Battery energy storage systems: Assessment for small-scale renewable energy integration

Concerns arising due to the variability and intermittency of renewable energy sources while integrating with the power grid can be mitigated to an extent by incorporating a storage element within the renewable energy harnessing system. Thus, battery energy storage systems (BESS) are likely to have a significant impact in the small-scale integration of renewable energy sources into commercial building and residential dwelling. These storage technologies not only enable improvements in consumption levels from renewable energy sources but also provide a range of technical and monetary benefits. This paper provides a modelling framework to be able to quantify the associated benefits of renewable resource integration followed by an overview of various small-scale energy storage technologies. A simple, practical and comprehensive assessment of battery energy storage technologies for small-scale renewable applications based on their technical merit and economic feasibility is presented. Software such as Simulink and HOMER provides the platforms for technical and economic assessments of the battery technologies respectively.     

Integrated transport and renewable energy systems

No single technology can solve the problem of ever increasing CO₂ emissions from transport. Here, a coherent effort to integrate transport into energy planning is proposed, using multiple means promoting sustainable transport. It is concluded that a 100 per cent renewable energy transport system is possible but is connected to significant challenges in the path towards it. Biomass is a limited resource and it is important to avoid effecting the production of food. The integration of the transport with the energy system is crucial as is a multi-pronged strategy. Short term solutions have to consider the long term goal. In a short term proposal for 2030 it is concluded that it is possible both to reduce CO₂ emissions substantially and, at the same time, gain economic benefits. Biofuels are not able to solve the problems within the transport sector but play an important role in combination with other technologies.     

Electricity from renewable energy resources: Sustainable energy transition and emissions for developed economies

Previous studies cover the connection between production-based carbon emissions and economic, financial, and environmental indicators. However, the comprehensive analysis still needs empirical evidence concerning the consumption-based carbon emissions. The present analyzes 21 industrialized countries during 1990–2020 by using the second-generation panel techniques. The study's results reveal the existence of the long-run equilibrium stable connection between the variables. Due to asymmetric data distribution, this research employed the novel method of moment quantile regression and found that economic growth is the leading factor of consumption-based carbon emission throughout the selected quantiles. However, electricity from renewable resources, research and development in renewable energy, environmental related taxes, and development of environmental related technologies substantially reduce consumption-based emissions and encourage environmental sustainability. This study concludes that an energy transition is an important tool for developed economies to confront the issue of degraded environmental quality.     

Renewable energy potential and adoption of renewable portfolio standards

Thirty states have adopted renewable portfolio standards (RPSs) that set targets for renewable energy generation by mandating electric power utilities obtain a minimum percentage of their retail load from renewable sources. To date, a number of studies have consistently found that political and economic factors impact RPS adoption. Studies have also examined the impact of renewable energy potential in a state on the probability of RPS adoption, but results have largely been statistically weak and inconclusive. After controlling for political and economic factors, we estimate that a one standard deviation increase in wind potential is associated with an approximately 4.2 percentage point increase in the probability of having an RPS, and a one standard deviation increase in solar potential is associated with a 6.1 percentage point increase in the probability of having an RPS.     

Forecasting renewable energy utilization by Iran's water and wastewater industries

This paper studies forecasting the use of renewable energies in the water and wastewater industry. Different methods have been proposed to show energy recovery techniques and the use of renewable energy in wastewater treatment. The results indicate that increasing the carbon tax to more than 30 USD per ton of CO2 could reduce emissions from all fossil-fuel power plant types by 30%.     

A comparative life cycle assessment of hybrid osmotic dilution desalination and established seawater desalination and wastewater reclamation processes

The purpose of this study was to determine the comparative environmental impacts of coupled seawater desalination and water reclamation using a novel hybrid system that consist of an osmotically driven membrane process and established membrane desalination technologies. A comparative life cycle assessment methodology was used to differentiate between a novel hybrid process consisting of forward osmosis (FO) operated in osmotic dilution (ODN) mode and seawater reverse osmosis (SWRO), and two other processes: a stand alone conventional SWRO desalination system, and a combined SWRO and dual barrier impaired water purification system consisting of nanofiltration followed by reverse osmosis. Each process was evaluated using ten baseline impact categories. It was demonstrated that from a life cycle perspective two hurdles exist to further development of the ODN-SWRO process: module design of FO membranes and cleaning intensity of the FO membranes. System optimization analysis revealed that doubling FO membrane packing density, tripling FO membrane permeability, and optimizing system operation, all of which are technically feasible at the time of this publication, could reduce the environmental impact of the hybrid ODN-SWRO process compared to SWRO by more than 25%; yet, novel hybrid nanofiltration-RO treatment of seawater and wastewater can achieve almost similar levels of environmental impact.     

