A review on the complementarity of renewable energy sources: concept, metrics, application and future research directions

It is expected, and regionally observed, that energy demand will soon be covered by a widespread deployment of renewable energy sources. However, the weather and climate driven energy sources are characterized by a significant spatial and temporal variability. One of the commonly mentioned solutions to overcome the mismatch between demand and supply provided by renewable generation is a hybridization of two or more energy sources in a single power station (like wind-solar, solar-hydro or solar-wind-hydro). The operation of hybrid energy sources is based on the complementary nature of renewable sources. Considering the growing importance of such systems and increasing number of research activities in this area this paper presents a comprehensive review of studies which investigated, analyzed, quantified and utilized the effect of temporal, spatial and spatio-temporal complementarity between renewable energy sources. The review starts with a brief overview of available research papers, formulates detailed definition of major concepts, summarizes current research directions and ends with prospective future research activities. The review provides a chronological and spatial information with regard to the studies on the complementarity concept.Comment: 34 pages 7 figures 3 table

Wind Power: The Economic Impact of Intermittency

Wind is the fastest growing renewable energy source for generating electricity, but economic research lags behind. In this study, therefore, we examine the economics of integrating large-scale wind energy into an existing electrical grid. Using a simple grid management model to investigate the impact of various levels of wind penetration on grid management costs, we show that costs of reducing CO2 emissions by relying more on wind power depend on the generation mix of the existing electrical grid and the degree of wind penetration, with costs ranging from $44 to well over$1000 per tonne of CO2 reduced. Costs are lowest if wind displaces large amounts of fossil fuel production and there is some hydroelectric power to act as a buffer. Hydro capacity has the ability to store wind generated power for use at more opportune times. If wind does nothing more than replace hydro or nuclear power, however, the environmental benefits (reduced CO2 emissions) of investing in wind power are smal

IEA Wind Task 24 Integration of Wind and Hydropower Systems; Volume 2: Participant Case Studies

This report describes the background, concepts, issues and conclusions related to the feasibility of integrating wind and hydropower, as investigated by the members of IEA Wind Task 24. It is the result of a four-year effort involving seven IEA member countries and thirteen participating organizations. The companion report, Volume 2, describes in detail the study methodologies and participant case studies, and exists as a reference for this report

Hydropower in Scotland: Linking changing energy and environmental agendas with sustainability outcomes

As the UK energy sector moves to a greater contribution from low-carbon and renewable sources it faces significant challenges in delivering affordability, security of supply and sustainability. Although hydropower in Scotland emerged on a large scale in the mid-20th century against an influential, changing wider context of energy policy, environmental regulation and debate, it is now subject to an evolving renewables agenda. This further shapes the national and scheme level characteristics of hydropower and in turn outcomes for the water environment. Contingent upon these considerations, hydropower regulation must now deliver on EU obligations to protect and improve the ecological status of water bodies, whilst also supporting domestic efforts to meet high profile binding renewable energy targets. Yet, despite an acknowledged potential for energy policy to constrain the delivery of water policy objectives, there is little policy harmonisation between disciplines. As Scotland orientates itself as a leader in Europe on climate change, transitioning to increasing amounts of renewable generation across a handful of technologies, there is a gap in knowledge about how specific renewable policies and trends can influence hydropower sustainability outcomes and regulatory challenges. This thesis therefore contributes an innovative and timely critical examination of the effect a changing wider renewable energy and policy context has on hydropower sustainability in Scotland, at a scheme and national level. This research uses an interdisciplinary, temporal analysis to identify linkages and create dialogue between disciplines and scales, informing the pursuit of sustainable renewable energy through policy and regulation in a changing world. It finds firstly, that the changing national generation mix towards an increased contribution from renewable sources, including potentially intermittent technologies such as wind power, has contributed to an alteration in the operational characteristics and reservoir variability profile of Cruachan pumped-storage scheme, presenting positive outcomes for reservoir littoral habitats. Secondly, it finds that whilst not operating in isolation, renewable energy incentive policies, through their eligibility criteria, financial reward frameworks and timing, influence hydropower characteristics and sustainability challenges, providing trade-offs but also synergies for hydropower regulation. Finally, it finds that there is a degree of divergence in hydropower outcomes and challenges in Scotland and Norway, due to the characteristics and especially interaction of wider contextual elements such as topography, profile of precipitation input, national energy needs and the role of regional and municipal government. By highlighting these linkages, this thesis is of value to energy policy and environmental regulation in Scotland and across the EU, and is seen as a first step in addressing these uncertainties and supporting a more integrated and sustainable hydropower and renewables governance framework

