Assessing the Energy Renovation Impact on Public Building Performance: A Case Study of The Faculty of Natural Sciences and Mathematics in Banja Luka

Decomposing final energy use for heating in the residential sector in Austria

The industrial sector accounts for about 30% of the global final energy use and accounts for about 115 EJ of final energy use in 2005. 1Cement, iron and steel, chemicals, pulp and paper and aluminum are key energy intensive materials that account for more than half the global industrial use. There is a shift in the primary materials production with developing countries accounting for the majority of the production capacity. China and India have high growth rates in the production of energy intensive materials like cement, fertilizers and steel (12–20%/yr). In different economies materials demand is seen to grow initially with income and then stabilize. For instance in industrialized countries consumption of steel seems to saturate at about 500 kg/capita and 400–500 kg/capita for cement. The aggregate energy intensities in the industrial sectors in different countries have shown steady declines – due to an improvement in energy efficiency and a change in the structure of the industrial output. As an example for the EU-27 the final energy use by industry has remained almost constant (13.4 EJ) at 1990 levels. Structural changes in the economies explain 30% of the reduction in energy intensity with the remaining due to energy efficiency improvements. In different industrial sectors adopting the best achievable technology can result in a saving of 10–30% below the current average. An analysis of cost cutting measures for motors and steam systems in 2005 indicates energy savings potentials of 2.2 EJ for motors and 3.3 EJ for steam. The payback period for these measures range from less than 9 months to 4 years. A systematic analysis of materials and energy flows indicates significant potential for process integration, heat pumps and cogeneration for example savings of 30% are seen in kraft, sulfite, dairy, chocolate, ammonia, and vinyl chloride. An exergy analysis (second law of thermodynamics) reveals that the overall global industry efficiency is only 30%. It is clear that there are major energy efficiency improvements possible through research and development (R&D) in next generation processes. A comparison of energy management policies in different countries and a summary of country experiences, program impacts for Brazil, China, India, South Africa shows the features of successful policies. Energy management International Organization for Standardization (ISO) standards are likely to be effective in facilitating industrial end use efficiency. The effective use of demand side management can be facilitated by combination of mandated measures and market strategies. A frozen efficiency scenario is constructed for industry in 2030. This implies a demand of final energy of 225 EJ in 2030. This involves an increase of the industrial energy output (in terms of Manufacturing Value Added (MVA)) by 95% over its 2005 value. Due to normal efficiency improvements the Business as Usual scenario results in a final energy demand of 175 EJ. The savings possibilities in motors and steam systems, process improvements, pinch, heat pumping and cogeneration have been computed for the existing industrial stock and for the new industries. An energy efficient scenario for 2030 has been constructed with a 95% increase in the industrial output with only a 17% increase in the final energy demand (total final energy demand for industry (135 EJ)). The total direct and indirect carbon dioxide emissions from the industry sector in 2005 is about 9.9 GtCO 2 . Assuming a constant carbon intensity of energy use, the business as usual scenario results in carbon dioxide (CO 2 ) emissions increasing to 17.8 GtCO 2 annually in 2030. In the energy efficient scenario this reduces to 11.6 GtCO 2 . Renewables account for 9% of the final energy of industry (10 EJ in 2005). If an aggressive renewables strategy resulting in an increase in renewable energy supply to 23% in 2030 is targeted (23 EJ), it is possible to have a scenario of constant greenhouse gas (GHG) emissions by the industrial sector (at 2005 levels) with a 95% increase in the industrial output. Several interventions will be required to achieve the energy efficient or constant GHG emission scenario. For the existing industry measures include developing capacity for systems assessment for motors, steam systems and pinch analysis, sharing and documentation of best practices, benchmarks and roadmaps for different industry segments, access to low interest finance etc. A new energy management standard has been developed by ISO for energy management in companies. Its adoption will enable industries to systematically monitor and track energy efficiency improvements. In order to level the playing field for energy efficiency a paradigm shift is required with the focus on energy services not on energy supply per se. This requires a re-orientation of energy supply, distribution companies and energy equipment manufacturing companies. Planning for next generation processes and systems needs the development of long term research agenda and strategic collaborations between industry, academic and research institutions and governments.

