Renewable Energy Portfolio Research Articles

Can renewable energy portfolio standards and carbon tax policies promote carbon emission reduction in China's power industry?

The carbon emissions of the power industry in China rank the highest among all industries. There is an urgent need to explore the development path of the power industry under carbon peaking and carbon neutrality. Renewable portfolio standards (RPS) and carbon tax policy are effective policy instruments for realizing the low-carbon transition in the power industry. When both RPS and carbon tax policy are implemented, can they drive carbon reduction in the power industry? This paper constructs an electricity market equilibrium model and a system dynamics (SD) model to analyse the impact of multiple policies in electricity markets to address this question. There were several important results. (1) The increase in quota ratio and carbon tax price negatively impacts the generation of thermal power firms, which raises their willingness to invest in renewable energy. (2) The intensity of emissions reduction has a significant influence on the effectiveness of emissions reduction. The greater the emissions reduction intensity, the better the carbon emissions reduction effect, but the power supply declines. (3) Under multiple policies, green power firms choose cost padding to achieve profit maximization goals, which reduces green power generation and leads to market inefficiency.

A level-set approach to the control of state-constrained McKean-Vlasov equations: application to renewable energy storage and portfolio selection

We consider the control of McKean-Vlasov dynamics (or mean-field control) with probabilistic state constraints. We rely on a level-set approach which provides a representation of the constrained problem in terms of an unconstrained one with exact penalization and running maximum or integral cost. The method is then extended to the common noise setting. Our work extends (Bokanowski, Picarelli, and Zidani, SIAM J. Control Optim. 54.5 (2016), pp. 2568–2593) and (Bokanowski, Picarelli, and Zidani, Appl. Math. Optim. 71 (2015), pp. 125–163) to a mean-field setting.The reformulation as an unconstrained problem is particularly suitable for the numerical resolution of the problem, that is achieved from an extension of a machine learning algorithm from (Carmona, Laurière, arXiv:1908.01613 to appear in Ann. Appl. Prob., 2019). A first application concerns the storage of renewable electricity in the presence of mean-field price impact and another one focuses on a mean-variance portfolio selection problem with probabilistic constraints on the wealth. We also illustrate our approach for a direct numerical resolution of the primal Markowitz continuous-time problem without relying on duality.

Influence mechanism of renewable portfolio standard on energy producers

Renewable energy Portfolio Standard (RPS) policy plays a significant role in reducing carbon dioxide emissions and promoting the development of renewable energy. Based on bounded rationality, this paper constructed an evolutionary game model to analyze energy power production decision-making, involving both fossil and renewable power producers as participants. Through the discussion of evolutionary game equilibrium, the study revealed the following findings: (1) marketised TGC price benefits the reduction of fossil energy power production: (2) Tire implementation of RPS policy does not necessarily lead to an increase in total renewable energy production; (3) Under RPS policy, the higher proportion of renewable energy quota is not always advantageous for reducing fossil energy power production.

Designing Efficient Renewable Energy Portfolios for Optimal Coverage of European Power Demand under Transmission Constraints

In this paper, we consider spatially and technologically diversified portfolios of renewable energy resources (RES) on a European scale. These portfolios efficiently allocate wind and solar production capacity with a view on matching load and restricting conventional generation capacity in each country. We investigate the composition of optimal portfolios taking into account the existing cross-border transmission capacity as well as future expansion scenarios. For the purposes of our analysis, we develop several multi-criteria optimization models and apply them to a rich dataset of daily electricity load, RES capacity factors, and transmission capacity constraints for 32 European countries during the period 2010–2015. By exploring different scenarios for the composition of efficient portfolios and cross-border network connectivity, we quantify the effectiveness of the resource aggregation strategy in terms of reducing the energy production deficit or surplus in each country. Empirical evidence shows that the portfolio perspective provides a solid basis for strategic planning on the future expansion of the European grid.

Optimal Bidding Strategy Considering Bilevel Approach and Multistage Process for a Renewable Energy Portfolio Manager Managing RESs With ESS

This article presents a bilevel and multistage framework in whicha renewable energy portfolio manager (REPM) manages renewable energy sources (RESs) integrated with an energy storage system (ESS) to reduce imbalances and joins in the day-ahead market and the balancing market, including bilateral contracts. The total REPM gain is maximized in the upper level, whereas the loss of income of each portfolio participant in the lower level is minimized taking into account the specified income value. In the multistage structure, different decisions are taken regarding energy trade according to the hours of the day. Generations and price uncertainties that need to be addressed in optimum bidding problems are eliminated with a stochastic approach. Besides, risk management is evaluated through the conditional value-at-risk method. Besides, the test is carried out using real data from Spain in order to verify the effectiveness of the proposed model. According to the results obtained from the study, it can be stated that RESs with ESS increase the portfolio profit by 2%, and even in the case of expected generation, it is 4.1%, by better managing the energy imbalance of participants.

