Self-consumption Of Electricity Research Articles

Optimal design of renewable energy communities (RECs) in Italy: Influence of composition, market signals, buildings, location, and incentives

In Europe the concept of Renewable Energy Communities (RECs) renovates the need for decentralized energy generation among citizens and companies. The corresponding legal framework enables the creation of business models that shall support environmental, economic and social benefits, provided that adequate planning accounting for the local conditions is executed. The present work is focused on a thermal-electric co-simulation approach for the analysis of the energy exchanges within an Italian REC, aimed at sizing photovoltaics (PV) and energy storage systems. EnergyPlus is used to estimate the thermal and electric needs of the community, whose results are fed into the “EnergyCommunity.jl” tool for the design of the local power system. The influence of REC composition (prosumers/consumers), the building energy demands for heating, cooling, and appliances, the geography of the REC in Italian regions, the market data, and the total peak power of PV are examined. The self-consumed electricity, the energy shared among the community, and the social costs are evaluated in different scenarios, suggesting significant environmental and economic benefits for Energy Communities.

Heat Pumps with Smart Control in Managing Australian Residential Electrical Load during Transition to Net Zero Emissions

Australia, like many other countries around the world, is undergoing a transition toward net zero emissions. It requires changes and development in many sectors, which not only bring benefits but also challenges. The rapid growth in renewable energy sources (RESs) is necessary to decarbonise electricity generation but negatively affects grid stability. Residential buildings also contribute to this issue through specific load profiles and the high penetration of rooftop photovoltaic (PV) installations. Maintaining grid balance will be crucial for further emissions reductions. One of the potential solutions can be the replacement of conventional heating and cooling systems in houses with solutions capable of storing energy and shifting the electrical load. As presented in this paper, heat pumps and hydronic systems can significantly improve the electrical load of a typical South Australian household when they are controlled by algorithms reacting to the current grid conditions and household-generated electricity compared to conventional solutions. TRNSYS 18 simulations of air source and ground source heat pump systems with smart control based on measured electricity consumption and domestic hot water usage data showed the possibility of total energy consumption reduction, shifting the load from peak periods towards periods of excessive RES generation and increasing self-consumption of rooftop PV electricity. These improvements reduce the amount of emissions generated by such a household and allow for further development of other sectors.

Self-consumption potential and surplus compensation policy impact on rooftop photovoltaic systems in Spain

This research examines the viability of rooftop photovoltaic systems for electricity self-consumption in Spain's residential sector, analyzing municipality-level data on electricity demand, rooftop availability, solar irradiance, and various electricity market and surplus policy scenarios. Differences are found between rural and urban contexts, with rural areas exhibiting greater potential for photovoltaic systems deployment due to more available rooftop space. The study highlights the crucial role of surplus electricity management, showing that an efficient use can significantly boost self-consumption potential, particularly in rural areas where surplus constitutes about two-thirds of the photovoltaic production. Economic analyses under different electricity market conditions and surplus compensation policies show that these factors critically affect the attractiveness and viability of these systems. Current high electricity prices in Spain have reduced their payback period, but the prevalent surplus compensation policy, a 1-month net billing feed-in tariff, reduces their cost-effectiveness by up to 60 % compared to a hypothetical 12-month net billing approach. The findings underscore the need for policy adjustments to maximize rooftop occupancy and ensure fair compensation of surpluses, highlighting the importance of tailored strategies for effective sustainable photovoltaic systems deployment in residential contexts.

Techno-economic analysis on optimizing the value of photovoltaic electricity in a high-latitude location

