Wireless sensors networks consist of several tiny battery powered devices which are utilized to monitor and gather information of desired area, such as a Net Zero Energy Building. As there is no way to recharge the nodes’ energy and batteries, efficient energy consumption plays crucial role in prolonging nodes’ and network’ s lifetime. One of the most popular routing protocol is LEACH protocol, which suffers from drawbacks, despite several modifications have been deployed. This research aims to optimize the Leach protocol from three different aspects. Initially, the allocated energy of network is distributed to each nodes based on their distance with base station. The more distance between a node and BS, the more energy portion is allocated to the given node. Secondly, Genetic algorithm has been employed to select optimal cluster head set whose fitness function addresses number of CHs and distance between CHs and the BS. Lastly, sensor nodes are clustered by fuzzy clustering. Comparing the results with previous versions illustrates that the proposed modifications could prolong considering network and improve the energy consumption and the modified LEACH achieves 10% improvement in terms of survival rate of nodes.

Today, one of the most important issues related to human development is climate change. Due to the increasing trend of production and consumption of polymer products, the emission of greenhouse gases has increased in this sector and it is necessary to take effective measures to reduce the consequences of climate change. The aim of this study is to evaluate the effectiveness of greenhouse gas emission reduction scenarios in an integrated manner based on Net Zero guidelines. In this research, using the guidelines of Net Zero (combustion emission, per energy and material consumption) and the concept of carbon intensity of emission equivalent to carbon dioxide, the effectiveness of greenhouse gas emission reduction scenarios for the production of one ton of polyethylene has been evaluated. According to the results obtained in this research, the most effective scenarios are replacement with photovoltaic energy source, which reduces greenhouse gas emissions by 0.7% (5% replacement) to 6.3% (50% replacement). Also, electricity saving scenarios from 5% to 20%, in three scenarios with 5%, 10% and 20% electricity savings, which will reduce greenhouse gas emissions by 0.6% to 2.6%. On the other hand, the plan to recover combustible gases in the polyethylene production process, according to the available technologies, can contribute to the reduction of greenhouse gas emissions by 1.2%. In general, it can be stated that the recovery of combustible gases is more reasonable than costly scenarios such as replacing the energy source.

Achieving a net-zero emission power generation system is a significant global challenge for power suppliers and policymakers. This article examines four power supply scenarios aimed at reaching net-zero emissions by 2060: a baseline scenario and three net-zero emission scenarios. The baseline scenario determines power plant capacity based on existing policies. The net-zero emission scenarios include: optimizing renewable energy sources, utilizing carbon capture and storage (CCS) technology, and incorporating nuclear technology into power generation. Optimization calculations were performed using the Next Energy Modelling System for Optimization model within the Low Emissions Analysis Platform program. The findings indicate that achieving a carbon-free power production system by 2060 is feasible through these three net-zero emission scenarios. The scenario involving nuclear technology results in cumulative carbon dioxide emissions of 136 Mt and entails the highest total investment cost of 44 billion USD. However, it incurs the lowest cumulative planning cost, at 84.7 billion USD, compared to the other scenarios. Additionally, the nuclear power scenario is projected to generate the most jobs, adding 275 thousand laborers by 2060—a 60% increase over the baseline scenario—compared to 209 thousand and 206 thousand jobs created in the renewable energy and CCS scenarios, respectively.

Access to the appropriate quality and quantity of water is very important during the building life cycle and various stages of construction and operation. The fundamental importance of water is evident from the fact that two of the 17 sustainable development goals are directly related to water. Hot and dry climatic conditions, low rainfall and high evaporation, improper use of limited water resources, and pollution of quantitative and qualitative water crises have been determined on different scales in Iran. A large part of water loss occurs at the building scale (residential, commercial, and official). Therefore, in many parts of the country, especially in arid and semi-arid regions, it's inevitable the need to adopt strategies for the optimal use of water resources in the construction sector. The present study investigates the use of alternative water resources, water resources recovery methods to achieve net-zero water buildings, focusing on methods of reducing water consumption at the building scale. The research method is descriptive-analytical with a qualitative study. The data collection tool is a review of written sources, documents, and previous studies, and the method of data analysis is content analysis. Findings indicate that the creation and utilization of a sustainable water cycle in the building through rainwater harvesting systems, gray water collection and treatment systems as alternative water sources, collection, and treatment of black water to charge aquifers, or injection into water supply sources can provide a platform for the realization of the net-zero buildings.

The energy transition is a pathway to transform the global economy from its current reliance on fossil fuels to one with net-zero carbon dioxide emissions. This necessitates the rapid and large-scale deployment of renewable energy sources. However, most renewable energy sources, such as wind and solar, are intermittent and their production does not necessarily match demand. Moreover, energy storage in the form of sustainable energy carriers, such as hydrogen, is a key solution to overcome this challenge. Furthermore, underground hydrogen storage in natural formations such as salt caverns and porous rocks is an efficient and safe method for storing this clean energy source on a large scale. This method has also been used previously for storing natural gas and carbon dioxide. Despite its significant advantages, there are challenges such as hydrogen leakage, high costs, and a lack of knowledge and experience in this field. However, extensive efforts are underway to address these challenges and develop hydrogen storage technologies. Government and private investment in this area is increasing and several pilot projects are underway around the world, particularly in the Middle East. By overcoming existing challenges and developing new technologies, this method can be used as a sustainable and efficient solution for storing excess energy produced from renewable sources and promoting their use worldwide. This paper reviews the concepts and challenges associated with hydrogen energy and its underground storage. It also examines the current state of technology in the field of hydrogen, with reference to existing storage projects around the world, and provides recommendations for future work in this area. In addition, site selection criteria for hydrogen storage are reviewed based on current field experiences.

