Energy Supply Options Research Articles

Fuel and Energy System Control at Large-Scale Damages. II. Optimization Problems

In continuation of [1], the capabilities of the network flow modeling of resource supply processes are investigated in the case of a deterioration in their infrastructural properties. Within the multivariable model [1], energy supply options in spatially distributed systems after destructive impacts are analyzed. Mathematical formulations of the problems of optimization of energy flows in a damaged network are proposed. The strategies for controlling the flows based on a posteriori information on the change in the capacity of the arcs of the model network are determined. The control objective is the providing the users requirements as much as possible taking into account the regulatory constraints on the feasible levels of the accident/load on the network subsystems. This problem is considered as a multicriterion (MO) one. Different methods for the convolution of the criteria are analyzed depending on the emphasis attached to the content of the formulation.

Modelling the water energy nexus: should variability in water supply impact on decision making for future energy supply options?

Abstract. Many countries, like South Africa, Australia, India, China and the United States, are highly dependent on coal fired power stations for energy generation. These power stations require significant amounts of water, particularly when fitted with technology to reduce pollution and climate change impacts. As water resources come under stress it is important that spatial variability in water availability is taken into consideration for future energy planning particularly with regards to motivating for a switch from coal fired power stations to renewable technologies. This is particularly true in developing countries where there is a need for increased power production and associated increasing water demands for energy. Typically future energy supply options are modelled using a least cost optimization model such as TIMES that considers water supply as an input cost, but is generally constant for all technologies. Different energy technologies are located in different regions of the country with different levels of water availability and associated infrastructure development and supply costs. In this study we develop marginal cost curves for future water supply options in different regions of a country where different energy technologies are planned for development. These water supply cost curves are then used in an expanded version of the South Africa TIMES model called SATIM-W that explicitly models the water-energy nexus by taking into account the regional nature of water supply availability associated with different energy supply technologies. The results show a significant difference in the optimal future energy mix and in particular an increase in renewables and a demand for dry-cooling technologies that would not have been the case if the regional variability of water availability had not been taken into account. Choices in energy policy, such as the introduction of a carbon tax, will also significantly impact on future water resources, placing additional water demands in some regions and making water available for other users in other regions with a declining future energy demand. This study presents a methodology for modelling the water-energy nexus that could be used to inform the sustainable development planning process in the water and energy sectors for both developed and developing countries.

A techno-economic feasibility analysis of hybrid renewable energy supply options for a grid-connected large office building in southeastern part of France

This study gives emphasis to the techno-economic analysis of renovating the energy supply system of a grid-connected large office building through a Hybrid Renewable Energy System (HRES). The study is focused on how to minimize electricity consumption from the grid by producing as much as possible renewable energy, and in addition to that it also observes the economic impacts of integrating green vehicles, such as hydrogen cars, electric cars etc. which are indispensable elements of a sustainable city, in the proposed system. The work initiated collecting the sites monthly electrical load data, climate data and associated monetary data with the aim of investigating a renewable energy supply system feasibility study. Three alternative scenarios are developed according to the project needs and these scenarios are modelled by a hybrid renewable energy system design tool. The study concludes with a direct comparison of the economic feasibility, renewable energy fraction, and emissions among all systems, looking for the more appropriate and sustainable solution. It is found that integrating solar photovoltaic (PV) curtails more than 43% electricity consumption of the office building from the utility grid. The result also shows that per unit cost of electricity of PV/Grid system to satisfy the load demand is around 10% lower compared to the utility grid tariff and furthermore, it minimizes over 90% emission compared to the total emission in the study site. This study will provide helpful insights to the relevant stakeholders and policy makers in the development of grid connected HRES system.

Wave Energy Potential Assessment for Riva and Foça, Turkey

Humankind has been looking for alternative energy supply options. This search has always been a big challenge. Renewable energy sources blossom the most possibly nature-harmonized options with no harmful propagation or emissions. Turkey, as a developing country and a highly experienced candidate to European Union membership, determines relevant energy policies by assessing domestic energy potentials. However, no official target for energy utilization from the seas is officially set so far. Wave energy can be one of the alternatives that can contribute to the energy mix of Turkey. This contribution would also positively affect the fossil fuel import rates of the country while the wave energy conversion technologies mature and penetrate the energy markets. With this in mind, wave energy potentials have been calculated for two locations, Riva and Foca; based on the data measured and obtained from the Office of Navigation, Hydrography and Oceanography of Turkish Navy. Comparatively low wave energy level results are obtained, mainly caused by the measurement sites are not on the shores of open sea or oceans, but inner seas. These results would hopefully help the respective engineers to reach the most suitable designs for these wave characteristics.

Paper making in a low carbon economy

Paper and pulp manufacturing industry produces versatile products from renewable feedstock that are easily recycled. It is the fourth largest industrial sector in terms of energy use. Much of the energy used comes from biomass derived fuels or high efficiency combined heat and power plants so the industry is not considered as carbon intensive. But at production paper making emits five times the CO₂/tonne of steel; this is gradually removed from the atmosphere by the growth of replacement trees which can take between 7 and 90 years. This study reviewed existing literature to establish estimates for future energy requirements, and way that these could be met with minimum carbon emissions in a world where there are electricity grids with low carbon intensities, high recycling rates and growing demand for sustainable biomass. It was found that energy consumption could be reduced by 20% using technologies that have been demonstrated at an industrial scale. Most virgin pulp is made using the kraft chemical processing method. It was found that it should be possible to eliminate all fossil fuel use from this process, by combustion of by-product while exporting a small amount of electricity. Recycled paper is becoming the largest source of pulp. In this case the waste streams cannot provide sufficient energy to power the process, but process heat can be produced by burning some of the collected waste paper in steam plants or by using electric heat pumps. The energy needed to produce high quality office paper is nearly twice that required for non-deinked packaging paper. This couples with the lower pulp yields obtained with high quality pulp means that the environmentally preferred option for energy supply to the recycling process is dependent on the grade of pulp being produced.

