• Energy Research

This study examines the optimal integration of high proportions of wind energy into an electricity grid which traditionally depends on hydroelectricity. Wind power in the Brazilian Northeast (NE) is expected to generate 57% of the NE’s electricity supply by 2020. As rainfall in the NE region is susceptible to climate change, it is anticipated that wind energy could substitute lost hydroelectric availability. The Weather Research and Forecasting (WRF) Model is used to simulate wind speeds for all of 2014 and calculate wind power across the entire NE region of Brazil. The NE region’s aggregate hourly wind generation and net load curve are then estimated for increasing wind penetrations using the planned rollout of wind farms in the region as a baseline. The maximum wind energy penetration in the region is estimated to be approximately 50% before significant amounts of energy would need to be curtailed or exported to other Brazilian regions. It was found that wind energy generation from coastal wind farms in the region best correlates with the hourly and monthly variations of the NE subsystem’s load curve. Conversely, inland wind farms on the NE’s elevated plateaus typically generate more power late at night, but have higher capacity factors.

Abstract. A globally integrated carbon observation and analysis system is needed to improve the fundamental understanding of the global carbon cycle, to improve our ability to project future changes, and to verify the effectiveness of policies aiming to reduce greenhouse gas emissions and increase carbon sequestration. Building an integrated carbon observation system requires transformational advances from the existing sparse, exploratory framework towards a dense, robust, and sustained system in all components: anthropogenic emissions, the atmosphere, the ocean, and the terrestrial biosphere. The goal of this study is to identify the current state of carbon observations and needs for a global integrated carbon observation system that can be built in the next decade. A key conclusion is the substantial expansion (by several orders of magnitude) of the ground-based observation networks required to reach the high spatial resolution for CO2 and CH4 fluxes, and for carbon stocks for addressing policy relevant objectives, and attributing flux changes to underlying processes in each region. In order to establish flux and stock diagnostics over remote areas such as the southern oceans, tropical forests and the Arctic, in situ observations will have to be complemented with remote-sensing measurements. Remote sensing offers the advantage of dense spatial coverage and frequent revisit. A key challenge is to bring remote sensing measurements to a level of long-term consistency and accuracy so that they can be efficiently combined in models to reduce uncertainties, in synergy with ground-based data. Bringing tight observational constraints on fossil fuel and land use change emissions will be the biggest challenge for deployment of a policy-relevant integrated carbon observation system. This will require in-situ and remotely sensed data at much higher resolution and density than currently achieved for natural fluxes, although over a small land area (cities, industrial sites, power plants), as well as the inclusion of fossil fuel CO2 proxy measurements such as radiocarbon in CO2 and carbon-fuel combustion tracers. Additionally, a policy relevant carbon monitoring system should also provide mechanisms for reconciling regional top-down (atmosphere-based) and bottom-up (surface-based) flux estimates across the range of spatial and temporal scales relevant to mitigation policies. The success of the system will rely on long-term commitments to monitoring, on improved international collaboration to fill gaps in the current observations, on sustained efforts to improve access to the different data streams and make databases inter-operable, and on the calibration of each component of the system to agreed-upon international scales.

This paper presents an energy scheduling and output smoothing scheme for storage aided utility scale photovoltaic systems. A weighted energy scheduling approach is adopted for the peak load periods, and this ensures enhanced performance with well-fitted supply-demand curve and flat net load variation. A novel smoothing method is proposed by blending double grid search support vector machine power prediction with first-in-first-out robust smoothing. The actual hourly and minute interval data sets for Australia are used for case studies, demonstrating the effectiveness and efficiency of the proposed scheme.

