Net Zero Energy Research Articles

Net zero community: Housing framework with zero negative environmental impact

AbstractArchitecture has evolved to address challenges, giving rise to new concepts. Today, global warming is a critical challenge mainly due to greenhouse gas emissions from energy-intensive buildings. The construction industry, primarily focused on housing, is both a culprit and a potential solution. This exploration delves into sustainable housing development, recognizing its pivotal role in mitigating environmental impact. The objective is to devise a model encompassing environmental, social, and economic sustainability. The proposed solution involves creating a net-zero energy community, addressing the surging growth of urban areas, and escalating greenhouse gas emissions. Emphasizing sustainability as a lifestyle, this approach aims to mitigate the construction industry's impact on global warming.

Numerical Investigation of CO and NO Production From Premixed Hydrogen/Methane Fuel Blends

Abstract There is significant interest in utilizing hydrogen as an energy carrier in a net-zero carbon energy economy. A variety of fundamental and practical issues associated with premixed hydrogen/methane combustion must be addressed, particularly flame flashback, combustion instabilities, and NOx emissions. Significantly less attention has been given to CO emissions from hydrogen blending. However, recent H2 blending engine tests have clearly noted major reductions in CO emissions, reductions which substantially exceed what would be expected based upon C atom mass balances in the fuel. Moreover, NOx, CO, and combustor operability always tradeoff with each other, and so, for example, these CO reductions can also enable operational or design modifications to reduce NOx emissions and/or wider operability windows. This paper addresses H2 blending effects on CO emissions, addressing both the direct influences on CO emissions, as well as how it influences NOx–CO tradeoffs. The paper presents computations that differentiate between the kinetic and equilibrium effects of H2 blending, as well as how H2 blending can lead to reductions in both NOx and CO by moving the Pareto front downward. Finally, this work suggests that H2 blending, in addition to its CO2 reductions, can also increase plant operational flexibility and so provide additional value propositions to an evolving electricity market.

Mitigating risks in hydrogen-powered transportation: A comprehensive risk assessment for hydrogen refuelling stations, vehicles, and garages

Hydrogen is increasingly seen as a viable alternative to fossil fuels in transportation, crucial to achieving net-zero energy goals. However, the rapid expansion of hydrogen-powered transportation is outpacing safety standards, posing significant risks due to limited operational experience, involvement of new actors and lack of targeted guidelines. This study addresses the urgent need for a tailored comprehensive risk assessment framework. Using Structured What-If (SWIFT) and bowtie barrier analysis, the research evaluates a hypothetical pilot project focusing on hydrogen refuelling stations, vehicles, and garages. The study identifies critical hazards and assesses the adequacy of current risk mitigation measures. Key findings reveal gaps in safety practices, leading to 41 actionable steps and 5 key activities to help new actors manage hydrogen risks effectively. By introducing novel safety guidelines, this research contributes to the development of safe hydrogen use and advances the understanding of hydrogen risks, ensuring its sustainable integration into transportation systems.

Temperature-Dependent Kinetics of Plasma-Based CO2Conversion: Interplay of Electron-Driven and Thermal-Driven Chemistry.

The transformation of CO2 into chemical building blocks for various industries is considered a key technology in a net-zero energy future. To realize this, plasma discharges are one of the most promising approaches thanks to their electron-driven reactions and high operational flexibility. Most studies focused on room-temperature and vibrationally-excited discharges, however, lately, the importance of thermal reactions is considered. Therefore, we developed a temperature-dependent plasma-chemical reaction mechanism to investigate the temperature dependence of plasma-based CO2 conversion. Here, we present the various effects of thermally-driven reactions on the CO2 conversion as a function of the gas temperature and specific energy input. Our analysis pinpointed the key reactions controlling the plasma-based CO2 conversion, shifting from an electron-driven to a thermal-driven regime. Additionally, we used the mechanism to verify the theoretical upper boundary of the process' energy efficiency, and discussed how our findings could lead to the further development and optimization of plasma discharges for efficient CO₂ conversion in the future.

