A Smart Grid System for Reducing Energy Consumption and Energy Cost in Buildings in São Paulo, Brazil

The consumption of electric energy has increased in recent years. In Brazil there are issues related to the supply of this consumption that are able to reduce the impacts on the environment. Seeking to stimulate the efficient use of energy, the National Electric Energy Agency (ANEEL) established a new tariff modality for low voltage (LV) consumers, the White Tariff. In this perspective, this article presents an economic feasibility study of adherence to the White Tariff for rural consumers considering Distributed Generation (DG) constituted by solar energy and biomass. Hybrid Optimization Model for Electric Renewables software was used as a simulation tool for different load profiles. The results showed that the White Tariff can be more advantageous when used in parallel with the techniques of demand management in which the consumer manages his/her consumption habits at peak times with the off-peak time that has a lower cost of the White Tariff.

Desde o início deste século, nota-se uma crescente necessidade de suprimento energético e consequentemente o aumento das preocupações ambientais internacionais. Em resposta a essa demanda, a geração distribuída fotovoltaica surge como possibilidade de redução das emissões de gases de efeito estufa, além da redução do investimento em produção, transmissão ou distribuição. Outra forma de controle referente ao consumo energético é por meio do gerenciamento pelo lado da demanda que, no Brasil, surge como opção para o setor residencial com a tarifa Branca. Porém, a inserção destas estratégias, assim como a mudança para o novo regime tarifário, requer investimentos e planejamento, os quais devem ser cuidadosamente analisados. Nesse contexto, as simulações computacionais possibilitam visualizar possíveis cenários, facilitar análises e fomentar planejamentos futuros. Este trabalho avalia os efeitos da geração distribuída fotovoltaica e do novo regime tarifário para consumidores residenciais que aderirem à tarifa Branca. Unidades habitacionais localizadas em Bento Gonçalves, São Paulo e Belém, com ou sem geração fotovoltaica, foram estudadas. Mostra-se que apenas a adesão à tarifa Branca gera 12,7%, 17,1%, 23,4% de aumento de gastos nas respectivas localidades, o que ressalta a necessidade da mudança nos hábitos atualmente típicos do consumidor e da redução no uso de energia nos horários de pico. Em contrapartida, os casos com geração fotovoltaica foram majoritariamente mais econômicos com a tarifa Convencional. No entanto, houve casos com resultado contrário em Bento Gonçalves, onde a diferença não foi relevante ou a melhor opção foi a tarifa Branca, visto que o pico de consumo gerado pelo chuveiro elétrico foi eliminado com a inserção do sistema solar de aquecimento de água que acompanhou o sistema fotovoltaico. Este, por sua vez, levou o consumo das habitações à tarifa mínima, principalmente em São Paulo, onde os custos foram praticamente os mesmos, não importando o regime tarifário escolhido.

Nearly zero energy buildings (nZEBs) have been defined and standardised for certain developed countries. Most developing countries in the North Africa region lack building energy efficiency standards for their hot environments. With increased pressure on buildings to improve their energy and environmental performance, nZEB buildings are likely to gain popularity over the next few years. Their application in the MENA area can significantly reduce building energy consumption and CO2 emissions. As a result, it is critical to maximise both the energy use intensity (EUI) and the energy cost of a building through Building Information Modelling (BIM) technology for energy analysis. Therefore, this study aims to develop an energy-efficient building by evaluating several design options in terms of EUI and energy cost following ASHRAE 90.1 and Architecture 2030 standards. The baseline scenario’s energy consumption intensity was estimated at 400 kWh/m2/year. ASHRAE 90.1 standards’ adoption has the potential to save 40% of energy demand. The most energy-efficient architecture was identified to be Architecture 2030 with PV integration (92% of energy savings compared to the baseline scenario). In terms of energy costs, 28.5 $/m2/year was estimated to satisfy energy demand under the baseline scenario, 11.2 $/m2/year under ASHRAE standards, and a 3.83 $/m2/year payoff considering Architecture 2030.

Batteries with 80% of their lifespan are increasingly discarded with the popularization of electric vehicles. The aim of the study is to evaluate the use of second life batteries from electric vehicles in residential photovoltaic prosumers systems. Thus, carrying out an investment feasibility analysis considering the changes proposed in the net metering tariff model in Brazil. The operating strategy for a prosumer is optimized, considering real data from a retired second life battery with 70% of its useful life and its degradation in the second life, this ranging from 60% to 50% of its useful life. Four study scenarios were considered according to the absence or presence of Net Metering and the conventional and white tariffs. The results show the attractiveness of this investment when considering the white tariff and the need to extend the battery life by up to 50% for the scenario with conventional tariff.

