30 research outputs found
Integration of demand side and supply side energy management resources for optimal scheduling of demand response loads â South Africa in focus
© 2018 Elsevier B.V. The energy crisis of 2008 in South Africa, due to electricity demand surpassing supply and a depleted electricity reserve margin has exposed the need for more synergy between home energy management systems (HEMS) and supply side energy management systems (SSEMS). Demand side management (DSM) techniques have been investigated and proven to be viable means of regulating electricity demand from the consumer side. However, the viability of DSM is dependent on the participation of willing consumers. In this paper, a combined energy management system (CEMS) is proposed to provide a platform for incorporating the demands and constraints of consumers (time of dispatch, reduction of electricity costs, etc.) and suppliers (reduced operations cost, reduced emissions, etc.). The proposed CEMS utilizes dynamic pricing (DP) and a standard deviation biased genetic algorithm (SDBGA) in minimizing the DSM window to be allocated to the DSM loads of consumers based on the multi-objective constraints. The Medupi power plant which has been modelled to utilize carbon capture and sequestration (CCS) technology is used in carrying out the dispatch of the participating DSM loads (cloth washers, cloth dryers and dish washers) for 100,000 random residential customers. Results show that in dispatch option 1 (in which the user is in control of the start time), a lower cost of electricity of ZAR 373,218.40 is obtained compared to ZAR 416,280.20 by dispatch option 2 (in which the utility selects dispatch time for participating DSM loads) for the consumers. However, dispatch option 2 achieves a better minimized DSM window (14.94 MW), lower operating cost (about 1.6% lower than dispatch option 1), higher plant capacity utilization (87.92% efficiency) and a more evenly distributed profile
Electrons have no identity: Setting right misrepresentations in Google and Apple's clean energy purchasing
© 2018 Elsevier Ltd Aside dedicated generation, transmission and distribution networks, the hype around corporations and other entities purchasing so called clean energy may be considered a deliberate accounting misrepresentation. To illustrate this case in this short perspective, we begin by explaining the technical difficulties of remaining ârenewables pureâ. We then give case studies of two organisations â Apple Inc. and Google LLC â who are, arguably, at fault of making such claims. The method is a simple, non-systematic comparison between what is technically possible, and what is claimed to be possible. Given that incongruous renewables claims have the potential to further impoverish vulnerable households who must bear the financial costs of renewables integration, we conclude that a successful decarbonisation pathway must not have selective winners or losers
Modelling of artificial intelligence based demand side management techniques for mitigating energy poverty in smart grids.
Doctoral degree. University of KwaZulu-Natal, Durban.This research work proposes an artificial intelligence (AI) based model for smart grid initiatives
(for South Africa and by extension sub-Saharan Africa, (SSA)) and further incorporates
energy justice principles.
Spanning the social, technical, economic, environmental, policy and overall impact of smart
and just electricity grids, this research begins by investigating declining electricity consumption
and demand side management (DSM) potential across South Africa. In addition, technical
frameworks such as the combined energy management system (CEMS), co-ordinated centralized
energy management system (ConCEMS) and biased load manager home energy management
system (BLM-HEMS) are modelled. These systems provide for the integration of all aspects
of the electricity grid and their optimization in achieving cost reduction for both the utility and
consumers as well as improvement in the consumers quality of life (QoL) and reduction of emissions.
