Centralized Electricity Generation Research Articles

Socialism and Electricity: Renewables and Decentralisation Versus Nuclear

ABSTRACT A socialist energy supply system should be based on centralised electricity generation, primarily from nuclear power, Matthew Huber and Fred Stafford argue. They propose only a minor role for wind and solar, and see decentralised renewables as unworthy of support. Huber further contends that neoliberalism fostered decentralised renewables, while undermining centralised generation, and socialists seduced by “green” thinking have unwittingly become neoliberalism's allies. In this response, I propose that nuclear power has been opposed by socialists for good reasons: it requires a strong state, and is inherently linked to the military. The trend towards decentralisation of electricity networks has been underway for decades; claims that it is at odds with public ownership or socialist principles are unfounded. Portraying renewables as a burden on existing networks is misleading. Instead, we need discussion of whether, and how, socialism can challenge capital's control of these electricity technologies, including decentralised renewables, and turn them to our advantage. The potential of decentralised networks to enhance forms of common ownership and decommodification needs to be tested. Claims that renewables are, by comparison to nuclear, inherently inimical to labour organisation or public ownership, or that they are historically underpinned by neoliberal ideology, are baseless.

Comparative Analysis of Renewable Energy Community Designs for District Heating Networks: Case Study of Corticella (Italy)

In recent years, a rapid increase in the adoption of renewable energy sources and in the transition from a centralized electricity generation system to an increasingly distributed one has occurred. Within this scenario, in line with the European directives for achieving the objectives in the field of energy transition and climate change, energy communities are seen as potential contributors. The purpose of this work is to analyze the application potential of the energy community concept associated with district heating networks, leading to better overall energy-economic performance. This was demonstrated for a specific energy community in Italy, and it can be achieved by maximizing internal energy sharing—resulting from the electricity surplus generated by the photovoltaic system—and adopting different strategies that include heat pumps in order to maximize self-consumption and self-sufficiency, as well as to evaluate the most efficient investment in economic terms by exploiting the incentive tariff on shared energy. The results show that the performance of the system can be improved with the proposed design, achieving a significant reduction in the system’s energy demand, emissions and costs: compared to the reference case, the use of photovoltaics reduces primary energy demand by approximately 11%, while the addition of the energy community configuration allows emissions to be reduced by nearly 12%, with no additional investment.

Centralized Grid electricity and distributed electricity: A case study of Nigeria

The push for the liberalization of the electricity market and the concern over climate change is an impetus for the call to a paradigm shift in electricity generation mode. Electricity generation can either be centralized or distributed. The major selling points for distributed electricity generation are energy security and greenhouse gas reduction. However, some other factors weigh an impact on electricity generation. Nigeria is a country battling to meet the electricity demand of its populace. Some of the identified factors are localized to Nigeria to come up with a suitable generation model. This study considers factors such as energy security and reliability, environmental impact, energy efficiency, cost, and rural electrification. These factors led to a basis to propose a suitable generation model for the country based on her peculiarities. Distributed electricity generation promises an edge over centralized electricity generation while considering energy security, efficiency, rural electrification, and capital investment cost. Distributed generation allows access to the deployment of clean energy. However, this is not to construe that its adoption will automatically guaranty reduced emissions.

Assessing the societal benefits of energy storage in electricity systems with large shares of renewables

Energy storage systems (ESS) can offer significant benefits to electricity systems and hence to society. Some of them include avoiding the costs of expensive centralized electricity generation and its environmental impact. However, existing electricity market arrangements aiming at rewarding these benefits present large externalities and therefore fail to reward well the true societal benefits of energy storage. In particular, ESS could be operated to avoid the emissions of polluting centralized generation. Thus, ESS could also avoid the damage cost of those emissions such as the social cost of climate change and the damage on population health. These large externalities are likely much higher than typically seen carbon taxes and prices. In this paper, we present an empirical assessment of the locational societal benefits of energy storage in a real electricity system that has a significant presence of solar and hydro power generation, and important transmission constraints. The assessment is performed via a linear programming model that is applicable for small scale ESS. Major conflicts were found between energy and emission arbitrage in zones with hydrothermal generation, yet strong synergies in zones with high solar generation. Transmission congestion has a significant impact on this. Energy storage benefits associated with the provision of reserve services are the highest source of societal benefit. Finally, it is shown that a battery system may be an attractive investment from a societal perspective.