This study performs a techno-economic analysis of different photovoltaic (PV) systems suitable for detached houses in high-latitude locations and quantifies the key economic indicators affecting their competitiveness. Residential PV systems providing different temporal power production profiles are compared, accounting for the electricity price variations in the day-ahead market and the possibility of self-consuming the produced electricity. The procedure allows novel and comprehensive case study analysis that captures PV production, self-consumption, and dynamic electricity pricing, ultimately revealing the value of the produced PV electricity. This procedure is applied to a hundred case studies representing single-family houses with different PV systems, electricity load profiles, and electricity contracts. Vertical East-West mounted bifacial panels (VBPV) reached superior performance, with 9.1% higher overall production (with 2019 weather data) and 7.4%–10.9% higher economic value (with 2019 and 2022 electricity price data) for the produced PV electricity compared with monofacial PV. Thus, VBPV is an excellent choice for households economically, but the availability of suitable installation sites in the urban environment limits the possibility of its utilization. The economic value of PV electricity strongly correlates with self-consumed electricity due to avoided transmission fees and taxes, and a significant drop in total production causes only a minor reduction in value if the amount of self-consumed electricity remains similar. Thus, for a small-scale producer who orients the panels toward the East and the West instead of the South with a 45° tilt, the economic loss is significantly smaller (even as low as 12.6%) than the production loss (23.2%).

From Local Energy Communities towards National Energy System: A Grid-Aware Techno-Economic Analysis

Energy communities are key actors in the energy transition since they optimally interconnect renewable energy capacities with the consumers. Despite versatile objectives, they usually aim at improving the self-consumption of renewable electricity within low-voltage grids to maximize revenues. In addition, energy communities are an excellent opportunity to supply renewable electricity to regional and national energy systems. However, effective price signals have to be designed to coordinate the needs of the energy infrastructure with the interests of these local stakeholders. The aim of this paper is to demonstrate the integration of energy communities at the national level with a bottom–up approach. District energy systems with a building scale resolution are modeled in a mixed-integer linear programming problem. The Dantzig–Wolfe decomposition is applied to reduce the computational time. The methodology lies within the framework of a renewable energy hub, characterized by a high share of photovoltaic capacities. Both investments into equipment and its operation are considered. The model is applied on a set of five typical districts and weather locations representative of the Swiss building stock. The extrapolation to the national scale reveals a heterogeneous photovoltaic potential throughout the country. Present electricity tariffs promote a maximal investment into photovoltaic panels in every region, reaching an installed capacity of 67.2 GW and generating 80 TWh per year. Placed in perspective with the optimal PV capacity forecast at 15.4 GW peak at the national level, coordinated investment between local and national actors is needed to prevent dispensable expenses. An uncoordinated design is expected to increase the total costs for residential energy systems from 12% to 83% and curtails 48% of local renewable electricity.

Performance of vertically mounted bifacial photovoltaics under the physical influence of low-rise residential environment in high-latitude locations

This study focuses on finding suitable installation sites for vertical bifacial photovoltaic (VBPV) panels in urban low-rise neighborhoods at high latitudes. The power production of east-west-oriented VBPV systems matches well with domestic electricity consumption profiles, increasing the self-consumption of PV electricity. Furthermore, PV electricity adds economic value by avoiding transmission fees and taxes. These systems are especially beneficial in high-latitude locations characterized by a low solar elevation angle. However, these low angles expose VBPV panels to a high risk of shading losses from their surroundings, and it is unknown how much shading limits the number of suitable installation sites. Here, environmental shading on VBPV panels is quantified for three low-rise residential neighborhoods in Helsinki, a high-latitude location, by comparing the specific yields (annual electricity production per kilowatt peak) of VBPV and monofacial PV (MPV) systems. The results showed that unshaded VBPV systems have a higher specific yield than their MPV counterparts. However, in densely built neighborhoods with tall trees, the lack of suitable installation sites for VBPV panels severely limits the peak power of these systems. Roof ridge VBPVs usually yield high production, while façade- and ground-mounted systems lose between 30% and 70% compared to roof ridge VBPV systems depending on their installation locations. South-oriented MPVs perform better than VBPVs on north-south-facing roofs, both in terms of specific yield and total annual production. Conversely, VBPVs installed on the ridges of unshaded roofs aligned closely with the north-south axis outperform MPVs on east- and west-facing roofs by 20%–30%.