Résumé. Un système d'observation et d'analyse du carbone intégré à l'échelle mondiale est nécessaire pour améliorer la compréhension fondamentale du cycle mondial du carbone, pour améliorer notre capacité à projeter les changements futurs et pour vérifier l'efficacité des politiques visant à réduire les émissions de gaz à effet de serre et à augmenter la séquestration du carbone. La construction d'un système intégré d'observation du carbone nécessite des avancées transformationnelles du cadre exploratoire clairsemé existant vers un système dense, robuste et durable dans toutes ses composantes : les émissions anthropiques, l'atmosphère, l'océan et la biosphère terrestre. L'objectif de cette étude est d'identifier l'état actuel des observations de carbone et les besoins d'un système mondial intégré d'observation du carbone qui peut être construit au cours de la prochaine décennie. Une conclusion clé est l'expansion substantielle (de plusieurs ordres de grandeur) des réseaux d'observation au sol nécessaires pour atteindre la haute résolution spatiale pour les flux de CO2 et de CH4 et pour les stocks de carbone afin de répondre aux objectifs politiques pertinents et d'attribuer les changements de flux aux processus sous-jacents dans chaque région. Afin d'établir des diagnostics de flux et de stocks sur des zones éloignées telles que les océans du sud, les forêts tropicales et l'Arctique, les observations in situ devront être complétées par des mesures de télédétection. La télédétection offre l'avantage d'une couverture spatiale dense et de revisites fréquentes. Un défi clé consiste à amener les mesures de télédétection à un niveau de cohérence et de précision à long terme afin qu'elles puissent être efficacement combinées dans des modèles pour réduire les incertitudes, en synergie avec les données au sol. Apporter des contraintes d'observation strictes sur les émissions de combustibles fossiles et de changement d'affectation des terres sera le plus grand défi pour le déploiement d'un système intégré d'observation du carbone pertinent pour les politiques. Cela nécessitera des données in situ et de télédétection à une résolution et une densité beaucoup plus élevées que celles actuellement atteintes pour les flux naturels, bien que sur une petite superficie (villes, sites industriels, centrales électriques), ainsi que l'inclusion de mesures indirectes de CO2 de combustibles fossiles telles que le radiocarbone dans les traceurs de combustion de CO2 et de carbone. En outre, un système de surveillance du carbone pertinent pour les politiques devrait également fournir des mécanismes pour concilier les estimations des flux régionaux descendants (basés sur l'atmosphère) et ascendants (basés sur la surface) sur toute la gamme des échelles spatiales et temporelles pertinentes pour les politiques d'atténuation. Le succès du système reposera sur des engagements à long terme en matière de suivi, sur une meilleure collaboration internationale pour combler les lacunes dans les observations actuelles, sur des efforts soutenus pour améliorer l'accès aux différents flux de données et rendre les bases de données interopérables, et sur l'étalonnage de chaque composante du système à des échelles internationales convenues. Resumen. Se necesita un sistema de observación y análisis de carbono integrado a nivel mundial para mejorar la comprensión fundamental del ciclo global del carbono, para mejorar nuestra capacidad de proyectar cambios futuros y para verificar la efectividad de las políticas destinadas a reducir las emisiones de gases de efecto invernadero y aumentar el secuestro de carbono. Construir un sistema integrado de observación de carbono requiere avances transformacionales desde el marco exploratorio escaso existente hacia un sistema denso, robusto y sostenido en todos los componentes: las