Local Renewable Sources Research Articles

Enabling industrial decarbonization: A MILP optimization model for low-carbon hydrogen supply chains

This study develops a an optimization model focused on the layout and dispatch of a low-carbon hydrogen supply chain. The objective is to identify the lowest Levelized Cost of Hydrogen for a given demand. The model considers various elements, including electricity supply from the local grid and renewable sources (photovoltaic and wind), alongside hydrogen production, compression, storage, and transportation to end users. Applied to an industrial case study in Sweden, the findings indicate that the major cost components are linked to electricity generation and investment in electrolyzers, with the LCOH reaching 5.2 EUR/kgH2 under typical demand conditions. Under scenarios with higher peak demands and greater demand volatility, the LCOH increases to 6.8 EUR/kgH2 due to the need for additional renewable energy capacity. These results highlight the critical impact of electricity availability and demand fluctuations on the LCOH, emphasizing the complex interdependencies within the hydrogen supply chain. This study provides valuable insights into the feasibility and cost-effectiveness of adopting hydrogen as an energy carrier for renewable electricity in the context of decarbonizing industrial processes in the energy system.

Socioeconomic Impacts of Climate Mitigation Actions in Greece: Quantitative Assessment and Public Perception

Appropriately designed and implemented climate mitigation actions have multiple co-benefits (yet some trade-offs cannot be excluded) that result in substantial social and economic value beyond their direct impact on reducing energy consumption and GHG emissions. Despite their wider acknowledgement by the research community, decision makers and the public have incomplete information on these multiple effects. This paper has a twofold objective: First, through analytical bottom-up approaches, it assesses, in quantitative terms, the macroeconomic effects and the public health benefits attributed to a variety of mitigation actions under consideration in the context of the Greek Energy and Climate Plan. Second, it investigates, through a social survey, how citizens perceive climate change and value these multiple impacts of mitigation actions, and to what extent they are willing to pay for them and support the adoption of policy measures aiming at the green transition of the Greek economy. We show that mitigation actions bring about significant health benefits, particularly in cities, and generate significant positive macroeconomic effects, particularly if mitigation actions focus on the decarbonization of the building sector and on the exploitation of local renewable sources. We also argue that most people do not realize that climate mitigation actions can have wider benefits for society, such as tackling energy poverty, improving public health, and creating new jobs. Unwillingness to pay tends to be the prominent attitude. People who are more reluctant to cover a part of the cost of environmental protection are less likely to perceive that climate change is one of the main challenges at global and national level and support the adoption of climate mitigation policies. In this context, the national strategy for climate change should focus on effectively informing and engaging the public in climate mitigation strategies, strengthening the public trust in government institutions, promoting mutually acceptable solutions with the local communities, and providing incentives for changing citizens’ behavior towards climate-related actions.

Ice Composites Strengthened by Organic and Inorganic Nanoparticles

Extensive development of the Arctic, rich in various natural resources, requires a lot of cheap ecologically safe construction materials preferably using local renewable sources. Ice being easily available in regions with a cold climate meets all the above criteria but has low strength, high fragility and a tendency to creep. Known strengthening techniques using macroscopic and microfiber additives have many drawbacks. This paper describes a new approach to ice strengthening by adding organic or inorganic 50–100 nm nanoparticles (NPs) to the water to be frozen and presents experimental results and possible mechanisms analysis of polycrystalline ice strengthening using NPs. Cellulose and silica NPs have been tested as typical representatives of such additives. Both are hydrophilic, ecologically safe, widespread, cheap and can be produced from local renewable raw materials. It is shown that the addition of 0.01 to 5 wt.% of NPs results in a reduction of ice composite average grain size by a factor of 5.3 ± 0.7 and an increase of its compression strength by a factor of 2.5 ± 0.3. The highest sensitivity of ice strength to NPs concentration is between 0.1 and 1 wt.%. In this concentration range, the increase in strength is reversely proportional to the square root of the average grain size. Experimental data fit Griffith’s relation better than Hall–Petch, so ice strength is limited by cracks with the length proportional to average grain size.

A Mini-Review of Current Activities and Future Trends in Agrivoltaics

Agrivoltaics (Agri-PV, AV)—the joint use of land for the generation of agricultural products and energy—has recently been rapidly gaining popularity, as it can significantly increase income per unit of land area. In a broad sense, AV systems can include converters of solar energy, and also energy from any other local renewable source, including bioenergy. Current approaches to AV represent the evolutionary development of agroecology and integrated PV power supply to the grid, and can result in nearly doubled income per unit area. AV could provide a basis for a revolution in large-scale unmanned precision agriculture and smart farming which will be impossible without on-site power supply, reduction of chemical fertiliser and pesticides, and yield processing on site. These approaches could dramatically change the logistics and the added value production chain in agriculture, and so reduce its carbon footprint. Utilisation of decommissioned solar panels in AV could halve the cost of the technology and postpone the need for bulk PV recycling. Unlike the mainstream discourse on the topic, this review feature focuses on the possibilities for AV to become more strongly integrated into agriculture, which could also help in resolution of relevant legal disputes (considered as neither rather than both components).

