Renewable Sources For Electricity Generation Research Articles

Crowbar Protection Scheme for Fault Ride Through in a Doubly-fed Induction Generator

This study focusses on using a crowbar protection scheme to overcome the symmetrical voltage dips in a doubly fed induction generator (DFIG). The crowbar protection scheme is integrated into the wind energy conversion system of the DFIG. The implementation of this scheme provides automated fault ride-through during sudden transients which may otherwise lead to over current faults. The increased use of renewable sources for electricity generation leads to a reduction in pollution which directly benefits the environment. Sustained usage of renewable resources will be beneficial for the environment.

Electrification of New Zealand transport: Environmental impacts and role of renewable energy

New Zealand's goal to be carbon neutral by 2050 has led to the development of strategic policies and schemes to encourage the use of electric vehicles (EVs). However, most studies are focused on the greenhouse gas emissions of EVs while limited studies are available on their other potential environmental impacts. Using life cycle assessment (LCA), the environmental impacts of EV adoption, specifically the battery electric vehicle (BEV), were assessed to determine the future environmental challenges for New Zealand. Due to 87.1 % share of renewable sources of electricity generation in New Zealand in 2022, EV adoption has demonstrated its strong potential to reduce the CO2 emission of the transport sector. Results showed that lithium-ion battery (LIB), including production and disposal, is the major contributor to the environmental impacts of BEV adoption. The direct environmental impacts of BEV in New Zealand range from 0.34 % to 42.5 % across its life cycle. The results are sensitive to the assumptions of the driving range and number of LIB replacements where they could increase up to 34.5 % per km and up to 48.9 % per replacement of LIB on environmental impacts, respectively. Scenario analysis also showed that when the renewable energy share in electricity production is increased to 100 %, the environmental impacts of the BEV life cycle could be reduced by up to 14.5 % while it could decrease by up to 69.6 % in New Zealand. Additionally, reusing the spent LIB for other purposes would have the least environmental impacts on disposal among the options considered in the study. Therefore, New Zealand would benefit the most from BEV adoption by generating 100 % electricity from renewable sources, and developing policies and schemes to repurpose LIB at its end of life.

Reducing emissions using renewable sources for electricity generation in Stewart Island

The electricity is generated in a traditional way extensively using diesel in off-grid areas. However, it increases the consumption of fossil fuels and carbon emissions and therefore it is essential to find alternative solutions to help reaching sustainability goals. The case study is Stewart Island, where the electricity is provided by a distribution network powered by up to five diesel generators at a central diesel power station. Local residents believe that reducing the consumption of diesel and having a renewable source of electricity generation are two of the island’s highest priorities. HOMER PRO software is used to compare current diesel generators system with a hybrid system merging a tidal energy source (predictable) with wind (unpredictable) and diesel (back-up), through a microgrid. Using two wind and four tidal turbines, plus one diesel generator for back-up, produces the highest renewable fraction (61.1%) and reduces the fuel consumption and green gases emissions (GHGs) 199,176 l and 534,061 kg/yr, respectively, in comparison with using diesel station. Its levelized cost at 21 c/kWh is also more cost-effective rather than 23 c/kWh in the present scenario.

Experimental Study on the Effect of Soiling at Various Tilt Angles of Photovoltaic Modules

Abstract: Power generation from a solar photovoltaic system is one of the glowing research fields these days, even governments are also planning toward installation and production of power generation from renewable energy sources because in the future its feasibility and crisis of conventional energy sources will increase. Further government liberalization and technical developments vitalize the use of renewable sources for electricity generation in terms of solar power. In any power production plant, improvement in the efficiency of the plant is a big and important issue. After installing the solar power plant, it is very urgent to get maximum performance from them. With all other factors, the tilt angle and azimuth angle affect the efficiency of the plant. Thus, it is very important to orient the solar modules at optimum tilt angle and azimuth angle for any given location because they are most efficient when they are perpendicular to the sun's rays. A comparison study was executed to achieve the power variation and dust deposition with different tilt angle in natural environment of Ajmer. Powers generated by solar cells over study period are in range of 5.10W and 3.0W. It is evident that Solar module tilted at 260 generate higher power than Solar module tilted at 00 tilted module, followed by Solar module tilted at 450

New Assessment of Wave Energy in Relation to Geomorphological and Demographic Characteristics on the Pacific Coast of Baja California, Mexico

