Dispatchable hydrogen production by multiple electrolysers to provide clean fuel and responsive demand in Libya

The Publisher's final version can be found by following the DOI link.The use of hydrogen as a fuel carries major environmental advantages because there are a number of ways of producing it by low-carbon methods. When electrolysis is used, additional benefits are obtained by flexible operation that offers the opportunity to reduce the cost of hydrogen production by absorbing electricity during off-peak hours, and stopping operation during peak hours. This can also act as a tool in support of balancing electrical systems. In this research, off-peak electricity is used to produce hydrogen via electrolysis, which is sold as a fuel at six garage forecourts in Darna, a small city on the east coast of Libya. In addition to the six forecourt electrolysers, a centralised electrolyser plant will be included in the system to consume the surplus energy and to satisfy any deficiency in hydrogen production at the forecourt. The capital cost of both forecourt and centralised electrolyser systems, plus fixed costs, were financed by bank loans at a 5% rate of interest over seven years. A MATLAB model with optimisation tools was used to formulate this problem. This research shows that forecourt hydrogen production at off-peak times (and without the centralised electrolyser) can satisfy nearly 53.93% of the fuel demand. This represents 59.82% of the total surplus renewable energy. The average hydrogen sale price at the forecourts is between £10.82-11.71/kg. After adding the centralised electrolyser, nearly 78.83 % of the total surplus power was absorbed and the average hydrogen selling prices were between £15.04-19.80/kg The centralised electrolyser can meet 43%, 49%, 50%, 42%, 57% and 53% of the deficit in consumption for stations 1, 2, 3, 4, 5 and 6, respectively

Management of Demand Profiles on Mini-Grids in Developing Countries Using Timeslot Allocation

Stand-alone mini-grids provide vital energy access to rural communities across the Developing World where economic constraints necessitate optimal cost-effectiveness without compromising reliability or quality of service. Managing electricity demand to match supply availability – for example, by incentivizing consumers to operate loads at specific times – can contribute to this aim. This paper addresses a method to achieve this, whereby timeslots are sold in which additional power is made available to participating consumers with high-powered, commercial loads, such as grain mills. Using a low-cost microprocessor to control remotely-switchable power sockets by wireless communications, circuits are activated according to the timeslots purchased without interruption of low-power (e.g. lighting and phone-charging) circuits. Informed by site survey data, laboratory tests demonstrated the system to be reliable and effective in maintaining demand closer to supply availability while avoiding overloads. This reduces losses and the need for storage while increasing energy access and return on investment

Preliminary Findings From a Pilot Study of Electric Vehicle Recharging From a Stand-Alone Solar Minigrid

open access articleThe symbiosis between smart minigrids and electric mobility has the potential to improve the cost and reliability of energy access for off-grid communities while providing low-carbon transport services. This study explores the commercial viability of using electric vehicles (EVs), recharged by solar minigrids, to provide transport services in off-grid communities. Preliminary findings are presented from a field trial in The Gambia that aims to assess the techno-economic feasibility of integrating sustainable energy and transport infrastructures in sun-rich regions of the Global South. As a dispatchable anchor load, an EV can improve the technical and economic performance of a minigrid by providing demand-side response services. In the developing world, rural communities are often among the poorest, and inadequate transport services remain a major barrier to wealth-creation. Some solutions to this situation may be transferrable to island communities, which share similar challenges in terms of access to energy and fuel. The first of its kind in Africa, this field trial uses an electric minivan, operating from an off-grid village where it has access to a minigrid whose 4.5 kWp of photovoltaic modules form the roof of a parking shelter for the vehicle. While there, the taxi can recharge, ideally during sunny periods when the photovoltaic array produces surplus power, thus allowing the EV’s battery to recharge while bypassing the minigrid’s own accumulator. This improves system reliability and cost effectiveness, while providing pollution-free energy for the taxi. Ultimately, the intention is to test different vehicles in a variety of circumstances, but this paper outlines only the preliminary findings of the first of these trials. Early results provide convincing new evidence that commercial viability of such a concept is possible in Sub-Saharan Africa. Some promising scenarios for commercial viability are identified, which warrant further investigation, since they suggest that a taxi driver’s earnings could be increased between 250 and 1,300% in local operations, and even 20-fold in tourist markets, depending on vehicle type, minigrid configuration and target market. It is hoped that these may encourage the rollout of solar-recharged EVs where the nexus of sustainable energy and transport systems are likely to make the greatest contribution to addressing the UN’s Sustainable Development Goals, by helping to solve the trilemma of providing energy security, social benefit and environmental sustainability in low-income countries

