Conference Paper

The Battle of Edison and Westinghouse Revisited: Contrasting AC and DC microgrids for rural electrification

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Abstract

As distributed renewable energy (DRE) systems expand rapidly as a means of electrification for the off-grid population, the debate over the relative merits of AC- versus DC-based systems has intensified. Given that most of the DRE generators as well as batteries deliver DC power and that the majority of appliances being used in rural areas (can) run on DC, it follows that DC-based microgrids are a logical and efficient choice as a solution for electrification. This hypothesis is analyzed in detail for a developing country setting applying the new multi-tier methodology for measuring energy access as introduced by ESMAP. Further, a case study is conducted on an innovative DC nanogrid in Bangladesh as a real world test of practicability. Results show that a re-evaluation of current safety concerns is needed as both theory and commercial practice are superior for DC systems. Further, system performances and efficiency results as well as higher affordability of DC-based microgrids, lead to their comparative advantage. Despite these advantages, the dissemination of DC microgrids still lags far behind AC microgrids. This is due to a number of reasons. Despite a long history, microgrid implementations remain un-standardized and are still in their infancy. Given this relative immaturity, markets tend towards what is already familiar, such as the AC configuration and the prevalence of AC-based appliances that dominates large-scale utility grids, as originally promoted by Westinghouse. Thus, despite the ‘new market’ that microgrids represent, we see strong signs that lock-in effects from the AC power still prevail despite the advantages of DC power and despite the favorable greenfield environment of rural electrification in the Global South.

