Natural Gas Boiler Research Articles

Source Profiles of VOCs for Different Types of Industrial Boilers in Sichuan, China

Seven different types of industrial boilers in Sichuan Province were selected to determine the VOC emission components and the source profiles of VOCs containing 115 components were established using Teflon sampling and GC-MS/FID analysis. The ozone formation potential （OFP） and emission factors of VOCs from different types of industrial boilers were analyzed. The results showed that the VOC components emitted from different types of industrial boilers were different. Oxygenated volatile organic compounds （OVOCs） and halogenated hydrocarbons were the major components of biomass boilers, with a total contribution rate of more than 60%. The primary VOC emission species included dichloromethane, ethylene, acetone, acetaldehyde, acetylene, and toluene. Halogenated hydrocarbons （50.7%） were the chief emission components of coal-fired boilers, followed by aromatic hydrocarbons and OVOCs. Dichloromethane, ethylene, acetaldehyde, ethyl acetate, and benzene hydrocarbon were the major VOC emission species. The emission of alkanes （59.7%） in natural gas boilers was prominent, particularly ethane and isopentane. The OFP values of VOC emissions from coal-fired, biomass, and natural gas industrial boilers were 6.1, 28.7, and 4.7 mg·m-3, respectively. Alkenes were the primary OFP contributors （35.1%-59.5%） in different types of industrial boilers. OVOCs （32.8%） in biomass boilers and aromatic hydrocarbons （43.0%） in coal-fired boilers also contributed significantly to OFP. The VOC emission factors of coal-fired, biomass, and natural gas industrial boilers in Sichuan Province were （17.3 ± 10.7） g·t-1, （90.6 ± 42.1） g·t-1, and 0.10 g·m-3, respectively. The VOC emission level of biomass boilers was higher than that of coal-fired boilers and VOC emission control could not be ignored.

Performance assessments of ground source heat pump assisted by various solar panels to achieve zero energy buildings in cold climate conditions

This paper aims to perform a comprehensive performance analysis of a solar-assisted ground source heat pump (SAGSHP) system connected to various types of solar panels to enhance overall energy efficiency. While previous studies have examined integrating solar panels with heat pumps, comprehensive solutions like those presented here and performance evaluations in the zero energy building context have been lacking. This study developed various scenarios using three types of solar panels, photovoltaic (PV), photovoltaic-thermal (PVT), and solar thermal collectors (ST), to explore their simultaneous use. TRNSYS software was employed to analyze the complex system, comparing it to a conventional natural gas boiler system as a baseline. The findings revealed that the on-site energy use intensity (EUI) decreased from 78.6 kWh/m2 to 53.3 kWh/m2, a reduction of approximately 33 %, due to the SAGSHP's implementation. The combination of PVT and PV panels emerged as the most suitable option for the SAGSHP, aligning with the net zero energy concept. The SAGSHP system achieved a low EUI of 10.4 kWh/m2 in terms of primary energy. Additionally, the solar fraction, indicating the proportion of solar energy used, reached approximately 90 %. Thus, this study underscores the significance of evaluating various solar panel configurations during the preliminary design phase of SAGSHP systems to optimize energy performance and progress toward zero energy buildings.

THEORETICAL EVALUATION OF DISTRICT HEATING AND COOLING NETWORKS CONNECTED TO HEAT PUMPS

This article conducts a comprehensive theoretical analysis containing operational, carbon footprint, and economic aspects of a medium-high temperature heat pump (HP) employing R-1234ze(E). The study contains a total of three scenarios, where the first (single stage/two stage (SS/TSC)) scenario uses waste heat for district heating. The second (SS/TSC) scenario produces heating and cooling for district heating and cooling. The third (TSC) scenario uses heat from the district heating network (DHN) for conventional boiler applications. Regarding the energy analysis, the internal heat exchanger (IHX) presents a positive impact across all scenarios. Moreover, the TSC configuration exhibits a lower coefficient of performance (COP) than SS for scenario 1, and higher for scenario 2. The first scenario (SS) results in the highest COP (4.1), due to presenting the lowest compression ratio among the three scenarios. From a carbon footprint perspective, compared to a natural gas boiler, the first scenario achieves the highest reduction in emissions. Regarding the economic analysis, TSC configurations exhibit higher costs than SS ones. The first (SS) and second (SS) scenarios present the lowest capital expenditure (CAPEX), 35134 € and 44371 €, respectively. Economic viability analysis reveals that only the first and second scenarios with SS configuration are feasible.