Optimal sizing and assessment of grid-tied hybrid renewable energy system for electrification of rural site

In the developing countries, rural and remote sites are rarely connected with the national grid due to the lack of transmission and distribution infrastructure. The development of hybrid renewable energy model is an alternate solution to provide electricity accessibility in such areas. In the present research work, a grid-connected hybrid system model has been developed based on the available renewable resources. The proposed model consists of local renewable sources i.e., solar and biomass along with batteries for storage purposes. Major objectives of the study are to optimize the sizing of PV panels and batteries with power sales or purchases from the grid. The net present cost of the system has been minimized which is subjected to power reliability, SOC of batteries, upper and lower bound of SPV and batteries. Discrete Harmony Search (DHS) Algorithm has been adopted to optimize the system. Among the various considered scenarios, optimal configuration includes 30 kW biomass, 83.50 kWp solar PV, 78.70 kW converter and 38.40 kWh battery bank. Further, the optimization result yields the minimum cost of energy and net present cost as 4.66 INR/kWh and 13.07 million INR respectively.

Energy Cost Minimization with Hybrid Energy Storage System Using Optimization Algorithm

The purpose of this study is to develop an effective control method for a hybrid energy storage system composed by a flow battery for daily energy balancing and a lithium-ion battery to provide peak power. It is assumed that the system operates behind the meter, the goal is to minimize the energy cost in the presence of a PV installation (as an example of a local renewable source) and energy prices are determined by 3-zone tariffs. The article presents the application of an optimization method to schedule the operation of each battery in the system. The authors have defined an optimization method aimed at minimizing the total cost of the system, taking into account energy costs and batteries depreciation. The techno-economical model of the system, including battery degradation, is constructed and the cost optimization methods are implemented in Python. The results are validated with real energy and price profiles and compared with conventional control strategies. The advantages of optimization in terms of energy cost are discussed. The experiment shows that not only is a hybrid energy system successful in lowering the total operation cost and in increasing self-consumption but also that the implemented methods have slightly different properties, benefits and issues.

Analysis of the Possibility of Achieving Energy Self-Sufficiency on the Communal Level in North-Eastern Poland

The pursuit of energy self-sufficiency is understandable, as there can exist many reasons standing behind such pursuit. When considering commune level, many factors can influence the possibility of achieving energy self-sufficiency, but one thing is certain - this idea can be achieved by utilizing local renewable sources of energy, saving energy and using it more efficiently. Such approach allows dealing with both climate change and energy crisis and can be beneficial for the local population, environment and economy. The main aim of the work is to answer the question whether it is possible to achieve energy self-sufficiency on the communal level in north-eastern Poland. Five communes were analysed in terms of achieving both electric and heat self-sufficiency. We also checked whether there is an impact of selected municipal parameters on the value of energy potential of local energy sources. The results of our study indicate that achieving self-sufficiency is easier in terms of electricity than in terms of heat and local factors have great influence on energy potential of individual communes.

Energy mapping and district heating as effective tools to decarbonize a city: Analysis of a case study in Northern Italy

The process of achieving decarbonization and greenhouse emissions’ reduction goals is facilitated and accelerated by the implementation of renewable-based DH rather than multiple individual renewables systems. This work presents an application case that demonstrates how an energy system based on conventional and carbon-emitting heat supply sources can be converted in a fully renewable network.In its current configuration, the city under study, located in Northern Italy, gets 40% of the total 160GWh of heat demand of the DH from a waste-to-energy plant, 9% from a biomass-fuelled ORC, 33% from natural gas cogeneration and 18% from natural gas boilers. In order to support the city’s municipality in developing decarbonization measures through the modernization of the current district heating network, the aim of this work is to investigate in detail the possibility to integrate local renewable and excess heat sources, whose availability and synergy with the heat demand has been highlighted by a recent mapping-based project developed with the Italian DH Association, AIRU, on the whole Italian territory. The present work can be therefore seen as a validation case study of the methodology developed at large-scale level in the latter project. The results of that analysis show that there are the conditions to meet 90% of the heating needs of the DH with renewables and waste heat recovery from two already existing plants, namely a wastewater treatment plant (WWTP) and a steelwork. The approach used in this work, in which different scenarios of integration are simulated in energyPRO, brought to the definition of the energy mix which evidenced a favourable cost–benefits ratio: 59% of thermal energy from the steelwork, 31% from the WWTP, 5% from the natural gas CHP and 5% from the boilers.