Characterisation of a nickel-iron battolyser, an integrated battery and electrolyser

open access articleElectricity systems require energy storage on all time scales to accommodate the variations in output of solar and wind power when those sources of electricity constitute most, or all, of the generation on the system. This paper builds on recent research into nickel-iron battery-electrolysers or “battolysers” as both short-term and long-term energy storage. For short-term cycling as a battery, the internal resistances and time constants have been measured, including the component values of resistors and capacitors in equivalent circuits. The dependence of these values on state-of-charge and temperature have also been measured. The results confirm that a nickel-iron cell can hold 25% more than its nominal charge. However, this increased capacity disappears at temperatures of 60°C and may be dissipated quickly by self-discharge. When operating as an electrolyser for long-term energy storage, the experiments have established the importance of a separation gap between each electrode and the membrane for gas evolution and established the optimum size of this gap as approximately 1.25 mm. The nickel-iron cell has acceptable performance as an electrolyser for Power-to-X energy conversion but its large internal resistance limits voltage efficiency to 75% at 5-h charge and discharge rate, with or without a bubble separation membrane

SDRC 9.6: An assessment of the public acceptance of Demand Side Response of EV charging using Esprit

This report describes the research conducted by De Montfort University as part of the My Electric Avenue project to investigate public acceptance of the Esprit system for control of electric vehicle (EV) charging. Esprit provides ‘demand side response’ (DSR) for local electricity network protection by intervening in the charging of electric vehicles (EVs) when demands on the local electricity network reach a certain threshold. The aim of the research was to provide a response to SDRC 9.6 set out in the Project Direction: And to address the additional learnings: T.1.1.1 - How does a trial encourage the uptake of low carbon technology? T.1.1.2 - What social factors have an impact on the use of the Technology? T.1.1.3 - How can a trial be used to educate customers about the electricity network and low carbon technologies? Acceptability of Esprit Research findings suggest that the Esprit system for control of EV charging was acceptable to the majority of participants in the My Electric Avenue Technical Trial. The degree of acceptability of Esprit was not related to whether or not participants experienced curtailment of charging by Esprit Most of the participants in the Domestic Clusters whose charging was curtailed were either not aware of the curtailment, or were not impacted by it. In face-to-face data collection, only one participant reported a significant issue with curtailment where changes to plans were required due to insufficient charge in the vehicle. Curtailment of charging by Esprit was more of an issue for participants in the Workplace Cluster of the Technical Trial. The majority of participants opted not to charge at the workplace after curtailment began due to the uncertainty of receiving sufficient charge. This uncertainty may result from the interaction of Esprit and the load profile for the Workplace Cluster which caused Esprit to operate in an impractical way. In face-to-face data collection with Workplace Cluster participants those individuals who needed to charge at the workplace reported being very unhappy with the technology. Acceptability of Esprit by the Workplace Cluster participants as a whole, however, was comparable to the acceptance by Domestic Cluster participants. This may be due to the majority of the Workplace cluster participants choosing to charge at home rather than at work and therefore not being impacted by curtailment. 9.6 An assessment of the public acceptance (or otherwise) to Demand Side Response of EVs using this sort of technology. SDRC 9.6: Public Acceptance of Esprit My Electric Avenue (I²EV) – SSET205 4 The control of charging by Esprit was more acceptable to participantsin the Technical Trial who viewed EVs more positively (as measured by Experience of and Attitude towards EVs). This greater degree of acceptance was the case whether or not participants had experienced curtailment by Esprit during the course of the trial. The relationship between the acceptability of Esprit and a positive view of EVs suggests that the concept and reality of curtailment are more acceptable to drivers with a more positive view of EVs. Acceptability of Esprit was also found to be greater among participants who were more comfortable with a lower level of charge in their battery. Additionally, participants with greater confidence in finding alternative charging locations to their home charger had a higher level of acceptance of Esprit. The types of journeys (e.g. commuting, shopping, transporting others) for which EVs were used over the trial period did not appear to affect participants’ view of Esprit. However, with regard to trip length, drivers who had a higher proportion of journeys between 11 and 30 miles at the end of the trial were more likely to find Esprit acceptable; acceptability was also higher amongst those drivers who took more unplanned trips. Overall there were few changes in either charging patterns or travel patterns following the introduction of curtailment. This lack of change suggests that Esprit control of charging had little impact on the use of EVs or attitudes towards them. Uptake of Low Carbon Technology Findings suggest that the My Electric Avenue Trial encouraged the uptake of low carbon technology with some participants installing or intending to install PV, adopting energy efficiency measures, and/or intending to acquire EVs after the trial. By allowing direct experience of a low carbon technology, such as EVs, in a supportive social and economic environment, participants were able to familiarise themselves with the technology, which encouraged them to consider investing in EVs after the trial. A few participants also felt that being involved with the trial had raised their awareness of low carbon technology more generally. Social Factors Social factors did not appear to be related to the use of the technology (Esprit). However, the trial participants were not representative of the UK population as a whole in terms of socio-demographics or household composition. Knowledge of the Electricity Network and Low Carbon Technologies Pre-trial involvement with the My Electric Avenue trial increased participants’ awareness and understanding of both the electricity network and low carbon technologies. Awareness and understanding of low carbon technologies continued to increase during the course of the trial, with actual experience of the technology being the most important factor in increasing both awareness and understanding. The trial also appeared to be successful in educating both participants and the wider community about EVs

