A city scale physically disaggregated bottom-up energy model: technical options for decarbonising Belgrade residential stock

The residential stock is one of the key consumers of energy and hence is important in the drive to reduce both national and global CO2 emissions. A comprehensive domestic stock energy and carbon model is seen as a useful tool to provide policymakers with estimates for the effectiveness of policies and can help to identify the most beneficial technological measures. This thesis describes the development of the first domestic energy and carbon model in Serbia which has been used to investigate the technological feasibility of achieving space heating energy consumption and associated CO2 emission reductions within Belgrade’s housing stock by 2030. BElgrade’s Domestic and Energy and carbon Model combines external and on-site generated data, the whole building dynamic energy simulation software ‘TRNSYS’, and a generic optimisation program called ‘GenOpt’. Whilst this model is primarily demand side orientated, it also considers changes in energy efficiency on the supply side. The BEDEM model has been used to develop five probabilistic explorative scenarios, namely: a ‘Base Model’, a ‘Demand 1’, a ‘Demand 2’, a ‘Supply’, and a ‘Demand 2 and Supply’ scenario. The overall results suggest that the largest domestic space heating energy reductions could be achieved by combining the energy-efficiency performance upgrade of dwelling fabrics and district heating system seasonal efficiency improvement. Yet, in the shorter-term, the improvement of the district heating system’s seasonal efficiency is the most beneficial measure. While the model is of considerable value as a policy tool, the results of uncertainty analyses revealed that a lack of knowledge of just a few key input parameters generate rather large uncertainty in the model predictions. Therefore, for any recommendations based on model predictions to be of use in policy formation, the models need to be validated against existing data and uncertainties within the model investigated thoroughly and, where possible, quantified

Comparison of the thermal comfort and air quality in two Belgrade theatres with different mechanical ventilation systems

Using a newly refurbished Belgrade theatres, Belgrade Drama Theatre and Terazije Theatre, this study investigates weather two different mechanical ventilation systems are able to provide adequate thermal comfort and air quality and which one of them performs more satisfactory. In order to achieve the given objectives the four faze work was carried out. The first was the analysis of different ventilation strategies implemented in the theatres using the 'as installed' engineering drawings. Next step was the continuous monitoring of the following parameters such as: carbon dioxide levels (indoor and outdoor), air temperature, relative humidity, air velocity, and heat flux through the walls. Third was a detailed occupant survey. Finally, a detailed three dimensional CFD modeling of one of the theatres (Terazije Theatre) was carried out. It was find out that the measured air temperatures, air velocities , relative humidity and carbon dioxide concentration (C02) ware within the limits of thermal comfort standards, although temperature and C02 concentration were located at the extreme of the limits. Furthermore, the predicted results of Terazije Theatre showed good distribution of airflow characteristics and temperature gradients. Moreover, these were in agreement with the empirical measurements. In addition, recommendations were made to improve the thermal comfort, air quality and reduce the build-up of C02 concentration in the investigated theatres

Analysis of thermal comfort and indoor air quality in a mechanically ventilated theatre

Theatres are the most complex of all auditorium structures environmentally. They usually have high heat loads, which are of a transient nature as audiences come and go, and from lighting which changes from scene to scene, and they generally have full or nearly full occupancy. Theatres also need to perform well acoustically, both for the spoken word and for music, and as sound amplification is less used than in other auditoria, background noise control is critically important. All these factors place constraints on the ventilation design, and if this is poor, it can lead to the deterioration of indoor air quality and thermal comfort. To analyse the level of indoor air quality and thermal comfort in a typical medium-sized mechanically ventilated theatre, and to identify where improvements could typically be made, a comprehensive post-occupancy evaluation study was carried out on a theatre in Belgrade. The evaluation, based on the results of monitoring (temperature, relative humidity, CO2, air speed and heat flux) and modelling (CFD), as well as the assessment of comfort and health as perceived by occupants, has shown that for most of the monitored period the environmental parameters were within the standard limits of thermal comfort and IAQ. However, two important issues were identified, which should be borne in mind by theatre designers in the future. First, the calculated ventilation rates showed that the theatre was over-ventilated, which will have serious consequences for its energy consumption, and secondly, the displacement ventilation arrangement employed led to higher than expected complaints of cold discomfort, probably due to cold draughts around the occupants feet. (C) 2007 Elsevier B.V. All rights reserved

Application of a Monte Carlo model to predict space heating energy use of Belgrades housing stock