Net Zero and Just Energy Transition in the Middle East and North Africa Region

No abstract

Resiliency evaluation of sheltering in a net-zero energy house during summer power outage

This study examines the growing issue of power outages caused by natural disasters and proposes the use of net-zero energy houses (ZEH) as a safe alternative to traditional shelters. A ZEH, equipped with an independent energy system, can maintain essential living standards such as thermal comfort and 24-hour air conditioning during a summer power outage, reducing the risk of heatstroke. The research tested a ZEH in Japan, confirming its ability to support critical household appliances like refrigerators, lighting, and water heaters for up to 72 h. This demonstrates the ZEH's potential for offering safe, comfortable shelter during emergencies while addressing problems like poor sanitation and lack of privacy found in typical shelters. The experimental ZEH is located in Shizuoka, Japan, is a steel structure, and has a floor area of 110.94 m2 and overall heat transmission coefficient (UA) of 0.48 W/m2·K. The ZEH was equipped with a 5.1 kW photovoltaic system and 5.6/11.2 kWh storage battery (BT), which produced an output of up to 2.0/4.0 kVA. A ZEH with a 5.6 kWh BT can provide for ventilation and living/dining room/kitchen air conditioning (AC), refrigerator, television, lighting, mobile phone charging, rice cooker, microwave, electric kettle, and heat pump water heater during a 72-h power outage. The ZEH with a 11.2 kWh BT can also provide bedroom AC and high-load home appliances for lunch and dinner, in addition to a 5.6 kWh BT. The use of AC in a self-supporting circuit maintained the thermal environment at a low heat stroke risk.

Design and performance analysis of a net-zero energy building in Owerri, Nigeria

Building cooling load depends on heat gains from the outside environment. Appropriate orientation and masonry materials play vital roles in the reduction of overall thermal loads buildings. A net-zero energy building performance has been analyzed in order to ascertain the optimum orientation and wall material properties, under the climatic conditions of Owerri, Nigeria. Standard cooling load estimation techniques were employed for the determination of the diurnal interior load variations in a building incorporating renewable energy as the major energy source, and compared with the situation in a conventionally powered building. The results show a 19.28% reduction in the building’s cooling load when brick masonry was used for the wall construction. It was observed that a higher heat gain occurred when the building faced the East-West direction than when it was oriented in the North-South direction. Significant diurnal cooling loads variation as a result of radiation through the windows was also observed, with the east facing windows contributing significantly higher loads during the morning hours while the west facing windows contributed higher amounts in the evening. The economic analysis of the net-zero energy building showed an 11.63% reduction in energy cost compared to the conventional building, with a 7-year payback period for the use of Solar PV systems. Therefore, the concept of net-zero energy building will not only help in energy conservation, but also in cost savings, and the reduction of carbon footprint in the built environment.

The effects of formation inclination on the operational performance of compressed carbon dioxide energy storage in aquifers

Compressed CO2 energy storage in aquifers (CAESA) is a net-zero energy storage technology. Due to the widespread existence of inclined aquifers in nature, it is of practical significance to study the influence of inclined reservoirs on CO2 migration, safety and energy efficiency of the storage system. We build 3D numerical models with different dips (0°–16°), analyze the hydrodynamic and thermodynamic behavior of the system, and discuss the effects of injection schemes (temperature and pressure) on wellbore pressure, temperature, and energy efficiency. The results show that formation dip affects the energy storage characteristics of the system mainly by affecting the migration and distribution of CO2 in the aquifer. The greater the formation dip, the greater the difference in CO2 distribution, and the farther the CO2 diffuses upward along the dip direction. The farthest migration distances in the low- and high-pressure aquifers, occurring in the case of 16° formation dip, increase by 100 and 53 m, respectively, compared with those of the flat formation. The average daily energy storage efficiency decreases with the increase in formation dip angle. The dip angle of aquifer which is selected for compressed CO2 energy storage should not exceed 8°.

Multi-period operation of integrated electricity and gas systems with hydrogen blending considering gas composition dynamics

Green hydrogen from renewable sources can be blended with natural gas and serves as a potentially feasible measure for contributing to the net zero energy sector. The time-varying nature of hydrogen injection, influenced by stochastic renewable generations, can result in fluctuations in gas concentrations in the entire network. It poses a potential threat to the secure regulation of integrated electricity and gas systems (IEGS). For managing the operating condition and guaranteeing the security of IEGS during operation, a multi-period operation framework with alternative gas (e.g., hydrogen) blending is developed. First, a convex gas security range is derived using the Dutton method. Then, the multi-period operation framework is devised to mitigate the impacts of alternative gas injection on gas security over the entire operational period. Both the dynamics from gas composition and gas flow are modelled, accurately describing the real-time travel of alternative gas concentrations. The dynamics in the gas mixture properties (e.g., relative density) are fully revealed with time-varying gas concentrations. To tackle the high non-convexities in the optimization problem, second-order-cone relaxation is well-tailored and firstly used in the case of varying gas compositions, making the motion equations and advective transport equations more tractable. An advanced second-order-cone sequential programming is devised to drive the relaxation tight more efficiently. Finally, our operation strategy is illustrated in IEEE and Belgium Electricity and Gas Systems. Results indicate that hydrogen concentrations take about 12.5 h to travel from the injection point to the end of the pipeline route in the Belgium gas system. By incorporating this unique characteristic into the model, operational scheduling and dispatch in IEGS can be more practical when integrating hydrogen in the future.