Analysis of the performance and operation of a photovoltaic-battery heat pump system based on field measurement data

Photovoltaic-heat pump (PV-HP) combinations with battery and energy management systems are becoming increasingly popular due to their ability to increase the autarchy and utilization of self-generated PV electricity. This trend is driven by the ongoing electrification of the heating sector and the growing disparity between growing electricity costs and reducing feed-in tariffs in Germany. Smart control strategies can be employed to control and optimize the heat pump operation to achieve higher self-consumption of PV electricity. This work presents the evaluation results of a smart-grid ready controlled PV-HP-battery system in a single-family household in Germany, using 1-minute-high-resolution field measurement data. Within 12 months evaluation period, a self-consumption of 43 % was determined. The solar fraction of the HP amounts to 36 %, enabled also due to higher set temperatures for space heating and domestic hot water production. Accordingly, the SPF decreases by 4.0 % the space heating and by 5.7 % in the domestic hot water mode. The combined seasonal performance factor for the heat pump system increases from 4.2 to 6.7, when only considering the electricity taken from the grid and disregarding the locally generated electricity supplied from photovoltaic and battery units.

Techno-economic analysis of residential rooftop photovoltaics in Spain

In response to the European Commission's renewable energy targets for 2030, this study presents a comprehensive, data-driven evaluation of the potential for electricity self-consumption in the Spanish residential sector based on rooftop PV systems. Utilizing real-time hourly electricity demand data and various surplus compensation policies, the research highlights the significance of data granularity, indicating that annual data-based PV estimations can lead to rooftop PV self-consumption capacity overestimations when compared to hourly data assessments. Furthermore, geographical variations reveal distinct rooftop PV self-consumption capacities between urban and rural areas, driven mainly by the prevalent building typologies. This discrepancy suggests that while rural regions, with their predominance of single-family dwellings, offer higher PV generation potential due to more available rooftop space, urban areas, dominated by multi-story buildings, face significant constraints in rooftop surface availability. Economically, the current surplus compensation policy in Spain reduces the profitability of PV installations, underscoring the necessity for enhanced policies to fully utilize all the available rooftop areas in the residential sector. The study's findings, particularly the revelation that residential rooftops in Spain may not be enough to meet the current electricity demand, emphasize the need for adaptive, region-specific policies and the potential role of energy communities. Policymakers and industry stakeholders are urged to prioritize rooftop utilization, ensuring the deployment of PV systems is both promoted and economically viable, steering Spain closer to its renewable energy and sustainability aspirations.

Just sharing? Energy injustices in the Norwegian solar policy mix for collective prosuming

There is increasing evidence that the energy transition incorporates new types of inequalities for different types of energy consumers. In many places, detached dwellings are highly overrepresented among the building types with solar PV installed. Based on document analysis and high-level interviews, this article analyses the policy mix for rooftop solar energy in Norway through an energy justice lens, focusing on multi-apartment buildings and housing cooperatives. Such cooperatives resemble both a Renewable Energy Community and a Citizen Energy Community as defined in the EU's ‘Clean Energy for all Europeans’-package. We identify several energy injustices in the solar PV policy mix, which effectively impede residents in multi-apartment buildings from collectively producing their own electricity. As a result, very few multi-apartment buildings and housing cooperatives produce their own electricity. Most importantly, current regulations add electricity taxes, grid fees and VAT to the collectively self-consumed electricity as soon as it enters each individual dwelling. By contrast, detached households are allowed to practise hourly net-metering, thereby consuming their self-produced electricity behind the meter without any additional taxes or fees. Finally, our findings show that perceptions of a ‘fair’ policy mix vary considerably, and that equal rules affect various groups of residents differently.

A cost analysis of decarbonizing the heavy-duty road transport sector

We introduce a static cost model that simulates the cost of decarbonizing the heavy-duty road transport sector. This time-variant model aims to refine existing estimations of investment needs under different scenarios. The paper advances sustainability transition’s cost analysis in three ways: 1) providing a novel methodological tool, 2) including the financing cost in the analysis, and 2) testing the cost variance under different charging strategies for battery-electric vehicles and financing interest rates. A plausible scenario is applied to test the model. The paper discusses charging opportunities reliant on charging place, time, power effect, and electricity self-consumption within the charging strategies. Our results highlight the vital contribution of charging strategies to fuel and capital expenses for the system. Moreover, system cost analysis reacts to the change in financing policies, stressing the criticality of sustainable financing in the sustainability transition’s advancement.

