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This study examines renovation strategies among owners of rental housing in Sweden in response to European energy policies that promote deep renovation as a means to reduce carbon emissions from residential buildings. Case studies of eleven housing companies, seven public and three private, were designed with the aim to examine housing owners' attitudes and renovation strategies, and how policies
For district heating systems, prediction of the heat load is a very important topic for energy storage and optimized operation. For large and complex heating systems, most prediction models in previous publications only considered the influence of outdoor temperature, whereas the indoor temperature and thermal inertia of buildings were not included. For an energy-efficient residential building in
Heat transfer enhancement is of great importance for energy efficiency improvement. The utilization of spirally corrugated tubes is one of the efficient ways to strengthen heat transfer. In this article, based on a validated numerical model, the effects of geometric parameters of a six-start spirally corrugated tube, including the pitch p and the corrugation depth e, on the shell side heat transfe
The need for more functionality and higher performance has increased the number of transistors to billions in current processors. A high number of transistors on the same chip area increases the power density, which in turn heats up the devices and lowers the life time of batteries. The increasing demand for devices relying on battery and harvested energies in the Internet of Things (IoT) era has
Fuel cells are promising due to advantages with higher energy conversion efficiency and lower emissions of SOX, NOX and CO2 than conventional power systems. Solid oxide fuel cell (SOFC) is a high temperature fuel cell, which operates at 600-1000 ºC. The high operating temperature and the anode material allow SOFCs to operate with different types of fuels from both fossil and renewable sources due
The win-win opportunities connected to green growth are appealing to academics and policy makers alike, but empirical evaluations about the effectiveness of green growth policies are still scattered. Taking South Korea as case study, which set up a highly ambitious green growth program in 2009, our research casts light on the extent to which the Korean Green Growth Strategy has been effective in d
Our future built environment will not only consume energy, it will also produce (partly) its own energy need. Solar energy has been proven to be a valid strategy for producing on-site renewable energy. Planning for integrating solar energy in buildings involves many players and decision-making. In this article, a process map defining which decisions regarding solar energy needs to be discussed in
Stripping gas is generally used to improve hydrogen yields in fermentations. Since CO2 is relatively easy to separate from hydrogen it could be an interesting stripping gas. However, a higher partial CO2 pressure is accompanied with an increased CO2 uptake in the liquid, where it hydrolyses and induces an increased requirement of NaOH to maintain the pH. This enhances the osmotic pressure in the c
The increase in efficiency of RF power generation for future large accelerators is considered a high priority issue. The vast majority of the existing commercial high-power RF klystrons operates in the electronic efficiency range between 40% and 55%. Only a few klystrons available on the market are capable of operating with 65% efficiency or above. In this paper, a new method to achieve 90% RF pow
Different designs of flat-tube heat exchangers with plain fins have been evaluated theoretically in a parameter study in order to evaluate their performance potential in indirectly cooled display cabinets. Two different types of flat-tube heat exchangers were considered; one with serpentine fins and one with continuous plate fins. Both flat-tube heat exchanger types were adapted to the laminar flo
The German “Energiewende” (energy transition) is meant to be a contract between generations. The rebuilding of the whole energy system is designed and financed today in order to safeguard our children and grandchildren against fundamental risks: the enormous economic, social and environmental costs of a fossil-nuclear energy system, the risks of the nuclear fuel-cycle and the impacts of climate ch
Lignocellulosic materials, such as wood, waste products from the forestry industry, agricultural residues and herbaceous crops, serve as an abundant and comparatively cheap feedstock with the potential to be used for large-scale ethanol production. However, the complex structure of lignocellulosic materials, the presence of various hexose and pentose sugars in hemicellulose, and the presence of va
The energy hub concept is gradually getting popular due to its capability to integrate renewable energy technologies into the energy grid with a minimum impact. Designing distributed energy hubs is a challenging task due to the coupling of optimum dispatch and energy system sizing problems. Operation of the system needs to be considered for 8760 time steps and energy system sizing optimization can
Until recently, the methylotrophic yeasts, including Hansenula polymorpha, have not been considered as a potential producer of biofuels, particularly, ethanol from lignocellulosics. However it is already known that the thermotolerant methylotrophic yeast H. polymorpha is capable to ferment xylose, glucose and cellobiose, the main sugars of lignocellulosic hydrolysates, under elevated temperature.
Fouling on heat exchanger surfaces can weaken the heat-transfer capability, increase the energy consumption, and even cause the failure of the whole system. In coaxial heat exchangers, spirally corrugated tubes perform better than smooth ones concerning heat transfer and antifouling. In this article, a parametric study on the antifouling performance of a six-start spirally corrugated tube is carri
This work aims to analyze thermal performance for an electric heater filled with different nanofluids, including SiO2-water nanofluid, Fe3O4-water nanofluid, and Cu-water nanofluid. The effect of nanoparticle concentration (0.1–2.0 wt%) is also discussed. Results indicate that Cu-water nanofluids show better heat transfer performance than the other nanofluids. The highest heating efficiency for th
A piece about a just transition to a low-carbon future (contribution to UNESCO Inclusive Policy Lab 'Think pieces' that explores emerging issues in inclusive policies as well as offering cutting edge solutions).
Ion exchange membranes (IEMs) have consolidated applications in energy conversion and storage systems, like fuel cells and battery separators. Moreover, in the perspective to address the global need for non-carbon-based and renewable energies, salinity-gradient power (SGP) harvesting by reverse electrodialysis (RED) is attracting significant interest in recent years. In particular, brine solutions
This paper documents the development of a sustainable greenhouse system which incorporates a greenhouse, reverse electrodialysis (RED), reverse osmosis, and a dehumidification desalination system aiming to support water and energy self-sufficient agriculture in arid regions with a saline groundwater feed. The system is referred to as the sustainable greenhouse (SGH). The aim is to generate enough
Liquid hydrogen is a promising energy carrier due to its excellent performance. However, liquid hydrogen sloshing usually causes serious issues on its safety production, storage, transportation, application and management. To study fluid sloshing in cryogenic storage tanks, a numerical calculation model is developed with considerations of the environmental heat leakage and phase change occurring a
