Matteo Manganelli

Design of a fuzzy-based control system for energy saving and users comfort

Building automation systems (BAS) allow automated control of equipment and eventually control of indoor conditions. Indeed, BAS are becoming a powerful tool to improve the energy performance and occupant comfort, introducing the concept of “intelligent building”. At this regard, there is a need to build a knowledge base and to develop suitable algorithms for a smart management. Fuzzy logic is a valuable candidate for building robust algorithms. The aim of the present work is to demonstrate that a fuzzy logic approach is able to optimize the level of energy performance and comfort taking advantage of solar energy and BAS in an office space. In fact, solar energy can be used in the form of daylight and solar heat gain, benefiting both energy performance and psychophysical comfort, provided that dynamic façade elements and integrated multi criteria decision making methods are used. In this paper has been developed a virtual model of a smart office room (SOR), equipped with dynamic shading, lighting and air conditioning control system. Different scenarios were considered as follows: i) control versus no-control; ii) economy versus comfort mode; iii) summer versus winter scenario; iv) fluorescent versus LED lighting; v) dimming versus switching lighting control. The configured control model makes comfort mode energy performance similar to that of economy mode, thus demonstrating that the use of solar energy and BAS benefits energy saving and comfort as well. In addition, both economy comfort mode exhibited a better energy performance than non-controlled scenarios. In conclusion, the proposed model is a valuable tool to optimize comfort features and yet decreasing the energy demand.

Demand Side Management in Microgrids for Load Control in Nearly Zero Energy Buildings

The paper presents a feasible model of architecture for the technical building systems (TBS) particularly suitable for nearly zero energy buildings (NZEBs). The suggested model aggregates the users around an electric node in order to reach up the threshold value of electric power, and to get a more virtuous and flexible cumulative load profile. Present proposal is a full electric common smart micro grid with a single point of connection, with heating and domestic hot water generated by a centralized electric heat pump system. The renewable energy is provided by a photovoltaic field connected to the common grid. A building automation control system operates those electric TBS modulating the global load for a building demand response (DR). The effectiveness of the proposed model consists of exploiting thermal inertia as an energy storage, by forcing both local and central set points of heating and air conditioning systems. The control is based on the integrated and common operation of all users and all systems of the building as one unique “large user.” The integrated management of the grid is operated to control the whole electric demand exploiting the self-consumption, avoiding peaks, and maintaining a flat load profile. The suggested microgrid model allows concretely the possibility to realize a building DR with benefits for the end-users in a consumer view point. A study of the effect of these control opportunities on whole electric demand is done by simulation on a case study.

Net metering benefits for residential buildings: A case study in Italy

Contrary to expectations, the development of smart (mini) grids is slow. Due to drastic improvements in innovative technologies, the reasons are not strictly technical but the problem mainly lies in regulatory barriers. The current business models are centric to utilities rather than customers. Net metering is a key enabling factor for smart (mini) grids. This paper addresses the economic benefits of net metering for individual residential customers. Energy demand for the individual apartments and common areas is calculated using the daily energy consumption behavior of occupants for typical days of each month of the year. Photovoltaic generation is estimated via PVGIS for a residential building in Italy. The proposed net metering scheme is applied on the aggregate energy demand of selected building without any modification in the current energy billing and net metering tariffs. Results show the noticeable difference in the savings of individual apartments.

Smart micro grids for Nearly Zero Energy Buildings

The paper presents a feasible model of architecture for the technical building systems (TBS) particularly suitable for Nearly Zero Energy Buildings (NZEBs). NZEBs are buildings where the energetic consumption are optimized by means of solutions that drastically reduce both electric and thermal demand, while residual required energy has to be provided by local renewable generation. The suggested model aggregates the users around an electric node in a common microgrid in order to reach up the threshold value of electric power and to get a more virtuous and flexible cumulative load profile. The building (or a group of buildings) represents the natural limit of the aggregation of the electric systems, like in the heating systems. Present proposal is a full electric smart micro grid with heating and domestic hot water generated by a centralized electric heat pump system. The renewable energy is provided by a photovoltaic field. The authors suggest to control the whole electric demand of the building by exploiting its thermal inertia as an energy storage by forcing both local and central set points of heating and air conditioning systems and time shifting opportunities of smart appliances. A case study is presented.

Small scale ESS for LV prosumers: An economic feasibility and sensitivity analysis

In a framework of fast evolving power systems in terms of structure and operation, the implementation of energy storage systems (ESSs) is a key element. The aim of the present work is to identify economic conditions for the effective application of ESSs for LV residential prosumers, i.e. consumers with local power generation. An economic feasibility and sensitivity analysis is performed. Three cases are considered, basing on current Italian incentive policy. Each case study is analyzed in two conditions in reference to the derating and replacement of ESS. The comparison of the two conditions gives a measure of the impact of technology on economic effectiveness of its application. Another analysis is reported, based on introduction of support policies as the German ones. Results show that implementation of a residential ESS could be advantageous in case of introduction of suitable support policies or decreasing ESS costs.