Adaptive Control Strategy for Stationary Electric Battery Storage Systems with Reliable Peak Load Limitation at Maximum Self-Consumption of Locally Generated Energy

Nowadays, stationary battery storage systems are generally used to optimize the self-consumption of electricity generated locally or to limit the peak load of the local grid connection. Self-consumption optimization aims to achieve economic benefits by using more of the self-generated electricity within the local grid. Batteries used for the optimization of self-consumption tend to present low states of charge and, therefore, normally do not contribute to peak load limitation. Peak load limitation is used to minimize the grid connection power to enable more cost-efficient grid connections. However, this function can only be achieved year-round if there is sufficient surplus electricity production or if the battery can be charged from the grid. In the latter case, the batteries are often fully charged and do not significantly optimize the self-consumption. This study presents a new operating strategy that combines all the advantages of the previous operating modes with none of the disadvantages. This can be accomplished by combining the operation modes depending on the particular situation, together with a variable battery charging process. Furthermore, a simulation-based optimization procedure is introduced for the optimal configuration of the parameters. The potential of this operating strategy is demonstrated based on application examples. As a result, the operating strategy enables reliable peak load limitation all year round while simultaneously optimizing self-consumption. The operating strategy can easily be adapted to meet changing requirements such as the increasing charging power demands of electric vehicles. Thanks to a simple process based on common measured variables, the operating strategy can be integrated smoothly into practical applications.

Optimization of Feed-in Tariff mechanism for residential and industrial photovoltaic adoption in Hong Kong

Due to the late introduction of Feed-in Tariff (FiT) Scheme to Hong Kong's context, its effectiveness, efficiency, and optimization have merely been investigated yet. Therefore, this study proposes two FiT mechanisms according to the policy characteristics and structure elucidated from existing literatures (i.e., payoff, tariff, and contract structures) (i) Mechanism 1 (i.e., M1): follows the current policy characteristics with a short-term contract structure, which terminates in 2033; and (ii) Mechanism 2 (i.e., M2) introduced a widely adopted policy characteristic with a long-term contract structure, which allows to sell all electricity generated to the power grid. The proposed FiT rate under M1 and M2 guarantees the profitability of the solar photovoltaic (PV) installers with different scales. For residential PV installers (i.e., small-scale PV systems with installed capacity less than10 kW), 6–10 years of discounted payback period (DPB) is considered as the optimization objective. As for industrial PV installers (i.e., large-scale PV systems with installed capacity of 200–1000 kW), 8–12% of internal rate of return (IRR) is considered as the optimization objective. Results indicate that the current FiT rate is slightly high for residential PV installers, and it is recommended to be lowered after 2024 to fit the proposed FiT range, and then levered up in 2028 to ensure the profitability of late participation under M1. Meanwhile, the current FiT rate is found significantly low for industrial PV installers, and it is suggested to be levered up to the proposed FiT range. Furthermore, policy reform is highly recommended altering from M1 to M2 when current policy expires (i.e., 2033). In terms of the techno-economic analysis based on the calculation of levelized profit of electricity (LPOE) where self-consumption of PV system-generated electricity is considered as energy bill savings under M1, the long-term profitability for industrial PV installers under M1 is found to be higher than M2, whereas the opposite is observed for residential PV installers. The contribution of this study is attributed to the flexibility and applicability of the optimized results, the context-specific investigation of the market-independent renewable energy development, and the comprehensive parameters considered in the model development. The results of this study are believed to shed light on policy implications, grid parity, and investment recommendations for the government, utility companies, and PV installers in the long run.

Analysis of the Impact of the Level of Self-Consumption of Electricity from a Prosumer Photovoltaic Installation on Its Profitability under Different Energy Billing Scenarios in Poland

Renewable Energy Sources (RES) have been gaining popularity on a continuous basis and the current global political situation is only accelerating energy transformation in many countries. Objectives related to environmental protection and use of RES set by different countries all over the world as well as the European Union (EU) are becoming priorities. In Poland, after years of a boom in photovoltaic (PV) installations, the Renewable Energy Sources Act has been amended, resulting in a change to the billing system for electricity produced by individual prosumers. The change in the billing method, also in pursuance to the provisions of EU laws, has contributed to the inhibition of the PV installation market for fear of energy prices and investment payback time. In this paper, by using the Net Present Value (NPV) method, three mechanisms of billing of electricity from prosumer micro-installations—based on the net-metering principle and net-billing principle (using monthly and hourly prices)—have been analysed. Particular attention has also been paid to the aspects of electricity self-consumption and energy storages, which play a significant role in the economy of PV installations in the net-billing system.