A Review of Thermochemical Energy Storage Systems for District Heating in the UK

Thermochemical energy storage (TCES) presents a promising method for energy storage due to its high storage density and capacity for long-term storage. A combination of TCES and district heating networks exhibits an appealing alternative to natural gas boilers, particularly through the utilisation of industrial waste heat to achieve the UK government’s target of Net Zero by 2050. The most pivotal aspects of TCES design are the selected materials, reactor configuration, and heat transfer efficiency. Among the array of potential reactors, the fluidised bed emerges as a novel solution due to its ability to bypass traditional design limitations; the fluidised nature of these reactors provides high heat transfer coefficients, improved mixing and uniformity, and greater fluid-particle contact. This research endeavours to assess the enhancement of thermochemical fluidised bed systems through material characterisation and development techniques, alongside the optimisation of heat transfer. The analysis underscores the appeal of calcium and magnesium hydroxides for TCES, particularly when providing a buffer between medium-grade waste heat supply and district heat demand. Enhancement techniques such as doping and nanomaterial/composite coating are also explored, which are found to improve agglomeration, flowability, and operating conditions of the hydroxide systems. Furthermore, the optimisation of heat transfer prompted an evaluation of heat exchanger configurations and heat transfer fluids. Helical coil heat exchangers are predominantly favoured over alternative configurations, while various heat transfer fluids are considered advantageous depending on TCES material selection. In particular, water and synthetic liquids are compared according to their thermal efficiencies and performances at elevated operating temperatures.

Optimizing Energy Efficiency and Environmental Sustainability in Gas Distribution Station: A Comprehensive Analysis and Technological Solutions

It is important to address the world‘s energy crisis, increasing energy demand and changing climate by finding ways to recover unused energy and minimise primary and secondary energy use and emissions. The natural gas sector, which consists of the transmission network and gas distribution stations, is an important part of the global and Lithuanian energy sector. However, due to the operating principle of gas pressure regulators, the energy potential of high-pressure gas is not efficiently utilized in gas distribution stations. As a result, natural gas boilers are used for gas preheating, and gas distribution stations cause additional environmental pollution. This study aims to find ways to optimise the efficiency of gas distribution stations and reduce their negative environmental impact by identifying areas where energy is wasted and proposing alternative technological solutions: turbine expander (as an alternative for gas pressure regulator), ground heat pumps, solar collectors and photovoltaic solar cells (as gas preheating alternatives). The best alternative technological solution for the gas distribution station is evaluated based on energy efficiency, economic viability, and environmental impact (3E criteria).

Techno-economic and environmental study of a hybrid solar ground source heat pumps for a heating-dominated community in a cold climate; a case study in Toronto

Employing ground source heat pumps (GSHP) in heating-dominated areas presents challenges, including load imbalance and decreased efficiency. This study examines using solar energy to prevent soil thermal depletion in cold climates by comparing two systems. The first system (HPPV) uses geothermal heat pumps, borehole thermal energy storage, and photovoltaic modules. The second system (ST-HPPV) adds solar thermal collectors to reduce soil thermal depletion over long-term operation. Both systems supply hot or chilled water to the community's fan-coil systems via a short-term storage tank and heat exchanger. Their energy performance, greenhouse gas emissions, and costs were compared with a conventional fossil-fueled system (natural gas boiler and absorption chiller). Results showed the ST-HPPV system outperformed the HPPV system by 15 % in the seasonal coefficient of performance in heating mode after 20 years. However, solar thermal collectors did not benefit the cooling mode due to the community's load characteristics. Cost analysis revealed the HPPV system is more cost effective and reliable due to lower operating and carbon costs. The findings recommend the ST-HPPV system for communities where the annual heating load is 75 % or more of the cooling load.