The electrical grid of the Baja California peninsula, Mexico, operates separately from the National Interconnected System, with Baja California connected to the Western Electricity Coordinating Council of the USA; and Baja California Sur having an isolated, independent network. Based on the need for alternative renewable sources of electricity generation in the region, this work evaluates the wave energy power at specific locations on the Pacific coast of the peninsula, and identifies wave generation sites (WEGS). The WEGS were defined as rocky shore sites associated with a wave energy potential of over 10 kW/m (where the installation of oscillating water columns (OWC) is feasible) and the presence of coastal settlements that are less than 10 km from the shoreline. It was found that 370 km of the Pacific coast of the peninsula have characteristics suitable for the installation of OWC, and up to 1.4 million inhabitants could be benefited by this wave energy harvesting.

Trash to Hryvnias: The economics of electricity generation from landfill gas in Ukraine

Utilization of landfill gas for electricity generation should be an attractive option for Ukraine in light of the country’s rapidly growing municipal solid waste problem, the influx of intermittent renewable electricity into the national grid, and renewable energy adoption commitments. However, the deployment of landfill gas power plants has been slow vis-à-vis other alternative energy technologies despite the existing government incentives. This article aims to help understanding this trend by investigating the economic feasibility of landfill gas power plants. The research focuses on determining the Levelized Cost of Electricity of these electricity generation facilities and comparing it to the feed-in tariff available to landfill gas electricity producers. The results show making an investment into a landfill gas-fired power plant is an appealing strategy due to a potential high and quick return on investment at 5.1 years. This leads to the ultimate conclusion that economic feasibility is not a cause for the slow adoption of landfill gas as a source of renewable electricity generation in Ukraine. In addition, the article identifies several potential barriers to landfill gas electricity generation deployment to be investigated in future research.

Life Cycle Assessment of the High Performance Discontinuous Fibre (HiPerDiF) Technology and Its Operation in Various Countries

Composite waste is a growing issue due to the increased global demand for products manufactured from these advanced engineering materials. Current reclamation methods produce short length fibres that, if not realigned during remanufacture, result in low-value additives for non-structural applications. Consequently, to maximise the economic and functional potential, fibre realignment must occur. The High Performance Discontinuous Fibre (HiPerDiF) technology is a novel process that produces highly aligned discontinuous fibre-reinforced composites, which largely meet the structural performance of virgin fibres, but to date, the environmental performance of the machine is yet to be quantified. This study assessed the environmental impacts of the operation of the machine using life cycle assessment methodology. Electrical energy consumption accounts for the majority of the greenhouse gas emissions, with water consumption as the main contributor to ecosystem quality damage. Suggestions have been made to reduce energy demand and reuse the water in order to reduce the overall environmental impact. The hypothetical operation of the machine across different European countries was also examined to understand the impacts associated with bulk material transport and electricity from different energy sources. It was observed that the environmental impact showed an inverse correlation with the increased use of renewable sources for electricity generation due to a reduction in air pollutants from fossil fuel combustion. The analysis also revealed that significant reductions in environmental damage from material transport between the reclamation facility to the remanufacturing site should also be accounted for, and concluded that transportation routes predominantly via shipping have a lower environmental impact than road and rail haulage. This study is one of the first attempts to evaluate the environmental impact of this new technology at early conceptual development and to assess how it would operate in a European scenario.

Solar Chimney Power Plants: A Review of the Concepts, Designs and Performances

This research presents a comprehensive review of solar chimney power plants (SCPP) as a reliable source of renewable electricity generation. Solar chimney power plants differ from other renewable energy technologies because thermal and momentum effects result in 24-h electricity generation. However, they are influenced by a wide range of design, geometrical and operational parameters, and environmental conditions. This review evaluates the design aspects and the theoretical, numerical, experimental, and performance findings in previous works holistically and concisely. The study also extensively discusses the various optimization strategies, advantages, disadvantages, and limitations of solar chimney power plants. Energy storage aspects and hybrid system designs are also addressed in the present review in order to overcome the known handicaps and limitations of solar chimney power plants. The performance figures of the technology are clearly demonstrated as a function of the design and operational conditions, and future prospects are discussed in detail. It is hoped that designers and policymakers will gain valuable insight into the technological features and advancements of solar chimney power plants, assisting them in making a better-informed decision.

