Integration Of Renewable Electricity Research Articles

Enhancing Organic Electrosynthesis through Artificial Intelligence: The Case of Adiponitrile Electrohydrodimerization

The continuous increase of fossil fuel-derived carbon dioxide (CO2) emissions has made their impact in climate change self-evident. The chemical industry is a major contributor to this increase, accounting for more than 5.5% of the global CO2 emissions. The electrification of the chemical industry would thus be a major step in the integration of renewable electricity in the industrial sector, helping reduce its carbon footprint significantly. Inorganic electrosynthetic processes have been largely implemented at industrial scale (i.e. chloro-alkali and Aluminum production), however the deployment of electrosynthetic methods for the production of organic chemicals has been limited. Adiponitrile (ADN) is a large-volume (>1.5 million tons/year) precursor to Nylon 6,6 and it can be obtained via the electrohydrodimerization of acrylonitrile (AN). Although the electrochemical production of adiponitrile (ADN) is the largest organic electrochemical process in industry, it faces many challenges owing mainly to its energy conversion efficiency and selectivity. Optimizing the composition of the electrolyte has resulted in significant performance improvements, however mass transport limitations have proven to be a challenge at high current densities, where propionitrile (PN) is the main reaction by-product. In this study, we provide experimental insights on the effects of pulsed potential techniques on the mitigation of mass transport limitations and the effective control of product distribution. Moreover, an integrated approach combining experimental insights and artificial intelligence-driven models is proposed for the rapid optimization of operation conditions and the maximization of reaction performance. The regulation of electron-transfer rates with the use of complex pulse potential waveforms is implemented to control the electrochemical environment surrounding the reaction surface, ultimately favoring ADN production. Electrochemical pulses are used to balance reactant diffusive fluxes to the electrode and the generation/consumption of species in the electrical double layer (EDL), helping mitigate mass transport limitations at high current densities. This, together with their effect on interaction between electroactive species and the reaction surface can help improve reaction selectivity. An improvement of over 250% in the production ratio of ADN:PN (desired to undesired product) was achieved optimizing pulse duration and amplitude. Furthermore, the careful control of overall reaction time and composition of the EDL led to a 20% increase in ADN production with respect to DC operation. The integrated use of machine learning algorithms enabled the prediction of ADN formation in a complete landscape of pulse durations. From this, a new set of optimal conditions was identified, leading to a 30% increase in ADN production with respect to DC operation for periodic pulses varying from -60 mA cm-2 (120 ms) to 0 mA cm-2 (5 ms). A new paradigm in organic electrosynthesis research is proposed, where a combination of electrochemical design principles, artificial neural networks, and judiciously designed experimental campaigns are used to uncover new electrosynthetic processes.

A Long-Lifetime All-Organic Aqueous Flow Battery Utilizing TMAP-TEMPO Radical

Summary The massive-scale integration of renewable electricity into the power grid is impeded by its intrinsic intermittency. The aqueous organic redox flow battery (AORFB) rises as a potential storage solution; however, the choice of positive electrolytes is limited, and the aqueous-soluble organic positive redox-active species reported to date have short lifetimes. Here we report a stable organic molecule for the positive terminal, 4-[3-(trimethylammonio)propoxy]-2,2,6,6-tetramethylpiperidine-1-oxyl (TMAP-TEMPO) chloride, exhibiting high (4.62 M) aqueous solubility. When operated in a practical AORFB against a negative electrolyte comprising BTMAP-viologen at neutral pH, the flow cell displayed an open-circuit voltage of 1.1 volts and a Coulombic efficiency of >99.73%. The capacity retention rate is among the highest of all-organic AORFBs reported to date, at 99.993% per cycle over 1,000 consecutive cycles; the temporal capacity fade rate of 0.026% per h is independent of concentration.

Integration of compressed air energy storage with wind generation into the electricity grid

Integration of renewable electricity from wind farms into the electricity grid presents challenges because wind is a highly variable resource whereby the amount of power generated depends on local wind speed, air density and wind turbine characteristics. Energy storage is one possible approach to mitigate power fluctuations and quality issues. Among presently available technologies to store energy, Compressed Air Energy Storage (CAES) shows many attractive features. This work focuses on techno-economic modelling and analysis for the integration of wind turbines with CAES into the power grid. To have a deep understanding of the performance, characteristics and benefits of system integration, technical and economic models for CAES processes are developed in the processes simulation software ECLIPSE. To conduct this study, two scenarios that are each dependent on generation scales and locations were proposed; (1) centralised CAES (based on the diabatic method) (2) distributed CAES (based on the adiabatic approach). The nominal power generation of centralised and distributed CAES systems were given as 280 MWe and 5 MWe, respectively. The impact of CAES systems on the electricity market is also discussed. Techno-economic analysis of the modelled centralised CAES system showed round-trip efficiency of around 53.6% (and around 56.7% for the modelled distributed CAES system). Specific investment was found to be around €585/kWe (€2452/kWe) and break-even electricity selling price to be around €111/MWh (€275/MWh). Their CO2 emissions were found to be compatible with the average CO2 emissions of UK CCGT power generation.

