Heat Production Costs Research Articles

Optimization of the pipe diameters and the dynamic operation of a district heating network using a robust initialization strategy

District heating networks (DHN) are systems offering a substantial solution for the decarbonization of heat production. As these systems involve significant costs, the development of digital tools for their optimization becomes a necessity. In the literature, there is a lack of studies optimizing the sizing of the DHN while considering a dynamic operation of the system with a detailed physics. In this work, we developed a Non-Linear Programming (NLP) optimization used in a case study of a DHN where the pipe sizing and the operation are optimized with a precise modeling of the distribution network. The method of Orthogonal Collocation on Finite Elements (OCFE) was employed to discretize the partial differential equation (PDE) governing the temperature evolution in the pipes. In addition, the pressure drops were modeled using the Darcy–Weisbach equation. Three optimization criteria were used: investment cost of the pipes, operational cost, and the global cost. The optimization provided the pipe diameters that best fit each optimization criterion. Furthermore, several initializations were tested to verify if the obtained optimum was a confidence optimum and if the resolution was robust. Finally, the optimization provided a coherent response to the variation in the cost of heat production.

The risks of electrified district heating in Finland's cold climate

Decarbonizing fossil fuel-dependent district heating systems is essential for achieving carbon neutrality, particularly in cold climates. In Finland, district heating operators are concentrating on electrifying these systems. However, the 2022 energy crisis in Europe has highlighted concerns about heat production costs and the security of heat supply with this approach. This study examines the economic feasibility and risks associated with electrified district heating systems and the early decommissioning of thermal power plants in the interconnected district heating systems of Helsinki, Espoo, and Vantaa. The case study is simulated and optimized to find the least-cost solution while meeting heat demand for various 2025 scenarios, assuming high energy market prices as in 2022 and more normal circumstances. Simulation results indicate that shutting down fossil fuel-based combined heat and power plants in Helsinki and Espoo would create a shortfall in base-load heat production, increasing dependency on heat imported from Vantaa. Both cities are expected to employ more cost-competitive biomass boilers to mitigate the reduction in coal-based heat production, which would decrease operational costs but also reduce revenue from electricity sales due to reduced combined heat and power capacity. Consequently, Vantaa is likely to benefit from its substantial storage and waste and biomass combined heat and power capacity, enabling efficient heat production at reduced costs. Across both scenarios, the analysis demonstrates a significant decrease in emissions and less reliance on imported fuels, highlighting the potential benefits of electrified district heating systems even amidst high electricity market prices.

Future of District Heating Systems – Investigation of Various Technologies in Danish Context

In response to the urgent need for decarbonization, district heating (DH) systems must explore emission-reducing investments that simultaneously lower operational costs of the plant. The recent years with wildly fluctuating gas and electricity prices put even more emphasis on finding the optimal combination of generation units for DH systems. This article aims at investigating which of the available technologies are the future of district heating. Solar collectors, photovoltaics (PV) and wind turbines and their combinations with other technologies are considered. The analysis is done based on Assens District Heating located in Funen, Denmark, where the annual heat production is approximately 96 000 MWh. The plant has already invested in an East-West oriented PV plant and a heat pump. However, for the purpose of this paper, an assumption is made that this investment can be redone based on the present investment costs in Denmark. The analysis is made in the energy system analysis tool energyPRO, where different combinations of technologies are analyzed. The study investigates the operational and investments costs, looking into the influence on Net Heat Production Cost (NHPC) and quantifying the investment yearly benefit. The results demonstrate profitability and feasibility of integrating renewable energy resources into district heating systems within the Danish context. The ambition is to showcase the possibilities and provide decision makers with insight into robust investments in renewable energy systems. Furthermore, by highlighting the success and potential of renewable energy integration in district heating systems in Denmark, this study aims to inspire further research and innovation in the field in other European countries, where the DH systems are primarily based on fossil fuels.