Background  Over 80 countries have now signed up to the COP26 Health Programme—a World Health Organization (WHO)-led initiative on climate change and health—of which 45 countries have committed to reaching net zero emissions before 2050. Efforts to reduce healthcare’s carbon footprint raise conceptual, ethical and practical challenges for efficient and fair resource allocation. This study investigates how civil servants leading the development and implementation of national net zero healthcare strategies conceptualise the responsibility of health systems to cut emissions and describe potential trade-offs along the way. Methods  We undertook 11 online, semi-structured qualitative research interviews between September 2022 – May 2023 with civil servants leading national net zero healthcare strategies. The interview guide explored three main areas: responsibility for emissions, priority setting and international perspectives. Interviews were coded and analysed the data using Malterud’s systematic text condensation (STC). Results  Four main themes emerged: obligation to act, leadership, governance, and prioritization. Participants described that the healthcare system should take responsibility for its entire carbon footprint, including harms inflicted beyond national borders. We also found indications of synergistic, multi-scalar health leadership—clinical, civil service, and political—helping to accelerate the net zero healthcare agenda. Participants generally rejected the notion of direct “tradeoffs” between efforts to reduce emissions and patient care, emphasising ways net zero healthcare can leverage societal health improvements more broadly. These empirical findings inform the emerging literature exploring how health systems should account for their environmental impacts. Conclusion  Our findings highlight the sincerity of ambitions to deliver net zero healthcare and uncertainties on how to get there. Further work characterising the types of constraints and trade-offs policy-makers face on the path to net zero healthcare systems, including examples of how these have been overcome, could help integrate climate concerns into healthcare decision-making and resource allocation processes.

Due to low energy price, economic optimization of consumption has no justification for users in Iran. Nowadays, the issue of ending fossil fuels, production of greenhouse gases and the main role of building in consumption of considerable amount of energy has drawn the focus of global researches to a new concept called net zero energy building. In this study, modeling, simulation and energy analysis have been used for considered building in Zahedan weather condition which has a dry and warm climate to draw the related equations and perform analysis. Multi-Objective optimization has been performed for simultaneous reduction of total energy consumption and total cost where the main decision making variables including thermal comfort, cooling, heating and lighting systems and other variables have been influential. The comparison of an ordinary optimized building and the intended optimized building which uses renewable energy resources indicates that it is possible to get to net zero energy building in addition to selling surplus 2 MWh electrical energy to electricity grid with simultaneous use of solar and wind renewable energies.

In this study, the feasibility of achieving the net-zero energy (NZE) target has been studied in a bioethanol production complex (Zist Faravarde Sepahan) based on different NZE definitions, including net-zero site energy, net-zero source energy, net-zero energy cost, net-zero energy emission, and net-zero exergy. In the technical investigations, the energy required for each approach has been determined, and then the corresponding photovoltaic power plant has been simulated in photovoltaic systems software (PVsyst) and transient systems simulation program (TRNSYS) by considering the generated and consumed energy. Afterward, the annual cumulative data of generation, consumption, export, and delivery energies of the complex have been extracted in the transient hourly conditions. The load matching, self-consumption, and electricity self-sufficiency indices were determined and compared in different approaches based on the hourly data. In the next step, β factor that is a fraction of the net present value (NPV) definition has been studied for the economic evaluation of the approaches in three pricing strategies: a) Buy all sell all (BASA), b) Net energy measurement (NEM) and c) Net billing (NB). Based on the technical evaluation, the net-zero energy cost approach is the most appropriate option to achieve the NZE target in the complex. Considering economic considerations, the net-zero energy cost in the BASA pricing strategy with a nominal power of 1.2 MWp < /sub> and a self-consumption index of 84.2% has the best results in both technical and economic investigations. β factor and NPV indices are 1.97 and $ 1,579,512 in this approach, respectively. The profitability phase (NPV = 0) will start after 10.1 years operation of the system.

Due to technological improvement and the development of photovoltaic (PV) systems, the application of PV installation for net-zero energy buildings (NZEBs) is promising. However, to achieve more reliable results, precise energy analysis is necessary to take into consideration both the urban plans restrictions and the climatic conditions of renewable energy resources and building energy consumption. This study aims to define the most favorable configuration of building components and PV installation to meet NZEB requirements, considering urban development plans limits. First, a sensitivity analysis was performed to indicate the most influential variables that affect building energy demand and cost. Next, an optimization process was conducted to concurrently minimize the building energy consumption and capital cost. Besides, a different configuration for PV panel installation was used for quantifying the possibility of achieving NZEB. The results show that in a residential 3-story building the optimized configuration of the building envelope and systems can reduce electricity consumption by 20%. The rooftop PV account for 87.2% and PV installation on the southern façade contributed to 12.8% of total electricity generation. PV installation on the south façade and roof covers 88.2% of the building's electricity demand.