Research

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15 pages, 3411 KiB

Open AccessArticle

The Potential of Wind Power-Supported Geothermal District Heating Systems—Model Results for a Location in Warsaw (Poland)

by Bartłomiej Ciapała, Jakub Jurasz and Alexander Kies

Energies 2019, 12(19), 3706; https://doi.org/10.3390/en12193706 - 27 Sep 2019

Cited by 7 | Viewed by 2922

Abstract

Geothermal heat is considered a sustainable energy source with significant global potential. Together with heat distribution networks, it can provide clean thermal energy to individual and commercial consumers. However, peaks in heat demand can require additional peaking sources at times. In this paper, [...] Read more.

Geothermal heat is considered a sustainable energy source with significant global potential. Together with heat distribution networks, it can provide clean thermal energy to individual and commercial consumers. However, peaks in heat demand can require additional peaking sources at times. In this paper, we investigated how wind turbines can act as a peak energy source for a geothermal district heating system. We studied a model consisting of a geothermal heat source, a heat storage and wind power generator using historical weather data of Warsaw (Poland) and showed that wind power could increase the renewable share to supply a considerable heat demand compared to a geothermal heat source alone. The results indicate that wind power can be a suitable complement for a geothermal heat source to provide energy for heating. It is shown that a theoretical geo-wind-thermal storage based district heating network supplying 1000 m², which requires 100 W/m² at an outdoor temperature of −20 °C should have the following parameters: 4.8 MWh of thermal energy storage capacity, 45 kW of geothermal capacity and 5 kW of wind capacity. Such a system would ensure minimal wind curtailment, high utilization of geothermal source and high reliability of supply. Full article

(This article belongs to the Special Issue District Heating)

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20 pages, 1875 KiB

Open AccessArticle

Evaluation of the Cost-Effectiveness of the Installation of Heat-Cost Allocators in Multifamily Buildings in Croatia

by Sunčana Slijepčević, Davor Mikulić and Kristijan Horvat

Energies 2019, 12(3), 507; https://doi.org/10.3390/en12030507 - 05 Feb 2019

Cited by 5 | Viewed by 3567

Abstract

In order to improve energy efficiency, the Croatian government introduced an individual metering obligation for all district heat network users. The purpose of the research was to evaluate this policy measure regarding its effects on tenants’ behavior and energy savings, but also from [...] Read more.

In order to improve energy efficiency, the Croatian government introduced an individual metering obligation for all district heat network users. The purpose of the research was to evaluate this policy measure regarding its effects on tenants’ behavior and energy savings, but also from the perspective of cost-effectiveness. The sample includes approximately 20% of all Croatian users of district heat energy. Energy savings related to the installation of heat cost allocators are calculated by comparing the specific heat energy consumption, corrected for the number of heating degree days, in periods before and after the installation of the heat cost allocators. The cost-effectiveness assessment is based on the concept of the net present value. The transition to individual metering in Croatia resulted in significant energy savings averaged from 20 to 35%. However, low heat energy prices in cities with a dominant share of heat energy consumption did not ensure a positive net present value of investment for all buildings. Full article

(This article belongs to the Special Issue District Heating)

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18 pages, 2685 KiB

Open AccessFeature PaperEditor’s ChoiceArticle

City Scale Demand Side Management in Three Different-Sized District Heating Systems

by Kaisa Kontu, Jussi Vimpari, Petri Penttinen and Seppo Junnila

Energies 2018, 11(12), 3370; https://doi.org/10.3390/en11123370 - 01 Dec 2018

Cited by 24 | Viewed by 4899

Abstract

Demand side management can add flexibility to a district heating (DH) system by balancing the customer’s hourly fluctuating heat demand. The aim of this study is to analyze how different demand side management control strategies, implemented into different customer segments, impact DH production. [...] Read more.

Demand side management can add flexibility to a district heating (DH) system by balancing the customer’s hourly fluctuating heat demand. The aim of this study is to analyze how different demand side management control strategies, implemented into different customer segments, impact DH production. A city scale heat demand model is constructed from the hourly heat consumption data of different customer segments. This model is used to build several demand side management scenarios to examine the effect of them on both, the heat producer, and the customers. The simulations are run for three different-sized DH systems, representing typical DH systems in Finland, in order to understand how the demand side management implementations affect the production. The findings imply that the demand side management strategy must be built individually for each specific DH system; the changing consumption profiles of different customer segments should be taken into consideration. The results show that the value of demand side management for a DH companies remains low (less than 2% in cost savings), having an effect mostly upon the medium loads without any significant decrease in annual peak heat loads. Also, the findings reflect that the DH pricing models should be developed to make demand side management more attractive to DH customers. Full article

(This article belongs to the Special Issue District Heating)

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17 pages, 1927 KiB

Open AccessArticle

Life Cycle Cost of Heat Supply to Areas with Detached Houses—A Comparison of District Heating and Heat Pumps from an Energy System Perspective

by Moa Swing Gustafsson, Jonn Are Myhren and Erik Dotzauer

Energies 2018, 11(12), 3266; https://doi.org/10.3390/en11123266 - 23 Nov 2018

Cited by 8 | Viewed by 2868

Abstract

There are different views on whether district heating (DH) or heat pumps (HPs) is or are the best heating solution in order to reach a 100% renewable energy system. This article investigates the economic perspective, by calculating and comparing the energy system life [...] Read more.