Feasibility of UTS Smart Home to Support Sustainable Development Goals of United Nations (UN SDGs): Water and Energy Conservation

The Sustainable Development Goals of the United Nations strive to maximize development needs, while minimizing environmental deterioration, without jeopardizing the needs of future generations. Nevertheless, due to urbanization, the escalating trend in natural-resource use, particularly electricity and water, is currently a crucial challenge for sustainable development. One of the promising options is the smart home, which is an extension of building automation with smart characteristics in monitoring, analyzing, controlling, and cloud computing with networked smart devices. Due to the lack of appropriate infrastructure and conscious consumption, its global adoption in the construction industry remains low. We present a technical feasibility of a multi-functional experimental smart home to support the Sustainable Development Goals of the United Nations in terms of water and energy conservation. The layered architecture of the cloud platform with an application program interface enables seamless integration of heterogeneous smart-home technologies and data sources. Use cases demonstrated its capacity to conserve electrical energy and water resources in support of the United Nations’ Sustainable Development Goals. Aside from that, the smart home’s electricity self-consumption of at least three autonomy days was confirmed with zero emissions and electricity bills, and a reduced supply-water consumption.

An energy, environmental, management and economic analysis of energy efficient system towards renewable energy community: The case study of multi-purpose energy community

The Renewable Energy Directive drives the European Countries to enhancement of independent energy systems and self-consumption users such as Renewable Energy Communities. The recent directives about energy communities represent a development of previous ones about energy sharing systems defined in the early 2000s. In this work, the past and current directives about energy sharing have been investigated by considering technical and management aspects. The social, economic, technical aspects of Renewable Energy Communities have defined in order to show the advantage of them and their upgrade with respect to previous energy sharing directives. In addition, a case study has been considered by using an energy, environmental and economic analysis in a multi-purpose energy community by considering three different configurations for end-users: simple users, energy close sharing system and energy community. The energy community loads and energy conversion systems have been modelled and simulated by using a commercial software. The results about community configuration by following recent directive show an annual electricity self-consumption index equal to 56%. The renewable energy community allows to avoid 39.5 t/y of CO2 emissions with respect to the traditional configuration without sharing approach. The index of renewable energy source local self-consumption of energy community results higher than the sharing system referred to previous directives. People involved in this community could be more aware for environment issues and they could develop a more sustainable attitude.

Renewable energy communities: Do they have a business case in Flanders?

Renewable energy communities (RECs) are prominent initiatives to provide end consumers an active role in the energy sector, raise awareness on the importance of renewable energy (RE) technologies and increase their share in the energy system thus reducing greenhouse gas (GHG) emissions. The economic viability of RECs though, depends on multiple interdependent factors that require careful examination for each individual context. This study aims at investigating the impact of electricity tariffs, ratio of electrification of heating and transportation sectors, prices of RE technologies and storage systems, and internal electricity exchange prices on the annual cost for electricity provision of a REC and its GHG emissions. A mixed-integer linear model is developed to minimize energy provision costs for a representative REC in Flanders, Belgium. The results indicate that RECs have the potential to reduce these costs by 10 to 26% and emissions by 5 to 13% compared to business-as-usual. The cost reduction depends on the type of electricity tariffs and the level of uptake of flexible assets such as heat pumps and electric vehicles. The shift towards a higher power component in the electricity tariff makes electricity storage systems more attractive, which leads to higher electricity self-consumption. The introduction of flexible assets adds the possibility to shift demand when tariffs are lower and makes higher installed capacities of photovoltaic systems economically viable due to the increase in the total electricity demand. However, RECs cost reduction compared to individual smart-homes amounts to only 4%–6% in the best cases. Uncertainties stemming from the costs of setting up a REC may reduce the estimated benefits.

