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The transition of the Net Zero Energy (NZE) concept from building to settlement scale has been theoretically approached in a number of studies. This paper examines the benefits and barriers associated with the implementation of the NZE concept at a settlement scale, by adopting a comprehensive approach for the design, construction, and monitoring of NZE settlements that was developed in the EU Horizon 2020 ZERO-PLUS project and implemented in four case studies. First, the ZERO-PLUS approach is presented, followed by an analysis of associated benefits and encountered barriers. Next, the roles of different stakeholders involved in the process are identified through stakeholder analysis. Finally, new dynamics that emerge and are critical to the successful implementation of NZE settlements are discussed. The ZERO-PLUS approach leads to achieving NZE settlements with an initial cost that is on average 16% lower than the cost of a typical NZEB, while achieving a net regulated energy consumption of less than 20 kWh/m2/year and renewable energy production of more than 50 kWh/m2/year. The implementation of NZE settlements revealed two main issues: 1) the external barriers that were raised by the planning policies and regulations; and 2) the challenge of managing and integrating the needs and requirements of project stakeholders. To overcome these barriers while reaping the benefits of the approach, the management of such projects needs to focus from the outset on the establishment of a project management structure that will ensure the coordination and integration of various stakeholders. The use of a standardized collaboration protocol from the preliminary design stage is recommended to facilitate future projects. Simultaneously, regulations need to be updated towards facilitating NZE settlement implementation.

“Net-zero energy”, a burning concept of the current world, has been being considered and applied on a building scale for the last few decades, however, there are significant advantages to moving to the community level. This study identifies the technological advancements of net-zero energy communities through in-depth literature review study. 23 case study settlements have been identified and analyzed based on their design methodology along with some practical applications around the globe. The focus of this work is on technologies and measures utilized for the reduction of energy consumption, minimization of greenhouse gas (GHG) emissions, and the generation of electrical and thermal energy by renewables. We identified different mitigation strategies adopted for outdoor heat sources, building adaptation techniques, and renewable energy technologies along with control strategies. The study reveals that all the settlements mainly focus on the onsite energy generation, while 17 settlements among them, additionally, consider various adaptation techniques that have significantly lessened the energy demand of the buildings. A few studies (4 settlements only) incorporate some mitigation strategies to mitigate the outdoor heat sources that enable to lower the ambient temperature along with diminishing the GHGs emissions as well as minimizing the energy demand of the community. In addition, the climate zones have significant impacts on selecting the building adaptation tools and measures. Alongside the energy balance, we have also epitomized the effects of various energy management and control strategies adopted for the smooth operation of energy. Finally, we shed light on the problems and challenges of existing net-zero energy settlements and make recommendations by considering the environment, energy, and economy towards achieving the net-zero energy purpose at the community level.

The aim of this study is to obtain more realistic estimations of the achievable capacity factor and availability of waste-to-energy power plants to better understand their economics, and hence facilitate appropriate deployment. Towards this aim, we introduce Markov analysis and off-design considerations into the calculation of plant performance. Parameters such as increasing failure rates as a result of aging, infant mortality failures, and overhauls are all taken into account with our approach. Meanwhile, the effect of failures on such plant's operating mode is evaluated, and Stodola's cone law is applied to calculate the actual power generation in off-design mode. A system divided into three main sub-components, two steam generation blocks and a power generation block, each of which has its own failure and repair rates, is proposed for this study. The state-space diagram of the proposed system is constructed and simplified, and the transient differential equations governing the state-space diagram are solved numerically. Having obtained the availability of the system and off-design performance, the capacity factor is calculated and compared with actual field data. Also, a new availability-based formulation is presented to obtain the net present value of the cash flow. Results show that by using a time-varying failure rate, the availability of the power plant declines about 23% over 20 years, a significant difference to estimated availability if a constant failure rate was assumed. Our findings highlight that the present price of electricity, $0.057 per kWh, for generation from the plant is insufficient to encourage investment in this technology in Iran at present, and greater deployment will require some form of policy intervention.

The transition of the Net Zero Energy (NZE) concept from building to settlement scale has been theoretically approached in a number of studies. This paper examines the benefits and barriers associated with the implementation of the NZE concept at a settlement scale, by adopting a comprehensive approach for the design, construction, and monitoring of NZE settlements that was developed in the EU Horizon 2020 ZERO-PLUS project and implemented in four case studies. First, the ZERO-PLUS approach is presented, followed by an analysis of associated benefits and encountered barriers. Next, the roles of different stakeholders involved in the process are identified through stakeholder analysis. Finally, new dynamics that emerge and are critical to the successful implementation of NZE settlements are discussed. The ZERO-PLUS approach leads to achieving NZE settlements with an initial cost that is on average 16% lower than the cost of a typical NZEB, while achieving a net regulated energy consumption of less than 20 kWh/m2/year and renewable energy production of more than 50 kWh/m2/year. The implementation of NZE settlements revealed two main issues: 1) the external barriers that were raised by the planning policies and regulations; and 2) the challenge of managing and integrating the needs and requirements of project stakeholders. To overcome these barriers while reaping the benefits of the approach, the management of such projects needs to focus from the outset on the establishment of a project management structure that will ensure the coordination and integration of various stakeholders. The use of a standardized collaboration protocol from the preliminary design stage is recommended to facilitate future projects. Simultaneously, regulations need to be updated towards facilitating NZE settlement implementation.

Over three million people live below the poverty line in Australia. Low-income households suffer from overheated or cold homes and experience problems associated with energy inefficiency and poor indoor environmental quality (IEQ), which ultimately affect residents’ quality of life, comfort, well-being, physical and mental health. These circumstances are the main drivers of a social challenge known as Energy Poverty (EP) when residents have difficulties in paying the electricity bills. EP needs to be addressed by i) implementing energy efficiency measures in social housing, ii) educating low-income families about energy saving practices and behaviours, iii) developing new energy policies. We investigated the level of EP in social housing located in New South Wales, Australia. Indoor thermal environment and air quality were monitored in 106 low-income households over the winter and summer periods 2018/2019. Questionnaire responses informed the real living conditions of participating families, including their medical history and behaviours concerning energy use. The information presented here will be used to investigate the possible evolution of IEQ and EP as a function of climate change and extreme weather events on housing and suggest countermeasures and target policies to benefit the vulnerable households and alleviating the EP level of the region.