Cost-optimal electricity systems with increasing renewable energy penetration for islands across the globe

Cost-optimal electricity system configurations with increasing renewable energy penetration were determined in this article for six islands of different geographies, sizes and contexts, utilizing photovoltaic energy, wind energy, pumped hydro storage and battery storage. The results of the optimizations showed strong reasoning for islands to invest in renewable energy technologies (particularly wind energy), as compared to conventional power generation. Levelized cost of systems for electricity generation decrease considerably with increasing renewable energy penetrations, to an optimal point in the range of 40–80% penetration. Furthermore, renewable electricity integration in the order of 60–90% could still be achieved with no added cost from the initial situation. Cost increases after these optimal points are attributed to the growing inclusion of storage, required to meet the higher renewable energy shares. However, with battery costs forecast to fall in the coming years, and a cost reduction of 50–70% already causing lithium-ion batteries to overtake pumped hydro as a cost-favorable storage option in this model, there is a real case for islands to begin their transition in a staged process; first installing wind and PV generation, and then - as storage costs decrease and their renewable energy capacities increase - investing in storage options.

Promotion of renewable energy in some MENA region countries

In recent years Middle East and North African (MENA) countries, are showing efforts about the integration of renewable electricity into their power markets. Indeed, installations were already achieved and renewable energy programs were launched. The Algerian program remains one of the most ambitious with its installation capacity up to 22GW of power generating to be installed by 2030. More than 60 % of the total capacity is planned to be solar photovoltaic (PV). Like Algeria, Morocco has integrated development project with a target to develop by 2020 a 2000 MW capacity of electricity production from solar energy. The Tunisian government has launched its first phase of the renewable power generation program, with an objective to install 1,000 MW of renewable power capacity over the 2017-2020 periods, where 650 MW of the total capacity is planned to be solar and 350 MW wind. One of the leading Arab country in wind energy, these recent years is Egypt, with its more than 700 megawatt of operational power generation plants and has launched significant projects development in solar energy. Regarding Jordan, the government has taken different steps in this field of energy with a Strategy plan 2007-2020, by implementing a large scale of projects on renewable energy sources, with an objective to cover 10% of the country’s energy supply, from renewable sources by the year 2020. Concerning Lebanon, the country is looking to attain an integration of 12 % by 2020.

Power system and market integration of renewable electricity

Power system and market integration of renewable electricity

The Italian hydrogen mobility scenario implementing the European directive on alternative fuels infrastructure (DAFI 2014/94/EU)

The European commitment to promote a sustainable (green and clean) mobility has been strengthening in recent years. An important milestone is the DAFI Directive 2014/94/EU, targeting the deployment of an alternative fuels infrastructure in the European Union, to be implemented through national policy frameworks. The DAFI Directive has been implemented in Italy through the Legislative Decree n. 257 (December 2016), including hydrogen in the list of alternative fuels. Concerning the hydrogen mobility, this paper describes the methodology and the main results of the Scenario MobilitàH2IT. On behalf of the Italian Ministry of Economic Development, it summarized the common vision of several stakeholders joined in the initiative “Mobilità Idrogeno Italia” (MH2IT), established in June 2015. Moreover, these results are reproduced in the Annex III of the Legislative Decree n. 257, thus representing an official reference. With a 2050 time horizon, the applied methodology considers: (1) Sizing of the FCEV fleet and hydrogen demand at the refueling stations; (2) Hydrogen production for the transport sector and integration of renewable electricity with hydrogen storage; (3) Sizing of the hydrogen refueling stations; (4) The consumer perspective; (5) Reduction of CO2 emissions and other harmful pollutants; (6) Measures to support the national policy framework. This methodology can be replicated in other national studies and the Italian results can be checked as a comparison term.

Model-based investigation of residual load smoothing through dynamic electricity purchase: The case of wastewater treatment plants in Germany

Energy systems with a high share of renewable electricity generation face a challenge associated with surplus electricity generation. Flexibility options may help to integrate renewable electricity and reduce the need for electricity from fossil fuels. Load shifting is one of the flexibility options that lead to residual load smoothing in energy systems. In this paper, the effects of load shifting by dynamic electricity purchase on future residual load smoothing was assessed using wastewater treatment plants (WWTPs) in Germany as a case study. As dynamic electricity purchase is motivated economically, a consumer’s demand for supplying flexibility options needs a price signal. Therefore, electricity wholesale prices on an hourly basis were modeled for 2030 using a merit order simulation for two scenarios. Relevant data for WWTPs was obtained from primary data suppliers, which was then aggregated. The effects on residual load smoothing were assessed by optimizing WWTPs electricity purchase costs on a daily basis. Our results show that German WWTPs have a potential to integrate 120MWel of surplus electric power. The developed methodology has a high potential to be applied to other potential load shifting actors when assessing the potential of residual load smoothing and renewable electricity integration. This can be achieved by adapting boundary constraints to other electricity consumers.