Uniform Modeling of Heat Production Costs in Single-Family and Multi-Family Houses

To ensure a fair and extensive comparison of different heating systems four representative buildings including their heat demand for space heating and domestic hot water were defined. A model for the heat production costs has been developed based on existing methods like the VDI 2067 part 1 [1] and the simplified approach for the calculation of the "Levelised Cost of Heat" (LCoH) of the IEA SHC Task 54 "Price Cost reduction in solar thermal systems" [2]. The developed model includes the costs of purchase, installation, operation, maintenance and disposal and was implemented in an EXCEL calculation tool which enables the calculation of the total life cycle costs (LCC), the levelized cost of heat (LCoH) and the CO2 emissions over the lifetime of the system.

Аналіз сонячного промислового теплопостачання

The future of Ukraine is only impossible without integration into the European community, including in the fight against climate change. It is possible to make the production of thermal energy more environmentally friendly thanks to the introduction of solar technologies. Solar thermal technologies are necessary for the decarbonization of the industrial sector. Information from open sources on the state and prospects for the development of solar industrial heat supply systems in the world has been analyzed. Analysis of the development of solar heat and steam production for industry in the world has shown that the solar thermal energy market is currently in an early stage of development, but it is actively developing and many projects will be commissioned in the near future. Specific investment costs and economy of solar industrial heat supply systems of various capacities are determined. The average weighted cost of thermal energy for the life cycle is used as a criterion of economy in world practice. Specific investment costs for installing solar systems are significantly reduced when their thermal power is increased. Approximate dependences of average specific investment costs on thermal power were obtained. The specific investment costs of installation and the number of hours of operation significant impact on the average cost of solar heat and steam production for industry. Approximate dependences of the average cost of heat on thermal power at different discount rates and at different power on discount rates were obtained. In Ukraine, it is possible to organize the supply of industry with heat and hot water from the use of solar technologies in a short period of time. A promising direction is the use of solar heat supply systems in combination with other thermal energy sources. Keywords: thermal energy; industrial heat supply, powerful solar systems, investment costs, cost of thermal energy.

Advancements and trends in GaN HEMT

Gallium Nitride based High Electron Mobility Transistors (GaN HEMTs) technology has made significant advancements, revolutionizing the field of power electronics. With their unique properties such as high breakdown voltage, high frequency, and high electron mobility and high-power capabilities, GaN HEMTs offer significant advantages over traditional silicon-based devices, such as improved power density, higher operating temperature, and enhanced reliability. GaN HEMTs have shown great potential in sensing applications, such as gas and biosensors. This thesis explores the advancements and trends in GaN HEMT technology, including crystal growth technology, sensing applications, packaging technology, and performance optimization. Despite significant progress, challenges such as heat dissipation, production costs, and yield and reliability issues need to be addressed. Future research directions may focus on improving integration with other technologies, exploring potential applications in emerging fields such as 5G communication, and addressing these challenges. Overall, GaN HEMT technology has made significant advancements and is set to play a pivotal role in various industries.

Multi-source district heating system full decarbonization strategies: Technical, economic, and environmental assessment

Implementing innovation and sustainable development of district heating requires sound energy planning at the national and local levels. However, a research gap still exists on technically and economically viable solutions for developing fully decarbonized heat supply systems and assessing their environmental impact to provide a holistic analysis. Therefore, the case study-based research includes in-depth analyses of the current situation and existing operating conditions of the solar field, biomass and natural gas boilers, and thermal storage tank. The future fossil-free scenarios analyze the additional thermal storage capacity, and integration of heat pumps and local waste heat sources to reduce fossil fuel consumption, increase energy efficiency and minimize heat production costs.The results show that the waste heat utilization and heat pump integration allow to phase-out of natural gas for the peak load coverage. However, increasing thermal storage capacity by more than 50 % is crucial to store the thermal energy for peak demand-supply. The increased thermal storage tank volume allows higher biomass production rates and aligns the heat production with the available waste heat sources. The total heat production costs in a low-temperature heat pump scenario decrease by 5 %. The environmental impact assessment shows that the low-temperature heat pump scenario decreases the resource category by 61 % and the climate change category by 17 % in comparison with the Reference scenario due to higher solar yield and higher overall efficiency.