Harnessing the power of environmental flows: Sustaining river ecosystem integrity while increasing energy potential at hydropower dams

Hydropower comprises the largest portion of the world's renewable energy portfolio yet induces significant environmental effects in river and floodplain ecosystems. Many countries are seeking to increase hydropower capacity primarily through the construction of new dams; however, this overlooks the potential energy that can be gained from optimizing existing hydropower infrastructure. Environmental regulatory protocols globally, and especially in the US, require hydropower facilities to provide environmental flows to downstream riverine ecosystems. Most of these facilities, however, fail to capture additional hydropower energy from these releases, such as passing them through smaller turbines. Herein, we conducted a US-wide analysis of the potential additional hydropower capacity and generation that could be available if environmental flows were harnessed for energy. We used two approaches based on availability of information: one reliant on available stream flow data to identify specific optimal turbine sizes, and another using a design-envelope approach, to accommodate situations where flow data was unavailable. Using available historical flow data and plant characteristics from over 200 existing hydropower facilities, the addition of minimum flow turbines could provide up to 730 MW of capacity and generate nearly 1.8 TWh of energy annually. Across the remaining hydropower fleet, the envelope approach suggests there may be anywhere from 12 TWh to 66 TWh of additional energy, supplied from a capacity increase of 2.5 GW–13.5 GW annually. Ultimately, this suggests that uncaptured environmental flows provide anywhere from 4% to 18% potential increase in US hydropower capacity and 4%–24% increase in generation.

The effect of spatial granularity on optimal renewable energy portfolios in an integrated climate-energy assessment model

Renewable energy planning is key to achieving target levels of renewable-energy penetration and electricity demand in the European Union. Mean–variance analysis can be used to identify the optimal spatial and technological deployment of variable renewable energy (VRE) sources in terms of maximizing VRE penetration and minimizing supply risks. We investigate the extent to which optimizing capacities at the scale of climate-data grid points, instead of administrative regions (a common approach due to data availability and computation costs), helps generate more optimal renewable deployment scenarios. A finer description of climate resources, and thus the VRE capacity factors, results in a better exploitation of complementarities, partly due to the increased degrees of freedom in the optimization. A detailed analysis of the causes behind these improvements shows that better describing local conditions leads to two advantages over less granular counterparts: higher average capacity factors and generation combinations that offer lower covariances. This analysis also reveals that more granular approaches significantly reduce variability in daily and annual climate frequencies in renewable generation under the optimal scenario. These results provide evidence of the need to account for detailed climate information to accurately identify optimal renewable deployment scenarios and support stakeholders and policy makers when it comes to making sustainable commitments.

Clean energy strategies and pathways to meet British Columbia's decarbonization targets

AbstractBritish Columbia (BC) recently released the CleanBC policy framework to promote clean energy and mitigate greenhouse gas (GHG) emissions. However, CleanBC lacks concrete measures to reverse the growth of energy demand. Although BC has rich biomass and hydroelectric resources, it remains unclear whether these renewable resources will be enough to meet future energy demand. In this work, the potential in BC for increasing production and use of bioenergy, renewable electricity, and low‐carbon hydrogen was assessed, and the most efficient measures were identified. Energy scenarios were constructed to explore BC's future renewable energy demands for meeting GHG mitigation targets. The results show that CleanBC will drastically raise renewable energy demands but fail to achieve the 2030 target without radical demand reduction. Seen as the core strategy in CleanBC, electrification will require at least 60 PJ of additional electricity supply for 2030 and 160 PJ for carbon neutrality in 2050. This implies implementing wind and solar generation in capacities comparable to massive hydroelectric projects. Alternative to electrification is the bioenergy‐centred strategy. Existing waste biomass must be fully exploited; even then, roughly 250 and 460 PJ of additional primary bioenergy will be needed for 2030 and 2050, respectively, well beyond any foreseeable waste supply within BC. Hence, it is essential to utilize all the available biomass and renewable electricity resources and promote a diversified renewable energy portfolio. Hydrogen used as an energy carrier must be produced from natural gas with carbon capture to avoid competition for the limited renewable energy resources.