Optimising building performance for a resilient Future: A Multi-Objective approach to Net Zero energy strategies

The escalating impacts of climate change on urban environments underscore the imperative for energy-efficient buildings. As the building sector constitutes approximately 40% of global energy consumption, the implementation of NZE designs is critical for emission reduction. This study utilised Building Performance Optimisation methodologies alongside a multi-stage optimisation framework to evaluate energy consumption, Life cycle cost and carbon emissions under various climate scenarios (RCP 2.6, 4.5, and 8.5) in three Algerian cities—Constantine (semi-arid), Algiers (Mediterranean), and Ghardaïa (arid).The results revealed that the integration of passive, active, and renewable energy strategies significantly curtailed energy consumption and CO2 emissions across different climatic contexts. Specifically, passive measures achieved reductions in energy use ranging from 39% in Ghardaïa to 15% in Constantine. Active systems, including high-efficiency HVAC technologies, resulted in energy savings of 59% in Ghardaïa, 52% in Algiers, and 47% in Constantine. Furthermore, renewable energy sources, with a focus on solar photovoltaics, contributed additional reductions: 44% in Algiers, 26% in Ghardaïa, and 20% in Constantine. The multi-stage optimisation approach also enhanced computational efficiency, significantly reducing simulation time and facilitating the rapid identification of optimal strategies.These findings highlight the efficacy of integrating a range of energy strategies to achieve NZE. Nevertheless, while these systems demonstrate robust performance under current conditions, their effectiveness diminishes under future climate scenarios, underscoring the necessity for adaptive and resilient design approaches. Ongoing optimisation and innovation will be essential to maintaining the efficacy of NZE strategies in the face of extreme future climate conditions.

Building retrofitting towards net zero energy under climate change

Abstract The challenge in Net-Zero Energy Building (NZEB) retrofitting is to identify the most effective measures to address energy performance issues. This paper presents a machine learning model for optimizing retrofit measures to achieve NZEB under the influence of climate change. Specifically, the non-dominated sorting genetic algorithm (NSGA-III) minimizes energy consumption and the predicted percentage of dissatisfaction (PPD) while achieving a NZE balance, thereby obtaining the Pareto front. The Order of Preference by Similarity to Ideal Solution (TOPSIS) ranking technique is then applied to the Pareto front to obtain an optimal solution. Various passive energy retrofit measures are investigated, and renewable retrofit measures are employed to cover the required energy. This process is repeated for different time frames to consider the impact of climate change on selecting retrofit measures. The results clearly indicate that, for retrofitting a residential NZEB, higher insulation values are needed for future scenarios compared to the present scenario due to the effects of climate change. Using the future scenarios defined by the Shared Socioeconomic Pathways framework, a higher level of envelope insulation and renewable retrofit measures are required to achieve NZEB in the Sustainable Future scenario compared to the Fossil Fuel-dependent Future scenario, with increases of 35% and 50%, respectively.

Reviewing of the net-zero energy buildings and housings in Japan

Abstract The buildings and construction sectors play a pivotal role in combating climate change. Globally, they account for 30% of the final energy consumption and 27% of total energy sector CO2 emissions. Buildings currently consume up to 40% of the world’s total energy, and it is projected to increase to 50% by 2030. The world faces a significant challenge in addressing these issues related to global energy production. From the Paris Agreement in 2015 to the United Nations Climate Change Conference in Glasgow (COP26),Japan has committed to developing and implementing robust greenhouse gas (GHG) emission reduction measures using its resources. They have declared their intention to achieve carbon neutrality by 2050, improving the energy efficiency of structures. This involves measures such as regulating electricity usage, imposing restrictions on design specifications concerning the built environment and raw materials and promoting the use of sustainable energy sources to minimize the environmental impact of buildings. These efforts have given rise to the concept of net-zero energy buildings (ZEB) and net-zero energy housing (ZEH). This paper aims to provide a comprehensive review of ZEB/ZEH in a general context and to assess its feasibility and practicality within the specific context of Japan.