Final energy use in IEA countries: The role of energy efficiency

Evaluation of energy use for heating in residential building under the influence of air exchange modes

Energy efficiency improvement is an effective way of reducing energy demand and CO2 emissions. Although the overall final energy savings potential in chemical industry has been estimated in a few countries, energy efficiency potentials by concrete measures applicable in the sector have been scarcely explored and their associated costs are hardly analyzed. In Switzerland, the production of chemicals and pharmaceuticals exceeds all other industrial sectors in terms of energy use and CO2 emissions, and it accounted for 22% of the total industry's overall final energy demand and 25% of the CO2 emissions related to non-renewable energy sources in 2016. In this study, the economic potentials for energy efficiency improvement and CO2 emissions reduction in the Swiss chemical and pharmaceutical industry are investigated in the form of energy efficiency cost curves. The economic potential for final energy savings and CO2 abatement based on energy-relevant investments is estimated at 15% and 22% of the sector's final energy use and fossil fuel-related CO2 emissions in 2016, respectively. Measures related to process heat integration are expected to play a key role for final energy savings. The economic electricity savings potential by improving motor systems is estimated at 15% of the electricity demand by these systems in 2016. The size of economic potential of energy efficiency improvement across the sector decreases from 15% to 11% for 0.5 times lower final energy prices while the size increases insignificantly for 1.5 times higher final energy prices. The additional power generation potential based on Combined Heat and Power plants is estimated at 14 MW for 2016. This study is a contribution to the so far limited international literature on economic energy efficiency measures applicable in this heterogeneous sector and can support policy development. The results for specific costs of energy efficiency measures can also be adapted to other parts of the world by making suitable adjustments which in return may provide useful insights for decision makers to invest in economically viable clean energy solutions.

Long-term energy efficiency analysis requires solid energy statistics: The case of the German basic chemical industry

In Flanders, an obligatory software tool (EPR) is used to assess the energy performance of new buildings offering a simplified procedure to estimate the energy use for heating. This calculation approach is based on the principle of multiplying the building’s heating demand with standardised (sub)system efficiencies. In this paper, the accuracy of this simplified approach is assessed for a traditional, hydronic heating system in non-residential buildings. To do so, integrated dynamic simulations are performed in TRNSYS for a series of building design variants with varying insulation quality, thermal capacity, window-to-wall ratio and orientation. From the integrated simulations, monthly subsystem efficiencies are deduced. Results show that the efficiencies are significantly influenced by the part load ratio. As however losses of efficiencies are noticed only in periods of low heat demands, the overall effect on the annual use is limited. Energy assessment by the simplified method is within an error of <2.5 kWh/(m2·a) or <10%. Therefore, the simplified approach as currently applied in the EPR calculation tool in Flanders is concluded to be suited for the calculation of the final energy use. An evaluation of tabulated values for the overall system efficiencies used in this simplified method is however recommended.

A wider deployment of nearly zero energy buildings (NZEBs) is expected to contribute to the transition to a decarbonized and energy-efficient building sector in Europe. This study proposed an integrated energy-economic analysis to exemplify the feasibility of NZEB renovation in temperate climate. A parametric analysis was performed to identify technical building system configurations that give minimum share of renewable energy systems contributing to NZEB level. Final energy savings, global costs and cost-effectiveness of renovating a building to NZEB level are analysed, considering active and passive energy efficiency measures (EEMs). The active EEMs included efficient water taps and heat recovery ventilation, and the passive EEMs encompassed insulations to roof, exterior walls and ground floor, and improvements of windows and doors. The building had initial final energy use of 133 kWh/m2 year for space heating, domestic hot water production (DHW) and facility electricity. The results show that NZEB level is achieved with active and passive EEMs, without renewable energy systems for scenarios with low discount rates and high future energy price escalations. The annual final energy use for space heating, DHW and facility electricity is reduced cost-effectively by 37-54%. Furthermore, increasing size of PV-system enhanced cost-effectiveness by lowering total global costs.

Bottom-up analysis of energy efficiency improvement and CO2 emission reduction potentials in the Swiss cement industry

This paper models the energy and emissions scenarios for a circular economy based clean energy transitions in a 140,000-population town in China, taking into account the new situation encountered by the COVID-19 pandemic. The modelled scenarios propose new clean energy transition roadmaps towards a sustainable urban system through the implementation of circular economy strategies. This is represented by the cascading use of industrial excess heat to form symbiosis between factories and to cover the growing building heat demand, as well as by the electrification of the transport sector and reusing the batteries for a second life as energy storage devices. The results show that for a circular economy scenario, during 2020–2040, an accumulated saving of 7.1 Mtoe final energy use (34%), a decline in 14.5 Mt CO2 emissions (40%) and 592 t PM2.5 emissions (43%) could be achieved compared with the business-as-usual scenario. The outcomes of the circular economy strategies are at least 7% better than the new policy scenario which simply has energy efficiency improvements. The outbreak of the COVID-19 tremendously impacts the socio-economic activities in the town. If taking the pandemic as an opportunity to enhance the circular economy, by 2040, compared with the scenario without introducing circular economy measures, the extra avoided final energy use, CO2 emissions and PM2.5 emissions could be 1.6 Mtoe (8%), 3.8 Mt (11%) and 229 t (17%) respectively.