Decision Making on the Renewable Energy Penetration in Malaysia via SWOT-PESTLE Analysis: Hydrogen Fuel Cell and Solar Photovoltaic Thermal Technology

Malaysia is actively working to move towards renewable energy (RE) generation for sustainable growth. Hydrogen fuel cell (HFC) and solar photovoltaic thermal (PVT) feature emerging RE technologies that can supersede conventional power generation performance. HFC and PVT utilize renewable resources, which are hydrogen, oxygen and sunlight, to produce electricity without compromising the environment. However, no in-depth evaluation has been conducted to assist the decision-making of Malaysia’s HFC and PVT technology penetration. This study provides decisions on the feasibility and viability of HFC and PVT based on the Strength, Weakness, Opportunities, Threat (SWOT) and Political, Economic, Social, Technological, Legal, Environment (PESTLE) analyses. Based on the SWOT-PESTLE analysis, PVT exhibits great potential in Malaysia’s RE portfolio compared to HFC. Technology readiness and social acceptance are the merits of PVT diffusion in Malaysia. Nevertheless, this preliminary decision entails validation from the industries and experts to underpin the shorthand assessment of the present work

Water for Tomorrow: A Living Lab on the Creation of the Science-Policy-Stakeholder Interface

The proactive sustainable management of scarce water across vulnerable agricultural areas of South Europe is a timely issue of major importance, especially under the recent challenges affecting complex water systems. The Basin District of Thessaly, Greece’s driest rural region, has a long history of multiple issues of an environmental, planning, economic or administrative nature, as well as a history of conflict. For the first time, the region’s key-stakeholders, including scientists and policymakers, participated in tactical meetings during the 19-month project “Water For Tomorrow”. The goal was to establish a common and holistic understanding of the problems, assess the lessons learned from the failures of the past and co-develop a list of policy recommendations, placing them in the broader context of sustainability. These refer to enhanced and transparent information, data, accountability, cooperation/communication among authorities and stakeholders, capacity building, new technologies and modernization of current practices, reasonable demand and supply management, flexible renewable energy portfolios and circular approaches, among others. This work has significant implications for the integrated water resources management of similar south-European cases, including the Third-Cycle of the River Basin Management Plans and the International Sustainability Agendas.

Maximizing financial benefits of investment tax allowances in renewable energy portfolios

ABSTRACT Policy makers offer fiscal incentives to encourage companies to invest in renewable technologies. This work considers generation companies that take advantage of fiscal incentives to minimize income tax. Thus, a novel mixed-integer linear optimization model that minimizes total tax payments of a company owning a portfolio of energy projects is designed. The model strategically manages depreciation, tax loss carryforward, and tax incentive use for minimizing discounted income tax. A set of revenue scenarios was employed to analyze model results. The proposed model yields tax savings between 8.2% and 19.2% of the company’s taxes. Tax savings are significantly larger for companies with a large generation portfolio; which represents a clear advantage over small generation companies. The proposed model can also be employed by policy makers to adjust future ITA policies by taking advantage of the anticipative knowledge of the optimal tax strategies implemented by generation companies.

Study of blockage and wakes for an on-shore Wind Farm using SCADA data and CFD simulations

The ever-changing energy scenario call for a central role of wind energy exploitation within the renewable energy portfolio; the wind resource nowadays is a very precious means of clean energy production and year by year its degree of reliability and efficiency is pushed towards the optimum. For these reasons two topics are now very important for the improving further the conversion performances: the study of the blockage, as nowadays a lot of machines are planned to be installed in the neighbors of existing ones, and the analysis of wakes, as they represent still the main source of losses and reliability issues. For this reason in the present study, which is an example of collaboration between academia and industry, a deep analysis of wind farm flow, blockage, and wake effects was developed using numerical simulations and real-world operational data from an on-shore windfarm owned by Lucky Wind. Results demonstrate the fundamental role of CFD numerical simulation in understanding and interpreting the complex physics of wakes and the overall importance of blockage effects.