Policy and economy-wise, this research work further proposes and models an integrated electrification
and expansion model (IEEM) for South Africa, and also addresses the issue of rural
marginalization due to poor electricity access for off-grid communities. This is done by proposing
a hybrid generation scheme (HGS) which is shown to satisfy sufficiently the requirements of
the energy justice framework while significantly reducing the energy burden of households and
reducing carbon emissions by over 70%
Energy (in)justice in off-grid rural electrification policy: South Africa in focus
© 2018 Elsevier Ltd Generally speaking, increasing rural marginalisation in sub-Saharan Africa has sat alongside a rise in energy poor homes in rural off-grid communities. Even measures meant to improve electricity access have exacerbated the energy access gap between grid connected and off-grid homes. For example, the South African Non-Grid Electrification Policy Guidelines for electrifying off-grid, rural poor homes promote the adoption of Solar Home Systems (SHS), which are expected to produce 7.5 kWh/month on average. However, for poor homes within grid coverage, the Free Basic Electricity (FBE) programme allocates 50 kWh/month. This paper investigates the resulting disparity in terms of electricity cost (ZAR/kWh), including associated costs for heating, cooking and other needs. It does so through the energy justice framework, highlighting the mismatch in policy formulation (procedural injustice), resource distribution (distributive injustice) and spatial distribution (injustice in the recognition of population groupsâ special needs). Through a combination of mathematics and social science perspectives, it then moves beyond a critique of the current SHS system to proposes a new one: a hybrid generation approach with a flexible pricing scheme and centralized system of operation that is both ethically compliant and capable of improving electricity access to off-grid communities with standards comparable to grid access
Oil well characterization and artificial gas lift optimization using neural networks combined with genetic algorithm
This paper examines the characterization of six oil wells and the allocation of gas considering limited and unlimited case scenario. Artificial gas lift involves injecting high-pressured gas from the surface into the producing fluid column through one or more subsurface valves set at predetermined depths. This improves recovery by reducing the bottom-hole pressure at which wells become uneconomical and are thus abandoned. This paper presents a successive application of modified artificial neural network (MANN) combined with a mild intrusive genetic algorithm (MIGA) to the oil well characteristics with promising results. This method helps to prevent the overallocation of gas to wells for recovery purposes while also maximizing oil production by ensuring that computed allocation configuration ensures maximum economic accrual. Results obtained show marked improvements in the allocation especially in terms of economic returns. © 2014 Chukwuka G. Monyei et al
Imaginaries on ice:Sociotechnical futures of data centre development in Norway and Iceland
In 2018, Norway promoted itself as a âDatacentre Nationâ. In terms of low cost, renewably generated sources of electricity and low ambient temperatures, Nordic countries and the data centre sector are potentially mutual beneficiaries â yet, there are also negative impacts associated with the necessary electric power production. With this as a starting point, for Norway and Iceland, we explore how data centre proponents promulgate similar techno-environmental imaginaries, but achieve differing degrees of stabilisation. To this end, we use three sources of imaginaries relating to data centre development in Iceland and Norway: those implicit in promotional imagery originating within the countries concerned; those implicit in international newspapers, as indicative of external perceptions; and those implicit in focus groups with the Norwegian and Icelandic public. We show how data centre advocates deploy visual imagery to create a promotional techno-environmental imaginary that marries nature with the digital in a symbiotic form, and we observe that this is largely consistent with the more mundane international imaginary of Norwegian data centres. For Iceland, however, the external imaginary is dominated by associations of excess energy consumption by bitcoin mining. For the publics questioned, there are multiple imaginaries of data centres, with significant notes of moral and other forms of scepticism. Looking ahead, we suggest that for long-term stabilisation of positive data centre imaginaries, conducive to investment, the capacity of Iceland and Norway to equitably supply sufficient renewable power will need to be addressed as a matter of urgency.</p
Examining energy sufficiency and energy mobility in the global south through the energy justice framework