The (Non) impact of the Spanish “Tax on the Sun” on photovoltaics prosumers uptake

There is increasing scientific evidence of anthropic climate change. The need to shift to more sustainable energy systems is therefore compelling. Individuals are becoming key actors in the energy transition, as producers and sellers of the renewable energy they produce on-site. However, the practice of self-consumption requires to be underpinned by adequate policy mechanisms. Under this perspective, the Spanish Royal Decree (RD) 900/2015, also so-called “Tax on the Sun”, aiming at regulating energy self-consumption and enhancing the engagement of Spanish citizens in the energy transition as prosumers, by the installation of photovoltaics, represents a challenging case study. There is anecdotal evidence that instead of supporting the diffusion of electricity self-consumption, the “Tax on the Sun” has had the opposite effect. Thus, this work aims at testing this proposition by using the synthetic control methodology (SCM), which permits to evaluate the effect of a treatment in absence of a suitable control group, as in this case. This study finds that indeed at the regional level the “Tax on the Sun” has had a negative impact, if any at all. The current barriers to prosumerism, and more broadly to the active involvement of citizens in the energy transition, are still many and policy-makers should address these shortcomings if they want to fully employ the potential that prosumerism has to offer to a just energy transition.

Impact of the Self-Consumption of Electricity on the Profitability of the Investment into a Photovoltaic Installation: The Case of a Company in Poland

Impact of the Self-Consumption of Electricity on the Profitability of the Investment into a Photovoltaic Installation: The Case of a Company in Poland

Power Flow Analysis in Urban Distribution Networks with Implementation of Grid-Connected Photovoltaic Systems

In the last few years, renewable energies became more socially and economically relevant, and among them, photovoltaic systems stand out. Residential self-consumption of electricity is a field with great potential, and implementation of grid-connected photovoltaic systems (GCPS) is in full rise. The installation of distributed generation systems in residential environments could alter the performance of low-voltage distribution networks, since these are designed for unidirectional power flow and adding these generators means fluctuations in power-flows. For these reasons, a study of the fundamental magnitudes of three low-voltage distribution networks located in Madrid was made for various photovoltaic penetration rates, making use of simulations via the software OpenDSS and subsequent analysis of results. The research concludes that, among other aspects, GCPS produce load flow variations that are dependent on: the penetration rates; the distance from the point of interest and the distribution transformer, increasing the voltage variation between the most productive hours and the night hours with that distance; and on the rate between consumption and generation, so that when it diminishes, the self-sufficiency of the system increases, and with it the voltage of all the buses that tend to the rated voltage. Moreover, there are wide seasonal fluctuations: specifically, in summer months, generation profiles override consumption fluctuations, while in winter months consumption guides voltage and power profiles. Both the code implemented and the results of the analysis were published in an open source website using a free software license.

Towards Nearly-Zero Energy in Heritage Residential Buildings Retrofitting in Hot, Dry Climates

Retrofitting “nearly-zero energy” heritage buildings has always been controversial, due to the usual association of the “nearly-zero energy” target with high energy performance and the utilization of renewable energy sources in highly regarded cultural values of heritage buildings. This paper aims to evaluate the potential of turning heritage building stock into a “nearly-zero energy” in hot, dry climates, which has been addressed in only a few studies. Therefore, a four-phase integrated energy retrofitting methodology was proposed and applied to a sample of heritage residential building stock in Egypt along with microscale analysis on buildings. Three reference buildings were selected, representing the most dominant building typologies. The study combines field measurements and observations with energy simulations. In addition, simulation models were created and calibrated based on monitored data in the reference buildings. The results show that the application of hybrid passive and active non-energy generating scenarios significantly impacts energy use in the reference buildings, e.g., where 66.4% of annual electricity use can be saved. Moreover, the application of solar energy sources approximately covers the energy demand in the reference buildings, e.g., where an annual self-consumption of electricity up to 78% and surplus electricity up to 20.4% can be achieved by using photo-voltaic modules. Furthermore, annual natural gas of up to 66.8% can be saved by using two unglazed solar collectors. Lastly, achieving “nearly-zero energy” was possible for the presented case study area. The originality of this work lies in developing and applying an informed retrofitting (nearly-zero energy) guide to be used as a benchmark energy model for buildings that belong to an important historical era. The findings contribute to fill a gap in existing studies of integrating renewable energy sources to achieve “nearly-zero energy” in heritage buildings in hot climates.