Detailed domestic stock energy models can be used to help formulate optimum energy reduction strategies. However, there will always be considerable uncertainty related to their predictions due to the complexity of the housing stock and the many assumptions required to implement the models. This paper presents a simple Monte Carlo (MC) model that can be easily extended and/or transformed in relation to data available for investigating and quantifying uncertainties in both the housing stock models predictions and scenario assumptions. While 90% of the MC model predictions fell within a range which is +/- 19% the mean value, 50% of them were within +/- 8% of the mean. The findings suggest that the uncertainties associated with the model predictions and scenario assumptions need to be acknowledged fully and - where possible - quantified as even fairly small variability in the influential variables may result in rather large uncertainty in the aggregated models prediction

Characteristics of indoor temperatures over winter for Belgrade urban dwellings: Indications of thermal comfort and space heating energy demand

A lack of empirical data for residential indoor temperature has important implications for policy-makers in terms of energy performance objectives and the use of energy demand models for the building stock. This study investigates winter indoor temperatures, relative humidity and vapour pressure excess in 2009-2010 across various types and ages of buildings using half-hourly monitoring of 96 dwellings representative of residential buildings in Belgrade, including those with district heating (DH) with no direct occupant control in which heating is charged on a floor area basis. The average daily living room temperature of 22.8 degrees C (95%CI: 21.9-22.7) in DH dwellings was 2.3 degrees C higher than those with other heating types, including individual central heating (ICH) and non-central heating (non-CH), daily bedroom temperature of 22.3 degrees C (95%CI: 21.9-22.7) was 3.0 degrees C higher. Evening living room and night bedroom temperatures in ICH dwellings were 22% and 37% of the time respectively below 18 degrees C, and 10% and 27% of the time respectively in non-CH dwellings. The high degree of overheating in DH dwellings indicates the considerable potential to reduce energy consumption, if user controls and heating bills reflected household consumption were introduced. (C) 2012 Elsevier B.V. All rights reserved

Energy Pathways for Future Residential Building Areas in Norway

Due to stricter building energy requirements, future buildings will be characterized with low base loads and occasional high peaks. However, future building areas will still contain existing and historical buildings with high energy use. Additionally, there is a requirement that future building areas have to get energy from renewable energy sources, while existing buildings need to make transition to the renewables. The aim was to analyze different energy systems and technologies that can help to reduce CO2 emissions in the future building areas in Norway. In this study, different methods were combined: detailed building simulation, energy supply technology simulation, heat demand aggregation, and data post-processing. The results showed that the energy pathways would be very dependent on the CO2-factors for the energy sources and it is hard to tell which CO2-factor is correct. An increasing housing stock development would slightly increase the CO2 emission towards 2050, even though the new buildings used half the energy than the existing buildings and the existing buildings undergone energy efficiency improvements. A constant housing stock would decrease the CO2 emission by around 22–27% depending on energy supply systems. The results showed that the influence of implementing stricter building codes had a lower impact on the total CO2 emissions, compared to the influence of the CO2-factors and energy supply technologies. Regarding the existing buildings, the requirements such as: limited use of direct electric heating, requirements on the service systems, and definition on hot tap water use should be emphasized

Multi-agent Architecture of a MIBES for Smart Energy Management

International audienc

Statistical modelling of district-level residential electricity use in NSW, Australia

Electricity network investment and asset management require accurate estimation of future demand in energy consumption within specified service areas. For this purpose, simple models are typically developed to predict future trends in electricity consumption using various methods and assumptions. This paper presents a statistical model to predict electricity consumption in the residential sector at the Census Collection District (CCD) level over the state of New South Wales, Australia, based on spatial building and household characteristics. Residential household demographic and building data from the Australian Bureau of Statistics (ABS) and actual electricity consumption data from electricity companies are merged for 74 % of the 12,000 CCDs in the state. Eighty percent of the merged dataset is randomly set aside to establish the model using regression analysis, and the remaining 20 % is used to independently test the accuracy of model prediction against actual consumption. In 90 % of the cases, the predicted consumption is shown to be within 5 kWh per dwelling per day from actual values, with an overall state accuracy of -1.15 %. Given a future scenario with a shift in climate zone and a growth in population, the model is used to identify the geographical or service areas that are most likely to have increased electricity consumption. Such geographical representation can be of great benefit when assessing alternatives to the centralised generation of energy; having such a model gives a quantifiable method to selecting the 'most' appropriate system when a review or upgrade of the network infrastructure is required