Purposes. The main purpose of this article is to provide a comprehensive analysis of the introduction of digital technologies into energy management in the construction sector, paying special attention to examples of their application and effectiveness in world practice. This study focuses on evaluating various strategies and approaches to energy management in buildings using modern digital tools. The study analyzes the problems of implementing demand management systems in buildings, as well as opportunities to improve energy efficiency and reduce energy costs in buildings in the context of digitalization. Relevance. The relevance of the topic is due to the need for effective energy consumption management in connection with the development of technologies, in particular digital ones, the increasing demand for electricity and the requirements of power supply safety. Research methods. The methodological basis of the analysis approach is the collection, generalization and systematization of information within the framework of the studied aspects of the impact of digitalization on energy management of buildings. The main results. A comprehensive analysis of the latest information on the topic under study has been carried out, as a result of which strategies, problems and opportunities of the digitalization process in the field of energy management in construction are described.

Optimal control of building's HVAC (Heating Ventilation and Air Conditioning) system as a demand response may not only reduce energy cost in buildings, but also reduce energy production in grid, stabilize energy grid and promote smart grid. In this paper, we describe a model predictive control (MPC) framework that optimally determines control profiles of the HVAC system as demand response. A Nonlinear Autoregressive Neural Network (NARNET) is used to model the thermal behavior of the building zone and to simulate various HVAC control strategies. The optimal control problem is formulated as a Mixed-Integer Non-Linear Programming (MINLP) problem and it is used to compute the optimal control profile that minimizes the total energy costs of powering HVAC system considering dynamic demand response signal, on-site energy storage system and energy generation system while satisfying thermal comfort of building occupants within the physical limitation of HVAC equipment, on-site energy storage and generation systems.

Optimal control of building's HVAC (Heating Ventilation and Air Conditioning) system as a demand response may not only reduce energy cost in buildings, but also reduce energy production in grid, stabilize energy grid and promote smart grid. In this paper, we describe a model predictive control (MPC) framework that optimally determines control profiles of the HVAC system as demand response. A Nonlinear Autoregressive Neural Network (NARNET) is used to model the thermal behavior of the building zone and to simulate various HVAC control strategies. The optimal control problem is formulated as a Mixed-Integer Non-Linear Programming (MINLP) problem and it is used to compute the optimal control profile that minimizes the total energy costs of powering HVAC system considering dynamic demand response signal, on-site energy storage system and energy generation system while satisfying thermal comfort of building occupants within the physical limitation of HVAC equipment, on-site energy storage and generation systems.

Artificial Intelligence (AI) for carbon reduction through Renewable Energy Systems (RES) in buildings can offer several significant benefits, which contribute to both environmental sustainability and operational efficiency. Through efficient energy management, predictive analytics, and optimized integration of renewable energy sources, AI can reduce energy costs in buildings. AI allows buildings to scale their renewable energy and carbon-reducing initiatives. As more buildings or districts adopt AI-integrated RES, the system can scale efficiently without needing significant redesigns or new infrastructure. Additionally, AI systems are adaptable, meaning that they can evolve and adjust to new technologies, renewable energy sources, and carbon reduction strategies. By optimizing energy use, facilitating better integration of renewable resources, and ensuring continuous performance monitoring, AI can significantly contribute to making buildings more sustainable and carbon-neutral.

Optimal HVAC Control as Demand Response with On-site Energy Storage and Generation System

This paper deals with the problem of determining the optimal size of a residential grid-connected photovoltaic system to meet a certain \(\mathrm{CO }_2\) reduction target at a minimum cost. Ren et al. proposed a novel approach using a simple linear programming that minimizes the total energy costs for residential buildings in Japan. However, their approach is based on a specific net tariff system that was used in Japan until October 2009, and it is not applicable to Japan’s current net tariff system. We propose a modified approach for Japan’s current tariff system. The mathematical formulation is general in the sense that it includes formulations for other tariff systems as special cases. Therefore, the approach is applicable not only to the Japanese system but also to other tariff systems (e.g., gross feed-in tariff system). We further extend this approach by using a robust optimization technique to cope with the uncertainty in photovoltaic power generation caused by weather variability. Numerical experiments show the minimum size requirements of solar photovoltaic systems for meeting \(\mathrm{CO }_2\) reduction targets and their economic costs in nominal and robust cases.