Engine performance and PM concentrations from the combustion of Iraqi sunflower oil biodiesel under variable diesel engine operating conditions

The most desirable alternative fuels are biodiesel among several of alternative fuels to use in diesel engines. The biodiesel used in this study is sunflowers oil which derived from local renewable sources. Also, biodiesel considered a best alternative to conventional diesel because it clean and environment friendly. The experimental results shown that the biodiesel blends (B20, B50, and B100) increased the brake specific fuel consumption (BSFC) compared with pure diesel fuel. According to the results, it is indicated that the biodiesel blends reduced the brake thermal efficiency (BTE) and exhaust gas temperatures (EGT) during the combustion of B20, B50, and B100 for all engine operating conditions. The exhaust gas temperature and BSFC increased with increase the operating conditions of engine loads and speeds. The data indicated that PM concentrations reduced with biodiesel blends combustion compared with diesel under variable engine loads and speeds. Besides that the concentrations of PM reduced by 16.847, 28, and 43.34% combustion of B20, B50, and B100, when compared with petroleum diesel under the same conditions of engine loads and speeds. The results give insight that the oxygen content in the biodiesel has favourable effect on reducing the PM concentrations.

An MILP approach for the optimal design of renewable battery-hydrogen energy systems for off-grid insular communities

The optimal sizing of stand-alone renewable H2-based microgrids requires the load demand to be reliably satisfied by means of local renewable energy supported by a hybrid battery/hydrogen storage unit, while minimizing the system costs. However, this task is challenging because of the high number of components that have to be installed and operated. In this work, an MILP optimization framework has been developed and applied to the off-grid village of Ginostra (on the Stromboli island, Italy), which is a good example of several other insular sites throughout the Mediterranean area. A year-long time horizon was considered to model the seasonal storage, which is necessary for off-grid areas that wish to achieve energy independence by relying on local renewable sources. The degradation costs of batteries and H2-based devices were included in the objective function of the optimization problem, i.e., the annual cost of the system. Efficiency and investment cost curves were considered for the electrolyzer and fuel cell components in order to obtain a more detailed and precise techno-economic estimation. The design optimization was also performed with the inclusion of a general demand response program (DRP) to assess its impact on the sizing results. Moreover, the effectiveness of the proposed MILP-based method was tested by comparing it with a more traditional approach, based on a metaheuristic algorithm for the optimal sizing complemented with ruled-based strategies for the system operation. Thanks to its longer-term storage capability, hydrogen is required for the optimal system configuration in order to reach energy self-sufficiency. Finally, considering the possibility of load deferral, the electricity generation cost can be reduced to an extent that depends on the amount of load that is allowed to participate in the DRP scheme. This cost reduction is mainly due to the decreased capacity of the battery storage system.

A Micro-trigeneration Geothermal Plant for a Smart Energy Community: The Case Study of a Residential District in Ischia

Improvements for islands sustainability subjected to strong anthropogenic pressures could be obtained by innovative solutions for energy supply by using local energy renewable sources. This paper analyses the possible benefits of a geothermal energy community, consisting of residential users, located in Ischia, an island of Naples in South of Italy. The proposed system is mainly based on an Organic Rankine Cycle plant interacting with a medium temperature geothermal source. This system satisfies both community’s pure electric load and electricity requests of the electric-driven heat pumps for space conditioning and domestic hot water demands. The entire system and residential users were modelled and dynamically simulated by considering hourly electric, thermal/cooling and domestic hot water loads variation during three reference days for winter, summer and intermediate season. The proposed plant was compared to a traditional system in which the electricity to meet the total community’s electric loads, is taken from the national power grid. The results highlight that the use of proposed system instead of traditional one allows to avoid 29.9 tons per year of CO2 emissions. Furthermore, this proposed system ensures the island-operation of community exploiting local renewable energy source and improving the energy independency.