Natural Gas Has Role in Decarbonizing the Australian Electricity Supply

This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 202210, “Future Roles for Natural Gas in Decarbonizing the Australian Electricity Supply Within the NEM: Total System Costs Are Key,” by Stephanie Byrom, University of Queensland; Geoffrey Bongers, Gamma Energy Technology; and Andy Boston, Red Vector, et al., prepared for the 2020 SPE Asia Pacific Oil and Gas Conference and Exhibition, originally scheduled to be held in Perth, Australia, 20–22 October. The paper has not been peer reviewed. Electricity systems around the world are changing, with the Paris Agreement of 2015 a catalyst for much current change. The Australian government ratified the agreement by committing to 26–28% emissions reductions below 2005 levels by 2030. Reduction in emissions from electricity generation has become the focus of these targets. To decarbonize the grid to meet targets while building firm, dispatchable generation capacity to support the system, a new metric is required to measure success. The complete paper explores the outputs of the model of energy and grid services (MEGS), illustrating outcomes if a single technology group is favored. Introduction The majority of electricity in the Australian National Energy Market (NEM) is provided by synchronous thermal power generation, which also has delivered services required for grid stability such as inertia and frequency control. The NEM commenced operation in December 1998 and includes five regional market jurisdictions: Queensland, New South Wales (including the Australian Capital Territory), Victoria, South Australia, and Tasmania. In 2020, the NEM incorporated approximately 40,000 km of transmission lines and cables, connecting approximately 57 GW of generation capacity to consumers. This thermal generation mostly has consisted of coal- and gas-based technologies. Electricity grids are also changing from largely centralized electricity generation systems to more decentralized ones and from unidirectional electricity flows to bidirectional flows as part of the effort to reduce emissions. However, with increasing penetration of variable renewable energy (VRE) generation, it is important to plan for and manage generation-asset investment to track the lowest possible total system cost and highest reliability path to a low-emissions future. A Competent, Diverse Grid A competent electricity grid is one that can keep the lights on, so to speak, within the legislated tolerance for outages and performance. A competent grid is adequate, reliable, secure, operable, and robust against externally driven disruptions. In practice, the reliability of the electricity grid often seems to be taken for granted; however, it is an essential element of the modern economy, and, with a changing grid, reliability is increasingly important. When a decision must be made to build or replace an individual power plant, stakeholders (individual investors) have traditionally considered the levelized cost of energy (LCOE) of the alternative generation options, which di-vides the total cost of an installation or plant by the kilowatt-hours it produces over its lifetime. However, metrics such as LCOE, based on grid-independent formulae to help power plant investors to maximize returns, are inappropriate for comparing technologies that deliver and demand a complex menu of services specific to the grid. A different metric is required to evaluate each technology’s contribution to the grid.

Local Energy Projects on Islands: Assessing the Creation and Upscaling of Social Niches

Islands have great potential for renewable energy, and several pilot and experimental projects have been set up on islands globally, aiming to promote clean energy and self-sufficiency. Many of these decentralized energy initiatives oppose the established regimes of centralized electricity generation and introduce new forms of organization and management. Thus, they can be considered social niches. The aim of the present study is to explore the transition potential of renewable energy projects on three islands located in southern Europe. The analysis mobilizes literature on the strategic niche management theory (SNM) with a focus on the role of the various actors and the different management models. Through a systematic analysis of policy documents and the literature, enriched by interviews, the paper identifies different types of renewable energy projects and discusses the potential for scale up. The paper concludes that these projects are currently in the inter-local phase, and decentralization is not only an important innovation for energy production, but also a new form of energy management often dominated by different actors than the established electricity system.

Application of Distributed Electricity Generation Systems in Agricultural Greenhouses

Use of distributed electricity generation systems is currently increasing due to their economic and environmental benefits. Agricultural greenhouses require heat and electricity for covering their energy needs while their annual energy requirements vary significantly. Aim of the current work is the investigation of applying various distributed electricity generation systems in greenhouses. A review of different distributed generation systems currently used in various sectors as well as in greenhouses has been implemented. Various technologies are examined utilizing either renewable energies or fossil fuels in very efficient energy systems. Most of them are mature and cost-effective having lower environmental impacts compared with traditional centralized electricity generation technologies. Their use in greenhouses results in many benefits including the creation of an additional income for the farmer, reduction of carbon emissions into the atmosphere and increasing stability of the electric grid. It is suggested that distributed electricity generation systems should be used more in greenhouses when the necessary conditions are favorable.