Net Zero Energy Building technologies – Reversible Heat Pump/Organic Rankine Cycle coupled with Solar Collectors and combined Heat Pump/Photovoltaics – Case study of a Chilean mid-rise residential building

In the following years, the building sector will have to considerably reduce its final energy demand and emissions by adopting new technologies.This paper introduces two innovative technologies capable of reducing the final energy demand of residential buildings: A Heat Pump/Organic Rankine Cycle system coupled to solar thermal collectors (HP/ORC-COL), and a Heat Pump coupled with Photovoltaic panels (HP-PV). The HP/ORC-COL system alternates between generating either heat or electricity, whereas the HP-PV system produces them separately. The goal is to compare both systems through their Seasonal Performance Factor (SPF), equivalent emissions, operational cost, and Net Zero Energy Building (NZEB) potential. Additionally, the impact on the heating demand of retrofitting existing buildings with the Passivhaus Standard is studied.The heating, domestic hot water, and electricity demands are determined by considering the climate conditions of three polluted Chilean cities: Santiago, Concepción, and Temuco. The proposed systems are evaluated through numerical models developed in Python and validated with data from manufacturer catalogues. The validation of the models allows to enhance the result accuracy of the integrated overall model by closely aligning outputs with real conditions, and therefore increases the reliability of the prediction on the potential of the building to reach net zero energy.Results show that applying the Passivhaus standard allows to reduce heating requirements by up to 30% in all cities. The SPF and electricity production of the HP-PV system is better than the HP/ORC-COL, reaching a NZEB potential of 76.3% in Santiago, 66.6% in Concepción and 60.4% in Temuco. The average cost reduction of the HP/ORC-COL system compared to oil, natural gas, and wood pellet boilers is 82.7%, 90.4%, and 72.3%, whereas for the HP-PV system is 93.3%, 96.3%, and 89.2% respectively. On the CO2 emissions, the HP/ORC-COL system presents an average reduction of 63.6% and 59.7% compared to an oil and natural gas boiler, while the HP-PV system has an average reduction of 72.5% and 69.5% respectively.

To Zone or Not to Zone When Upgrading a Wet Heating System from Gas to Heat Pump for Maximum Climate Impact: A UK View

Domestic heating systems across northern Europe are responsible for a substantial fraction of their countries’ carbon footprints. In the UK, the vast majority of home space heating is via natural gas boilers with ‘wet’ hydronic radiator systems. Most of those use TRVs (thermostatic radiator valves) for micro-zoning, to avoid overheating, improve comfort and save energy. To meet Net Zero targets, 20 million such UK gas systems may be retrofitted with heat pumps. Heat pump system designers and installers are cautious about retaining TRVs in such systems in part because of worries that TRV temperature setbacks that lower heat demand may raise heat pump electricity demand in a “bad setback effect”, thus wasting energy. This paper presents a new view of heat pump control and provides the first exploration of this issue through the development of a simple physics-based model. The model tests an installation industry claim about the negative effect of TRVs, and finds that though real it should not apply to typical UK retrofits with weather compensation. The energy efficiency benefits of TRVs for older and partly occupied homes, and to keep bedrooms cooler, remain valid. Comfort-seeking householders and installers should know that setting ‘stiff’ temperature regulation may invoke the bad setback effect and cost dearly in energy and carbon footprint.

Synthetic natural gas in the private heating sector in Germany: match or mismatch between production costs and consumer willingness to pay?

BackgroundThe residential heating sector in many European countries requires a fundamental transformation if it is to become climate neutral. Besides the introduction of efficiency measures and updating heating systems, scholars and practitioners consider replacing fossil fuels in existing heating systems a viable approach. Drop-in renewable gases such as biomethane and synthetic natural gas (SNG) cause considerably fewer carbon dioxide (CO2) emissions than natural gas and can be used in natural gas boilers, the dominant heating system in many European countries. To move the ongoing debate around e-fuels forward, this study reports on a Discrete Choice Experiment with 512 respondents in Germany that analyzed consumer preferences and willingness to pay (WTP) for SNG. I build on these insights by comparing WTP to the production costs, making evidence-based decision-making possible.ResultsThe results show that consumers prefer renewable gases over natural gas. Comparing the two types of renewable gases, SNG and biomethane, reveals that consumers clearly favor the latter despite the criticism it has come under in the last 10–15 years. Consumers show a surprisingly high WTP for increasing shares of SNG, with premia of 40 to almost 70% over a natural gas-based tariff. Comparing production costs to the WTP reveals that only tariffs with small shares of SNG (5% and 10%) can be offered at cost-covering prices.ConclusionsGiven the urgent need for a fundamental transition of the residential heating sector, marketers and policymakers should consider carefully whether it is worth channeling a rather unknown and expensive product like SNG into the voluntary market for heating gas, especially as biomethane is already established in the market and clearly a cheaper and more popular alternative.

