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.     

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.     

Sustainable urban planning for a successful energy transition on Reunion Island: From policy intentions to practical achievement

Numerous studies have investigated how small vulnerable territories are adapting to climate change, particularly non-interconnected islands with focus on Renewable Energy Sources (RES) and self-sufficiency. A key to success is an energy plan with appropriate policy tools. This paper first presents a discussion on barriers to RES deployment. Then, we present the energy situation and the legislative energy framework in Reunion Island. Are the legislative and policy frameworks sufficient to achieve the energy transition? This paper proposes an original view discussing the potential of a territory and available tools to develop RES. Energy transition is also view as an opportunity.     

Comparison of energy systems in Small Island Developing States

Small Island Developing States (SIDS) have been amongst the most neglected group with regard to energy access until recently when several voices were raised to highlight the vulnerabilities of these small nations. Since then, their levels of energy access have become the focus of significant attention. These levels vary over a wide range, where some SIDS still have a low energy access although they may have the resources. The energy mix for electricity production is mostly dominated by fossil fuels where the transportation cost results in high cost of fossil fuels and this leads to a high cost of electricity.     

Introduction to integration of renewable energy in demand controlled hybrid ventilation systems for residential buildings

In the scope of the EU supported project RESidential buildings HYbrid VENTilation (RESHYVENT), the possible integration of renewable energy solutions (RES) into hybrid ventilation systems has been analysed. The focus has been on solar and wind applications to substitute the use of fossil fuel. The feasibility of the investigated options depends on the ventilation concept the RES is integrated into, the location of the building geographically, placement of the RES in the building and on the urban environment. This paper describes the different renewable technologies, options and constrains in connection with integration into hybrid ventilation systems.     

Economic evaluation of variable renewable energy participation in U.S. ancillary services markets

Variable renewable energy (VRE) is not yet meaningfully participating in U.S. ancillary services (AS) markets. VRE participation in AS markets could provide a new source of revenue for VRE resource owners to offset declining energy and capacity values and a new tool for power system operators to address emerging system constraints. This paper uses a price-taker dispatch model and historical prices to estimate the economic value of standalone and hybrid (battery-paired) VRE participation in AS markets, from the resource owner and electricity system perspectives, in each of the seven U.S. independent system operator and regional transmission organization (ISO/RTO) markets where ancillary service prices are set. Across ISO/RTO markets, average (2015–2019) simulated incremental revenues from power regulation market participation were $0.0–2.9/MWh (+0–15% of revenue without participation) for standalone VRE owners and $1–33/MWh (+1–69%) for hybrid VRE owners. However, ISO/RTO reserve markets are relatively thin and have the potential to become saturated by energy storage projects that are currently in ISO/RTO interconnection queues. In most markets, standalone and hybrid VRE could provide power regulation reserves during periods with high power regulation prices, suggesting that VRE participation in AS markets could have high system value. The analysis highlights the relevance of separate upward and downward power regulation products and indicates that ISOs/RTOs might consider initially focusing on enabling hybrid VRE provision of AS.     

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.     

Automatic generation of energy conservation measures in buildings using genetic algorithms

Building energy simulations are key to studying energy efficiency in buildings. The state-of-the art building energy simulation tools requires a high level of multi disciplinary domain expertise from the user and many technical data inputs that curb the usability of such programs. In this paper an IT tool is presented, which has the capability of predicting a building's energy utilization configuration based on the reported annual energy and a few non-technical inputs from the user; and correspondingly generates cost effective energy conservation measures for the intended savings.The approach first identifies the system variables that are critical to a building's energy consumption and searches for the combination of these parameters that would give rise to the annual energy consumption as reported by the facility. Genetic algorithms are utilized to generate this database. A statistical fit is formulated between the system variables and the annual energy consumption from the database. Using this correlation, system configuration for the target energy efficiency is determined with corresponding energy conservation measures. A cost analysis is carried out to prescribe the most cost effective energy conservation measures. Competency of the tool is demonstrated in the paper through case studies on three geographies with different climate conditions.     

A perspective on clean power and the future of US energy politics and policy

United States energy policy is undergoing a historic transformation. For the first time, the federal government has taken the lead in aligning energy and environmental regulation. The Environmental Protection Agency has asserted itself under the auspices of an administrative rule known as the Clean Power Plan (CPP) that specifically targets electric utilities, most notably coal-fired utilities, for the express purpose of reducing carbon emissions. The CPP requires states, either individually or through multi-state arrangements, to submit compliance plans in either 2016 or 2018 if an extension is granted. The EPA has suggested three principal “building blocks” for formulating state compliance plans. In the wake of this new regulatory landscape, this paper describes the CPP, identifies the specific challenges facing the electric industry, and provides potential responses to those challenges. The paper concludes that the Clean Power Plan provides the necessary context for the US transition to a clean energy future.     