Achieving net zero energy penalty in post-combustion carbon capture through solar Energy: Parabolic trough and photovoltaic technologies

The adoption of carbon capture systems presents a pivotal strategy for mitigating greenhouse gas emissions, notably carbon dioxide. Nevertheless, the substantial surge in energy consumption associated with such systems remains a significant challenge. Addressing this challenge necessitates the integration of renewable energy sources. This study is dedicated to optimizing the conventional post-combustion carbon capture configuration, focusing on energy, exergy, and exergoeconomic considerations. The optimized configuration showcases a noteworthy 10 % reduction in overall energy penalties compared to its conventional counterpart, primarily attributed to diminished energy utilization in the reboiler. To achieve absolute sustainability and eliminate energy penalties in the optimized configuration, integration of a parabolic trough collector for steam provision to the reboiler and photovoltaic solar collectors for powering the plant’s equipment was undertaken. Furthermore, the incorporation of solar thermal storage tanks and batteries enables the storage of excess heat and electricity, ensuring operational continuity for up to 13 h in the absence of sunlight, such as during nighttime. The final optimized configuration manifests a commendable 14 % enhancement in exergoeconomic performance relative to the conventional configuration, thereby realizing zero energy penalties. This achievement renders the optimized configuration a compelling and viable choice for carbon capture units.

Large-scale energy storage for carbon neutrality: thermal energy storage for electrical vehicles

AbstractThermal Energy Storage (TES) systems are pivotal in advancing net-zero energy transitions, particularly in the energy sector, which is a major contributor to climate change due to carbon emissions. In electrical vehicles (EVs), TES systems enhance battery performance and regulate cabin temperatures, thus improving energy efficiency and extending vehicle range. The enhanced efficiency reduces overall energy consumption in EVs. Consequently, this reduction in energy demand can lead to decreased infrastructure needs, minimising the scale and investment required in energy production and distribution systems. Furthermore, the integration of TES with existing infrastructure allows for the simultaneous charging of thermal and electrical energy, leveraging waste heat or renewable energy sources. This not only cuts costs by optimizing resource use but also bolsters sustainability by minimising reliance on non-renewable energy sources. The widespread adoption of TES in EVs could transform these vehicles into nodes within large-scale, distributed energy storage systems, thus supporting smart grid operations and enhancing energy security. Strategic investments and regulatory updates are essential to realise a sustainable, carbon-neutral transportation future, underpinned by robust, cost-efficient infrastructure.

Energy management of residential buildings using innovative passive techniques

Abstract Recently, efforts on sustainability and energy savings in buildings have increased due to the growing global awareness of the energy use of buildings and the negative impacts of carbon dioxide emissions on climate change. As a result, it is critical to propose effective strategies to reduce such energy consumption. The goal of this project is to advance the idea of net-zero energy buildings as a worldwide mitigation method for climate change. Thus, a numerical model was developed and validated to investigate the passive cooling capabilities of an innovative phase change material (PCM)-based phase cube in residential buildings. The proposed phase cube includes six various PCM-compact storage module (PCM-CSM) configurations including Rubitherm’s SP-24E plates (Horizontal), Half Circular Inline, Half Circular Staggered, Vertical plates, Inline Cylindrical and Staggered Cylindrical compact storage modules. All the proposed designs were numerically simulated, and the obtained results were compared and analysed at an inlet air temperature and velocity of 35°C, and 4m/s, respectively and each phase cube contained the same mass of Rubitherm’s SP-24E PCM, which was 30.326 kg. The results showed that the Horizontal, Half Circular Inline and Vertical phase cubes can absorb heat at a higher rate from fresh air at nearly 496.19w, 465.9w and 458.16w, respectively translating the lowest outlet air temperature of about 25°C from the cube. Integrating such phase cubes into residential buildings for indoor passive air cooling substantially decreased the building cooling loads, resulting in reduced electric energy consumption by the air conditioning system.

Multi-objective optimization of energy demand and net zero energy building design based on climatic conditions (Case study: Iran)

Multi-objective optimization of energy demand and net zero energy building design based on climatic conditions (Case study: Iran)

Innovation Ecosystems and Green Building Techniques for a Sustainable Future: Leveraging Advanced Technologies

The global movement towards environmental stewardship and sustainability largely depends on innovation ecosystems, green building techniques, and sustainable development. This study explores their future potential, focusing on how advanced technologies, eco-friendly materials, and sustainable practices could mitigate climate change and enhance environmental quality. Innovation ecosystems are crucial for advancing green technology, circular economy principles, and sustainable urban design by fostering collaboration among corporations, governments, academic institutions, and civil society. The study also investigates how the effectiveness and impact of these ecosystems can be enhanced through digital transformation technologies such as blockchain, the Internet of Things (IoT), and artificial intelligence (AI). Employing green building techniques is essential for reducing a building’s environmental impact throughout its lifecycle. This study highlights recent advancements in green technology, including sophisticated building management systems, energy-efficient HVAC systems, improved insulation materials, and the integration of renewable energy sources. The establishment of sustainability standards and the promotion of environmentally friendly practices rely heavily on certifications like Leadership in Energy and Environmental Design (LEED) and the Building Research Establishment Environmental Assessment Method (BREEAM). The paper addresses the necessity of integrated solutions to balance environmental, social, and economic dimensions for sustainability. It also examines the role of regulations, the promotion of sustainable culture through public awareness and education, and innovative concepts such as net-zero energy buildings and biophilic design. By leveraging these advancements and concepts, we can pave the way for a more environmentally sensitive and sustainable future.