There are different views on whether district heating (DH) or heat pumps (HPs) is or are the best heating solution in order to reach a 100% renewable energy system. This article investigates the economic perspective, by calculating and comparing the energy system life cycle cost (LCC) for the two solutions in areas with detached houses. The LCC is calculated using Monte Carlo simulation, where all input data is varied according to predefined probability distributions. In addition to the parameter variations, 16 different scenarios are evaluated regarding the main fuel for the DH, the percentage of combined heat and power (CHP), the DH temperature level, and the type of electrical backup power. Although HP is the case with the lowest LCC for most of the scenarios, there are alternatives for each scenario in which either HP or DH has the lowest LCC. In alternative scenarios with additional electricity transmission costs, and a marginal cost perspective regarding the CHP investment, DH has the lowest LCC overall, taking into account all scenarios. The study concludes that the decision based on energy system economy on whether DH should expand into areas with detached houses must take local conditions into consideration. Full article

(This article belongs to the Special Issue District Heating)

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14 pages, 1250 KiB

Open AccessArticle

Aspects of Heat Supply Security Management Using Elements of Decision Theory

by Bożena Babiarz

Energies 2018, 11(10), 2764; https://doi.org/10.3390/en11102764 - 15 Oct 2018

Cited by 9 | Viewed by 2831

Abstract

Security in heat supply systems plays an important role in social, technical and political terms. It includes three main components: energy security, security of heat supply, security of people. The differences concern the subject, area, scope, as well as the degree and purpose [...] Read more.

Security in heat supply systems plays an important role in social, technical and political terms. It includes three main components: energy security, security of heat supply, security of people. The differences concern the subject, area, scope, as well as the degree and purpose of the analyses. The article is a continuation of research conducted by the author, presenting the concept of security of heat supply as a necessary “umbrella” supported by reliability and system resilience to threats, constituting a set of actions aimed at minimizing the risk. The subject of the analysis of this article is the security of heat supply, analysed in the context of heat supply management to recipients and risk analysis related to the lack of heat supply. The elements of decision theory were used as adequate for this purpose. Different configurations of heat distribution in the system have been taken into account when determining the expected values of risk related to the occurrence of power limitation for various degrees of restrictions and various network configurations. The author’s use of elements of decision theory in heat supply systems illustrated at the work gives the opportunity to assess and manage the security of heat supply to the recipient. It takes into account the possibility of different heat distribution configurations in the system at the operational stage, as well as may be the basis for optimizing changes in the distribution of power supply areas and selecting the most advantageous network configuration at the design stage. Full article

(This article belongs to the Special Issue District Heating)

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19 pages, 374 KiB

Open AccessFeature PaperEditor’s ChoiceArticle

Is District Heating Combined Heat and Power at Risk in the Nordic Area?—An Electricity Market Perspective

by Kristo Helin, Behnam Zakeri and Sanna Syri

Energies 2018, 11(5), 1256; https://doi.org/10.3390/en11051256 - 14 May 2018

Cited by 21 | Viewed by 4786

Abstract

The Nordic power market has exceptionally low carbon emissions. Energy efficient combined heat and power (CHP) plays an important role in the market, and also produces a large share of Nordic district heating (DH) energy. In future Nordic energy systems, DH CHP is [...] Read more.

The Nordic power market has exceptionally low carbon emissions. Energy efficient combined heat and power (CHP) plays an important role in the market, and also produces a large share of Nordic district heating (DH) energy. In future Nordic energy systems, DH CHP is often seen as vital for flexibility in electricity production. However, CHP electricity production may not be profitable in the future Nordic market. Even currently, the prevailing trend is for CHP plants to be replaced with heat-only boilers in DH production. In this work, we aim to describe the future utilisation of CHP in the Nordic area. We use an electricity market simulation model to examine the development of the Nordic electricity market until 2030. We examine one main projection of electricity production capacity changes, and based on it we assess scenarios with different electricity demands and CO₂ emission prices. Differences between scenarios are notable: For example, the stalling or increasing of electricity demand from the 2014 level can mean a difference of 15 €/MWh in the average market price of electricity in 2020. The results of this paper underline the importance of considering several alternative future paths of electricity production and consumption when designing new energy policies. Full article