Barriers and perspectives for the expansion of wind farms in BRAZIL

The use of renewable sources for electricity generation has as main benefits the preservation of natural resources, security in the distribution of electricity and the reduction of greenhouse gas emissions. Research has shown that the participation of wind in the Brazilian electrical matrix has increased considerably in recent years, despite the existence of multiple barriers to the implementation of wind farms in the country. This study aims to identify and evaluate the current barriers to the expansion of wind farms in Brazil, suggesting ways to overcome them. Based on a systematic review of the literature, the evaluation of the complexity level and associated risk, the barriers were categorized into seven groups. The results indicated that four barriers are more relevant in relation to the expansion of wind farms in Brazil: unstable macroeconomic environment, government policy uncertainty, system constraints, and lack of infrastructure. On this basis, apart from the recent growth of wind energy in Brazil, actions must be taken to mitigate the identified barriers, as the most complex barriers need government intervention to be removed or mitigated, since the electricity market is highly regulated and complex in Brazil. Further research is needed to rank and analyze more deeply the barriers that were identified here, through interviews with stakeholders and visits to wind farms.

Electricity Pricing for Renewable Markets- A Simulation Approach for the Colombian Case

An important technological transformation is taking place in the electricity markets. Increases in the use of non-conventional renewable sources for electricity generation is challenging the system reliability, especially from the suppliers perspective. This context stands out the need to seek market designs and electricity pricing schemes that favor the proper functioning of markets, contributing to the system sustainability and social welfare. This work develops a simulation model that allows evaluating different electricity market designs and pricing schemes under different scenarios of non-conventional renewable sources penetration, using the Colombian electricity market as an application case. Schemes are evaluated under six indicators including price volatility, maximum electricity prices, unattended system demand, average usage of thermal sources, CO2 emissions and generation surpluses. Model results reveal that the market designs and pricing schemes that use levelized costs of electricity provide a favorable performance of the electricity market when the installed capacity of renewable sources increases, considering price volatilities, system CO2 emissions and demand coverage.

If one goes up, another must come down: A latent class hybrid choice modelling approach for understanding electricity mix preferences among renewables and non-renewables

Many countries, states, and territories have set short and long term targets to increase the share of renewable sources for electricity generation as part of their respective energy policies. Increased reliance on renewables can occur from several sources (e.g., biomass, solar, hydro, wind). Similarly, when increasing renewables, a decreased reliance on one or more non-renewable (e.g., coal, gas, oil, nuclear) sources must occur. However, each region is different with respect to its present profile and capabilities to generate electricity. Complicating this is that demand can differ across individuals, states and territories. By using a discrete choice experiment and latent class hybrid choice model (LCHCM), we estimate individual willingness to pay (WTP) values among four renewable and four non-renewable energy sources for residents across Australia’s states and territories. The model identifies two latent segments in relation to WTP, which can be described using differences in pro-environmental attitudes and socio-demographics. The findings reveal that preferences in terms of energy mix composition for electricity generation are heterogeneous across Australia states and individuals. WTP is found to be higher for biomass, whilst those who are younger, males and those holding pro-environmental attitudes are also supportive of hydro and solar over gas and nuclear sources.

An Optimization Model for Operations of Large scale Hydro Power Plants

Globally, there is an increase in the proportion of renewable sources for electricity generation. Among renewable sources, hydropower is the most widespread. For this reason, the improvements of their applications have been the focus of researches. Hydroelectric power plants have numerous aspects which might represent several economic advantages, if they are operated efficiently. Mathematical optimization models are interesting tools that help in the decision-making processes. In this context, this paper introduces a new Mixed Integer Lineal Programming model that determines the most convenient combination of units to operate a large-scale hydro power plant. Several aspects of reality are taken into account, which are sometimes not considered, such as the variation of the hydraulic head and the performance of other elements besides the turbines, as floodgates. To prove the effectiveness of the new model, the Itaipú Power Plant is selected as a case study. It has an installed power capacity of 14,000 MW and holds the world record in terms of annual generation with 103 million MWh. Three possible scenarios are evaluated in order to analyze the behavior of this plant in normal and extreme situations. The results indicate that the model effectively reduces computational times, and that power generation is influenced by market price variations and reservoir limitations..