Effect of reference state on the performance of energy and exergy evaluation of geothermal district heating systems: Balcova example

In this paper, we undertake a parametric study to investigate how varying reference temperature from 0 to 25 °C will affect the energy and exergy efficiencies of the Balcova geothermal district heating system (BGDHS) and develop two significant correlations (with a correlation coefficient of 0.99) that can be used for predicting the efficiencies. The exergy losses in the overall BGDHS are quantified and illustrated using exergy flow diagram particularly for a reference temperature of 11.4 °C for comparison purposes. This reference temperature is taken as an average value of the ambient temperatures measured during the past 5 years for the day of 2nd January to reflect the actual situation. The results show that the exergy losses within the system occur mainly due to the losses in pumps, heat exchangers, reinjection sections of the geothermal water back into reservoir and pipeline, and account for 1.75%, 8.84%, 14.20%, and 28.69%, respectively. In addition, we study energy and exergy efficiencies to determine the possibilities to improve the system, and energy and exergy efficiencies of the system are found to be 42.36% and 46.55%, respectively, for 2nd January 2004.     

Effects of remittances on renewable energy consumption: Evidence from instrumental variable estimation with panel data

This study investigates the impact of remittances on renewable energy consumption (REC) using a panel of 25 top remittance-receiving countries for 1990–2018. We use a generalized two-stage least squares random effect model to estimate the impact of remittance on renewable energy use. Results showed that remittances and REC have a generally positive relationship among the studied nations. Governments may create a system to incentivize remittance-receiving households to adopt and utilize more carbon-neutral energy devices at a lower cost if they pay with remittances. This approach could lead to higher societal adoption and consumption of green energy.     

The financials of constructing a solar PV for net-zero energy operations on college campuses

The LACCD has a goal of establishing net-zero energy operations across its nine campuses. The project faces many challenges, including limited open areas for installing solar PV, increasing energy consumption challenges associated with campus energy growth and the high cost of installing solar PV. A previous study by Kwan and Hoffmann (2010) found that the LACCD would need to install a 9.5 MW solar PV array in order to meet total campus energy demand on a college campus through the year 2020. This paper attempts to evaluate the financial feasibility of such a project, taking into account the current local, state and federal renewable energy incentives available. We find that despite the availability of financial incentives by local municipal utility companies including installation rebates and net metering, the cost of electricity generated by solar PV still remains approximately 30% higher than electricity generated by fossil fuels. We also find that the optimal solar PV array size from a financial standpoint is one that is sized to generate and meet all electrical demand during sunlight hours. Any array larger than this yields diminishing returns. Finally our analysis examined the influence of per kW installation cost and found that only when prices dropped to $3.00 per installed watt did a net-zero energy solar PV array have an NPV of 0.     

Environmental benefits of energy poverty alleviation,renewable resources,and urbanization in North Africa

Addressing energy poverty via expanding renewable energy sources and advancing sustainable development strategy is a crucial goal for developing nations. Therefore, the study aims to investigate relationships between carbon dioxide emission, renewable and nonrenewable energy resources, economic growth, urbanization, and energy poverty in the North African region, namely: Tunisia, Sudan, Morocco, Libya, and Egypt from 1993 to 2021, by employing Panel PMG ARDL and Granger causality approaches. According to empirical results, addressing energy poverty (access to electricity), economic growth, and using renewable and nonrenewable energy sources worsen the environment. Two-way causal relationships are founded between environmental deterioration and other variables: economic growth, energy resources, and urbanization. Based on the findings, policymakers should step up their efforts to promote green urbanization and alleviate energy poverty through renewable energy sources.     

Effects of corruption,technological innovation,globalisation, and renewable energy on carbon emissions in Asian countries

This study attempts to identify the role of corruption along with technological innovation, globalisation, renewable energy, and economic growth on CO₂ emissions in Asian countries using the panel data for 1960–2020. Driscoll and Kraay's standard error technique and Panel Corrected Standard Error (PCSE) model have been applied for empirical estimation where the findings disclose that corruption, technological innovation, globalisation, and GDP increase, whereas the renewable energy and square of GDP reduce the CO₂ emissions in the study areas. The causal associations between the studied variables under pairwise Granger causality are also exposed.     

Effect of courtyard proportions on solar heat gain and energy requirement in the temperate climate of Rome

The present study focuses mainly on the effect of solar heat gain on the energy demand of courtyard building form with different proportions. Several methods can be employed to improve the building's utilization of solar heat gain. This includes using light colours for the external surfaces to reduce the solar radiation absorption in summer, using shading devices and improving the thermal properties of the external walls and roof. However, it is of great importance before using any of these methods to have the courtyard building's architectural design adapted to have full advantage of the available solar heat gain. Therefore, the main objective of the present examination was to find out to what extent the building's solar heat gain and consequently the energy requirements are influenced by the building's configurations. A computer Tool (IES) was used to carry out the investigation taking Rome as an empirical background to temperate climate. The results showed that the proportions of the courtyard building considerably influence the need for heating and cooling.     