emisiones antropogénicas, la atmósfera, el océano y la biosfera terrestre. El objetivo de este estudio es identificar el estado actual de las emisiones de carbono y las necesidades de un sistema global integrado de emisiones de carbono que pueda construirse en la próxima década. Una conclusión clave es la expansión sustancial (en varios órdenes de magnitud) de las redes de observación terrestres necesarias para alcanzar la alta resolución espacial para los flujos de CO2 y CH4, y para las reservas de carbono para abordar los objetivos relevantes para las políticas y atribuir los cambios de flujo a los procesos subyacentes en cada región. Para establecer diagnósticos de flujo y stock en áreas remotas como los océanos del sur, los bosques tropicales y el Ártico, las observaciones in situ deberán complementarse con mediciones de teledetección. La teledetección ofrece la ventaja de una cobertura espacial densa y una revisión frecuente. Un desafío clave es llevar las mediciones de teledetección a un nivel de consistencia y precisión a largo plazo para que puedan combinarse de manera eficiente en modelos para reducir las incertidumbres, en sinergia con los datos basados en tierra. Traer restricciones observacionales estrictas sobre las emisiones de combustibles fósiles y el cambio en el uso de la tierra será el mayor desafío para el despliegue de un sistema integrado de observación de carbono relevante para las políticas. Esto requerirá datos in situ y teledetectados con una resolución y densidad mucho más altas que las que se logran actualmente para los flujos naturales, aunque en una pequeña superficie de tierra (ciudades, sitios industriales, centrales eléctricas), así como la inclusión de mediciones indirectas de CO2 de combustibles fósiles, como el radiocarbono en CO2 y los trazadores de combustión de combustibles de carbono. Además, un sistema de monitoreo de carbono relevante para las políticas también debe proporcionar mecanismos para conciliar las estimaciones regionales de flujo de arriba hacia abajo (basadas en la atmósfera) y de abajo hacia arriba (basadas en la superficie) en toda la gama de escalas espaciales y temporales relevantes para las políticas de mitigación. El éxito del sistema dependerá de los compromisos a largo plazo con el monitoreo, de una mejor colaboración internacional para llenar los vacíos en las observaciones actuales, de esfuerzos sostenidos para mejorar el acceso a los diferentes flujos de datos y hacer que las bases de datos sean interoperables, y de la calibración de cada componente del sistema a escalas internacionales acordadas. Abstract. A globally integrated carbon observation and analysis system is needed to improve the fundamental understanding of the global carbon cycle, to improve our ability to project future changes, and to verify the effectiveness of policies aiming to reduce greenhouse gas emissions and increase carbon sequestration. Building an integrated carbon observation system requires transformational advances from the existing sparse, exploratory framework towards a dense, robust, and sustained system in all components: anthropogenic emissions, the atmosphere, the ocean, and the terrestrial biosphere. The goal of this study is to identify the current state of carbon observations and needs for a global integrated carbon observation system that can be built in the next decade. A key conclusion is the substantial expansion (by several orders of magnitude) of the ground-based observation networks required to reach the high spatial resolution for CO2 and CH4 fluxes, and for carbon stocks for addressing policy relevant objectives, and attributing flux changes to underlying processes in each region. In order to establish flux and stock diagnostics over remote areas such as the southern oceans, tropical forests and the Arctic, in situ observations will have to be complemented with remote-sensing measurements. Remote sensing offers the advantage of dense spatial coverage and frequent revisit. A key challenge is to bring remote sensing measurements to a level of long-term consistency and accuracy so that they can be efficiently combined in models to reduce uncertainties, in synergy with ground-based data. Bringing tight observational constraints on fossil fuel and land use change emissions will be the biggest challenge for deployment of a policy-relevant integrated carbon observation system. This will require in-situ and remotely sensed data at much higher resolution and density than currently achieved for natural fluxes, although over a small land area (cities, industrial sites, power plants), as well as the inclusion of fossil fuel CO2 proxy measurements such as radiocarbon in CO2 and carbon-fuel combustion tracers. Additionally, a policy relevant carbon monitoring system should also provide mechanisms for reconciling regional top-down (atmosphere-based) and bottom-up (surface-based) flux estimates across the range of spatial and temporal scales relevant to mitigation policies. The success of the system will rely on long-term commitments to monitoring, on improved international collaboration to fill gaps in the current observations, on sustained efforts to improve access to the different data streams and make databases inter-operable, and on the calibration of each component of the system to agreed-upon international scales. الخلاصة. هناك حاجة إلى نظام متكامل عالميًا لمراقبة الكربون وتحليله لتحسين الفهم الأساسي لدورة الكربون العالمية، وتحسين قدرتنا على توقع التغييرات المستقبلية، والتحقق من فعالية السياسات التي تهدف إلى الحد من انبعاثات غازات الدفيئة وزيادة عزل الكربون. يتطلب بناء نظام متكامل لمراقبة الكربون تقدمًا تحويليًا من الإطار الاستكشافي المتناثر الحالي نحو نظام كثيف وقوي ومستدام في جميع المكونات: الانبعاثات البشرية المنشأ والغلاف الجوي والمحيطات والمحيط الحيوي الأرضي. الهدف من هذه الدراسة هو تحديد الوضع الحالي لملاحظات الكربون والاحتياجات لنظام عالمي متكامل لمراقبة الكربون يمكن بناؤه في العقد المقبل. الاستنتاج الرئيسي هو التوسع الكبير (بعدة مرات من حيث الحجم) لشبكات المراقبة الأرضية المطلوبة للوصول إلى الاستبانة المكانية العالية لتدفقات ثاني أكسيد الكربون والميثان، ولمخزونات الكربون لمعالجة الأهداف ذات الصلة بالسياسات، وعزو تغييرات التدفق إلى العمليات الأساسية في كل منطقة. من أجل إنشاء تشخيصات التدفق والأرصدة في المناطق النائية مثل المحيطات الجنوبية والغابات الاستوائية والقطب الشمالي، يجب استكمال الملاحظات في الموقع بقياسات الاستشعار عن بعد. يوفر الاستشعار عن بعد ميزة التغطية المكانية الكثيفة وإعادة الزيارة المتكررة. ويتمثل أحد التحديات الرئيسية في الوصول بقياسات الاستشعار عن بعد إلى مستوى من الاتساق والدقة على المدى الطويل بحيث يمكن دمجها بكفاءة في نماذج للحد من أوجه عدم اليقين، بالتآزر مع البيانات الأرضية. سيكون فرض قيود صارمة على مراقبة الوقود الأحفوري وانبعاثات تغير استخدام الأراضي هو التحدي الأكبر أمام نشر نظام متكامل لمراقبة الكربون ذي صلة بالسياسات. وسيتطلب ذلك بيانات في الموقع ومستشعرة عن بعد بدقة وكثافة أعلى بكثير مما هو متحقق حاليًا للتدفقات الطبيعية، على الرغم من أنها على مساحة أرض صغيرة (المدن والمواقع الصناعية ومحطات الطاقة)، بالإضافة إلى تضمين قياسات وكيل ثاني أكسيد الكربون للوقود الأحفوري مثل الكربون المشع في ثاني أكسيد الكربون وتتبع احتراق الوقود الكربوني. بالإضافة إلى ذلك، يجب أن يوفر نظام رصد الكربون ذي الصلة بالسياسة أيضًا آليات للتوفيق بين تقديرات التدفق الإقليمية من أعلى إلى أسفل (القائمة على الغلاف الجوي) ومن أسفل إلى أعلى (السطحية) عبر نطاق المقاييس المكانية والزمنية ذات الصلة بسياسات التخفيف. سيعتمد نجاح النظام على الالتزامات طويلة الأجل بالرصد، وعلى تحسين التعاون الدولي لسد الثغرات في الملاحظات الحالية، وعلى الجهود المستمرة لتحسين الوصول إلى تدفقات البيانات المختلفة وجعل قواعد البيانات قابلة للتشغيل المتبادل، وعلى معايرة كل مكون من مكونات النظام وفقًا للنطاقات الدولية المتفق عليها.