Smart distribution grids: New solutions for system operation in emergency conditions

A notable spread of Dispersed Generation (DG) power plants, connected at Medium Voltage (MV) distribution grids, takes place in the Italian power system, with a big impact on the operation, both in normal and in emergency conditions, especially during transients determining frequency variations. Enel Distribuzione, the biggest Distribution System Operator (DSO) in Italy, proposed to install some special devices, on its distribution grid, to improve the effectiveness of management of DG and loads, during frequency transients in automatic way. The paper describes the solution proposed by Enel Distribuzione, that gives the possibility to better manage the DG and loads connected in MV in favor of the whole power system in presence of frequency transients, as the Italian Transmission System Operator (TSO) with its Defense Plan (DP) requires. Some numerical results for demonstrating the need and effectiveness of the application of the proposed solution in the real operation of the system are reported.

Classification of smart metering systems for zero-energy buildings

A zero-energy building can be defined as a building with almost zero net energy consumption. This means that the total amount of energy spent in the building in a year is approximately equal to the amount of energy generated on the site by renewables or cogeneration. A smart meter system is very important for these buildings in order to manage and control the energy flows. In fact, the smart meter system monitors, supervises, visualizes and stores the energy generated and the energy consumption in the building providing the information to the users. Typically, it consists in a complex architecture with a central server with a supervisory system. The scope of the present work is to propose an innovative approach for the implementation of smart metering systems in zero-energy buildings and a practical methodology to classify the systems. The proposed classification rates the system performance via a set of weighted indicators - according to the positioning of meters, measured data, system architecture, data visualization and monitored loads -, then calculates an overall grade.

Design and classification of smart metering systems for the energy diagnosis of buildings

At present, buildings account for a great share of energy consumption. It is well known that building automation control systems allow for increasing opportunities of improvement in the performance of buildings, with respect to e.g. energy performance and indoor comfort. As system within a building become more and more complex, buildings can be regarded not merely as a load but as a smart micro grid, with the possibility of actively interacting with a smart grid. In the depicted context, metering is essential for assessing the performance of management and detecting improvement opportunities. The scope of the present work is to propose a best practice for the implementation of smart metering systems in buildings and a practical methodology to classify the systems. In the present work, a novel classification protocol is devised; an existing metering system is then evaluated and an improved metering system is proposed. The proposed protocol rates the system performance via a set of weighted indicators -according to positioning of meters, measured data, system architecture, data visualization and monitored loads -, then calculates an overall grade. The protocol is tested on an existing metering system in an educational building. The metering system returns a poor rating and a number of flaws are detected thanks to the benchmark protocol. An improved metering system is then proposed which fixes existing flaws and returns a much better grade. In conclusion, the designed classification protocol allowed diagnosing an existing metering system and pinpointing improvement opportunities and it can be a useful practice in diagnostics or design of smart metering systems.

Adaptive control for lighting, shading and HVAC systems in near zero energy buildings

Due to the increasing amount of energy consumption and CO2 emissions, Building Automation Systems have been developed in order to increase energy performance in buildings and guarantee indoor comfort at the same time. However, along with the development of the hardware itself, the need to develop also suitable control systems and methods for improving the management of smart buildings, is arising. In this framework, fuzzy logic may be a valuable tool for developing suitable control systems. In this paper, fuzzy logic has been used in order to optimize comfort features and energy demand in an office. Starting from the model defined in a previous work, the aim of the paper is to simulate different configurations of the room and compare the results in order to evaluate the impact of room variations (window geometry, glass properties and wall reflectance) on the fuzzy control system. Given the same solar radiation inputs, it was noticed that different room configurations require a diversified management of the shading systems and artificial lighting control in order to achieve a good balance between comfort and energy consumption.

Design and energy performance assessment of high-efficiency lighting systems

Indoor lighting efficiency is a major opportunity for energy efficiency in buildings, towards near zero energy buildings. In addition to increasing lamp efficacy, lighting design has evolved from a “night-time” approach to a “day-time approach”, taking advantage of control equipment and strategies and of daylight contribution. To date, lighting efficiency is committed to the designers skill, while an aided design tool could allow for a real-time efficient design. In this work, evaluation procedures are reviewed and a design tool is devised. A set of case studies is then evaluated, returning reference values and comments for an efficient lighting design. An efficient lighting system is then proposed, according to design comments. In conclusion, a real-time design aid can be a useful tool for efficient lighting design.