© 2018 Elsevier Ltd The widespread adoption of the energy justice framework notwithstanding, arguments offered have not been able to provide tangible definitions of sufficientarianism and energy mobility. Considering widening disparities on what constitutes sufficient energy (electricity) access between the global north (North America, Europe, Australia) and the global south (sub-Saharan Africa, SSA), this paper highlights the influence of âwestern realityâ on the energy narrative. This paper also attempts to propose a model that evaluates off-grid electrification projects (in the global south) and their ability to guarantee sufficientarianism by examining the prospects of such projects in providing connected households access (energy security and sustainability of energy supply) and mobility (transition from a lower to higher energy level through the purchase of additional electrical equipment). Furthermore, this paper explores and provides arguments on energy bullying (by industrialized nations on developing countries mostly in SSA) while also offering suggestions for improvements in Clean Development Mechanism (CDM) projects. In essence, this paper formulates the endemic problems of energy access and energy mobility (plaguing the global south) as a justice problem and further provides insight into the exacerbation of injustice and bullying exhibited by the global north. Examples from South Africa have been utilized as case study
Nigeria's energy poverty: Insights and implications for smart policies and framework towards a smart Nigeria electricity network
© 2017 Elsevier Ltd A thorough and exhaustive review of relevant literature and associated works is carried out to critically examine energy poverty in Nigeria with respect to ownership and income. Using the desktop approach and empirical formulas, the persistent failure of public infrastructure like healthcare, education and security to the poor electricity generation, transmission and distribution capacity in the country is examined; alongside current government's contribution to buoying our generation capacity and electricity access through policies and investment. The findings of the review reveal the urgent need for the smart roll out of distributed generation units in order to stimulate and encourage the ongoing diversification of the economy and also the need for a sustainable road map that incorporates the successes of countries faced with similar challenges. This review paper also proposes the need for palliatives in form of subsidized solar home systems (SHSs) through a sustainable and economically viable means for off grid homes to assuage the effects of non-availability of grid electricity
A smart grid framework for optimally integrating supply-side, demand-side and transmission line management systems
© 2018 by the authors. Licensee MDPI, Basel, Switzerland. A coordinated centralized energy management system (ConCEMS) is presented in this paper that seeks to integrate for optimal grid operation-The supply side energy management system (SSEMS), home energy management system (HEMS) and transmission line management system (TLMS). ConCEMS in ensuring the optimal operation of an IEEE 30-bus electricity network harmonizes the individual objective function of SSEMS, HEMS and TLMS to evolve an optimal dispatch of participating demand response (DR) loads that does not violate transmission line ampacity limits (TLMS constraint) while minimizing consumer cost (HEMS constraint) and supply side operations cost (SSEMS constraint). An externally constrained genetic algorithm (ExC-GA) that is influenced by feedback from TLMS is also presented that intelligently varies the dispatch time of participating DR loads to meet the individual objective functions. Hypothetical day ahead dynamic pricing schemes (Price1, Price2 and Price3) have also been adopted alongside an existing time of use (Price0) pricing scheme for comparison and discussion while a dynamic thermal line rating (DTLR) algorithm has also been incorporated to dynamically compute power limits based on real time associated data
Positive externalities of decarbonization: quantifying the full potential of avoided deaths and displaced carbon emissions from renewable energy and nuclear power
Earlier research in this journal suggests that nuclear power systems have prevented 1.84 million air pollution-related deaths from 1971 to 2009 and could save an additional 7 million deaths by 2050. Building on that work, we adopt a broader lens that looks at renewable energy and nuclear power as well as a greater range of energy pathways. We examine via 10 hypothetical scenarios and two time frames the varying impact of different technology configurations on the full potential of avoided carbon emissions and avoided mortality across China, the European Union, India, and the United States. From 2000 to 2020, we estimate the substitution of fossil fuels by nuclear power has saved as many as 42 million lives. Similarly, substituting fossil fuels with hydropower has saved 42.1 million lives (slightly more than that for nuclear power). Finally, other forms of renewable energy have saved another 38 million lives . We project that from 2021 to 2040, nuclear power could save an additional 46.1 million lives and displace 1198 GtCO2; hydropower could save a further 46.2 million lives and displace 1281.47 GtCO2; substituting fossil fuels with other renewable energy could similarly save an additional 41.2 million lives as well as displace over 1250 GtCO2. We offer a critical thought experiment on just how much potential low-carbon options have to provide positive externalities compared to fossil fuels