Comparative study between measured and estimated wind energy yield

This paper proposes a power-speed (P-V) model of the wind turbine by assuming three different functions for the first performance region; cubic, quadratic and uncorrected cubic. These three functions have been compared with the manufacturer models of five different wind turbines which were installed in five different locations in Jordan; Tafila, Hofa, Fujeij, Al Rajef, and Deahan. The wind turbine of these wind farms are considered as large scale HAWT in the range of Mw. The generated P-V models are developed by applying a new method described in this paper which is basically based on generating a multiplier factor x. In this study, the quadratic model shows the highest correlation compared with the other models. The wind energy yield for the selected wind farms has been estimated by a mathematical modelling based on Rayleigh distribution function, derived in this paper. The energy yield using this mathematical model has been compared with the measured energy output of four wind farms, Tafila, Hofa, Al Rajef, and Deahan. The measured energy were provided by the operators of these wind farms which are: Jordan Wind Project Company(JWPC), Central Electricity Generation Company (CEGC), Green Watts Renewable Energy (GWRC)and Korean Southern Power Company(KOSPO). Results show that the estimated energy using the quadratic wind turbine model for all wind farms are very close to the actual output. Accuracy analysis for the quadratic model resulted in an error of less than 10% between the measured and estimated energy output for all wind farms. The capacity factors for the selected wind farms have been estimated using the quadratic P-V model. Results show that Tafila wind farm has the highest capacity factor which is around 47%.

Cross-Scale Linkages of Centralized Electricity Generation: Geothermal Development and Investor–Community Relations in Kenya

Based on a study of Kenya’s geothermal-energy development in Baringo-Silali, we explore how and with whom government actors and local communities in rural and peripheral areas interact when planning and implementing large-scale power plants. Starting from a comparison of decentralized and centralized energy systems, we demonstrate that the development of this large-scale infrastructure project and the associated investor-community relations are governed by various cross-scale linkages. To this end, we adapt the concept of cross-scale linkages from the literature on natural-resource governance to explore actors, rules, and practices at local, regional, national, and international levels.

Impact of electricity market feedback on investments in solar photovoltaic and battery systems in Swedish single-family dwellings

The profitability of investments in photovoltaics (PVs) and batteries in private households depends on the market price of electricity, which in turn is affected by the investments made in and the usage of PVs and batteries. This creates a feedback mechanism between the centralised electricity generation system, and household investments in PVs and batteries. To investigate this feedback effect, we connect a local optimisation model for household investments with a European power generation dispatch model. The local optimisation is based on the consumption profiles measured for 2104 Swedish households. The modelling compares three different scenarios for the centralised electricity supply system in Year 2032, as well as several sensitivity cases. Our results show total investment levels of 5–20 GWp of PV and 0.01–10 GWh of battery storage capacity in Swedish households in the investigated cases. These levels are up to 33% lower than before market feedback is taken into account. The profitability of PV investments is affected most by the price of electricity and the assumptions made regarding grid tariffs and taxes. The value of investments in batteries depends on both the benefits of increased self-consumption of PV electricity and market arbitrage.

Preliminary Attempt toward Better Understanding the Impact of Distributed Energy Generation: An Agent-Based Computational Economics Approach

AbstractThe increasing adoption of small-scale electricity generation technologies represents a transition from a hub-and-spoke system of centralized electricity generation to distributed energy re...

Microgrids for Disaster Management: An Ethical Risk Perspective

Microgrids are interconnected distributed energy generation and storage systems that can act as either an extension of the existing grid or operate independently of the grid, in so-called island mode [1]. As a power supply technology, microgrids are attractive as they can be more reliable than existing infrastructure and reduce societies? reliance on nonrenewable energy sources [1]. As a valid alternative to reliance on centralized electricity generation and grid distribution, microgrids have value that materializes when disasters render grids inoperable and microgrids remain as islands of service. It is these specific disaster conditions that reveal the latent value of microgrids as disaster management tools, whereas under nondisaster conditions, their value remains hidden. Microgrids can thus be leveraged to manage disaster relief efforts while remaining connected to donor sources and the broader humanitarian relief supply chain.