District heating utilizing waste heat of a data center: High-temperature heat pumps

Data centers are energy-intensive facilities with substantial low-grade waste heat. High-temperature heat pumps can be critical in boosting the data center’s waste heat for district heating, improving the system-level energy efficiency of data centers, and reducing CO2 emissions in district heating. This study built thermodynamic models to assess high-temperature heat pumps with six configurations using low global warming potential refrigerants to supply heat up to 120 °C. The heat pump configurations include single-stage or two-stage cycles with advanced components, such as internal heat exchanger, economizer, flash tank, or parallel compressor. The refrigerants include R1234ze(Z), R1233ed(E), R1224yd(Z), R600, and R600a, and R245fa is used as a reference. A case study was carried out to recover the waste heat from the Frontier high-performance computing data center and provide hot water for district heating at the US Department of Energy’s Oak Ridge National Laboratory campus. The optimized performance of high-temperature heat pumps is characterized with various effectiveness of internal heat exchangers, and the operating parameters of economizer or flash tank, as well as their combination. The results show that the configurations of two-stage cycles with internal heat exchanger + flash tank and internal heat exchanger + economizer/parallel-compressor provide the highest coefficient of performance under scenarios of the maximum allowable value and a fixed value (0.3) of the internal heat exchangers’ effectiveness, respectively. R1234ze(Z) and R600a are the most promising refrigerants, considering trade-offs between the coefficient of performance and the volumetric heating capacity. The single-stage cycle with internal heat exchanger + economizer/parallel-compressor using R1234ze(Z) is recommended for utilizing Fronter’s waste heat in district heating. A one mega-watt high-temperature heat pump will reduce 33,100–33,200 metric tons of CO2 emission annually, corresponding to 85.4 %–85.6 % of equivalent CO2 emissions from natural gas boilers. This study provides good guidelines for designing and deploying high-temperature heat pumps to support sustainable data centers and decarbonize district heating in the US.

Heat and the planning system: how can local authorities encourage deployment of low and zero-carbon heating?

There is widespread recognition of the need for new homes to feature only low or zero-carbon (LZC) heating. However, residential developers continue to choose conventional high-carbon options such as natural gas boilers over net-zero compatible alternatives. This study explores how UK local authorities (LAs) within the English planning system can encourage residential developers to deploy LZC heating systems within their projects. We adopt an embedded case study design and analyse 30 residential project proposals within two LA areas. Our study examines local planning policies and interactions between developers and LA officers, along with the resultant outcomes, through documentary analysis and expert interviews with local stakeholders. We find that LAs can encourage developers to adopt LZC heating technologies above and beyond what is required nationally. The conditions for this to occur are (1) a planning policy which restricts allowable heating technology options, (2) empowering LA officers to enforce policies, (3) advice and support for developers to consider alternatives, and where necessary, (4) political backing to challenge unwilling developers. Study findings highlight the important role of LAs in creating the conditions for the transition to LZC heating, which show how they can use powers within the planning system to encourage developers to make low carbon choices without the need for direct investment.

Life cycle assessment of an innovative alcohol-to-jet process: The case for retrofitting a bioethanol plant for sustainable aviation fuel production

This paper aims to carry out an integrated Life Cycle Assessment to evaluate the environmental performance of retrofitting an existing first-generation ethanol plant for sustainable aviation fuel production. Two scenarios are defined, considering: (i) the incorporation of an alcohol-to-jet conversion pathway into a current bioethanol plant in Spain to produce synthetic paraffinic kerosene with aromatics biofuel, and (ii) the operation of two different plants, namely, an existing bioethanol production facility and a new-build ATJ plant. Results indicate that the global warming impact associated with the retrofitting of the bioethanol facility is 44.15 gCO2eq per MJ of final fuels produced. The main GHG impact is associated with the operation of both the cogeneration system (∼42 %) and the natural gas boilers (∼25 %) to cover the heat and power requirements of the bioethanol facility. Findings concerning the climate change impact of the new-build ATJ plant exhibit analogous behavior; the GHG impact is estimated at 44.53 gCO2eq/MJfuels. Future electricity supply mixes with high shares of renewables could lead to substantially lower GHG emissions (up to 61 %) in aviation fuel production, as compared to conventional jet fuels. The replacement of natural gas with sustainable alternatives could further decrease the global warming impact up to 97 %.

