This study aims to investigate the impact of the PJS on the performance of multi-jet stratum ventilation. A validated Computational Fluid Dynamics (CFD) model was used to conduct the year-round multivariate analysis. A total of eight PJSs, four inlet locations and five climate zones were discussed synthetically. Air distribution performance index (ADPI), ventilation effectiveness (Et) and economic comfort coefficient were employed as the evaluation indicators to assess the thermal comfort and energy efficiency in various scenarios. Research results indicated that the PJS showed different influences on the indoor thermal comfort and energy utilization efficiency as a result of cooperative effect including energy dissipation, air short-circuit probability, air distribution uniformity and airflow path. Combining with building energy simulation method, the optimum PJSs of stratum ventilation with different air inlet positions in five climate zones were obtained, which can help provide a comfortable indoor thermal environment and improve energy efficiency in a low-cost way.
Direct cloud-enabled sensor nodes offers certain advantages over low-power wireless communication technologies but require high-power. Conventional wireless sensor nodes, which are battery-powered, have relatively low lifespan. In a battery powered direct cloud-enabled sensor nodes, the peak current needed during the data transmission process will add extra burden on the already strained battery resources and may accelerate the capacity degradation, further reducing battery life. The condition deteriorates where applications require frequent data transmission. This paper proposes a novel power management device architecture tailored to direct cloud-enabled sensor nodes’ requirements for indoor applications with extended lifespan. This research also recommends using Photovoltaic energy harvesting with a hybrid storage technique consisting of a battery and supercapacitor to power the node. The work’s novelty lies in the use of a supercapacitor-battery hybrid storage scheme, which provides the required peak current during the data transmission, sufficient enough to fulfill the load requirement during the data transmission process. A novel drip charge controller synchronized with the sleep period, and the active period of the sensor node is introduced. The power management unit was designed simulated and validated experimentally to verify performance with the indoor application.
This paper presents the comfort platform created within a research project carried out at KTH Live-In Lab in Stockholm, Sweden. The KTH Live-In Lab is a platform of buildings to test and promote innovation into the built environment. The Live-In Lab includes several buildings with state-of-the-art and expandable sensor infrastructure.
The comfort platform has been created to manage user feedbacks in buildings. The comfort platform includes a user-friendly web application and a cost efficient sensor device that allow to exchange feedbacks with the building users.
The comfort platform is proposed as a possible solution to bridge the gap between modern smart buildings and existing buildings with limited sensor capability.
This paper describes the comfort platform and the environment where it has been tested. The paper also summarizes the preliminary findings and the potential large-scale implementation.
Reductions of environmental footprint and lifetime costs are nowadays key aspects of most of human activities. Such concerns are also present in the aquaculture sector which involves the cultivation of aquatic organisms as well as all activities related to their processing, seeking to ensure sustainable growth. This paper deals with the environmental and economic aspects of aquaculture systems (involving aquaculture farms and relevant farm vessels) with a high share of renewable energy sources (RES). The energy needs of a typical aquaculture system are identified and Life Cycle Assessments (LCAs) of different power system configurations are performed. These configurations are also compared from the economical viewpoint, by the Life Cycle Cost Assessment (LCCA). Electrification of farm vessels is recognized as a key solution to reduce both the environmental footprint and operating costs. However, as shown by LCA, due to specific operating profile of farm vessels their energy needs can not be completely covered by RES, since an amount of electricity supplied from the national grid is needed. Therefore, the share of renewables will be dependent on the percentage of RES in the energy mix of the specific location of the aquaculture system. The LCCA analysis has shown that this form of integration requires larger investment which, if an unfavourable form of RES is chosen, may cause financial losses.
Increased social awareness on the greenhouse gases led to climate agreements setting their strict reduction targets. In order to achieve decarbonization of the shipping industry, some technical measures can be applied, such as replacement of classical ship power system with diesel engine as a prime mover with some alternative solution. This paper investigates the applicability of alternative power system configurations that can be implemented on board passenger and cargo ships from Croatian inland waterway fleet. The environmental impact of three different potential power system configurations (diesel engine-powered ship, battery-powered ship and photovoltaic cells-battery-powered ship) was investigated through the Life Cycle Assessment (LCA) by means of GREET 2019 software. The comparison identified the photovoltaic cells-battery-powered ship configuration as the most environmentally friendly power system configuration.
One of the major barriers to closing the energy efficiency gap is the failure to successfully inform the population about measures to conserve energy. This paper introduces the design of a mobile application developed to improve energy conservation of residential buildings by informing occupants of transferrable energy efficient green features in a green-certified, nonresidential building. The application was developed to investigate dissemination of transferable energy saving practices to explore spillover effects from nonresidential to residential buildings. Our research aims to capitalize on such spillover effects to narrow the energy efficiency gap.
The COVID-19 pandemic has caused problems all around the world. To control the spread of the virus, some governments have imposed restrictions on the mobility of their citizens. Specifically, in Spain, from the months of March to May, lockdown was imposed. The effect of these actions is reflected not only on epidemiological data, but also on the behavior of the population, and therefore, some of their sectors. One of these sectors is the energy consumption. In this sense, this paper studies the impact that the COVID-19 pandemic has had on energy consumption using the data from the Smart Meters of the secondary distribution network at low-voltage. This approach has de advantage that is not only able to obtain the impact at aggregated level but is also able to obtain the impact on smaller groups at customer level. The results show an increase in energy consumption on residential customers in contrast with a remarkable reduction on non-residential customers. In the case of non-residential customers, different consumption patterns have been found during the pandemic. These consumption patterns are highly correlated with the restrictions imposed to control de spread of the pandemic.
Airports have terminal buildings that are ideal places to deploy PV panels, which is able to power airport in an eco-friendly way with low carbon footprint. Ecaluate the PV potential at airports and its economic performance can help to understand the benefits airport PV will bring is important for decision-making. Thus, combining GIS data, image recognition, the PV integration potential at airports in China has been investigated. According to our research, airport PV potential is up to 2.67 GW in China. Detailed economic analysis manifests that all airport PV can be profitable.
A dual-purpose underground thermal battery (DPUTB) integrates a ground heat exchanger with underground thermal energy storage. It can be installed in shallow boreholes (less than 6 m deep) and thus is less expensive than the conventional ground heat exchangers. The thermal energy storage can be used to shave or shift the electric load for meeting the thermal demands of a building. The charging and discharging performance of a lab-scale DPUTB were tested. The test results show that the DPUTB can be fully charged within 4 h and can provide 34 W cooling continuously for 2.5 h with a supply water temperature below 14Â°C. A small amount of phase-change material significantly increased the thermal storage capacity.
This paper presents a critical evaluation of the performance of the first awarded EnerPHit building under the different climate zones of Greece following a digital twin approach. The thermal behavior and the relative humidity of the original building without active strategies have been numerically investigated for the four different climates. The results show that the Passive House design could be applied in all four climate zones in Greece with minimum updates in terms of insulation thickness, providing an avenue for mass prefabrication and application of the Passivhaus concept in Greece.