Hydration heat transformer: A groundbreaking technology for sustainable process heating

Dependency on energy is much higher than the past and it is clear that energy is vital for a sustainable and safer future. Therefore, urgent solutions are required not only to increase share of renewable resources but also more efficient usage of fossil fuels. This could be achieved with innovative power, air conditioning and refrigeration cycles utilising ‘long-term sustainable’ (LTS) fluids, especially air, water and CO2. In the article we provide a rational approach to the future use of working fluids based on our interpretation of the available technical evidence. We consider it self-evident that volatile fluids will continue to play major roles in cooling and power generation, however, new technologies will be needed that optimise energy efficiency and safety with minimum environmental impact. Concordantly we discuss the past and current situation of volatile fluids and present four innovative technologies using air/water cycles. Study results showed that there is a rapid development in heating, cooling and power generation technologies those use water/air as working fluid. These technologies demonstrate a potential to replace conventional systems, thereby to contribute to global sustainability in near future. However, further development on LTS fluids and materials also process intensification and cost reduction are vital parameters for future advancement of these technologies.

To decarbonize industry, we must decarbonize heat

Heating in built environments is an essential factor regarding energy consumption and CO2 emissions. Thus, the application of sustainable heating technologies is vital for reducing CO2 emissions. The literature indicates the requirement for a comprehensive assessment of the technical, economic, and environmental performances of various sustainable heating technologies and their implementation feasibility at the local level. Accordingly, this study presents a quantitative assessment relative to Harbin, a typical northern city with a coal-dominated heating system. Seven sustainable heating technologies were examined using current policy and future renewable scenarios. The results indicate that the examined heating technologies are technically feasible. Biomass heating saves costs and emissions (CO2 avoidance costs of 24–47 €/t), although fuel availability and storage management limit its implementation. Solar heating is a promising technology with reduced costs and low CO2 emissions (CO2 avoidance costs can decline by 50% from 2020 to 2050). However, its current resident acceptance is relatively low as lengthy investigations and periods for underground construction are required. Electric heating is preferable in terms of implementation feasibility; however, its economic competitiveness and environmental impact depend heavily on electricity prices and grid cleanliness (CO2 avoidance costs of 120–463 €/t). This study contributes to the existing literature on sustainable heat transition in China by providing informative local circumstances in Harbin and presenting assumption-making methods in detail when local data is not transparent. The integrated assessment provides solid evidence to facilitate decision-making in the clean heating transition in northern cities of China. The methods are applicable to other countries with similar heat-supply structures and climate conditions.

What came first, the pellet or boiler? Interacting leverage points within a sociotechnical system in the United States

Comparative costs of ground source heat pump systems against other forms of heating and cooling for different climatic conditions

The likely installation of, and potential energy savings from, low carbon technologies in domestic buildings is not only dependent on those who fit them, but also the broader supply chains of which they are part. Despite this, the role of supply chain actors has been largely overlooked in strategies seeking to encourage the installation of more sustainable domestic heating technologies. With reference to central heating, this paper responds through an ethnographic analysis of how plumbers' merchants and sales representatives can influence the work of heating installers in the United Kingdom. It applies two dimensions of the concept of ‘social capital’: relational and structural. Relational social capital focuses on the trust, loyalty and reciprocity at play in relations, whilst structural social capital considers how the strength of tie can influence those to whom people turn for advice and support. Together, these ideas demonstrate how relationships amongst these groups can serve to influence product choice and facilitate information exchange. The paper concludes by discussing how these supply chains might be engaged with as a means of encouraging the installation of low carbon domestic technologies.