From self-sufficient provision of water and energy to regenerative urban development and sustainability: exploring the potentials in Mashhad City, Iran

Increased resource demand due to rapid urbanization has made cities like Mashhad highly dependent on their surroundings for resource supply and waste disposal, and has negatively impacted their local-regional hinterlands. To reduce the metabolic footprint of cities and create an environmentally restorative relationship between cities and their supporting ecosystems, a transition toward local alternative and renewable sources is essential. This paper explores potentials for water and energy self-sufficient provision in Mashhad using the Urban Harvesting method to practically illustrate how cities could seek opportunities to meet their needs within their boundaries before relying on external supplies. Results showed that solar photovoltaic and biogas could provide 4495.2 and 472.6 GWh/yr electricity, altogether enabling Mashhad to offset 100% of its consumption. Water cascading and recycling have the potential to meet 72% of the demand, and replace around 125 mcm/yr of imported water. Similarly, water self-sufficiency would increase by 5%–8% (8.6–14.7 mcm/yr) when collecting rainwater from rooftops.

Local Heating Networks with Waste Heat Utilization: Low or Medium Temperature Supply?

District heating enables an economical use of energy sources that would otherwise be wasted to cover the heating demands of buildings in urban areas. For efficient utilization of local waste heat and renewable heat sources, low distribution temperatures are of crucial importance. This study evaluates a local heating network being planned for a new building area in Trondheim, Norway, with waste heat available from a nearby ice skating rink. Two alternative supply temperature levels have been evaluated with dynamic simulations: low temperature (40 °C), with direct utilization of waste heat and decentralized domestic hot water (DHW) production using heat pumps; and medium temperature (70 °C), applying a centralized heat pump to lift the temperature of the waste heat. The local network will be connected to the primary district heating network to cover the remaining heat demand. The simulation results show that with a medium temperature supply, the peak power demand is up to three times higher than with a low temperature supply. This results from the fact that the centralized heat pump lifts the temperature for the entire network, including space and DHW heating demands. With a low temperature supply, heat pumps are applied only for DHW production, which enables a low and even electricity demand. On the other hand, with a low temperature supply, the district heating demand is high in the wintertime, in particular if the waste heat temperature is low. The choice of a suitable supply temperature level for a local heating network is hence strongly dependent on the temperature of the available waste heat, but also on the costs and emissions related to the production of district heating and electricity in the different seasons.

Optimal Operation Strategy for Electric Vehicles Charging Stations with Renewable Energy Integration

This paper proposes an aggregator for the optimal scheduling of a Electric Vehicle (EV) charging station. Assuming that the station charging can consume energy from the power grid and also from a renewable source at no cost, Day-Ahead and Real-Time strategies are developed for the station, considering uncertainty in the local renewable generation source. First, a scheduler decides the energy to buy in the day ahead market from the power grid considering a renewable source forecast and an EVs schedule. An autoregressive model developed from 5 years of historical solar radiation data is applied. In real time, a model predictive control strategy is designed to follow the scheduled power from the grid, compensating variations in renewable generation by exploiting flexibility in the EVs charging process. The resulting optimization problems are convex programming problems that can be solved efficiently. Simulation analysis show the effectiveness of the strategy in absorbing the variability of the renewable source, minimizing the deviations between the day ahead schedule and the actual real time consumption from the grid.

Cooperatives governing energy infrastructure: A case study of Berlin’s grid

At present, as energy security has become one of the highest priorities discussed globally, swift social, ecological and economic changes in the energy market are taking place. In many countries, local cooperatives have been established that intend, among other goals, to purchase power grids and increase renewable energy production. This paper presents the outcomes of a research project devoted to one specific case – BürgerEnergie Berlin (BEB). This cooperative, which is bidding for a twenty-year concession to the Berlin power grid (the biggest in Germany), intends to modernise it after the purchase in order to change it into a smart grid and enable a number of local renewable sources to connect to it. A key success factors model for this cooperative – based on field studies and the use of inductive reasoning – is the original contribution to existing research on energy cooperatives. The presented qualitative analysis, taking into account the details of the process of bidding for the concession, can be an inspiration to cooperative researchers and practitioners and a contribution to a future discussion on alternative solutions to the issues of public utilities ownership and their management.

Using Different ML Algorithms and Hyperparameter Optimization to Predict Heat Meters’ Failures

The need to increase the energy efficiency of buildings, as well as the use of local renewable heat sources has caused heat meters to be used not only to calculate the consumed energy, but also for the active management of central heating systems. Increasing the reading frequency and the use of measurement data to control the heating system expands the requirements for the reliability of heat meters. The aim of the research is to analyze a large set of meters in the real network and predict their faults to avoid inaccurate readings, incorrect billing, heating system disruption, and unnecessary maintenance. The reliability analysis of heat meters, based on historical data collected over several years, shows some regularities, which cannot be easily described by physics-based models. The failure rate is almost constant and does depend on the past, but is a non-linear combination of state variables. To predict meters’ failures in the next billing period, three independent machine learning models are implemented and compared with selected metrics, because even the high performance of a single model (87% true positive for neural network) may be insufficient to make a maintenance decision. Additionally, performing hyperparameter optimization boosts the models’ performance by a few percent. Finally, three improved models are used to build an ensemble classifier, which outperforms the individual models. The proposed procedure ensures the high efficiency of fault detection (>95%), while maintaining overfitting at the minimum level. The methodology is universal and can be utilized to study the reliability and predict faults of other types of meters and different objects with the constant failure rate.