Accelerating Energy & Environmental Transition in Europe through digital

Digitalization is becoming ubiquitous in the energy sector, enabling a more decentralized energy system and blurring the traditional energy sector boundaries, with more integration with buildings, mobility solutions and industry. Digitalization is accelerating the pace of the energy transition, mainly thanks to three levers: 1) enhancing customer interaction with the energy system, 2) optimizing operations, and 3) enabling new business models for traditional energy actors as well as opening up space for new entrants from other sectors and energy startups. Digital technologies are also facilitating a cost-effective, clean energy transition, mainly by increasing energy efficiency and flexibility, as well as enabling the integration of renewable electricity into smart(er) grids and developing low-carbon solutions.This article gives a brief overview of the digitally-enabled innovations in Europe’s energy markets and how various players are positioning themselves to take advantage of these opportunities. It concludes by highlighting some of the policy issues this transformation raises and the challenges ahead for European businesses to reap the benefits.

The hidden economic benefits of large-scale renewable energy deployment: Integrating heat, electricity and vehicle systems

The transition to large-scale renewable energy in order to mitigate climate change is necessity. Much academic literature has begun to focus on the technical and economic plausibility of such a transition to renewable energy, but these studies often explore one to several potential energy systems and their costs and benefits as compared to the existing system. This paper summarizes the policy implications of a recent analysis that builds on the literature of the integration of renewable electricity, electric vehicles and electric heat by modeling and testing nearly 86 million different combinations of wind, solar, natural gas, vehicle-to-grid capable electric vehicles, and electric heat. After each system was modeled for four years of operation to ensure reliability, the costs of energy systems were then calculated both with and without externalities to better understand how this cost affects implementation. We present the results and policy implications of our analysis across the 86 million energy systems and conclude with the role of social science in future research.

Power system and market integration of renewable electricity

This paper addresses problems of power generation markets that arise under high shares of intermittent generation. After discussing the economic fundamentals of wind and photovoltaic investments, the paper introduces the concept of the “Merit order effect of renewables”. According to this concept electricity prices on wholesale power markets become smaller in periods during which large volumes of wind and photovoltaic generation is available and squeeze out relative expensive gas-fired power generation. The merit order effect of renewables has a couple of consequences. Among others it challenges the profitability of conventional power generation. If such generation capacities are still necessary, at least during a transitory period, a capacity mechanism may be put in place that generates an additional stream of income to the operators of conventional power generators. Another consequence of growing intermittent power generation is the need for concepts and technologies that deal with excess generation. Among these concepts are virtual and physical power storage capacities. In the last parts of the paper models are presented that are able to analyze these concepts from an economic point of view.

The effect of PV siting on power system flexibility needs

Locations of photovoltaic (PV) systems affect the variability and uncertainty of their power generation, and as a result the amount of flexible resources needed to balance supply and demand. However, studies on the integration of renewable electricity into power systems focus on the total amount of renewable generation, and not their locations. This paper uses a hidden state, spatial-statistical model to simulate how locational arrangements and balancing policies affect the need for reserves—load following and regulation—in California’s power system when including 12GW of photovoltaic generators and 9.5GW of wind.Our results show that locations of utility-scale PV systems significantly affect on the amount of reserves needed for balancing their variability and uncertainty. When PV is geographically dispersed the additional load following and regulation reserve needs are small; on average <1.2% and <0.05% of installed PV capacity respectively. These rise to 5.6% and 0.2% in centralized scenarios. Most the benefits of this dispersion can be achieved with relatively few, 25, systems. These are sized at roughly 500MW each, which is about the size of the largest systems in California today. Almost all of the load following reserve need is driven by errors in the hourly forecasts of solar generation. These can be mitigated either by better forecasts, or dispersing plants.Siting policies for PV must weigh system flexibility against other locational concerns, such as the energy and capacity value of the solar resource in an area. We find a small trade off between energy and reserves; where dispersed systems require less reserves but also have lower capacity factors than more centralized systems. However, we find a much greater trade-off between energy and capacity value in California; where the regions that produce the most energy on average—in the Mojave desert—tend to be cloudy during current peak demand hours, which occur during Summer afternoons.