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... Still they fail to cater to large shares of their (rural) populations, as 1.3 billion people lack access to basic electricity [IEA, 2012]. For an acceleration of economic and social development these challenges need to be addressed as they are inhibiting -or at least delaying-people's development paths [Groh, 2014]. Higher and more volatile resource costs and infrastructure resilience to climate change are yet to be adequately considered. ...
... Further, discussions are often reduced to on-grid and offgrid population, leaving potential solutions for an estimated one billion people out of scope [AGECC, 2010]. This group has been referred to as the " temporarily on/off-grid sector " and is further targeted in the step-wise electrification approach presented here [Groh, 2014, p. 85]. Furthermore, a consensus has been formed on the imminent need of low carbon development scenarios for developing countries in order to prevent dangerous anthropogenic climate change but without undermining their development goals [Jakob et al., 2013]. ...
... Groh [2014] introduces the concept of an energy poverty penalty arguing that poor energy services rooted in infrastructural handicaps inhibit or at the very least delay people " s economic development. He states that " poor energy service quality can refer to insufficiencies, unreliability, dangers in usage, low durability, unfitness, lack of after-sales service and even non-affordability, in the sense of poor financial services " [Groh, 2014, p. 83]. As a consequence, better energy service quality could serve as an essential tool to fight the energy poverty penalty and ultimately help achieve the Millennium Development Goals (MDGs) [UNDP, 2005]. ...
Conference Paper
This paper outlines a bottom-up concept for microgrids. A case study for Bangladesh illustrates the potential for building on the existing infrastructure of solar home systems and underlines the strength of the approach: it aims at economic and infrastructure development created from the communities themselves. Individual stand-alone energy systems are linked together to form a microgrid that can expand towards and eventually interconnect with national or regional grids. This approach can be likened to the concept of swarm intelligence, where each individual node brings independent input to create a conglomerate of value even greater than the sum of its parts.
... Still they fail to cater to large shares of their (rural) populations, as 1.3 billion people lack access to basic electricity [IEA, 2012]. For an acceleration of economic and social development these challenges need to be addressed as they are inhibiting -or at least delaying-people's development paths [Groh, 2014]. Higher and more volatile resource costs and infrastructure resilience to climate change are yet to be adequately considered. ...
... Further, discussions are often reduced to on-grid and offgrid population, leaving potential solutions for an estimated one billion people out of scope [AGECC, 2010]. This group has been referred to as the " temporarily on/off-grid sector " and is further targeted in the step-wise electrification approach presented here [Groh, 2014, p. 85]. Furthermore, a consensus has been formed on the imminent need of low carbon development scenarios for developing countries in order to prevent dangerous anthropogenic climate change but without undermining their development goals [Jakob et al., 2013]. ...
... Groh [2014] introduces the concept of an energy poverty penalty arguing that poor energy services rooted in infrastructural handicaps inhibit or at the very least delay people " s economic development. He states that " poor energy service quality can refer to insufficiencies, unreliability, dangers in usage, low durability, unfitness, lack of after-sales service and even non-affordability, in the sense of poor financial services " [Groh, 2014, p. 83]. As a consequence, better energy service quality could serve as an essential tool to fight the energy poverty penalty and ultimately help achieve the Millennium Development Goals (MDGs) [UNDP, 2005]. ...
Chapter
Full-text available
The study investigates a bottom-up concept for microgrids. A financial analysis is performed through a business model approach to test for viability when replacing a researched energy expenditure baseline in Bangladesh. A case study of Bangladesh illustrates the potential for building on the existing infrastructure base of solar home systems. Opportunities are identified to improve access to reliable energy through a microgrid approach that aims at community-driven economic and infrastructure development. Network effects are generated through the inclusion of localized economies with strong producer-consumer linkages embedded within larger systems of trade and exchange. The analyzed approach involves the linkage of individual stand-alone energy systems to form a microgrid that can eventually interconnect with national or regional grids. The approach is linked to the concept of swarm intelligence, where each individual node brings independent input to create a conglomerate of value greater than the sum of its parts.
... • Overall cost and reliability are better because fewer number of equipment pieces is needed (Groh et al., 2014). ...
... • DC-based appliances have higher efficiency than ACbased appliances (Groh et al., 2014;Bayoumi 2015Bayoumi , 2017. ...
... stand-alone SHS or isolated microgrids) towards the question which level of access in a gradual process is present or which quality of service is provided [Tenenbaum et al. 2014]. Therefore, this paper joins the effort to distance itself from a binary category of energy access towards a multi-tier framework in order to be able to measure a continuum of improvement [UN, 2014;ESMAP, 2014, Muench & Aidun, 2014Groh et al. 2014b]. ...
... First, there is an increasing number of examples where parallel infrastructures are at play, e.g. new microgrid connection overlaying diesel generators and SHS alike [Groh et al. 2014b] speaking in favour of the sunk cost principle. Second, again records from POs show that the offer to return back the SHS upon arrival of the national grid has hardly ever been exercised 4 . ...
Chapter
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... Also, in regard to the ability to utilize the energy access for productive use, there are clear restrictions [10]. On the other hand, the systems are generally oversized to assure high reliability, but ends up generating excess electricity which are lost while the batteries are full [11]. ...
Conference Paper
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... This legacy dualistic perspective is being steadily challenged through advances in policy and technologies. Field studies applying the MTF show that SHS perform equally if not better in a comparative assessment against national grid connected households in nearby areas in Bangladesh , whereas rapidly advancing energy-efficient DC-appliances enable household energy services at as little as 25W, enjoying a great advantage in a greenfield environment 1 (Phadke et al. 2015;Groh et al. 2014). Nonetheless, the majority of literature and case studies on rural electrification around the globe continue to follow the conventional centralised utility path based on AC grid infrastructure. ...
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The global off-grid energy and policy landscape has undergone a profound transformation on different levels during the last decade, leading to new empirical problems and research challenges for the emerging academic community working on access to energy. In this paper, the research group Microenergy Systems outlines and discusses avenues for future research on energy access, based on ten years of own cross-disciplinary research. Its key line of argument is that in order to reach universal electrification in a cost-effective way, it is necessary to overcome the dualistic perception of off-grid/ on-grid, which is associated with a wider set of assumptions about energy provision, often missing out vital aspects of energy use on the ground. This discussion paper begins by delineating the historical root causes for the low rates of rural electrification in countries of the Global South and their consequences on infrastructure legacies and discourse, such as the dichotomy on-grid/off-grid as a key criterion for measuring access to electricity. Taking up the current debate for alternative definitions of energy access, recent research results on the applicability of the multi-tier framework are discussed. Two case studies support the argument that patterns of electricity usage on both sides of the grid are increasingly converging among poor households. We further explore the swarm electrification concept and different service design approaches as examples of how technology and business model development are not only be informed by, but actively build on and advance the convergence of legacy dualistic perceptions. Finally, this paper discusses the implications this convergent process has on the dissemination of electronic devices in rural areas, warning of a sharp increase in electronic waste in the foreseeable future, and the need for new recycling concepts.
... This is because access to energy can also assist in the development of business activities where heating or cooling are needed, creating opportunities to raise income, and hence help to reduce what the authors regard as "energy poverty", i.e. poverty due to lack of access to energy. As shown in recent publications, this paper joins the effort to distance itself from a binary category of energy access towards a multi-tier framework in order to be able to measure a continuum of improvement (UN, 2014b;Muench and Aidun, 2014;Groh et al., 2014). The quality of electricity supply through the main grid varies substantially (e.g. in terms of black-& brown-outs, voltage fluctuation, among others) in different countries, regions of a country 1 and even parts of the same city. ...
... This is because access to energy can also assist in the development of business activities where heating or cooling are needed, creating opportunities to raise income, and hence help to reduce what the authors regard as "energy poverty", i.e. poverty due to lack of access to energy. As shown in recent publications, this paper joins the effort to distance itself from a binary category of energy access towards a multi-tier framework in order to be able to measure a continuum of improvement (UN, 2014b;Muench and Aidun, 2014;Groh et al., 2014). The quality of electricity supply through the main grid varies substantially (e.g. in terms of black-& brown-outs, voltage fluctuation, among others) in different countries, regions of a country 1 and even parts of the same city. ...
Conference Paper
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... This is because access to energy can also assist in the development of business activities where heating or cooling are needed, creating opportunities to raise income, and hence help to reduce what the authors regard as "energy poverty", i.e. poverty due to lack of access to energy. As shown in recent publications, this paper joins the effort to distance itself from a binary category of energy access towards a multi-tier framework in order to be able to measure a continuum of improvement (UN, 2014b;Muench and Aidun, 2014;Groh et al., 2014). The quality of electricity supply through the main grid varies substantially (e.g. in terms of black-& brown-outs, voltage fluctuation, among others) in different countries, regions of a country 1 and even parts of the same city. ...
Conference Paper
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Thesis
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