Modern active distribution grids are characterized by the increasing penetration of distributed energy resources (DERs). The proper coordination and scheduling of a large numbers of these small-scale and spatially distributed DERs can only be achieved at the nexus of new technological approaches and policies. As such, this paper presents a distributed optimal power flow formulation for the distribution grid, applied to the problem of Volt-VAR optimization (VVO). First, we propose a convex model to describe the power physics of distribution grids of meshed topology and unbalanced structure, based on current injection and McCormick Envelopes. Second, we employ the distributed proximal atomic coordination (PAC) algorithm, which has several advantages over other distributed algorithms, including reduced local computational effort and improved privacy. We implement VVO by optimally coordinating DERs including PV smart inverters and demand response. Results from the IEEE-34 bus network are presented, under different DER penetration scenarios and using different VVO objective functions. Our results show the need for DER coordination to achieve desired grid performance. Finally, we discuss the extension of such an optimal power flow formulation to the development of market derivatives to provide financial compensation to DERs providing grid services such as reactive power support and voltage support, within a local retail market framework.
Liquid fossil fuels (1) enable transportation and (2) provide energy for mobile work platforms and (3) supply dispatchable energy to highly variable demand (seasonal heating and peak electricity). We describe a system to replace liquid fossil fuels with drop-in biofuels including gasoline, diesel and jet fuel. Because growing biomass removes carbon dioxide from the air, there is no net addition of carbon dioxide to the atmosphere from burning biofuels. In addition, with proper management, biofuel systems can sequester large quantities of carbon as soil organic matter, improving soil fertility and providing other environmental services. In the United States liquid biofuels can potentially replace all liquid fossil fuels. The required system has two key features. First, the heat and hydrogen for conversion of biomass into high-quality liquid fuels is provided by external low-carbon energy sources–nuclear energy or fossil fuels with carbon capture and sequestration. The potential quantities of liquid biofuels are much smaller if biomass is used as (1) the carbon feedstock and (2) the source of energy for the conversion process. Using external energy inputs can almost double the energy content of the liquid fuel per unit of biomass feedstock by fully converting the carbon in biomass into a hydrocarbon fuel. Second, competing effectively with fossil fuels requires very large biorefineries—the equivalent of a 250,000 barrel per day oil refinery. This requires commercializing methods for converting local biomass into high-density storable feedstocks that can be economically shipped to large-scale biorefineries. Large-scale biorefineries also enable efficient coupling of nuclear reactors to the biorefinery.
Growing interest in greenhouse gas mitigation strategies to address global climate change has resulted in the rapid expansion of renewable electricity sources. Increasing energy generation from variable renewable electricity sources, such as solar photovoltaics and wind turbines, has made balancing electricity supply and demand across the power grid more challenging. Some grid management challenges include sharp ramp up needs when the sun goes down, and the overgeneration of renewables when demand is low. In absence of cost-effective, utility-scale batteries, demand response strategies that leverage flexibility in electricity consumption have gained interest as readily available resources to address the temporal mismatch between renewable energy availability and high energy demand periods. The water industry (i.e., water supply and wastewater systems) includes industrial customers that are particularly attractive in terms of demand response potential as they can offer flexibility through large water storage capacities, large interruptible pumping loads, and energy generation opportunities. This study highlights an illustrative case in California to demonstrate the emissions benefits of load shifting in the water industry, followed by discussions regarding potential flexibility opportunities based on the recent literature and directions for future research opportunities to support the implementation of flexibility measures.
Due to the environmental impacts brought by current energy schemes, the energy transition, a new paradigm-shift from fossil fuels to renewable energy, has been widely accepted and is being realized through collective international and local efforts. Electricity, as the most direct and effective use of renewable energy sources (RES), plays a key role in the energy transition. In this paper, we first discuss a viable pathway to energy transition through the electricity triangle, highlighting the role of RES in electricity generation. Further, we propose methodologies for the planning of wind and solar PV, as well as how to address their uncertainty in generation expansion problems. Finally, by using a web-based tool, “RES-PLAT” 1 , we demonstrate the scheme in a case study of the North Africa, which evaluates the impacts and benefits of a large-scale RES expansion.
In order to reveal the supersonic condensation characteristics of carbon dioxide (CO2) in natural gas under low temperature condition, the mathematical models and numerical schemes for the CH4-CO2 mixture gas under supersonic flow condition were established, and the influence of inlet CO2 concentration on the CO2 removal efficiency of Laval nozzle was investigated. The results show that with the increase of CO2 concentration at nozzle inlet, the initial nucleation position is closer to nozzle throat, the maximum nucleation rate and the droplet number decrease but the droplet radius increases significantly, which eventually leads to an increase in liquefaction rate. When the inlet CO2 mole fraction is lower (less than 10%), the CO2 fraction in gas phase is almost 0, which indicates that low-temperature separation technology is practicable for the removal of CO2 from natural gas.
Liquid droplet radiator (LDR) is characterized by the compact arrangement and the low mass per unit power. It is a promising cooling system for the high-power spacecraft. The characteristics of the droplet layer in LDR determine the performance of the heat dissipation. Thus, the study of the droplet radiation heat transfer mechanism is vitally important for the optimal design of the whole LDR system. In the present paper, the radiation heat transfer characteristics of a sparse LDR system are studied from the aspects of the single droplet. The results reveal that the smaller the droplet radius is, the higher the droplet radiation energy per unit mass is. The slower the initial emission speed is, the higher the radiation energy per unit mass is. The higher the initial temperature of the droplet, the higher energy of radiation power per unit mass of the droplet is. Meanwhile, the radiation heat transfer characteristics of different working mediums are also given. These conclusions can provide basis for the optimal design of the sparse droplet radiators and provide guidance for the subsequent research on LDR.