Fuzzy incorporated Black–Litterman model for renewable energy portfolio optimization

Fuzzy incorporated Black–Litterman model for renewable energy portfolio optimization

Optimising sustainable renewable energy portfolios using a multi-tolerance fuzzy goal programming approach

ABSTRACT The application of fuzzy multi-objective decision-making (F-MODM) to the optimization problems of renewable energy (RE) planning with uncertainties has become increasingly popular, although it is still rare in contrast to the use of traditional multi-attribute decision-making (MADM) methods. This study contributes to the domain of F-MODM modeling and the empirical applications of RE. Methodologically, as a recent trend to enhance the solution quality of fuzzy goal programming (FGP) in F-MODM is to introduce the “tolerance” (or admissible violation) concept to membership functions (MFs), this study proposes a novel ‘FGP-MT’ (multi-tolerance FGP) model to overcome the limitations of ‘single tolerance’ during FGP modeling (i.e. being unable to fit complicated ‘multitolerance’ decision contexts and running the risk of missing better optimality). The model is first verified using a numerical example from the F-MODM literature. Empirically, an application of the FGP-MT model is then considered for a SREPO (sustainable renewable energy portfolio optimization) decision, searching for the optimal electricity generation portfolio from multiple RE resources in Algeria for sustainable RE development, subject to the special preference structure of the decision-maker (DM) that involves manifesting two or more tolerances for a fuzzy goal. As the model performs well or even better in determining the most suitable SREPO decision under this condition, insights are gained for the studied case, and future applications of the model are therefore expected.

Public Preferences for Renewable Energy Options: A Choice Experiment in Rwanda

Rwanda has seen impressive economic growth in the past few years resulting from policy driven initiatives. However, one of the key challenges to economic development in Rwanda has been the provision of reliable and cost-effective energy. As a result, the country has planned to expand its renewable energy portfolio to meet its energy demand and mitigate greenhouse gas (GHG) emissions. Meeting these goals requires a robust policy framework that considers the perspective of the public. Moreso, for women who have been disproportionately affected by climate change especially in developing countries. Gender equality is a key for the Rwanda strategy as gender gaps remain a barrier to equal benefits from energy access to all. Several challenges abound in providing access to electricity and reducing the dependency on wood fuel for cooking, hence deliberate effort needs to be made to ensure gender responsiveness in energy programs and policies. This study applied a choice experiment analysis to determine how renewable energy attributes (type of energy, ownership, impact on environment, distance and visibility, community job creation and renewable energy tax) impacts public willingness to pay for renewable energy development in Rwanda. A nationwide survey was conducted on 1,006 households from which 58.35% were women. We applied both the conditional logit (MNL) and random parameter logit (RPL) framework. We found that the Rwandan public has a high utility for the following issues: environmental impact, distance and visibility, and type of renewable energy, respectively. Further analysis focused on the gendered impacts of renewable energy revealed that women had the strongest preference for interventions with low impact on the environment. From a policy standpoint women's input should be incorporated in future decision-making processes through public participation to guide policymakers in developing beneficial renewable energy programs.

Hydrogen production from landfill biogas: Profitability analysis of a real case study

Hydrogen is not only considered as a cornerstone within renewable energy portfolio but it is also a key enabler for CO2 valorisation being a central resource for industrial decarbonization. This work evaluates the profitability of hydrogen production via combined biogas reforming and water–gas shift reaction, based on a real case scenario for landfill biogas plant in Seville (Spain). A techno-economic model was developed based on a process model and the discounted cash-flow method. A biogas flow of 700 m3/h (input given by the landfill biogas plant) was used as plant size and the analysis was carried out for two different cases: (1) use of already available energy sources at the industrial plant, and (2) solar energy generation to power the process. The economic outputs obtained showed that under the current circumstances, this hydrogen production route is not profitable. The main reason is the relatively low current hydrogen prices which comes from fossil fuels. A revenues analysis indicates that hydrogen from biogas selling prices between 2.9 and 5.7 €/kg would be needed to reach profitability, which are considerably higher than the current hydrogen cost (1.7 €/kg). A subsidy scheme is suggested to improve the competitiveness of this hydrogen production process in the short-medium term. A cost analysis is also performed, revealing that electricity prices and investment costs have a high impact on the total share (23–40% and 8–22%, respectively). Other potential costs reduction such as catalyst, labour and manteinance & overhead are also evaluated, showing that cutting-down production costs is mandatory to unlock the potential of hydrogen generation from biogas. Our work showcases the techno-economic challenge that green energy policies face in the path toward sustainable societies.