Smart heat tariffs in transition to free market

Innovative pricing mechanisms should motivate heat suppliers and consumers to move toward more sustainable energy systems and introduce low-temperature district heating systems and sector coupling in smart energy systems. Therefore, district heating regulation regimes should also be changed to stimulate transformations in the energy sector. The district heating tariffs depend on many factors, including fuel prices, operational parameters, taxes, investments, and other criteria. Therefore, an analysis of the DH tariffs has been implemented to find solutions to motivate DH enterprises towards energy efficiency and climate neutrality. The analysis results are based on the decision-making assessment approach by selecting various criteria and evaluating them from five significant aspects: engineering, environmental, climate, economic and socioeconomic. The central elements within the developed fuzzy cognitive mapping model are investment costs, heat production costs, and primary energy consumption. Considering the set boundary conditions, the most beneficial method for smart heat tariff definition could be heat tariff benchmarking with integrated energy efficiency standards for DH operators.

Exergy, Economic and Environmental Analysis of a Direct Absorption Parabolic Trough Collector Filled with Porous Metal Foam

A direct absorption parabolic trough solar collector (DAPTC) integrated with porous foam as a volumetric absorber has the potential to be applied as an energy conversion integrant of future renewable energy systems. The present study comprehensively analyzes a DAPTC in terms of exergy, economic, and environmental analysis for different porous configuration inserts in the absorber tube. Ten different arrangements of porous foam are examined at several HTF flow rates (40–120 L/h) and inlet temperatures (20–40 °C). The exergy efficiency, entropy generation, Bejan number, and pumping power are investigated for all cases. Obtained results indicate that fully filling the absorber tube with porous foam leads to a maximum exergy efficiency of 20.4% at the lowest inlet temperature (20 °C) and highest flow rate (120 L/h). However, the Bejan number reaches its minimum value due to the highest pumping power in this case. Consequently, all mentioned performance parameters should be considered simultaneously. Finally, the environmental and economic analyses are conducted. The results show that fully filling the absorber tube with porous foam reflects the best heat production cost, which can reduced the embodied energy, embodied water, and CO2 emission by 559.5 MJ, 1520.8 kL, and 339.62 kg, respectively, compared to the base case at the flow rate of 120 L/h.

RESEARCH OF BROWN COAL BURNING PROCESSES IN THE VORTEX FIREPLACE BY COMPUTER MODELING

As part of the course for European integration in Ukraine, a new Energy Strategywas approved to reduce the share of coal among primary sources to 12.5 % by 2035, the share ofelectricity generation at TPPs and CHPs to 3 2%. In 2021, Ukraine joined the EU's Green Dealstrategy with a commitment to completely stop coal production and close coal energy and close coalenergy by 2050.At the same time, coal energy has advantages - significant reserves of domestic coal (first inEurope and eighth in the world), which make it a guarantor of energy independence.Given the growing share of "green" generation in Ukraine, the share of pulverized coalproduction should be kept at least 30% of total energy productionThe use of expensive imported natural gas in Ukraine's fuel balance stimulates the developmentof industrial and small energy based on cheap local fuels and combustible waste. The use of cheapcoal, peat, wood waste can reduce the cost of heat production in housing and communal services,industrial enterprises.Combustion of low-grade fuels is constrained due to the complexity of organizing a sustainablecombustion process.Local fuels are characterized by high humidity and ash content, low heat of combustion. Thezone of autogenous (self-sustaining) combustion is defined by the limits: combustible - more than25 %, moisture - less than 50 %, ash - less than 60% by working weight.Vegetation and wood are the starting point for the stages of metamorphism (carbonization):plant residues, peat, brown coal, coal, anthracite. Characteristics of humolites, the organic part of the fuel, by stages of metamorphism. Fuels ofdifferent types and different degrees of carbonization - peat, lignite is peroxidized and contain a lotof oxygen in the combustible mass, have the lowest thermal stability and the highest yield of volatilesubstances.In the process of metamorphism, oxygen is removed and the thermal stability of the organicmatter of the fuel is increased.