Abstract This paper is the first of a two part study that considers long term, least cost, GHG (greenhouse gas) abatement pathways for an electricity system. Part 1 formulates a planning model to optimise these pathways and presents results for a single reference scenario. Part 2 applies this model to different scenarios and considers the policy implications. The planning model formulated has several constraints which are important when considering GHG abatement and widespread uptake of intermittent renewable generation. These constraints do not appear to have been integrated into a single planning model previously, and include constraints on annual GHG emissions, unit commitment, storage, plant dynamics and intermittent renewable generation. The model prioritises overall abatement, and therefore does not include a price on carbon or support for any particular technology. The model is applied to Australia's NEM (National Electricity Market) as an example. All model inputs – for technologies, demand, and meteorological data – are from the most current and authoritative public sources. As such, the results are transparently derived and both policy and technology neutral. For the reference scenario presented here, key technologies are wind from 2015, gas generation from 2030, and solar generation from 2040.

Abstract This study sheds new light on the variability of wind power across the Australian NEM (National Electricity Market) and in doing so gives an insight on the potential network configuration for a high RE (Renewable Electricity) future. We present idealised cost-minimised simulations for the NEM utilising onshore wind, large-scale solar, pumped hydro and OCGT (open cycle gas turbines) technologies. A model using gridded meteorological data from the regional ACCESS-R (Australian Community Climate and Earth-System Simulator) simulates wind and solar technology output along with generation from OCGT to meet demand in the NEM for the period 2010–2011. A cost for connecting each location to the nearest major load centre is introduced and a base scenario created from an initial connection cost of $1 M/km. A sensitivity study reveals that a cost of $8 M/km results in the contraction of all renewable resources to four major wind installations. Compared to the base scenario the four major wind locations share much of the variability in renewable energy output, demonstrating that the NEM region has four distinct wind regimes. Separated by 1,400 km these four wind installations provide an optimisation-based decorrelation length for the NEM. This information is particularly useful for long-term planners of large-scale energy infrastructure.

As the global transition toward sustainable energy gains momentum, integrating electric vehicles (EVs), energy storage, and renewable energy sources has become a pivotal strategy. This paper analyses the interplay between EVs, energy storage, and renewable energy integration with Indonesia’s grid as a test case. A comprehensive energy system modeling approach using PLEXOS is presented, using historical data on electricity generation, hourly demand, and renewable energy, and multiple scenarios of charging patterns and EV adoption. Through a series of scenarios, we evaluate the impact of different charging strategies and EV penetration levels on generation capacity, battery storage requirements, total system cost, renewable energy penetration, and emissions reduction. The findings reveal that optimized charging patterns and higher EV adoption rates, compared to no EVs adoption, led to substantial improvements in renewable energy utilization (+4%), emissions reduction (−12.8%), and overall system cost (−9%). While EVs contribute to reduced emissions compared to conventional vehicles, non-optimized charging behavior may lead to higher total emissions when compared to scenarios without EVs. The research also found the potential of vehicle to grid (V2G) to reduce the need for battery storage compared to zero EV (−84%), to reduce emissions significantly (−23.7%), and boost penetration of renewable energy (+10%). This research offers valuable insights for policymakers, energy planners, and stakeholders seeking to leverage the synergies between EVs and renewable energy integration to pursue a sustainable energy future for Indonesia.

Abstract Renewable energy is increasingly replacing carbon-based technologies worldwide in electricity networks. This increases the challenge of balancing intermittent generation with demand fluctuation. DR (Demand response) is recognized as a way to address this by adapting consumption to supply patterns. By using DR technology, grid withdrawal of DSM (demand side management) devices such as heat pumps, electric vehicles or stationary batteries can be temporally shifted. Yet, the development of an accurate control and market design is still one of the greatest remaining DR challenges. We present a range of flexible price signals that can address this by acting as effective demand control mechanisms. The different tariffs consist of combinations of flexible energy and power price signals. Their impact on the unit commitment of automatable DSM devices is tested for a set of German households. The financial outcome for the respective stakeholders are quantified. Our results suggest flexible power pricing can reduce overall demand peaks as well as limit simultaneous grid withdrawals caused by real time pricing incentives. Furthermore, we prove that inefficient designs of flexible power pricing can lead to undesired bidding of automatable devices. We propose a specific tariff design that shows robust network performance and reduces energy procurement costs.