Renewable Energies in the Electricity System of Valle del Cauca (Colombia)

<p>W artykule opisano obecną sytuację i udział odnawialnych źródeł energii w systemie elektroenergetycznym jednego z departamentów Kolumbii – Valle del Cauca. W ramach badania dokonano interpretacji ram instytucjonalnych dotyczących energii odnawialnej w Kolumbii oraz ogólnej analizy światowego i kolumbijskiego systemu elektroenergetycznego. Kolejna kwestia to udział odnawialnych źródeł energii w wytwarzaniu energii elektrycznej w Valle del Cauca, głównie w zakresie produkcji i infrastruktury energii hydroelektrycznej, bioenergii i energii fotowoltaicznej. W dalszej części autorzy skoncentrowali się na kwestii potencjału elektrycznego energii odnawialnej w omawianym regionie. Ponadto przedstawiono szereg dyskusji na temat tego, jak omawiany departament skorzystał z ram instytucjonalnych dotyczących wykorzystania energii odnawialnej.</p>

Альтернативна модель конкурентного ринку електроенергії України (частина 2)

The development of a competitive electric energy commodity market in Ukraine does not guarantee the creation of the necessary conditions for the security of electricity supply and the adequacy in developing the energy system. The conflict of commercial interests with the physical needs of the energy system causes the need to introduce the capacities market as a complementary segment to the electric energy commodity market. Ukraine has determined that the capacities market will function in the form of competitive procedures according to the targeted scope-oriented approach. Ukrainian capacities market has not yet been launched, but it is already possible to assume its potential ineffectiveness and inefficiency. Significant disadvantages of the electric energy cycle of Ukraine prove the insufficiency of a targeted approach to its organization. In addition, there are also pathological systemic problems with regard to the electrical energy industry of Ukraine (narrow diversification, inflexibility, heavy overtime load of power units, isolation and rapid development of renewable sources of electricity generation). The article proposes an alternative model of Ukrainian capacities market, which provides for: the organization of the balancing capacities market for the preliminary dispatching of both physical and commercial electric energy flows in the energy system; formation of the market of traditional capacities to ensure the adequacy of the development of the energy system; development of the market of alternative capacities for the integration of renewable electric energy generation, taking into account the requirements of flexibility of the energy system. The authors have identified significant advantages of this model compared to the proposed one, which will ensure operational security of electricity supplies and adequacy of the development of the energy system.

Solar PV and Its Future Impact: Consumer Benefit and Grid Reliability

Interest and availability of photovoltaic solar (solar PV) as a source of renewable electricity generation is rapidly increasing across the country; however, its penetration on a national scale remains very low. There are many natural constraints that can serve as factors, including large upfront module costs, locations that do not receive enough sunlight throughout the year, and the inability to be self‐sufficient from using solar PV power alone. Although the use of this specific distributed energy resource (DER) universally throughout the United States in the near future is improbable, it is interesting to ponder a future where solar PV and other DERs are as common as the current methods we use to generate, transmit, distribute, and consume power. Thinking this way helps identify where we are prone to imprecisely estimating outcomes that could have far‐reaching impacts.

The merit order effect of wind and river type hydroelectricity generation on Turkish electricity prices

The environmental concerns and dependency on gas imports push Turkish policy makers to find ways of increasing the share of renewable sources in electricity generation. Providing incentives for renewable energy in the form of feed-in-tariffs is one of the measures to achieve this goal. Basing on the data of Turkish electricity market operator, we quantified the magnitude of the price effects of wind and river type hydro generations on hourly average of day-ahead prices. We find that wind and river type hydro plants reduced the spot electricity prices during the period of 2012–2017, and despite these resources get the same incentives, their impacts on the spot prices and price volatility are different: this can be useful for a more comprehensive cost benefit analysis aimed at differentiating incentive schemes. The paper also discusses possible underlying reasons of these different impacts such as high seasonality of hydro generation and volatility of wind generation. Finally, we show that, assuming more than 75% of the price reductions were reflected into the consumer prices in Turkey, the net impact of wind and river type hydro generation on final consumer prices would be negative. This finding contributes to the discussions on renewable energy incentive mechanisms.