Life Cycle Assessment of Power-to-Gas: Syngas vs Methane

Power-to-Gas enables the integration of renewable electricity and carbon into the chemical industry. The electricity is used to produce hydrogen, which is subsequently converted with CO2 as the renewable carbon source. The resulting products can be used as feedstock for the chemical industry replacing current fossil-based feedstock. Because the integration of renewable electricity and carbon into the chemical industry is mainly environmentally motivated, we identify the conditions under which Power-to-Gas pathways are environmentally beneficial. The conditions are expressed as environmental threshold values for electricity supply. The threshold values are derived by a comparative life cycle assessment (LCA) of Power-to-Gas pathways to fossil-based processes. We analyze Power-to-Gas pathways to synthetic natural gas (Power-to-SNG) and to syngas (Power-to-Syngas). SNG is produced by the Sabatier reaction; syngas by reverse water gas shift (rWGS) and dry reforming of methane (DRM). The threshold values for e...

The potential of grid-orientated distributed cogeneration on the minutes reserve market and how changing the operating mode impacts on CO2 emissions

Distributed cogeneration units are flexible and suited to providing balancing power, thereby contributing to the integration of renewable electricity. Against this background, we analysed the technical potential and ecological impact of CHP (combined heat and power) systems on the German minutes reserve market for 2010, 2020 and 2030. Typical CHP plants (from 1 to 2800 kWel) were evaluated in relation to typical buildings or supply cases in different sectors. The minutes reserve potential was determined by an optimisation model with a temporal resolution of 15 min. The results were scaled up to national level using a scenario analysis for the future development of CHP. Additionally, the extent to which three different flexibility measures (double plant size/fourfold storage volume/emergency cooler) increase the potential provision of balancing power was examined. Key findings demonstrate that distributed CHP could contribute significantly to the provision of minutes reserve in future decades. Flexibility options would further enhance the theoretical potential. The grid-orientated operating mode slightly increases CO2 emissions compared to the heat-orientated mode, but it is still preferable to the separate generation of heat and power. However, the impacts of a flexible mode depend greatly on the application and power-to-heat ratio of the individual CHP system.

Energetic Communities: Planning support for sustainable energy transition in small- and medium-sized communities

Energetic Communities: Planning support for sustainable energy transition in small- and medium-sized communities

Energetic Communities: Planning support for sustainable energy transition in small- and medium-sized communities

Energetic Communities: Planning support for sustainable energy transition in small- and medium-sized communities

Energetic Communities: Planning support for sustainable energy transition in small- and medium-sized communities

Energetic Communities: Planning support for sustainable energy transition in small- and medium-sized communities

Energetic Communities

Energetic Communities

Integration of wind power into the British system in 2020

This paper investigates the integration of renewable electricity into the UK system in 2020. The purpose is to find the optimal wind generation that can be integrated based on total cost of supply. Using EnergyPLAN model and the Department of Energy and Climate Change (DECC) energy projections as inputs, this paper simulates the total cost of electricity supply with various levels of wind generation considering two systems: a reference and an alternative system. The results show that 80 TWh of wind electricity is most preferable in both systems, saving up to 0.9% of total cost when compared to a conventional system without wind electricity production. The alternative system, with decentralized generation and active demand management, brings relatively more cost saving, and higher wind utilisation, compared to the reference case. The sensitivity analysis with alternative fuel and capital costs again confirms the superiority of the alternative over the reference system.

Solar and wind resource complementarity: Advancing options for renewable electricity integration in Ontario, Canada

In Ontario (Canada), the integration of renewable power is a priority policy goal. Since 2004, the circumstances under which the integration of renewable power is evaluated have changed due to successive changes in price as well as concerns that its over-production may add to grid congestion. This research investigates the value of increasing complementarity (both proximate and geographically dispersed) of wind and solar resources as a means by which electricity planners and researchers might advance electricity sustainability in Ontario. More specifically, this paper asks the following questions: 1) Does the combination of solar and wind resources in selected locations in Ontario serve to ‘smooth out’ power production, i.e., decrease instances of both high and low values, as compared to either resource producing individually? 2) Can this ‘smoothness’ be further improved by dispersing these resources geographically amongst locations? and 3) Does increasing the number of locations with solar and wind resources further ‘smooth out’ power production? Three years (2003–2005) of synchronous, hourly measurements of solar irradiance and wind speeds from Environment Canada’s Canadian Weather Energy and Engineering Data Sets (CWEEDS) are used to derive dimensionless indices for four locations in Ontario (Toronto, Wiarton, Sault Ste. Marie and Ottawa). These indices are used to develop three transparent and accessible methods of analysis: (1) graphical representation; (2) percentile ranking; and (3) using a theoretical maximum as a proxy for capacity. The article concludes that the combination of solar and wind within locations and amongst two locations improves ‘smoothness’ in power production, as compared to when each resource is produced on its own; moreover, it is further improved once more than two resources and two locations are combined. However, there is neither further benefit, nor drawback, associated with the geographic dispersion of complementarity between solar in one location and wind in another, when compared to both resources in one location.