Design and eco-technoeconomic analysis of a natural gas cogeneration energy management center (EMC) with short-term thermal storage

This work proposes a non-islanded cogeneration energy management center (EMC) that can be used to displace grid-level natural gas turbine systems and natural gas combustion systems for heat. The design of the proposed EMC included a weighted multi-objective optimization aimed at minimizing: i) natural gas consumption; ii) capital costs; iii) utility costs; and iv) unmet thermal demand. The decision variables consisted of the existence and capacity of the equipment comprising the EMC, including: i) a natural gas boiler; ii) an internal combustion engine that generates heat and electricity; and iii) a hot water thermal storage system. Four resulting candidates EMC designs were then compared with the status-quo (SQ) in an eco-technoeconomic analysis; The SQ draws electricity from the grid and heating for dwellings come from natural gas boilers. Emissions at grid level change which alternative is favored. The findings showed that, for a system that serves 4–5 dense urban city blocks over a 20-year lifetime, the SQ system had cumulative levelized costs of 9.6 million USD for the final consumer, while the levelized costs of the EMC designs ranged from 12.9 to 15.1 million USD. In terms of emissions, the SQ emitted 959 tonnes of CO2eq per year, while the EMC system produced around 500 tonnes of CO2eq per year depending on the year, yielding a CCA varying between 364 and 653 USD/tonneCO2eq

Identification of typical district configurations: A two-step global sensitivity analysis framework

The recent geopolitical conflicts in Europe have underscored the vulnerability of the current energy system to the volatility of energy carrier prices. In the prospect of defining robust energy systems ensuring sustainable energy supply in the future, the imperative of leveraging renewable indigenous energy sources becomes evident. However, as such technologies are integrated into the existing system, it is necessary to shift from the current centralized infrastructure to a decentralized production strategy. This paper presents a method to identify a panel of technological solutions at the district level, intended to reduce complexity for the integration of decentralized models into a national-scale model. The framework’s novelty lies in combining a global sensitivity analysis for solution generation with clustering to identify typical configurations. The global sensitivity analysis is performed on a mixed integer linear programming model, which optimally sizes and operates district energy systems. The sensitivity analysis determines the most influential parameters of the model using the Morris method and provides a representative sampling of the solution space by leveraging the Sobol sampling strategy. The latter is then clustered using a density-based algorithm to identify typical solutions. The framework is applied to a suburban and residential Swiss neighborhood. The first outcome of the research is the high sensitivity of the model to energy carrier prices. As a result, Sobol’s sampling space separates itself into two system types: those based on a natural gas boiler and those relying on a combination of electrical heaters and heat pumps. For both types, the electricity demand is either fulfilled by PV panels or electricity imports. The identified configurations showcase that the framework successfully generates a panel of solutions composed of various system configurations and operations being representative of the overall solution space.

Carbon Emission Comparison between Natural Gas and Electric Resistence for Water Heating

The use of electric showers has become a habit for most Brazilian people, being responsible for a great part in the house consumption of electric energy. This article aims to evaluate the difference between the use of electric showers or natural gas boilers in terms of energy use and greenhouse gases emissions, exposing both energy scenarios in Brazil: electric and natural gas. Therefore, it will be estimated the amount of energy necessary to heat the water average used by a person per year, for each type of shower, comparing the results and estimating the carbon emissions for both type of energies

Remodelling of the heating systems of a sports centre based on life cycle assessment. Part I: Boiler replacement.

The remodelling study of heating and cooling installations of the municipal sports centre of Ordizia (Spain) has been widened including a renewable energy proposal, integrating also the concept of life cycle analysis (LCA) of the installation which allows therefore, to analyze the environmental impact prior its approval and implementation. The analysis of the inclusion of two set of solar panels (thermal and photovoltaic) in addition to the substitution of the old diesel boiler by a more efficient natural gas equipment, in order to satisfy the power demand of the installations, has been studied by means of life cycle analysis. The supply directly from the grid is the alternative with the greatest impact, while the photovoltaic is the most efficient one from an environmental standpoint. However, when solar irradiation is insufficient for the needs of the sports centre, a hybrid system is the best choice. In a similar way, in order to satisfy the heat demand, the combination of thermal panels with the natural gas boiler has been proven to be a good solution.