Extremum Seeking Control for optimization of a feed-forward Pelton turbine speed controller in a fixed-displacement hydraulic wind turbine concept

With the sustained drive towards higher power ratings for offshore wind turbines, the size of the turbine rotor and drivetrain components scale accordingly. Compact hydraulic transmissions are widely applied in high-load systems and form a business case for application in multi-megawatt offshore turbines. The Delft Offshore Turbine (DOT) is a hydraulic wind turbine concept replacing conventional drivetrain components with a single seawater pump. In the DOT concept, pressurized seawater is directed to a Pelton turbine-generator combination, located at a central electricity generation platform. An in-field test campaign is performed using a prototype DOT turbine with a retrofitted 500 kW hydraulic drivetrain, consisting of fixed-displacement components. As a result of this configuration, a feed-forward Pelton speed controller is derived and implemented for operating the Pelton turbine at maximum efficiency. However, the controller tuning is based on estimations of physical system properties, of which the resulting optimality is unknown. For verification of the implementation, the model-free, gradient-based and data-driven Extremum Seeking Control (ESC) optimization scheme is employed. Results show fast convergence of the algorithm and an average maximum power increase of 3 %. The algorithm is well suited for application to real-world systems, due to its simplicity and ease of tuning.

Solar Photovoltaic Distributed Generation in Brazil: The Case of Resolution 482/2012

The current electric generation in Brazil to meet its demand is based on centralized electricity generation, however, a new decentralized model is emerging in light of the recent advance of distributed generation (DG), among them, solar photovoltaic DG. The objective of this article is to present an analysis of the evolution of solar photovoltaic DG in Brazil, after the Normative Resolution (NR) No. 482/2012 of the National Electric Energy Agency (Agência Nacional de Energia Elétrica - ANEEL). The methodology used was based on an exploratory, descriptive and bibliographic study that supported an information analysis on the growth and prospects of solar photovoltaic DG market in Brazil. Hypotheses that current national regulations need improvements, and there is a great potential for expansion to solar photovoltaic DG have been taken as a starting point. Analyzes of the Brazilian socioeconomic context and the impacts after the NR No.482/2012 on the development of a national market for photovoltaic DG in recent years were carried out. ANEEL regulations have been periodically revised and updated in an attempt to induce a growth of solar photovoltaic market in Brazil. The results indicate a growth of solar photovoltaic DG in the country since 2012, with a significant increase in 2015. In conclusion, despite the growing evolution of solar photovoltaic DG in Brazil, there is a need for further regulatory improvements to boost this market. In addition, this article proposes that existing regulations could be improved in order to: a) reduce or exempt taxes on equipment of solar photovoltaic DG, as well as provide government incentives; (b) enable consumers to enjoy greater benefits by allowing the surplus energy to be sold to the distributor or the free market; c) exempt taxes for non-profit institutions, and d) include in housing programs and projects, the requirement of energy efficiency and solar photovoltaic DG.

Utilization of eucalyptus for electricity production in Brazil via fast pyrolysis: A techno-economic analysis

Abstract A process model of a 2000 metric ton per day eucalyptus Tail Gas Reactive Pyrolysis (TGRP) and electricity generation plant was developed and simulated in Pro/II software for the purpose of evaluating its techno-economic viability in Brazil. Two scenarios were compared based on operational conditions in the country: a single biomass to bio-oil TGRP production facility and a distributed/satellite processing that consists of several small TGRP production facilities with aggregate capacity similar to the single one, both feeding into one centralized electricity generation plant. The selling price at the breakeven point of the electricity generated via TGRP was estimated to be US$0.34 and US$0.62 per kWh for the single and the distributed scenarios respectively, considering a 10-year payback period. The single capacity pyrolysis and electricity generation facility is found to have better economic benefits over the distributed plants of small sizes under the current conditions in Brazil. The results therefore indicate that pyrolysis of eucalyptus wood for electricity in a single facility cannot be competitive with the current electricity cost in Brazil (US$0.08–0.13/kWh) at present time. Considering auxiliary benefits such as climate change and carbon credits, plus the continuous increasing in the electricity market price in Brazil, both scenarios could be competitive in the future.

Who pays, who benefits? The financial impacts of solar photovoltaic systems and air-conditioners on Australian households

Increasingly, there are calls for the owners of photovoltaic (PV) systems to pay additional charges on the basis that they are not contributing their fair share to network revenue. Air conditioners (A/Cs) are even more widespread than distributed PV systems, and their use has increased demand peaks and the size of networks required to meet them, the cost of which is typically recovered from all customers. There appears to be limited analysis in the literature regarding the impacts of A/C and PV on the electricity bills of customers who do not have these technologies. While the impacts of renewable energy on centralised electricity generation have been explored in the literature, this paper proposes a methodology to estimate the financial impacts of PV and A/C that flow through network operators to other customers. The analysis indicates that, in the datasets used, A/C systems have most likely resulted in significant bill increases for customers who don’t have them. In contrast, PV systems have most likely had a minimal financial impact on customers who do not have them. While these analyses were undertaken using Australian data, the method is applicable to most countries with modifications to suit the local regulatory environment.