Environmental externalities of wood pellets from fast-growing and para-rubber trees for sustainable energy production: A case in Thailand

Wood pellets are one of biomass-based energy carriers considered important as renewable energy source. This study considers wood pellets for heat and power generation from fast-growing Leucaena and Acacia trees and para-rubber trees in a life cycle perspective. The objectives of this study are to estimate the actual cost (including environmental externalities) of heat and electricity production from wood pellets, and comparison with the external cost of fossil fuels, as well as forecasting the external cost arising from the increase in wood pellet demand. For both heat and electricity production, it was seen that when external costs are included, wood pellets are cheaper than lignite and fuel oil although the latter are cheaper when only internal costs are considered. Four recommendations for reducing the external costs of wood pellet production are: 1) to support sustainable agriculture for para-rubber trees and fast-growing trees, 2) to consider clean transportation in the supply chain, 3) wood pellet factory zoning, including good logistics, and 4) considering the external cost of wood pellets for polluter pays principle. These results and recommendations of the study can provide important information to consider towards adjusting the national energy plan and to have strict measures for avoiding problem shifting from the use of non-renewable resources (fossil fuels) to issues related to the use of biomass-based fuels (use of agro-chemicals, forest encroachment, and so on).

Decarbonization strategies of Helsinki metropolitan area district heat companies

District heating is of great significance for the Nordic countries due to the high heat demand. The Finnish government has set a national target of carbon neutrality in 2035. This implies a huge challenge and rapid system change. The Helsinki metropolitan area consists of Helsinki, Espoo and Vantaa, and in each city a different district heating company operates, and the technologies planned for decarbonization are different. This research aims to analyze these strategies with respect to carbon dioxide emissions and production costs, assuming different future European Union emissions carbon trading prices. The software EnergyPRO is used to provide least-cost optimal district heating operation solutions. From 2010 to 2030, carbon dioxide emissions from the Helsinki metropolitan area district heating will decrease by about 4.2 million tonnes. However, the average heat production costs are expected to increase considerably by almost threefold; while heat trade between the cities will reinforce the feasibility and decreases the system operation costs and total emissions. Helsinki will import heat, especially from Vantaa waste incineration plants. Higher carbon dioxide prices would reduce the total emissions, increase the total district heating operation costs, and lower the heat imported to Helsinki. As all the cities plan biomass as an alternative to fossil fuels, a higher biomass price would limit its consumption but increase natural gas usage the carbon dioxide emissions. In the future, combined heat and power plants will be used significantly less, leading to lost income on electricity sales and profoundly changing the business of the district heating companies.

Technical and Economic Analysis of Low-Emissions Modernization of Existing Heating Plants in Poland

An analysis is performed with regards to technologically outdated heating plants operating in many areas where fossil fuels such as coal and gas are utilized, in order to consider the alternatives of their modernization. By application of a chart using a variety of alternatives, the economic feasibility of executing two types of modernization of heating plants are explored: a single-fuel gas–steam CHP plant and a coal-fired heating plant to a coal-fired CHP plant with a condensing turbine. This study demonstrates how the selection of modernization technology is affected, in terms of profitability, by the value and variability in time of the price relationships between energy carriers, rapidly growing charges related to CO2 emission allowances, and costs depending on other pollutant emissions that originate from the operation of electricity and heat sources powered by fossil fuels. In both technical cases of modernization, lower prices of energy carriers coupled with CO2 emissions allowances lead to higher prices of electricity that can be sold as additional products following this modernization, and consequently, the specific cost of heat production in the repowered heat sources is lowered. The calculations were performed by the application of models of heating plant modernization applying continuous time notations, which offer the determination of the most suitable time of initiation of this modernization. Such relationships would be difficult to describe in the case of the use of traditional discrete models. In the case of a simultaneous increase in the prices of all main factors affecting the cost of heat generation, such as the price of gas, electricity and CO2 emissions, the fastest modernization of the heating plant to single-fuel gas–steam CHP provides the possibility of the best economic performance.

Continuous Monitoring of the Thermoregulatory Response in Endurance Horses and Trotter Horses During Field Exercise: Baselining for Future Hot Weather Studies.