Cost-benefit analysis of implementing a solar powered water pumping system – A case study

Solar-powered water driving scheme (SPWDS) has been successfully employed as a practical solution to guarantee reliable water supply in various hilly regions without electrical infrastructure. The Water Supply Systems / Schemes (WSS) focus on using pumping systems for delivering potable water to the community but face practical difficulties and financial hurdles at different implementation stages. These challenges encompass the practical complexities, the absence of non-renewable energy sources, and ongoing expenses for consumable and non-consumable items incurred during the water project's execution and maintenance. The present research study evaluates the performance of four water supply systems in Nepal which use solar energy as their primary power source. The key performance indicators are assessed, including the functionality index for facility distribution. Additionally, the research aims to evaluate the feasibility of transitioning from non-renewable to sustainable renewable energy source to achieve net zero energy consumption. This evaluation concentrates explicitly on calculating the cost-effectiveness index as a key metric. A proportional analysis is undertaken to evaluate the cost-benefit of the SPWDS, considering both the potential advantages and challenges associated with these initiatives. The present study affirms the technical feasibility and economic viability of operating a WSS using renewable and eco-friendly solar energy as the power source. This finding opens avenues for reducing energy consumption and contributes significantly to developing a policy framework to for tapping solar energy.

VOC emission rates from an indoor surface using a flux chamber and PTR-MS

Arising from the Chemical Assessment of Surfaces and Air (CASA) 2022 study at the National Institute of Standards and Technology (NIST) Net-Zero Energy Residential Test Facility (NZERTF), this paper presents the first evaluation of indoor surface emissions to a house measured with a surface flux chamber coupled to an online, non-targeted volatile organic compound (VOC) mass spectrometric detection. These surface emissions are compared to those assessed using ambient, whole house indoor VOC measurements and the outdoor air change rate. Chamber emission rates varied by almost four orders of magnitude across 35 quantified VOCs. The whole house emissions measured by campaign-long ambient measurements and the flux chamber emissions (when scaled to the painted surface area of the house) are similar, with an average ratio between the two of 1.3 ± 1.0. The general agreement between these two approaches indicates that the flux chamber was not solely measuring primary emissions from building materials located below the chamber. Rather, the results suggest that over the 12-year house lifetime, VOCs have been widely distributed around the house, migrating from their primary sources to secondary surface reservoirs. With the house in a quasi-steady state, the thermodynamic activities (i.e., the vapor pressures) of the VOCs within the different reservoirs become similar. Emissions of aromatics and monoterpenes have declined since the house was built, whereas aldehyde emissions have remained relatively constant.

Exploring the Opportunities and Gaps in the Transformation of Modern Rural Housing in Southern China to Net Zero Energy Buildings

This study explores modern residential buildings in rural areas of Wuhan and Guangzhou to assess the feasibility of achieving net zero energy buildings (NZEBs) through the transformation of existing buildings in southern China’s hot-summer–cold-winter and hot-summer–warm-winter regions. Energy simulations under various climatic scenarios identify effective energy-saving measures, such as the use of photovoltaic power generation. The results highlight substantial renovation potential, with energy reductions of approximately 85 kWh/m² (RCP2.6), 90 kWh/m² (RCP4.5), and 115 kWh/m² (RCP8.5). Living patterns significantly influence energy use, especially in buildings with more rooms, where the gaps in the energy demand with net zero standards can reach 560.56 kWh. At the monthly scale, different climate scenarios impact the feasibility of achieving NZEBs, particularly under RCP8.5, where eight rural housing types fail to meet the requirements, with six exceeding 200 kWh energy deficits and the largest energy deficit occurs in June 2090 in Guangzhou, reaching 592.53 kWh, while under RCP2.6, only two buildings with more rooms fail to meet NZE. In summary, in the hot-summer cold-winter region, the energy demand is higher but so is the solar yield. Therefore, under the most adverse RCP8.5 scenario, NZEBs are achievable for 9 months of the year, which is 2 months more compared to Guangzhou under similar conditions. Even after net zero transformation, new rural housing will face greater energy-saving challenges in future climatic conditions, especially under higher concentration pathways.