A Study on India's Status of Transition Towards a Green Economy

The study represents the status of India in its adoption of green economy and suggestions to address identified gaps. The research is qualitative and quantitative wherein secondary data for green economy growth indicators is obtained from reports of Organization for Economic Co-operation and Development (OECD), World Bank Group, etc. In India, the journey of transition towards a greener economy has commenced. India has obtained membership in Partnership for Action on Green Economy (PAGE). India is making significant progress in areas of environmental policies at national level, enhancement in renewable energy portfolio, improved access to basic services. India has improved in global positions and scores of green growth indexes. India lags in factors including degraded air quality, high greenhouse gas emissions and inefficient waste management. India has progressed but has a long way ahead to achieve its goals and commitments to emerge as a successful green economy.

Market-based solution in China to finance the clean from the dirty

Financial incentives play a key role in promoting renewable energy investments that can help China achieve the ‘dual carbon’ goal. The national emissions trading scheme (ETS) and the renewable energy portfolio standard (RPS) are two existing market-based policy instruments that can generate stable expected returns for low-carbon projects. This paper studies the interactive distribution effects of these two market-based instruments. We use the micro-level thermal power plant data to investigate the abatement effects of the national ETS, in which the details show that the existing rate-based ETS will result in higher negative impacts on power units, whose installed capacities are smaller than 400 MW. The interactive distribution effects between the two markets will occur when the permit allocation standards of the national ETS become stricter than the existing ones. Provinces in Eastern China and Northern China will face high pressure on costs in both ETS and RPS markets. When the levels of the permit allocation standards are set as 70% of the existing ones and the carbon price is assumed to be 200 yuan/ton in 2030, the annual market size of the national ETS will be nearly 100 billion yuan, and the annual market size is predicted to be 250 billion yuan. In the existing rate-based national ETS, the China Certified Emission Reduction (CCER) mechanism will have an offsetting effect, which should be taken into serious consideration during the policy-making processes in the future.

Noncooperative multiagent game model for the electricity market on the basis of the renewable energy portfolio standard

AbstractIn China, after the revision of the renewable energy policy, transactions among the main parties involved in the electricity market are becoming increasingly complicated. Nevertheless, the impact of the Renewable Energy Portfolio Standard (RPS) on market equilibrium has not been studied so far. Hence, in this study, a noncooperative multiagent game model for the electricity market was developed on the basis of the recently released RPS and by considering various factors, such as green certificate transactions and the changing of the selling entities. The improved firefly algorithm was used to solve the model, and problematic gaming was analyzed empirically. Once the new RPS is implemented, the price of bound electricity will become higher than that of nonbound electricity, and the trading volume of bound electricity will increase. Because fossil energy producers will no longer be responsible for the electricity quotas, their electricity trading volumes will now be more related to the market demand than they were earlier. Renewable energy companies will increase their revenues by reducing their bound electricity sales. If the RPS increases the electricity quota ratios, the costs incurred by electricity sales companies and large power users will also increase, leading the electricity sales companies to reduce their electricity trading volumes. The study findings will help analyze the impacts of implementing the RPS and provide a basis and a reference for policymakers to make improvements to the standard in the future.

Advancing bipartisan decarbonization policies: lessons from state-level successes and failures.

U.S. political polarization is at a high point since the Civil War, and is a significant barrier to coordinated national action addressing climate change. To examine where common ground may exist, here we comprehensively review and characterize successes and failures of recent state-level decarbonization legislation, focusing especially on bipartisanship. We analyze 418 major state-government-enacted bills and 450 failed bills from 2015 to 2020, as well as the political contexts in which they were passed or defeated. We use bivariate analyses and regressions to explore correlations and partial correlations between the policy characteristics and political contexts of bills, and their passage or failure, their bipartisanship, and vote shares they received. Key results include (i) nearly one-third of these state-level decarbonization bills were passed by Republican-controlled governments. (ii) Bipartisan or Republican co-sponsors disproportionately passed financial incentives for renewable energy, and legislation that expands consumer or business choices in context of decarbonization goals; Democrat-only co-sponsors disproportionately passed bills that restricted consumer and business choice, such as mandatory Renewable Energy and Efficiency Portfolio Standards (REEPS) and emissions standards. (iii) Bipartisan bills were disproportionately proposed in “divided” states, did not restrict consumer and business choice, had environmental justice components framed economically, and lacked environmental justice components framed either using academic social-justice jargon or non-neutrally with respect to immutable characteristics such as race. (iv) Bills that expand consumer or business choice were disproportionately enacted. Though climate change is a polarized issue, our results provide tangible insights for future bipartisan successes.Supplementary InformationThe online version contains supplementary material available at 10.1007/s10584-022-03335-w.