Establishing proper policies regarding the recognition and prevention of equine heat stress becomes increasingly important, especially in the face of global warming. To assist this, a detailed view of the variability of equine thermoregulation during field exercise and recovery is essential. 13 endurance horses and 12 trotter horses were equipped with continuous monitoring devices [gastrointestinal (GI) pill, heartrate (HR) monitor, and global positioning system] and monitored under cool weather conditions during four endurance rides over a total of 80 km (40 km loops) and intense trotter track-based exercise over 1,540 m. Recordings included GI temperature (Tc), speed, HR and pre- and post-exercise blood values. A temperature time profile curve of Tc was constructed, and a net area under the curve was calculated using the trapezoidal method. Metabolic heat production and oxygen cost of transport were also calculated in endurance horses. Maximum Tc was compared using an independent samples t-test. Endurance horses (mean speed 14.1 ± 1.7 km h–1) reached mean maximum Tc (39.0 ± 0.4°C; 2 × 40 km in 8 horses) during exercise at 75% of completion of Tc exercise and Tc returned to baseline within 60 min into recovery. However, the mean Tc was still 38.8 ± 0.4°C at a HR of 60 bpm which currently governs “fit to continue” competition decisions. Trotters (40.0 ± 2.9 km h–1) reached a comparable mean max Tc (38.8 ± 0.5°C; 12 horses) always during recovery. In 30% of trotters, Tc was still >39°C at the end of recovery (40 ± 32 min). The study shows that horses are individuals and thermoregulation monitoring should reflect this, no matter what type of exercise is performed. Caution is advised when using HR cut-off values to monitor thermal welfare in horses since we have demonstrated how Tc can peak quite some time after finishing exercise. These findings have implications for training and management of performance horses to safeguard equine welfare and to maximize performance.

Experimental and analytical optical-thermal performance of evacuated cylindrical tube receiver for solar dish collector

Evacuated cylindrical tube receiver (ECT) is a promising type of solar collector system, due to its mass production, low cost, and low heat loss. In this paper, a solar dish collector system with evacuated cylindrical tube receivers (SDEC) is proposed, designed and trial-manufactured. The optical-thermal efficiency and economic analysis are carried out to validate the comprehensive performance of the SDEC. The results show that the thermal efficiency of the SDEC is about 47.3%. The nonuniformity of the solar flux and temperature distributions at the top of the absorber are verified through the coupled multiphysics simulation with the result of 0–50 mm. In addition, over 10 years of the lifetime of the SDEC with 20 ECTs, the cumulative present worth of annual saving for heat production turned out to be approximately 34,041 $ and 13,460 $ with respect to electricity coiler and gas-fired boiler, respectively, when the cost of heat production per kWh is 0.0264 $ and the payback period is 1.88 years.

Investigation on sector coupling potentials of a 5th generation district heating and cooling network

In this paper the development and application of an urban building energy simulation model is presented to analyse an existing 5th generation district heating and cooling network (5GDHC) with regard to possible sector coupling potentials. It was evaluated, how the heat energy production through large industrial heat pumps and the total thermal capacities of the 5GDHC network can provide flexibilities for power to heat applications.In a first step a multi model dynamic simulation was set up using the simulation environment IDA ICE. A previously developed urban energy simulation model formed the basis to implement the special requirements of the investigated 5GDHC network. This was followed by the calibration of the multi model simulation utilising the monitoring data of the existing 5GDHC network. In a second step the flexibilities of network sub areas were systematically investigated using step response tests. This was done with respect to key performance indicators like heat-up time or electrical energy consumption as a function of different boundary conditions like indoor comfort or outdoor air temperature. The third step comprised of a cumulative network analysis using different heating setpoint control strategies to optimise the operation of the network regarding heat production costs.

Thermodynamic and economic analysis of effect of heat accumulator volume on the specific cost of heat production in the gas-steam CHP plant

The economic profitability of the operation of gas-steam CHP plants can be improved by using heat accumulators (HA) in them. Thanks to this at the peak of the needs of the National Power System (NPS), an additional amount of electricity will be produced, and in the condition of decreased demand in the NPS load valley, it will be reduced. The total production of electricity in the CHP plant will be at the same level as if there is no accumulator in it. In the article, an innovative methodology in a record with continuous time was used and technical with economic analysis was performed. The reduction of the specific cost of heat production in a CHP plants due to the use of a HA in it is significant and increases the economic profitability of its operation. The NPVaccuvalue of the profit with the relatively high price of gas and the low price of electricity may exceed the value of the NPV profit. For the gas price 24 PLN/GJ and the electricity selling price of only 205 PLN/MWh, the profit for the CHP with a HA with Vtmax=94342m3 volume is 40 mln PLN greater than without using an accumulator.