Estimation of demand diversity and daily demand profile for off grid electrification in developing countries

Describes software downloadable from: https://github.com/peterboait/ESCoBox_Load_Model Open AccessThe potential for small self-contained grid systems to provide electricity for currently unserved regions of the developing world is widely recognised. However planning and managing the electrical demand that will be supported, so that a mini-grid system is not overloaded and its available resource is used as fully as possible, is actually more difficult than for a large scale grid system. This paper discusses the mathematical reasons why this is the case, and describes a practical software tool for mini-grid demand estimation and planning that is complementary to the widely used HOMER software. This software tool is made available for download on an open source basis. Finally a conclusion is offered that mini-grid systems should aim to serve at least 50 households so that demand variability is more manageable and economies of scale can be realised

Potential economic benefits of carbon dioxide (CO2) reduction due to renewable energy and electrolytic hydrogen fuel deployment under current and long term forecasting of the Social Carbon Cost (SCC)

The 2016 Paris Agreement (UNFCCC Authors, 2015) is the latest of initiative to create an international consensus on action to reduce GHG emissions. However, the challenge of meeting its targets lies mainly in the intimate relationship between GHG emissions and energy production, which in turn links to industry and economic growth. The Middle East and North African region (MENA), particularly those nations rich oil and gas (O&G) resources, depend on these as a main income source. Persuading the region to cut down on O&G production or reduce its GHG emissions is hugely challenging, as it is so vital to its economic strength. In this paper, an alternative option is established by creating an economic link between GHG emissions, measured as their CO2 equivalent (CO2e), and the earning of profits through the concept of Social Carbon Cost (SCC). The case study is a small coastal city in Libya where 6% of electricity is assumed to be generated from renewable sources. At times when renewable energy (RE) output exceeds the demand for power, the surplus is used for powering the production of hydrogen by electrolysis, thus storing the energy and creating an emission-free fuel. Two scenarios are tested based on short and long term SCCs. In the short term scenario, the amount of fossil fuel energy saved matches the renewable energy produced, which equates to the same amount of curtailed O&G production. The O&G-producing region can earn profits in two ways: (1) by cutting down CO2 emissions as a result of a reduction in O&G production and (2) by replacing an amount of fossil fuel with electrolytically-produced hydrogen which creates no CO2 emissions. In the short term scenario, the value of SCC saved is nearly 39% and in the long term scenario, this rose to 83%

Exploring smart grid possibilities: a complex systems modelling approach

Smart grid research has tended to be compartmentalised, with notable contributions from economics, electrical engineering and science and technology studies. However, there is an acknowledged and growing need for an integrated systems approach to the evaluation of smart grid initiatives. The capacity to simulate and explore smart grid possibilities on various scales is key to such an integrated approach but existing models – even if multidisciplinary – tend to have a limited focus. This paper describes an innovative and flexible framework that has been developed to facilitate the simulation of various smart grid scenarios and the interconnected social, technical and economic networks from a complex systems perspective. The architecture is described and related to realised examples of its use, both to model the electricity system as it is today and to model futures that have been envisioned in the literature. Potential future applications of the framework are explored, along with its utility as an analytic and decision support tool for smart grid stakeholders

Power-to-hydrogen and hydrogen-to-X:Which markets? Which economic potential? Answers from the literature

Research carried out within the framework of Task 38 of the Hydrogen Implementing Agreement of the International Energy Agency. The task is coordinated by the Institute for techno-economics of energy systems (I-tésé) of the CEA, supported by the ADEME. The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link.With the expansion of renewable energy’s contribution to the energy mix, balancing the electricity grid is becoming increasingly challenging. Alongside other solutions, Power-to-Hydrogen concepts are gaining significant interest. In this paper, the “Task 38”, initiated by the Hydrogen Implementing Agreement of the International EnergyAgency, presents the first of a two-step literature review regarding Power-to-Hydrogen and Hydrogen-to-X concepts with a focus on prospective market and economic potential. The study reveals a large scope of literature that shows a considerable variety ofsuggested implementation schemes. The transportation sector is identified as the most promising consumer market. Hydrogen-to-Gas pathways will require subsidies in order to be profitable. Hydrogen-to-Power becomes an economically promising option in the context of systems with high shares of renewables and a need for longer-term storages. Additionally, key enablers for Power-to-Hydrogen concepts are identified; namely support policies, concurrently with ongoing progress on the development and implementation of industry standard