Simulation of an offshore wind farm using fluid power for centralized electricity generation

Abstract. A centralized approach for electricity generation within a wind farm is explored through the use of fluid power technology. This concept considers a new way of generation, collection and transmission of wind energy inside a wind farm, in which electrical conversion does not occur during any intermediate conversion step before the energy has reached the offshore central platform. A numerical model was developed to capture the relevant physics from the dynamic interaction between different turbines coupled to a common hydraulic network and controller. This paper presents a few examples of the time domain simulation results for a hypothetical hydraulic wind farm subject to turbulent wind conditions. The performance and operational parameters of individual turbines are compared with those of a reference wind farm based on conventional wind turbine generator technology using the same wind farm layout and environmental conditions. For the presented case studies, results indicate that the individual wind turbines are able to operate within operational limits. Despite the stochastic turbulent wind conditions and wake effects, the hydraulic wind farm is able to produce electricity with reasonable performance in both below and above rated conditions. With the current pressure control concept, a continuous operation of the hydraulic wind farm is shown including the full stop of one or more turbines.

Feasibility of Small Wind Turbines in Ontario: Integrating Power Curves with Wind Trends

Micro-scale/small wind turbines, unlike larger utility-scale turbines, produce electricity at a rate of 300 W to 10 kW at their rated wind speed and are typically below 30 m in hub-height. These wind turbines have much more flexibility in their costs, maintenance and siting, owing to their size, and can provided wind energy in areas much less suited for direct supply to the grid system. In the future under climate change, the energy landscape will likely shift from the present centralized electricity generation and delivery system to a more distributed and locally-generated electricity and delivery system. In the new system configuration, the role of relatively small sustainable electricity generators like small wind turbines will likely become more prominent. However, the small wind industry has been substantially slow to progress in Ontario, Canada, and there is much debate over its viability in a growing energy dependent economy. This study seeks to demonstrate the performance of a small wind turbine, and speculate on its potential power output and trend over Ontario historically over the last 33 years using the North American Regional Reanalysis (NARR) data. We assessed the efficiency of a Bergey Excel 1 kW wind turbine at the pre-established Kortright Centre for Conservation test site, located north of Toronto. Using a novel approach, the Bergey optimized power curve was incorporated with reanalysis data to establish power output across Ontario at three-hour resolution. Small turbine-based wind power around the Great Lakes and eastern James Bay increased during winter and fall, contributing up to 10% of the annual electricity demand in some regions in Ontario. We purport that increases in power output are driven by long-term reductions in sea and lake ice concentrations affecting atmospheric stability in surrounding regions.

Simulation of an offshore wind farm using fluid power for centralized electricity generation

A centralized approach for electricity generation within a wind farm is explored through the use of fluid power technology. This concept considers a new way of generation, collection and transmission of wind energy inside a wind farm, in which electrical conversion does not occur during any intermediate conversion step before the energy has reached the offshore central platform. A numerical model was developed to capture the relevant physics from the dynamic interaction between different turbines coupled to a common hydraulic network and controller. This paper presents two examples of the time-domain simulation results for an hypothetical hydraulic wind farm subject to turbulent wind conditions. The performance and operational parameters of individual turbines are compared with those of a reference wind farm with conventional technology turbines, using the same wind farm layout and environmental conditions. For the presented case study, results indicate that the individual wind turbines are able to operate within operational limits with the current pressure control concept. Despite the stochastic turbulent wind input and wake effects, the hydraulic wind farm is able to produce electricity with reasonable performance in both below and above rated conditions.

Prosumer clustering into virtual microgrids for cost reduction in renewable energy trading markets

Abstract Today’s electricity system is undergoing a transformation from a model of centralized electricity generation, to a more decentralized paradigm, where a large number of small energy prosumers (i.e. both producers and consumers) generate energy and may participate in the energy market. In these markets, energy is usually traded at a time prior to the time of delivery in an exchange, based on forecasts of the production and the consumption, and the cost for the prosumers is related to the accuracy of these forecasts, through the application of penalties when an imbalance appears. In this paper we study the problem of orchestrating the energy prosumers into virtual clusters, in order to participate in the market as a single entity and to reduce the total energy cost, through the reduction of the total relative forecasting inaccuracies. Using a real dataset of 33 prosumers located in Greece, we study different clustering algorithms, including spectral, genetic and an adaptive algorithm. The performance evaluation results show that significant cost reduction may be achieved, through the association of the prosumers into groups.