Photovoltaics.- Inverters.- Storage.- PV-Systems in the Tropics.- Energy Consumption for the Set-up of a PV Power Plant.- Energy Yield.- Energy Input by Dumping and Recycling.- Total Energy Balance.- Optimization.- Summary.

Grid-connected photo voltaic (PV) systems are being developed very fast and systems from a few kW to tenths of a MW are now in operation. As an important source of distributed generation (DS) the PV systems need to comply with a series of standard requirements in order to ensure the safety and the seamless transfer of the electrical energy to the grid. Multilevel voltage source converters (VSC) is a heart of the PV system and are emerging as an important power converter options for low, medium, and high-power applications. These VSCs have bought numerous advantages, especially in renewable energy systems such as PV and wind energy systems. In this article, several topologies of VSCs, which brings together some concepts from traditional converters and multi-level converters, are presented. Also, several control strategies for controlling current, voltage, active power and reactive power have also been reviewed. Various topologies with their technical aspects have been reviewed and the best suitable topology and control scheme for grid connected PV and wind energy systems has been suggested. Copyright © 2016 John Wiley & Sons, Ltd.

In this paper performances of different combinations of integrated RE systems are analyzed and compared for various suitable locations in India for a load demand of 1.5 MW. These combinations of integration of REs are wind energy system (WES) and photovoltaic (PV) system; PV system and biomass energy system (BES); and BES and WES. Maximum annual electricity generated by integrated PV system and BES 8,672 MWh while maximum annual income from electricity export is $ 561,078 from integrated BES and WES system. Reduction in net annual greenhouse gas (GHG) emission is found highest of 8,850 tonnes of CO2 in the case of integrated BES and WES with income from the GHG reduction of $ 177,013 and total annual saving/income of $ 738,091. Equity payback period of integrated BES and WES is estimated as minimum of 2.7 years when cash flow becomes positive. Performance analyses and cash flows of the integrated RE systems are carried out using RETScreen software tool. It is concluded from the results that integration of BES with another RE is more feasible than without BES in terms of electricity generation, electricity export income, GHG emission reduction, income from carbon trading and equity payback period.

Diesel generator sets are mostly used as the main electricity supply or as a backup for areas not connected to the main electricity grid. Natural gas can be used as an alternative fuel of generator set to replace diesel because of its abundant availability and is environmentally friendly. In addition to the generator set, the solar photovoltaic (PV) system is also suitable for implementation in remote areas since its primary energy sources are easy to obtain. The combination of these two types of power generation is expected to be reliable enough to supply the electricity for houses in remote areas. This study is conducted to observe the performance of the hybrid natural gas generator set/solar PV system in terms of specific fuel consumption (SFC) and power quality through a testbed, and further analyze the economic aspect. According to the result, the voltage and frequency generated by the natural gas generator set either integrated with a solar PV system or not is still within the allowable operating limits. Moreover, the SFC value of the hybrid system is higher than the one with natural gas generator set only.

In this paper innovative integration of wind turbines and solar panels along highways, presenting a multifaceted solution for renewable energy generation, reduced carbon emissions, and sustainable transportation infrastructure. A hybrid renewable energy system combining solar photovoltaic (PV) and wind power optimizes energy production, harnessing the synergies between these two clean sources. By integrating PV panels and wind turbines with advanced power conversion and energy storage, this system mitigates intermittency, ensuring a reliable and efficient DC power supply. Simulation models, leveraging the Single-Diode Model for PV and power coefficient curves for wind, accurately predict performance under varying environmental conditions. The installation of wind turbines and solar panels along highways can harness wind energy, reduce visual impact, and utilize existing infrastructure, while generating electricity for highway lighting, traffic management systems, and electric vehicle charging stations. The hybrid setup enhances overall efficiency, reliability, and power quality. By leveraging complementary seasonal patterns - solar radiation during summer and wind flows during winter - the system ensures a more consistent energy supply. Advanced control strategies and energy storage solutions further improve the system's performance. Case studies demonstrate significant increases in capacity factors and reductions in energy costs. In pioneering projects worldwide demonstrate the feasibility and effectiveness of this integrated approach, highlighting significant reductions in greenhouse gas emissions, energy costs, and reliance on fossil fuels. Technological advancements in turbine design, panel efficiency, and energy storage systems further enhance the potential of this renewable energy solution. This research provides a comprehensive analysis of the benefits, challenges, and future directions for harnessing renewable energy on highways, offering valuable insights for policymakers, engineers, and stakeholders invested in sustainable energy infrastructure development. Keywords: Wind turbine, Solar panels, Energy harvesting, Inverter circuits,etc