may be applied in the principal research. Full article

(This article belongs to the Special Issue Innovations-Sustainability-Modernity-Openness in Energy Research 2021)

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20 pages, 523 KiB

Open AccessArticle

Mitigating the Energy Consumption and the Carbon Emission in the Building Structures by Optimization of the Construction Processes

by Alireza Tabrizikahou and Piotr Nowotarski

Energies 2021, 14(11), 3287; https://doi.org/10.3390/en14113287 - 4 Jun 2021

Cited by 28 | Viewed by 5513

Abstract

For decades, among other industries, the construction sector has accounted for high energy consumption and emissions. As the energy crisis and climate change have become a growing concern, mitigating energy usage is a significant issue. The operational and end of life phases are [...] Read more.

For decades, among other industries, the construction sector has accounted for high energy consumption and emissions. As the energy crisis and climate change have become a growing concern, mitigating energy usage is a significant issue. The operational and end of life phases are all included in the building life cycle stages. Although the operation stage accounts for more energy consumption with higher carbon emissions, the embodied stage occurs in a time-intensive manner. In this paper, an attempt has been made to review the existing methods, aiming to lower the consumption of energy and carbon emission in the construction buildings through optimizing the construction processes, especially with the lean construction approach. First, the energy consumption and emissions for primary construction materials and processes are introduced. It is followed by a review of the structural optimization and lean techniques that seek to improve the construction processes. Then, the influence of these methods on the reduction of energy consumption is discussed. Based on these methods, a general algorithm is proposed with the purpose of improving the construction processes’ performance. It includes structural optimization and lean and life cycle assessments, which are expected to influence the possible reduction of energy consumption and carbon emissions during the execution of construction works. Full article

(This article belongs to the Special Issue Innovations-Sustainability-Modernity-Openness in Energy Research 2021)

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12 pages, 1659 KiB

Open AccessArticle

The Efficiency of the Biogas Plant Operation Depending on the Substrate Used

by Janina Piekutin, Monika Puchlik, Michał Haczykowski and Katarzyna Dyczewska

Energies 2021, 14(11), 3157; https://doi.org/10.3390/en14113157 - 28 May 2021

Cited by 18 | Viewed by 4916

Abstract

The study aimed to assess the most efficient solution of raw material management in selected biogas plants into the concept of circular economy and evaluate the most efficient solution of raw material management in selected biogas plants due to the quality and quantity [...] Read more.

The study aimed to assess the most efficient solution of raw material management in selected biogas plants into the concept of circular economy and evaluate the most efficient solution of raw material management in selected biogas plants due to the quality and quantity of the feed and the final product obtained, which is biogas, as well at the closed circulation (circular economy). The study evaluated two agricultural biogas plants on a real scale and one at the sewage treatment plant (in real scale) in northeastern Poland. A year-long study showed that in technical terms, the best work efficiency is achieved by agricultural biogas plants processing: silage, manure, apple pomace, potato pulp (biogas plant No. 1), followed by biogas plant No. 3 processing chicken manure, decoction, cattle manure, poultry slaughterhouse waste (sewage sludge, flotate, feathers), and finally, the lowest efficiency biogas plant was No. 2, the sewage treatment plant, which stabilized sewage sludge in the methane fermentation process. Moreover, based on the results, it was found that agricultural biogas gives the best efficiency in energy production from 1 ton of feed. Full article

(This article belongs to the Special Issue Innovations-Sustainability-Modernity-Openness in Energy Research 2021)

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