Evaluating the ancillary services market for large-scale renewable energy integration in China's northeastern power grid

The installed renewable energy capacity in China is the largest in the world. However, the curtailment of renewable energy remains problematic. To alleviate this problem, a pilot for integrating the ancillary service market for renewable energy in China's northeastern power grid began in 2017. Before this time, a compensatory ancillary service cost mechanism was implemented, in which thermal plants not providing ancillary service paid the costs of the thermal plants providing ancillary service under government supervision. The pilot ancillary service market allowed thermal plants providing ancillary service to make independent quotes. Renewable energy plants were included in those paying the ancillary service costs. We examine the effects of the ancillary service market in the context of large-scale renewable energy integration. The results show that this market has given rise to competing interests between renewable energy and thermal plants. Therefore, measures must be taken to improve the ancillary service market, including eliminating the ancillary service bidding limits, establishing a renewable auction mechanism, and transforming the spot market.     

Exploring options for a 100% renewable energy system in Mauritius by 2050

This paper aims at critically analyzing the present and the proposed energy resource mix in Mauritius in order to make recommendations for a 100% renewable energy system for the island by 2050. While the Long Term Energy Strategy for the period 2009–2025 devised by the Government of Mauritius sets pathways for the future in a sustainable manner, it does not evaluate the feasibility of the options that will help in supporting this transition. Its scope is limited as the proposed framework aims at achieving only 35% self-sufficiency in terms of electricity supply by 2025 against 20% currently. This paper explores the main building blocks of a new energy paradigm by extending the analysis to 2050 in view of identifying systemic and holistic policies and strategies that will pave the way to a clean and efficient energy supply. Most notably, we look beyond electricity only to assess the energy system comprehensively in terms alternative resources for primary uses, including energy-intensive transportation and cooling. Ultimately, it also enhances the near-term energy framework by setting more ambitious green energy targets as a stepping-stone towards 100% energy self-sufficiency by 2050.     

Enhanced supervision strategies for effective reduction of building energy consumption--A case study of Ningbo

The purpose of this paper is to investigate the reasons for ever growing energy consumption in buildings and to give enhanced supervision strategies for reduction of building energy consumption compared to regular ones. A case study of Ningbo city was used to make a detail analysis. Several factors were determined as the reasons for ever growing building energy consumption including climate change, household electricity load increase, the growth of real estate, fast-growing household electrical appliances, high energy consumption in existing buildings, changes in industrial structure and the lack of enhanced government supervision. Then the discussion of suitable countermeasures shows that only enhanced supervision strategies are currently applicable. Finally, it is concluded that enhanced government supervision strategies, including the establishment of a strict control system for new built buildings through information integration and encryption, establishing an energy efficiency supervision system of large-scale public building and a carrot-and-stick approach with added expert checklist for the building application of renewable energy, showed great advantages in promoting building energy efficiency in Ningbo, compared with other cities. These supervision strategies are applicable in other cities as they are in the similar situations in the enforcement of building energy efficiency.     

Sustainable development of renewable energy on Wangan Island,Taiwan

This study investigated the potential of achieving energy autonomy in Wangan Island, based on the use of renewable energy. The simulation results of air pollutants indicate that there could be a 30–40% reduction in emissions because of an improvement in energy efficiency. The reduction of CO₂ emissions exceeded 50% in two scenarios of energy integration systems after energy efficiency was improved. Renewables could replace costly diesel for electricity generation on Wangan, and become a successful condition example of sustainable development. Roadmaps are needed for Wangan to scale up its applications of renewables, whether in the power or transportation sectors. This requires support from central government and reform in regulatory arrangements in the energy sector.     

Hybrid utilization of renewable energy and fuel cells for residential energy systems

This paper describes field experiments and numerical simulations on hybrid utilization of renewable energy and fuel cells for a residential energy system. It presents results of empirical testing and evaluation of hybrid utilization involving solar energy. First, field experiments were conducted on an electric power and domestic hot water supply system that uses both solar energy and fuel cells. The system achieved a large amount of reduction in primary energy consumption compared with conventional systems. Secondly, a simulation was performed on the optimum scale and effect of introduction of the system. The simulation results proposed the optimum capacities of the solar energy utilization and fuel cells to minimize primary energy consumption of the system.     

反渗透海水淡化优劣评述

针对水资源出现严重短缺的现状,指出海水淡化是解决水危机的唯一途径,概述了各种海水淡化技术的特点,介绍了反渗透海水淡化的预处理、能耗和浓盐水处理,预计SWRO将成为21世纪主要的淡化方法。     

Efficacies of technological progress and renewable energy transition in amplifying national electrification rates: contextual evidence from developing countries

Since electricity is a basic human need, improving its accessibility is of global relevance. Hence, this study considers data from 74 developing countries for understanding the macroeconomic factors influencing their national electrification rates. Although the income-group-specific findings exhibit heterogeneity, the overall results endorse the electrification rate-boosting impacts of technological progress, renewable energy transition, economic growth, and institutional quality improvement. Besides, the joint electrification rate-boosting effect of technological progress and renewable energy transition is affirmed, while higher income inequality and prices of crude oil are found to inhibit improvement in electrification rates in the developing countries of concern. Accordingly, several electrification rate-boosting policies are suggested.     