Wind Power: The Economic Impact of Intermittency

Wind is the fastest growing renewable energy source for generating electricity, but economic research lags behind. In this study, therefore, we examine the economics of integrating large-scale wind energy into an existing electrical grid. Using a simple grid management model to investigate the impact of various levels of wind penetration on grid management costs, we show that costs of reducing CO2 emissions by relying more on wind power depend on the generation mix of the existing electricity grid and the degree of wind penetration, with costs ranging from $21 to well over$1000 per tonne of CO2 reduced. Costs are lowest if wind displaces large amounts of fossil fuel production and there is some hydroelectric power to act as a buffer. Hydro capacity has the ability to store wind generated power for use at more opportune times. If wind does nothing more than replace hydro or nuclear power then the environmental benefits (reduced CO2 emissions) of investing in wind power are small.Wind power, carbon costs, electricity grids, mathematical programming

Exploring the roles of storage technologies in the Spanish electricity system with high share of renewable energy

At operational level, fossil fuel phase-out and high shares of non-dispatchable renewable energy resources (RES) will challenge the system operator's (SO) ability to balance generation, and the demand at any time. The variability of RES output ranges from one hour to a season, and critical events such as low supply and high demand might occur more frequently and for more extended periods. When evaluating the role of Energy Storage Systems (ESSs) in this context, the need for a long time scope to capture the different RES variabilities must be reconciled with the need for modeling the hourly chronology. This paper presents a medium-term operation planning model, addressing both the energy dispatch and the balancing services. This study shows that representing the combined chronological variability of demand and RES production is essential to properly assess the roles of different kinds of ESSs in the future 2030 electricity mix. Otherwise, it would not be possible to appropriately capture the frequency, depth, and length of events for which ESSs are activated. The analysis also highlights the importance of considering balancing services, given the significant contribution of batteries to the reserve market. Finally, the results show that batteries and Pumped Storage Hydro (PSH) have different roles in the Spanish electricity system with a high renewable penetration. While PSH is mainly used to provide energy during critical periods, batteries mostly provide balancing services. © 2022 The Author(s)This research has been carried out thanks to the Spanish Ministry of Economy and Competitiveness MINECO through BC3 Mar?a de Maeztu excellence accreditation MDM-2017-0714 Maria de Maeztu Grant. The research has also benefited from the funding of the RETOS COLABORACI?N program of the Spanish Ministry of Science and Innovation and the Spanish State Research Agency (project ?Platform of innovative models to accelerate the energy decarbonization of the economy (MODESC)?, with reference number RTC2019- 007315-3). The authors would also like to acknowledge the Iberdrola Chair of Energy and Innovation for their helpful comments

Planning framework and methods to assess possible future high renewable penetrations in emerging economy electricity industries and security, affordability, and environmental implications for Indonesia’s Java-Bali grid

Electricity industries worldwide are transitioning away from fossil-fuels towards wind and solar generation. While these technologies are now often cost-competitive as well as environmentally preferrable alternatives to coal and gas options, their highly variable output does raise challenges for delivering secure, affordable, and clean energy. This is particularly challenging for the electricity industries of emerging economies giving growing demand and limited financial resources. This thesis aims to address some of the limitations with existing frameworks, methods, and tools for assisting policymakers to plan electricity industry development, with a particular focus on better assessing future electricity generation options for emerging economies. It uses an open-source evolutionary programming-based optimisation model, National Electricity Market Optimiser (NEMO), to assess future generation options for the case study of Indonesia’s Java-Bali electricity grid. NEMO can model geographically and temporally variable wind and solar resources and solve least cost generation mixes in a highly configurable and transparent manner. A first study assessed the potential industry costs savings possible by recognising the reality of lower reliability standards in emerging economies than often assumed for modelling exercises. Accepting lower reliability outcomes not only reduces industry costs but also supports greater solar and wind deployment, hence better environmental outcomes. Next, the underlying evolutionary programming optimisation of NEMO was used to assess not just the least cost generation mix but the wider solution space, including generation portfolios that deliver total industry costs within 5% of the least cost solution highlighted the wide range of possible technology mixes that could potentially deliver a low cost future industry. Finally, NEMO was used to explore the potential implications of high variable renewable penetrations for operating reserves and hence power system security. The inevitability of some periods with both low wind and solar availability means that high renewables portfolios still feature significant dispatchable generation capacity. This means that the power system will generally have greater levels of operating reserves to cover possible plant failures than mixes with predominantly dispatchable generation. In summary, this thesis contributes to better understanding of the challenges and opportunities of deploying possible future high renewables in emerging economy electricity industries