(This article belongs to the Special Issue District Heating)

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13 pages, 5141 KiB

Open AccessArticle

Experimental Research of a Water-Source Heat Pump Water Heater System

by Zhongchao Zhao, Yanrui Zhang, Haojun Mi, Yimeng Zhou and Yong Zhang

Energies 2018, 11(5), 1205; https://doi.org/10.3390/en11051205 - 09 May 2018

Cited by 19 | Viewed by 4720

Abstract

The heat pump water heater (HPWH), as a portion of the eco-friendly technologies using renewable energy, has been applied for years in developed countries. Air-source heat pump water heaters and solar-assisted heat pump water heaters have been widely applied and have become more [...] Read more.

The heat pump water heater (HPWH), as a portion of the eco-friendly technologies using renewable energy, has been applied for years in developed countries. Air-source heat pump water heaters and solar-assisted heat pump water heaters have been widely applied and have become more and more popular because of their comparatively higher energy efficiency and environmental protection. Besides use of the above resources, the heat pump water heater system can also adequately utilize an available water source. In order to study the thermal performance of the water-source heat pump water heater (WSHPWH) system, an experimental prototype using the cyclic heating mode was established. The heating performance of the water-source heat pump water heater system, which was affected by the difference between evaporator water fluxes, was investigated. The water temperature unfavorably exceeded 55 °C when the experimental prototype was used for heating; otherwise, the compressor discharge pressure was close to the maximum discharge temperature, which resulted in system instability. The evaporator water flux allowed this system to function satisfactorily. It is necessary to reduce the exergy loss of the condenser to improve the energy utilization of the system. Full article

(This article belongs to the Special Issue District Heating)

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18 pages, 2861 KiB

Open AccessArticle

Techno, Economic and Environmental Assessment of a Combined Heat and Power (CHP) System—A Case Study for a University Campus

by Khuram Pervez Amber, Tony Day, Naeem Iqbal Ratyal, Adnan Khalid Kiani and Rizwan Ahmad

Energies 2018, 11(5), 1133; https://doi.org/10.3390/en11051133 - 03 May 2018

Cited by 14 | Viewed by 4097

Abstract

Universities in the United Kingdom that have installed Combined Heat and Power (CHP) technology are making good moves towards achieving their CO₂ reduction targets. However, CHP may not always be an economical option for a university campus due to numerous factors. Identification [...] Read more.

Universities in the United Kingdom that have installed Combined Heat and Power (CHP) technology are making good moves towards achieving their CO₂ reduction targets. However, CHP may not always be an economical option for a university campus due to numerous factors. Identification of such factors is highly important before making an investment decision. A detailed technical, economic, and environmental feasibility of CHP is, therefore, indispensable. This study aims to undertake a detailed assessment of CHP for a typical university campus and attempts to highlight the significance of such factors. Necessary data and information were collected through site visits, whereas the CHP sizing was performed using the London South Bank University (LSBU) CHP model. The results suggest that there is a strong opportunity of installing a 230 kW CHP that will offset grid electricity and boilers thermal supply by 47% and 75%, respectively, and will generate financial and environmental yearly savings of £51k and 395 t/CO₂, respectively. A wider spark gap decreases the payback period of the project and vice versa. The capital cost of the project could affect the project’s economics due to factors, such as unavailability of space for CHP, complex existing infrastructure, and unavailability of a gas connection. Full article

(This article belongs to the Special Issue District Heating)

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Review

Jump to: Research

21 pages, 2105 KiB

Open AccessFeature PaperReview

District Heating Challenges for the UK

by Michael-Allan Millar, Neil M. Burnside and Zhibin Yu

Energies 2019, 12(2), 310; https://doi.org/10.3390/en12020310 - 19 Jan 2019

Cited by 36 | Viewed by 8844

Abstract

District heating uptake has grown with the increasing need for cleaner and more efficient energy supply. This has resulted in a rising number of new developments signing up to a district heating scheme, typically powered by Combined Heat and Power (CHP) boilers or [...] Read more.

District heating uptake has grown with the increasing need for cleaner and more efficient energy supply. This has resulted in a rising number of new developments signing up to a district heating scheme, typically powered by Combined Heat and Power (CHP) boilers or biomass boilers with supplemental electrical or gas grid connections. These schemes have advanced rapidly in recent years, with much of the research focus targeting lower carbon technologies, improved load prediction and peak demand management. We assess the current status of District Heating Networks (DHNs) in the United Kingdom using published case studies and suggest next steps to improvement. Our findings show that the United Kingdom has good potential for uptake of district energy given the current political climate and government incentives, however significant improvements must be made to further penetrate the heating market. Full article

(This article belongs to the Special Issue District Heating)

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