Microgrid Optimal Scheduling with Renewable Energy Sources Considering Islanding Constraints

The paper proposes a method for microgrid optimal scheduling with renewable energy sources considering islanding constraints. The main purpose of the paper is to reduce the total operating cost of microgrid which includes the purchased energy cost from main grid and total local resources generation cost in grid-connected mode, and generation cost of local generators and renewable sources in islanding mode. The problem of microgrid optimal scheduling is classified into two subproblems like grid-connected mode as a main master problem and islanding mode as a subproblem. The results of grid-connected mode microgrid optimal scheduling are examined in the next subproblem of islanding mode for possible islanding. For the feasible islanding, if sufficient generation is not available the scheduling results will be revised by suitable islanding Bender’s cuts. The suitable islanding Bender’s cut will revise generator unit scheduling, energy storage scheduling and adjustable load scheduling. Numerical simulation has been carried out by using MATLAB software to exhibit the effectiveness of the proposed method of optimal scheduling of microgrid with renewable energy sources.

Identification and optimal control of an electrical storage system for microgrids with renewables

Battery systems are becoming more and more widespread for stationary applications both at power grid level and user level. In this second context, small battery-based storage systems are frequently proposed for the installation in combination with local renewable sources, to increase the self-consumption of the locally generated renewable energy and, in some cases, even to enable the user to disconnect from the main network. Increasing use of storage devices for stationary applications implies a more detailed characterization of the “behavior at the terminals” of these systems. In the same time, the development of new Energy Management Systems is required in order to take advantage of both local information and data from the service provider, such as radiation forecasts from weather forecast services. In this paper, a new EMS is proposed, characterized by a two-level architecture: the higher level, based on a receding horizon control scheme, optimally schedules the operation of the storage by using information on radiation from a forecast service provider; the lower level implements a heuristic procedure (if–then) on a low-cost local controller, in order to perform corrective actions. The proposed architecture has been tested on a real case study.

Odnawialne źródła energii jako szansa na stworzenie proekologicznego wizerunku jednostki samorządu terytorialnego

W artykule została poruszona kwestia obowiązku samorządu terytorialnego dbania o środowiska naturalne. W tym celu jednostki samorządu terytorialnego powinien wykorzystywać najlepsze dostępne techniki, a więc m.in. alternatywne źródła energii. Odnawialne źródła energii zostały ukazane w kontekście zasad ogólnych wspólnotowegoprawa ochrony środowiska. Zgodnie z zasadą integracji polityki ochrony sektorowej z polityką ochrony środowiska, sektor energetyczny nie powinien szkodzić środowisku naturalnemu. Zasada prewencji wymaga działań zapobiegających zanieczyszczeniom powietrza, z kolei zasada ,,zanieczyszczający płaci” wprowadza kary za szkodliwą emisję.Zgodnie z zasadą wysokiego poziomu ochrony w każdym działaniu należy mieć na uwadze ochronę przyrody, a zasada usuwania szkód u źródła promuje stosowanie technologii czystej produkcji. Omówione zostały też zasady zrównoważonego rozwoju oraz partycypacjipublicznej, stanowiące podstawę zarówno ochrony środowiska, jak i udziału obywateli w decydowaniu o nim. Kolejna część artykułu dotyczy związków odnawialnych źródeł energii z samorządem terytorialnym na gruncie prawa krajowego w oparciu o polskie akty prawne, znajduje się tam też opis energetyki obywatelskiej z jej zaletami, sposobamifinansowania, a także z przykładami zarówno z Polski, jak i z krajów UE.

Solar thermal and wind energy applications: Case study of a small Spanish village

The present work examines the supply of heating and electricity to the Spanish village of Uruena, using biomass and other local renewable sources as a result of the growing interest worldwide towards the development of sustainable and energy independent small communities. Specifically, this case study considers the design of a district heating system consisting of a solar heating plant, a biomass plant using straw as a sustainable fuel for the base load and an oil boiler for the peak load, coupled with a hot water tank as a thermal energy storage option. Two alternative scenarios are analyzed for electricity generation purposes, namely a system consisting of three small wind turbines and a system with a single large wind turbine. The results show that the cost of large-scale electricity storage depends on the application and often involves significant capital investments.