This study investigates the role of peer effects in shaping the adoption of sustainable heating systems in two highly polluted communes in Southern Chile. Despite policies promoting cleaner alternatives, wood-burning stoves, a major source of particulate matter emissions, remain widespread. This research work addresses a critical gap in the literature by examining how peer influence—typically studied in relation to visible technologies like solar panels or electric vehicles—affects the adoption of less visible but essential sustainable heating technologies. The main objective of this study is to understand how peer networks can influence the attitudes of residents towards sustainable heating technologies in highly polluted urban environments. Employing a non-experimental, cross-sectional design with a sample of 244 participants, this study reveals that peer effects and health risk perception are significant predictors of positive attitudes towards sustainable heating systems. These findings contribute valuable insights for policymakers seeking to accelerate energy transitions in polluted regions.

Aquifer thermal energy storage (ATES) is a promising technology for sustainable and climate-friendly space heating and cooling. Compared to conventional heating and cooling techniques, ATES-based systems offer several benefits such as lower greenhouse gas emissions and reduced primary energy consumption. Despite these benefits and the availability of suitable aquifers in many places around the world, ATES has yet to see a widespread global utilization. Currently the vast majority of installed systems is located in the Netherlands, Belgium, Sweden and Denmark. Besides technical and hydrogeological feasibility, appropriate national policies driving ATES deployment are therefore of high importance. Hence, this study provides an international comparison of ATES policies, highlighting best practice examples and revealing where appropriate policy measures are missing. To this end, multi-disciplinary views from experts in geothermal energy and ATES from academia, companies, government authorities, national geological surveys and industrial associations in 30 countries were obtained through an online survey. Subsequent semi-structured interviews with a smaller selection of experts revealed further insights. The online survey results show significant differences regarding the existence and the strength of supporting policy elements between countries of different ATES market maturity. Going beyond these descriptive findings, the interviews provided more country-specific details on how favorable conditions came into effect and what obstacles have still to be overcome for an increased ATES deployment. Based on the lessons learned from the online survey and the expert interviews, recommendations for sophisticated ATES policies are derived which address the following areas: legislative and regulatory issues, raising awareness and expertise, the role of ATES in local energy transitions, and social engagement. This work aims at steering energy policy towards a wider international ATES deployment and better harnessing the potential of ATES to decarbonize buildings.

Aquifer thermal energy storage (ATES) is a promising technology for sustainable and climate-friendly space heating and cooling which can contribute to the energy transition, as it causes significantly less greenhouse gas (GHG) emissions than conventional space heating and cooling technologies. Using 3D thermo-hydraulic numerical models, this study quantifies the technical potential of shallow low-temperature ATES in the city of Freiburg, Germany. The numerical models consider various ATES configurations and different hydrogeological subsurface characteristics relevant for the study area. Based on the modeling results, spatially resolved ATES power densities for heating and cooling are determined and compared to the space heating and cooling energy demand. High ambient groundwater flow velocities of up to 13 m d-1 cause relatively high storage energy losses resulting in maximum ATES power densities of 3.2 W m-2. Yet, these still reveal substantial heating and cooling energy supply rates achievable by ATES systems. While heating energy supply rates of larger than 60 % are determined for about 50 % of all residential buildings in the study area, the cooling energy demand could be supplied entirely by ATES systems for 92 % of the buildings. Also, ATES heating alone could allow for greenhouse gas emission savings of up to about 70,000 tCO2eq a‑1, equivalent to 40 % of the current greenhouse gas (GHG) emissions from space and water heating in the study areas’ residential building stock. The proposed modeling approach in this study can also be applied in other regions with similar hydrogeological conditions to obtain estimations of local ATES supply rates and support city-scale energy planning.

Thermocells (TECs) represent a promising technology for sustainable low-grade waste heat (<100 °C) harvesting, offering distinct advantages such as scalability, structural versatility, and high thermopower. However, their practical applications are still hindered by low energy conversion efficiency and stability issues. In recent studies, electrolyte engineering has been highlighted as a critical strategy to enhance their thermopower by regulating the solvation structure and redox ion concentration gradient, thereby improving conversion efficiency. This review comprehensively summarizes progress in optimizing electrolytes for TECs, focusing on tailored strategies for four representative redox couples, namely, Fe(CN)64-/3-, Fe2+/3+, I-/I3-, and Cu/Cu2+. Key approaches, including modulating solvation structures via additives or co-solvents to amplify solvation entropy, and leveraging thermosensitive crystallization or phase separation to establish a redox ion concentration gradient, are thoroughly discussed. These discussions cover both liquid- and gel-type TECs, emphasizing performance enhancements in thermoelectrochemical Seebeck coefficients and normalized power densities, as well as advancements in device integration and applications. In the last section, challenges in efficiency, mass transfer, and long-term stability are critically proposed, highlighting potential directions for the future development of high-performance TECs.