Improving the environmental situation and safety of the megalopolis by modernizing the energy industry

Options are considered for modernization of the energy industry complex, which includes a large number of enterprises and combined heat and power plants (CHPP) with low-potential waste heat. For modernization, it is proposed to use heat pumps (HPI) in CHPP systems. A variant is presented of using the low-potential heat of the ice-free Yenisei River. The environmental and economic efficiency of the proposed options have been evaluated.The city of Krasnoyarsk located on both banks of the Yenisei River, is considered as an example. In Krasnoyarsk, there are large hydroelectric power plants that generate excess power for electricity. CHPP-1, CHPP-2 and CHPP-3 also operate, as well as a large number of boiler houses, whose harmful emissions are described in detail in the article. In addition, data on the number of low-potential sources are provided, and options for using low-potential heat sources in heat pump installations are considered. The output of low-potential heat by month is presented, and the calculation results are based on comparison of options for using HPI at three CHPPs. The possibility of closing inefficient coal-fired boilers has been examined, which would reduce harmful emissions into the atmosphere and reduce the cost of heat production in the megalopolis for district heating systems.The operation of the Krasnoyarsk Aluminium Plant is considered, which has harmful emissions (fluorine, sulfur oxides, dust, resinous substances), as well as primary energy losses of 13.5 million Gcal, of which only 40% goes to aluminium production, and 60% is lost and released into the environment. To reduce these losses by 1.5 times, it is proposed to install air heat exchangers. The prospect of using high-capacity HPIs is provided by the presence of river water from the Yenisei, the temperature of which does not fall below 3°C even in winter. Powerful HPIs with centrifugal compressors manufactured in Kazan will provide heat to administrative and residential buildings under construction in Krasnoyarsk with a total heat load of 803 Gcal/h. The payback period of systems with HPI is 6÷8 years.

An economic study of combined heat and power plants in district heat production

Combined heat and power plants are playing an essential role in Finland to reduce carbon dioxide emissions in district heat production. Some of the existing district heat producers need to adopt renewable energy sources to eliminate the use of fossil fuels. The northern countries face a challenge to tackle significant fluctuations of district heat consumption between summer and winter seasons concerning the production cost and the environmental impact of heat production. The municipality of Sodankylä is reorganising the district heat production to reduce emissions by constructing new wood-fuelled CHP plants. These plants will contribute to the existing district heating network. The profitability of CHP plants and the environmental impact in the region need evaluation. Results reveal that the profitable investment for the construction of CHP plants requires 16% subsidy with the predicted cost of heat production at 3.36 €/MWh. CO 2 emissions from fossil fuels can potentially eliminated by adapting renewable fuel in the existing plant. CH 4 and N 2 O emissions from district heat production reduced by 78% and 53%.

Methodology of determination of the optimal investment strategy in single-fuel CHP plants

This paper presents comprehensive diagrams applied in the search for the optimal strategy for investing in heat sources and analysis of the impact of technical and economic parameters on specific heat production costs in single-fuel combined heat and power plants. An innovative methodology was applied to find for the specific cost of heat production in various technologies. The results regarding the specific cost of heat production in combined power heat and sources systems are discussed in this paper. The graphs are universal and can be used with regard to various combinations of technical and economic parameters playing a decisive role in the cost of heat production. In addition, the results of the calculations are presented in the function of the value of the annual cogeneration factor, the value of which is dependent on the technology applied in combined heat and power production. Using the presented innovative methodology and graphs developed on its basis, it is possible to select the most favorable heat production technology, for which the specific cost of heat production is the lowest, for any cost of fuel, price of electric energy and cost of the purchase of CO2 emission permits.