Urbanization is one of the major events in the 21st century has caused rapid growth in the global construction area, which resulted in high consumption of building resources and long term environmental impacts. Analyzing the resource consumption of public buildings and identifying the key factors that affect the consumption of building resources is therefore important for the development of targeted policies. In this paper, we analyzed each branch of the People’s Bank of China based on energy, water, and land resource consumption as well as the structure of energy consumption. Based on resource-consumption indicators, we divided 31provincial administrative into four resources consumption levels; of these, 65% were in the middle or low resource consumption levels. Medium-sized institutions had the highest energy consumption level and more balanced energy consumption structure. Energy consumption per capita, water consumption, and utilization rate of small-sized institutions were low. To reduce resource consumption by public institutions, construction of large-sized institutions should be limited.
Numerous aspects must be measured earlier for implementing a Three-phase power generation system based on sustainable energy sources. Longstanding necessary data must be composed before creating any conclusions concerning the implementation of such a system. Potential of Solar, wind and hydel energy are precisely measured at Kadamparai location in TamilNadu, India. In this research, an effective analytical hybridization method is suggested for grid systems comprising exclusively of sustainable energy source like solar photovoltaic (PV), wind, and pumped hydro sources. One of the method was tested numerically and analytically, the results can be applied to achieve emission free power grid. Hydro, wind, and solar photovoltaic energy are the deepest sustainable energy sources in worldwide installed capacity. However, no reports have been printed about hybrid grid systems encompassed of all three sources, simulation model and analysis are the first of its kind anywhere. This investigation may be pragmatic as a real-world guide for applying similar systems in various places. Wherever renewable sources are used in India, the main combination is about solar and wind only. This is the first novel analytical approach presents for connecting renewable energy sources to a utility grid. Simulink analysis and mathematical modelling of renewable resources can extend year-round power supply to switchyard with use of underground water batteries. In future carbon emission percentage will be nullified and cure global warming and climate changes once implementing this project into real.
Southern region of India has more peak and valley on its geological surface which leads more waterfalls. Sustainable energies are trending now due to zero emission power generation. Earth is gifted by natural energy resources every routine of time. Energy storage system for combining all the resources provides uninterrupted power supply to year around. India assures reduction of Green House Gas emissions intensity per unit gross domestic product 35% below level of year 2005, using sustainable energies in generating power to Grid. The intermittency nature of energies affects the stability of grid can be avoided by energy storage system. Energy storing system also solving the extension of power grid, increasing percentage contribution of sustainable energy in power generation, and tallying demand, and supply of energy. Technology implementing for storing power still needed more new experiments to improve the interest on development of sustainable energy generation. Pumped hydro storage is bulky potential storage technology commonly used, however power generation in low water level due to depletion of monsoon, current frequency lag for pumping and reserve spinning are achievable only by gravity hydro storage. This research technically designs and testing the proposed model of gravity hydro storage in SIMULINK analysis tool for Kadamparai location at Tamil Nadu, India. The optimum design of cylinder and piston are analyzed by ANSYS WORKBENCH also dynamic modeling analysis of hybrid sustainable energies with proposed gravity storage is done. Hybrid model with energy storage can implement in large and small hydro power houses for year around generation. This paper also suggesting model makes all abandoned mines as zero emission energy batteries.
The paper presents the study, Erturan, Cekirge and Thorsen , that is introducing facts and capacity of continuously changing and evolving situation in the environment. In this paper , it is presented facts and indicators of the Planet Earth capacity factor considering questions of existing human activities’ safety and sustainability. These questions can be extended for advancing and developing our home planet without encountering a dilemma and future generations and civilization developments’ sufferings because of our movements. In order to get positive answers to these questions, we definitely need to improve our technological skills. It might be an appropriate explanation to understand our current timeline. As the 2020 COVID-19 pandemic demonstrates, nature can quickly become a formidable foe—particularly if humans are caught unprepared. Although Earth’s ideal conditions have provided humans with a perfect environment to thrive socially and economically, her natural resources are not limitless and her natural balances are delicate. It is critical to begin developing solar technology to meet the human race’s energy needs. The human race currently meets its energy needs mainly through fossil fuels. But not only are fossil fuel reserves limited but also excessive reliance on fossil fuels can cause long-term environmental damage. On the other hand, solar energy is bountiful, free and clean. As such, solar energy is a great alternative source of energy that will ensure that future generations enjoy a hospitable planet and healthy and economically stable living conditions. Planet Earth supports our current lifestyles, but there are obvious indications of unusual changes in her cycles. Only recently have we begun to consider plans regarding Earth’s capacity; historically, we have mostly considered local environmental factors. Unfortunately, the time for only thinking of local factors has passed – we must consider the planet’s capacity for continued human survival in order to create a sustainable lifestyle. As humans, we believe that we live in some sort of “infinite time spiral” – that is, we believe that the human race will live forever – but this is simply illusionary cortical brain activity. The mitigation measures are also presented by .