• Energy Research
• 11. Sustainability close

Exporting generated electricity by on-site renewable energy systems from buildings to the grid is only slightly profitable in many countries. Therefore, it is required to investigate the benefits of sharing generated energy in a microgrid within a community of buildings. Exploiting the benefits of peer-to-peer energy exchange between prosumers in a community can make the best use of the on-site generation while reducing their bills. This study elaborates the potential of energy management to minimize the electricity cost of a community consisted of multiple buildings and connected to a microgrid. To implement this, an energy management system is designed based on non-linear economic model predictive control and successive linear programming for sharing the on-site surplus generated electricity between the buildings in the community. Four buildings are simulated and studied as an example of a small community. These buildings are dissimilar in their age, thermal mass, insulation, heating system and on-site renewable energy systems. It is shown that considering the community of buildings as a single entity, the novel model predictive control can be efficiently used for minimizing the energy cost of the community that has various sources of energy generation, conversion and storage, including significant non-linear interactions. Three different scenarios of the energy management system for the studied community are investigated, and the results indicate that the annual electricity energy cost for single buildings can be reduced by 3.0% to 87.9%, depending on the building and its systems, and by 5.4% to 7.7% on the community level.

Residents’ willingness to use green energy products is a major concern for different stakeholders and policymakers due to the reformed Chinese electricity market since 2015. This study focused on the Chinese consumer’s willingness to opt and pay for environmentally-friendly electricity sources in Shanghai’s residential sector. A questionnaire survey was used to find out the influence of gender, age, education, awareness and income level on consumers’ attitudes to alter their energy sources to green ones. The results indicated that income level and awareness are significant barriers in the usage of green energy products. Increasing the respondent’s awareness about the issues of non-green energy products convinced 97% of them to change their electricity sources completely or partly, in line with their monthly income. This clearly shows that clarifying the benefits of green energy products is a key tool to achieve a green environment in China.

This study investigates Smart Grid Optimised Buildings (SGOBs) which can respond to real-time electricity prices by utilising battery storage systems (BSS). Different building design characteristics are assessed to evaluate the impact on energy use, the interaction with the battery, and potential for peak load shifting. Two extreme cases based on minimum and maximum annual energy consumption were selected for further investigation to assess their capability of utilising BSS to perform arbitrage, under real-time pricing. Three operational dispatch strategies were modelled to allow buildings to provide such services. The most energy-efficient building was capable of shifting a higher percentage of its peak loads and export more electricity, when this is allowed. When using the biggest battery (220 kWh) to only meet the building loads, the energy-efficient building was able to shift 39.68% of its original peak loads in comparison to the 33.95% of the least efficient building. With exports allowed, the shifting percentages went down to 31.76% and 29.46%, respectively, while exports of 18.08 and 16.34 kWh/m2 took place. The formation of a regulatory framework is vital in order to establish proper motives for buildings to undertake an active role in the smart grid.

Buildings are one of the largest contributors to energy consumption and greenhouse gas emissions (GHG) in the world. There is an increased interest in building performance evaluation as an essential practice to design a sustainable building. Building performance is influenced by various terms, for example, designs, construction-related factors such as building envelope and airtightness, and energy technologies with or without micro-generations. How well a building performs thermally is key to determining the level of energy demand and GHG emissions. Building standards and regulations, in combination with assessments (e.g., energy modeling tools) and certifications, provide sets of supports, guidelines and instructions for designers and building engineers to ensure users’ health and well-being, consistency in construction practices and environmental protection. This paper reviews, evaluates and suggests a sequence of building performance methods from the UK perspective. It shows the relationships between such methods, their evolutions and related tools, and further highlights the importance of post-occupancy analysis and how crucial such assessments could be for efficient buildings.

To reach net-zero emissions by 2050, buildings in the UK need to replace natural gas boilers with heat pumps and district heating. These technologies are efficient at reduced flow/return temperatures, typically 55/25 °C, while traditional heating systems are designed for 82/71 °C, and an oversized heating system can help this temperature transition. This paper reviews how heating systems have been sized over time in the UK and the degree of oversizing in existing buildings. It also reviews if lessons from other countries can be applied to the UK’s building stock. The results show that methods to size a heating system have not changed over time, but the modern level of comfort, the retrofit history of buildings and the use of margin lead to the heating system being generally oversized. It is not possible to identify a specific trend by age, use or archetype. Buildings in Scandinavia have a nascent readiness for low-temperature heat as they can use it for most of the year without retrofit. Limitations come primarily from the faults and malfunctions of such systems. In the UK, it is estimated that 10% of domestic buildings would be ready for a supply temperature of 55 °C during extreme external conditions and more buildings at part-load operation. Lessons from Scandinavia should be considered with caution. The building stock in the UK generally underperforms compared to other EU buildings, with heating systems in the UK operating at higher temperatures and with night set-back; the importance of providing a low-return temperature does not exist in the UK despite being beneficial for condensing boiler operation. Sweden and Denmark started to develop district heating technologies with limitations to supply temperatures some 40 years ago whereas the UK is only just starting to consider similar measures in 2021. Recommendations for policy makers in this context have been drawn from this review in the conclusions.

Energy consumption in cooling the buildings and occupant’s thermal comfort is significant, and any techniques to reduce this can bring great benefits, both locally in terms of reducing the need for expensive infrastructure and globally in terms of reduced carbon emissions. This study focuses on Northern Iraq, Kurdistan. This area suffers from a shortage of electricity production, alongside a high and growing demand due to the rapid expansion in the residential building sector over the last few decades through investment projects. The cooling energy performance of a typical house in Kurdistan was simulated, using DesignBuilder and EnergyPlus software. The study identified the most effective parameters of the building fabrications to be applied for enhancing the energy performance of residential buildings such as insulation, suspended ceiling, window glazing, overhang, and block type. The study found the parameters with the most impact on energy consumption to be suspended ceiling and insulation that could save a high rate of energy consumption. The impact of the clear double glazing and overhang of the windows are generally low, due to the low window/wall ratio and the availability of the internal curtain in the building. Finally, the optimum parameter values are identified and used in energy demand simulations, it showed that by using the optimum parameters of the building fabrications, 28.35% of the annual energy used could be saved from cooling in the house module.

The Energy Management System (EMS) is an efficient technique to monitor, control and enhance the building performance. In the state-of-the-art, building performance analysis is separated into building simulation and control management: this may cause inaccuracies and extra operating time. Thus, a coherent framework to integrate building physics with various energy technologies and energy control management methods is highly required. This framework should be formed by simplified but accurate models of building physics and building energy technologies, and should allow for the selection of proper control strategies according to the control objectives and scenarios. Therefore, this paper reviews the fundamental mathematical modeling and control strategies to create such a framework. The mathematical models of (i) building physics and (ii) popular building energy technologies (renewable energy systems, common heating and cooling energy systems and energy distribution systems) are first presented. Then, it is shown how the collected mathematical models can be linked. Merging with two frequently used EMS strategies, namely rule-based and model predictive controls, is discussed. This work provides an extendable map to model and control buildings and intends to be a foundation for building researchers, designers and engineers.