Different applications of Scheffler reflector for renewable energy: a comprehensive review

A fixed focus on receiver maintains constant temperature of receiver and it is achieved by Scheffler reflector. It is a best example of solar energy application used for medium-temperature applications. The present review shows a complete review of Scheffler reflector in solar thermal applications like desalination, coffee-making machine, agricultural application, electricity generation, hot water, cooking and plaster of Paris production. The Scheffler reflector is a best solar energy application in future emerging technologies.     

Is the renewable portfolio standard an effective energy policy?: Early evidence from South Korea

This study provides preliminary evaluation of South Korea's Renewable Energy Portfolio Standard (RPS) apropos capacity growth, technological innovation, cost impact, and market risk, compared to Feed-in Tariffs (FITs). Findings indicate that both effectively expand electricity generation from renewable energy sources (RES-Es). Early evidence suggests that the RPS appears to have further strengthened RES-Es' market growth, particularly biomass and solar PV. For most technologies, policy costs appear higher under the RPS than FITs, except for PV and fuel cells. Under the RPS, higher market risks are a major concern, particularly for smaller suppliers in the PV market, despite growing PV capacity.     

Reflections on the use of renewable power sources and nuclear energy in Portugal

This paper analyses the current energy balance of Portugal, considering the actual sources which are mainly traditional fossil fuels, hydroelectric power and renewables. Other potential sources are also discussed and taken into consideration in view of the previewed evolution of the country in energetic terms. Among these, nuclear power, once regarded as an option, is now being re‐considered. This paper also sums up the main issues to be considered in a future debate on the subject.     

Efficiency and productivity of renewable energy technologies: Evidence from U.S. investor-owned utilities across regional markets

This study employs a Data Envelopment Analysis (DEA) modeling technique to investigate the efficiency and productivity of renewable energy (RE) adoption across technologically diverse electricity-generating utilities. By employing metrics capturing policy effects, the study evaluates the RE adoption efficiency and productivity using a dynamic DEA model and the Malmquist DEA technique. First, the findings reveal that RE adoption is not significantly different across regional electricity markets. Second, the study revealed that RE adoption increased over the last three years. The total mean productivity change over the entire study period showed a mean improvement of 4.8%.     

A bird's eye view of Ghana's renewable energy sector environment: A Multi-Criteria Decision-Making approach

This study examines Ghana's renewable energy (RE) sector environment using PESTLE analysis (Political, Economic, Social, Technological, Legal, and Environmental). The Analytical Hierarchical Process (AHP) was employed to rank the various identified factors using inputs from 20 experts in Ghana's RE sector. The consulted experts ranked economic factors as the most critical challenge in the sector. According to them, the cost of capital in Ghana is too high, especially for long-term investments such as RE. The country's abundant RE resources and its geographical location were ranked highest in terms of the opportunities in the RE sector.     

An ensemble approach for electricity price forecasting in markets with renewable energy resources

With the restructuring of formerly vertically integrated utilities, the energy market behaves like a competitive market, which has resulted in an increased focus on the formulation of forecasting techniques. The contribution of this work is twofold. Firstly, we analyze and evaluate the impact of renewable sources on price forecasts and use them in model training. Next, we propose a bootstrap aggregated-stack generalized architecture for very short-term electricity price forecasting to facilitate market participants in formulating strategies in real time. The stacking phase integrates extreme gradient boosting and random forest, which is then bagged to obtain a computationally efficient model. The final combination of feature engineering and ensemble architecture is observed to outperform the existing techniques.     

Financial appraisal of wet mesophilic AD technology as a renewable energy and waste management technology

Anaerobic digestion (AD) has the potential to support diversion of organic waste from landfill and increase renewable energy production. However, diffusion of this technology has been uneven, with countries such as Germany and Sweden taking the lead, but limited diffusion in other countries such as the UK. In this context, this study explores the financial viability of AD in the UK to offer reasons why it has not been more widely used. This paper presents a model that calculates the Internal Rate of Return (IRR) on a twenty year investment in a 30,000 tonnes per annum wet mesophilic AD plant in the UK for the treatment of source separated organic waste, which is judged to be a suitable technology for the UK climate. The model evaluates the financial significance of the different alternative energy outputs from this AD plant and the resulting economic subsidies paid for renewable energy. Results show that renewable electricity and renewable heat sales supported by renewable electricity and renewable heat tariffs generates the greatest IRR (31.26%). All other uses of biogas generate an IRR in excess of 15%, and are judged to be a financially viable investment. Sensitivity analysis highlights the financial significance of: economic incentive payments and a waste management gate fee; and demonstrates that the fate of the digestate by-product is a source of financial uncertainty for AD investors.