Sustainable energy development in the farming sector is an essential strategy to respond the combined challenge of achieving a reliable and affordable solution but including mitigation and adaptation to climate change. Intensive breeding farms require maintaining an adequate indoor thermal environment that results in high energy demands, usually covered by fossil fuels and electricity. This paper addresses the application of the combined slurry technology for a particular pig farm that currently uses a diesel boiler to supply the piglet heating energy needs. The study also considers different options based on closed ground source heat pump systems. After the design of the slurry alternative and the geothermal ones, notable advantages are detected compared to the existing diesel system. Results show that the implementation of the slurry technology implies an important reduction of the operational costs, which, in turn, involves short amortization periods for this system in relation to the diesel one. Greenhouse gases emissions are also highly reduced in the slurry alternative based on the low electricity use of the heat pump. The environmental side is reinforced by the reduction of polluting substances such as methane of ammonia derived from the descent of temperature of the slurry.

Aquifer thermal energy storage (ATES) is a promising technology for sustainable and climate-friendly space heating and cooling which can contribute to lower greenhouse gas (GHG) emissions. Using 3D heat transport models, this study quantifies the technical potential of shallow low-temperature ATES in the city of Freiburg, Germany. The numerical models consider various ATES configurations and different hydrogeological subsurface characteristics relevant for the study area. Based on the modeling results, spatially resolved ATES power densities for heating and cooling are determined and compared to the space heating and cooling energy demands. High ambient groundwater flow velocities of up to 13&amp;#160;m&amp;#160;d-1 cause relatively high storage energy losses resulting in maximum ATES power densities of 3.2&amp;#160;W&amp;#160;m-2. Until now, these still reveal substantial heating and cooling energy supply rates achievable by ATES systems. While heating supply rates of larger than 60&amp;#160;% are determined for about 50&amp;#160;% of all residential buildings in the study area, the cooling energy demand could be supplied entirely by ATES systems for 92&amp;#160;% of the buildings. In addition, ATES heating alone could result in greenhouse gas emission savings of up to about 70,000&amp;#160;tCO2eq&amp;#160;a&amp;#8209;1. The proposed modeling approach in this study can also be applied in other urban areas with similar hydrogeological conditions to obtain estimations of local ATES supply rates and support city-scale energy planning for heating and cooling.

Chapter 217 - Solar Thermal Technology for Power Plants and Process Heat

An assessment of district heating research in China

Induction heating is an electromagnetic heating technology that has several advantages such as high safety, scalability, and high energy efficiency. It has been applied for a long time in metal processing, medical applications, and cooking. However, the application of this technology in food processing industry is still in its early stages. The objectives of this article were to review the basics of induction heating technology and the factors affecting its performance and to assess the application status of this technology in food processing. The research needs and future perspectives of this technology in food processing are also presented. Although several patents on using the induction heating to process food materials are available, there is still a need to generate more scientific data on the design, performance, and energy efficiency of the induction heating technology to be applied in different unit operations, such as drying, pasteurization, sterilization, and roasting, in food processing. It is needed to optimize different design and operational parameters, such as applied current frequency, type of equipment material, equipment size and configuration, and coil configurations. The information on the effect of the induction heating on sensory and nutritional quality of different food materials is lack. Research is also needed to compare the efficiency of the induction heating and other heating technologies, such as infrared, microwave, and ohmic heating, for food processing applications.