Multi-level supervisory emergency control for operation of remote area microgrid clusters

Remote and regional areas are usually supplied by isolated and self-sufficient electricity systems, which are called as microgrids (MGs). To reduce the overall cost of electricity production, MGs rely on non-dispatchable renewable sources. Emergencies such as overloading or excessive generation by renewable sources can result in a substantial voltage or frequency deviation in MGs. This paper presents a supervisory controller for such emergencies. The key idea is to remedy the emergencies by optimal internal or external support. A multi-level controller with soft, intermedial and hard actions is proposed. The soft actions include the adjustment of the droop parameters of the sources and the controlling of the charge/discharge of energy storages. The intermedial action is exchanging power with neighboring MGs, which is highly probable in large remote areas. As the last remedying resort, curtailing loads or renewable sources are assumed as hard actions. The proposed controller employs an optimization technique consisting of certain objectives such as reducing power loss in the tie-lines amongst MGs and the dependency of an MG to other MGs, as well as enhancing the contribution of renewable sources in electricity generation. Minimization of the fuel consumption and emissions of conventional generators, along with frequency and voltage deviation, is the other desired objectives. The performance of the proposal is evaluated by several numerical analyses in MATLAB®.

Four heuristic optimization algorithms applied to wind energy: determination of Weibull curve parameters for three Brazilian sites

Minimizing errors in wind resource analysis brings significant reliability gains for any wind power generation project. The characterization of the wind regime is one of fundamental importance, and the two parameters Weibull distribution is the most applied function for it. This study aims to determine the scale and shape factor in an attempt to establish acceptable criteria to a better utilization of wind power in the states of Pernambuco and Rio Grande do Sul, which is a national prominence in the use of renewable sources for electricity generation in Brazil. The following heuristic optimization algorithms were applied: Harmony Search, Cuckoo Search Optimization, Particle Swarm Optimization and Ant Colony Optimization. The fit tests were performed with data from the Brazilian Federal Government’s SONDA (National System of Environmental Data Organization) project, referring to Triunfo, Petrolina and São Martinho da Serra, states of Pernambuco and Rio Grande do Sul, cities in the northeast and south regions of Brazil, during the period of 1 year. The tests were made in 2006 and 2010, all at 50 m from ground level. The results were analyzed and compared with those obtained by the maximum likelihood method, moment method, empirical method and equivalent energy method, methods that presented significant results in regions with characteristics similar to the regions studied in this study. The performance of each method was evaluated by the RMSE (root mean square error), MAE (mean absolute error), R^2 (coefficient of determination) and WPD (wind production deviation) tests . The statistical tests showed that ACO is the most efficient method for determining the parameters of the Weibull distribution for Triunfo and São Martinho da Serra and CSO is the most efficient for Petrolina.

ON THE SIMULATION OF REGULAR WAVES IN A NUMERICAL WAVE TANK

The use of renewable sources for electricity generation has been accelerated because of high fuel prices of fossil fuels. In addition to this, the use of conventional fuel supplies is no longer able to cater for the ever increasing energy demands of the modern world which is experiencing an age of rapid expansion. Furthermore, use of renewable energy aims to mitigate the effects of climate change such as global warming and rising sea levels which is brought about by the use of fossil fuels. Fiji is not spared from the harsh reality of rising sea levels which poses a threat on their livelihoods as a result of climate change. It is important to find alternative energy source which is environmentally friendly and reduces dependence on fossil fuel. Generating power from waves offers a good option. As such in the present study commercial computational fluid dynamics (CFD) code ANSYS-CFX is used to model a piston type 3D numerical wave tank (NWT). An actual NWT is constructed to generate desired wave climate based on field measurement at a site in Fiji. The CFD results compared very well with analytical solutions. The difference is within 3% highlighting the validity of the CFD code.

Assessment of regional transmission connection capacity based on two novel indices

In deregulated market environments, transmission system expansion planning becomes a troublesome task as transmission system operators lose their direct control over plant investments. Moreover, the increase in the share of renewable sources in electricity generation creates an uncertainty about future generation investments in terms of location and size. Assessment of transmission connection capacities, which determines the boundaries of new generation amount that can safely be connected from a region, is a mechanism that facilitates economic and reliable transmission expansion. In this study, use of two novel indices, namely region-based evaluation index (REI) and line-based evaluation index (LEI), is proposed for this purpose. REI aims to indicate the suitability of a region for new generation investments from a holistic point of view. Its calculation is based on the loadings of the lines under N − 1 conditions, and their overloading probabilities. LEI, on the other hand, is usable to assess each variation of the considered line's loading. By tracking LEI of a line, one can follow if a line's loading exceeds limits during contingencies, and observe if the loading benefits from additional generation. It allows identifying the weak points of the analysed system. The proposed methodology was demonstrated on projected Turkish Transmission Network model of 2026.