A parametrical study on the energetic and exergetic assessment of a solar-assisted vertical ground-source heat pump system used for heating a greenhouse

An energetic and exergetic modeling of a solar-assisted vertical ground-source heat pump (GSHP) greenhouse heating system (SAGSHPGHS) for system analysis and performance assessment is presented in this study. Energy (heating coefficient of performance ‘COP’) and exergy efficiencies at various reference and entering water temperatures are also determined. The actual thermal data collected are utilized for the model calculations at different reference temperature values in the range of −0.69 to 25 °C. Furthermore, the performance of a SAGSHPGHS, installed in Solar Energy Institute of Ege University, Izmir, Turkey, is evaluated to show, how energy and exergy efficiencies values change with system. The exergy destructions in the overall SAGSHPGHS are quantified, particularly for a reference temperature of −0.69 °C on 7 January 2004 for comparison purposes. Based upon the measurements made in the heating mode from the 16th of December 2003 till 31st of March 2004, average heating COPs of the GSHP unit and the overall system are obtained to be 2.84 and 2.27, respectively. The best (peak) COP of the GSHP and system were found to be 3.14 and 2.79 on 7 January 2004, respectively. Average exergy efficiency of the system is determined to be 68.11%, while the best exergy efficiency peak values for the GSHP unit and the whole system on a product/fuel basis are obtained to be 76.2% and 75.6%, respectively.     

The impact of indoor thermal conditions,system controls and building types on the building energy demand

It is possible to evaluate the energy demand as well as the parameters related to indoor thermal comfort through building energy simulation tools. Since energy demand for heating and cooling is directly affected by the required level of thermal comfort, the investigation of the mutual relationship between thermal comfort and energy demand (and therefore operating costs) is of the foremost importance both to define the benchmarks for energy service contracts and to calibrate the energy labelling according to European Directive 2002/92/CE. The connection between indoor thermal comfort conditions and energy demand for both heating and cooling has been analyzed in this work with reference to a set of validation tests (office buildings) derived from a European draft standard. Once a range of required acceptable indoor operative temperatures had been fixed in accordance with Fanger's theory (e.g. −0.5 < PMV < −0.5), the effective hourly comfort conditions and the energy consumptions were estimated through dynamic simulations. The same approach was then used to quantify the energy demand when the range of acceptable indoor operative temperatures was fixed in accordance with de Dear's adaptive comfort theory.     

Effects of the circular economy,environmental policy,energy transition,and geopolitical risk on sustainable electricity generation

The recent global paradigm shift toward sustainable green development necessitates revealing the likely green determinants of sustainable electricity generation in order to derive key policy recommendations for dealing with the global energy crisis. As a result, the current study focuses on the drivers of global electricity generation (EG) and identifies environmental policy (EP), energy transition (ET), geopolitical risk (GPR), and circular economy (CE) as novel determinants. The study employs a battery of advanced econometric techniques, including quantile VAR, quantile slope estimate, and wavelet-based correlation methods, for empirical analysis. The quantile VAR-based connectedness confirms the modeled series' significant interconnectedness. Furthermore, the findings suggest that CE plays an important role in promoting the global EG process, as evidenced by positive effects across quantiles. When the effects of ET and EP are considered, a positive relationship between ET, EP, and EG is discovered, implying that ET and EP are important drivers of electricity generation. Furthermore, GPR has significant and negative effects on EG across most quantiles, indicating that the EG process suffers a significant loss as a result of GPR. Furthermore, the wavelet-based correlation method confirms the significant association between selected series, supporting the preceding findings. In order to achieve sustainable electricity generation, several results-based policies are proposed for local and global authorities.     

传统建筑屋顶的现代诠释--浅析现代住宅坡屋顶的可持续设计

屋顶是传统建筑尤其是中国传统建筑的显著特征.随着社会的发展,在重新审视能源、资源和环境问题的今天,传统建筑的屋顶被赋予了新的功能、形式和诸多的技术设计。该丈结合我国现阶段住宅坡屋顶的设计,探讨了其可持续的建筑设计理念、首先,指出了设计适宜的坡屋顶倾斜角度,可以节省规划用地的方法;其次,指出了充分利用坡屋顶内部空间,可以节约建筑成本的问题：第三,阐述了太阳热水器与坡屋顶一体化设计,可以节约能源的观点：最后,论述了坡屋顶结合露台进行绿化设计与保护环境的重要性。     

Effects of income inequality and governance on energy poverty alleviation: Implications for sustainable development policy

This paper examines the effects of income inequality and governance on access to electricity using a panel of 43 SSA countries from 1990 to 2017. The results from the two-step GMM estimator revealed that while income inequality substantially reduced access to electricity, governance has been ineffective in improving it. The findings showed that governance interacts with income inequality and economic growth to reduce access to electricity. Comparative analysis suggested that these findings vary among the SSA sub-regions. We argue that energy poverty alleviation requires firm political will and an effective governance system to close the income inequality gap.