According to the initiative "The Covenant of Mayors for Climate and Energy (CoM)" and within the framework of the EU-funded "Positive Energy Areas Project", the Municipality of Vidin should establish a "Sustainable Energy and Climate Action Plan". The city's sustainable energy development plans aim to reduce CO2 emissions by 40% up to 2030 and develop a comprehensive climate change adaptation strategy at the local level or integrate it into existing plans. The initiative envisages actions both for mitigating climate change and also for climate adaptation at the local level. This paper presents the results of the first part of the process for establishing the "Sustainable Energy and Action Plan of the Municipality of Vidin", including the assessment and calculation of the final energy use in the city by the different sectors. The research aims to present the main data sources necessary for СО2 emissions inventory at the city level and to process, validate, and analyze used statistical data for defining the final energy use by different sectors in one Bulgarian municipality. The purpose of this assessment is to determine final energy use by different sectors and by types of energy sources. The results from the analysis and evaluation of the final energy use in the sectors "Residential buildings", "Municipal buildings", "Industry", "Tertiary buildings", "Public lighting" and "Transport" will serve to conduct a baseline of CO2 emissions inventory, which is a part of the “Sustainable Energy and Climate Action Plan”. These results also could help the local authorities and key energy players to identify and implement the most suitable measures and actions for climate change adaptation and mitigation.

Cost-optimum analysis of building fabric renovation in a Swedish multi-story residential building

Interaction between building design, management, household and individual factors in relation to energy use for space heating in apartment buildings

As the world deals with the impacts of excessive energy use on climate change and sustainable development, the demand for energy-efficient solutions is rising. This thesis investigates Reinforcement Learning (RL)-based control strategies for collective heating systems, focusing on reducing energy use for Space Heating (SH) and Domestic Hot Water (DHW) while maintaining occupant thermal comfort. The goal is to develop adaptive, energy-efficient control approaches for residential collective heating systems. Heating accounts for 78% of final energy use in European households. In Belgium, achieving the ambitious target of a 46% reduction in GHG emissions by 2030 compared to 2005 levels requires significant improvements in heating system efficiency. Deploying low-temperature emitters in new and renovated dwellings and implementing collective heating systems offer promising pathways for decarbonizing thermal energy supply. However, the increasing complexity of these systems poses challenges for optimal control, which is crucial for maximizing energy efficiency. Advanced control techniques such as MPC and RL have gained prominence in building energy systems. While MPC relies on solving complex optimization problems at each control step, which makes it computationally intensive for large-scale systems, RL offers more adaptability and computational efficiency after training, making it a suitable choice for collective heating systems. Despite its potential, RL faces challenges related to scalability, adaptability, and privacy. This thesis addresses these challenges through the development of energy-efficient, adaptive control strategies for collective heating systems, with a focus on scalability and privacy-aware implementation. The research is presented through five papers, organized into three chapters: Chapter 3 explores RL-based control performance in real-world settings. In the absence of a collective heating system testbed, a single-dwelling case study using a heat pump as the heat production unit is utilized to assess RL’s ability to improve energy efficiency and occupant comfort under dynamic conditions. Chapter 4 focuses on centralized control using single-agent RL. As the scope ex pands from single dwellings to multiple dwellings in collective heating systems, RL agents must manage increased complexity, balancing energy and cost reduction with thermal comfort across multiple dwellings. The effectiveness of centralized RL in handling SH and/or DHW control is a key area of investigation. Chapter 5 addresses the challenge of scalable, distributed control in collective heat ing systems. The goal is to maintain the autonomy of individual dwellings while ensuring overall energy efficiency. This involves navigating issues of privacy-aware control, coordination, and conflicting objectives among distributed RL agents.

Global sensitivity analysis as a support for the generation of simplified building stock energy models