Thermal design and optimization of high-temperature heat pump integrated with district heating benchmarked in Denmark for process heat supply

This work aims to assess and optimize the performance of cascade high-temperature heat pump (HTHP) integrated with district heating (DH) to produce 1 MW steam at 160 °C for the industrial processes. The heat available in the primary loop of the DH network at 80 °C is considered as the heat source; which is cooled down 70 °C through the HTHP evaporator, before supplying the DH secondary loop. The use of alternative hydrocarbons in the low-temperature loop are examined; and considering the gas compressor limitation, the HTHP performance of using each refrigerant is optimized and compared to each other.The optimization results reveal that pentane- hydrocarbon with the highest critical temperature- is the most promising refrigerant to be paired with steam in the high-temperature loop, reaching the highest COP of 2.66. However, concerning safety and compressor sizing issues, butane is an excellent candidate; with volumetric heating capacity (VHC) of about two times more than that of pentane, in the expense of just about 4 % reduction in the HTHP COP. In addition, water injection theoretically controls the steam compressor discharge temperature successfully, with just 0.9 K superheating at the compressor outlet; and reduces its power consumption and the HTHP COP up to 4.3 % and 1.7 %, respectively. Moreover, techno-economic analysis demonstrates that the HTHP technology shows a better business case compared to the conventional natural gas and electric boilers.

Energy, economic, and carbon emission analysis of a residential building with an energy pile system

This paper investigated the combined energy, economic and carbon performances of energy piles used for heating and cooling buildings, an issue that has received limited interest in the past. To address this knowledge gap, a 30-year numerical simulation, calibrated using field data, was conducted for variable building thermal loads, pile spacing, pile length and number of energy piles for a six-storey residential building in Melbourne, Australia. The energy pile system in the annual heating-only mode demonstrated a 75 % reduction in energy consumption and a 5 % reduction in energy costs compared to a natural gas boiler. The energy piles performances in the annual heating-and-cooling mode were significantly higher than in the heating-only mode, demonstrating a 39 % reduction in energy consumption, carbon emissions and energy costs compared to an air-source heat pump. Increasing the pile spacing from 2.05 m to 6.4 m, pile length from 10 m to 20 m, and number of energy piles from 38 to 114 increased the energy, economic and carbon benefits of energy piles by 76 %, 77 % and 119 %, respectively. The results highlight the importance of building thermal loads and pile configuration on assessing the energy, economic and carbon performances of energy piles during early design stages.

Climate impact of coal-to-clean-energy shift policies in rural Northern China

China has implemented the coal-to-clean-energy shift policy in rural areas of northern China to improve air quality, optimize energy structure and reduce greenhouse gas emissions, resulting in a significant increase in natural gas and electricity consumption. The policies shifts can reduce CO2 emissions, but methane emissions from switching processes may contribute to short-term climate impacts. The climate impact during the policy transition is still unclear. Thus, this paper developed a lifecycle greenhouse gas (GHG) emissions framework for coal-to-clean-energy policies in rural northern China. The GHG emissions for heating and cooking, the two most energy intensive activities, were calculated. Four scenarios were designed based on energy types and equipment. Uncertainties in estimating lifecycle GHG emissions under different scenarios were analyzed. The technology warming potential values were calculated for the conversion of scenarios. Besides, the environmental benefits of natural gas versus electricity under emission reduction targets were compared. According to our findings, the total GHG emissions reduction of coal-to-clean-energy shift policies in rural northern China under global warming potential on a 100-year scale (GWP 100) is 1.83 million metric ton CO2 equivalent (MMT CO2 eq) in 2018. Since the climate benefits of policy shifts are driven by chosen technical routes, replacing coal with natural gas should be prioritized; heating with natural gas boilers can maximize GHG emissions reduction and climate benefits. By 2038, the climate benefits of electricity will be far superior to those of natural gas, based on emission reduction targets and electrical mix. There are numerous opportunities to reduce GHG emissions in China's energy sector, and there is a need for the energy industry to obtain better emissions data as well as to increase efforts to reduce GHG emissions.

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.