A Least Cost Long -Term Energy Supply Strategy for Sri Lanka using Petroleum, Coal and Natural Gas

Long term energy sector planning is essential for a country to achieve sustainable development in all its social, economic and environmental dimensions. Furthermore, it will ensure the energy supply security of the country. The energy supply side needs to deal with technical, economic and environmental assessments of all energy supply options such as natural resources, energy imports, energy exports etc. The energy supply side should follow policy directives of the government and should take into account all other related constraints. Similarly, the demand side too has to deal with the assessment of future energy needs of various consumption sectors, policy directives etc. In this study the software MESSAGE was used to model the energy chains associated with petroleum, coal and Natural Gas (NG) in relation to Sri Lanka. The national energy chain was modelled considering the modernizations of the existing refinery through the introduction of NG to the energy sector and the introduction of electric vehicles. In addition, the viability of constructing a urea plant was also explored.

Optimal energy supply structures for industrial food processing sites in different countries considering energy transitions

This study focuses on analysing the most energy efficient utility system supply structure in terms of carbon emissions, primary energy efficiency and energy costs. In the German food processing industry, the state-of-the-art technologies in the utility supply structure are a gas fired steam boiler for steam generation and ammonia chillers for chilled water generation. Low investment costs and its durability are attractive for industrial production sites. But, given the ongoing energy transition to renewable energy, opportunities to reduce emissions will become increasingly important. There are other energy supply options, such as Combined Heat and Power and Heat Pumps, that need to compete against the conventional energy supply systems. In the short-term, countries with presently high electricity Grid Emissions Factors (GEF) such as Germany and the USA, the use of decentralised CHP results in savings of primary energy and emissions. This option is less attractive for countries with already low GEF such as Norway. It is also less attractive in the long-term for countries like Germany as the on-going energy transition towards renewables is anticipated to decrease the current GEF by 50% in 2030. In these cases of low GEF, HP solutions provide the lowest emissions and highest primary energy efficiency.

Framework for the optimization of operation and design of systems with different alternative water sources

Water security has become an increasing concern for many water system managers due to climate change and increased population. In order to improve the security of supply, alternative sources such as harvested stormwater, recycled wastewater and desalination are becoming more commonly used. This brings about the need for tools to analyze and optimize systems that use such sources, which are generally more complex than traditional water systems. Previous methodologies have been limited in their scope and cannot be applied to all types of water sources and systems. The framework presented in this paper has been developed for holistic analysis and optimization of water supply and distribution systems that use alternative water sources. It includes both design and operational decision variables, water and energy infrastructure, simulation of systems, analysis of constraints and objectives, as well as policies and regulations which may affect any of these factors. This framework will allow users to develop a comprehensive analysis and/or optimization of their water supply system, taking into account multiple types of water sources and consumers, the effect of their own design and operational decisions, and the impact of government policies and different energy supply options. Two case study systems illustrate the application of the framework; the first case study is a harvested stormwater system that is used to demonstrate the importance of simulation and analysis prior to optimization, the second utilizes four different water sources to increase security of supply and was optimized to reduce pump energy use.

Enlightening grey portions of energy security towards sustainability

PurposeThe purpose of this paper is to determine priority order of Indian energy sector projects on investments and strategic dimension angles. Grey System Theory (GST) and COmplex PRroportional ASsessment (COPRAS-G) method, a flexible multi-criteria decision-making (MCDM) analyses, is used for this purpose to prioritize Indian energy sector projects, namely, coal, gas, hydro, solar and nuclear.Design/methodology/approachThe GST-based MCDM approach of COPRAS is used. Five projects of energy sector are compared based on various grey criteria. These criteria were selected on the perspectives of life-cycle costing and management-thinking approach for prioritizing these projects. The GST-based COPRAS-G is described, and results are discussed to draw a strategic road map for measuring the sustainability in the energy sector.FindingsOn applying COPRAS-G on five energy projects, solar projects get high-priority order, and realistic scenario of results shows that renewable energy projects are preferred over the conventional projects such as coal and gas.Research limitations/implicationsHere, COPRAS-G method is used as MCDM techniques. However, few other MCDM techniques such as fuzzy Preference Ranking Organization METHod for Enrichment Evolution, elimination and choice expressing reality and efficiency analysis technique with output satisficing can be also explored to outrank various Indian energy sector projects.Practical implicationsIndian energy sector involves high degree of complexity, and, therefore, it needs more flexibility to overcome the present barriers of effective decision-making. Grey decision theory-based method like COPRAS-G is able to address energy security dimensions on different scenario of energy supply, i.e. pessimistic, optimistic and realistic, precisely.Social implicationsThe results can provide guidance to the government or public sector regarding various possible investment options for energy supply and can help in drawing a rough trajectory of strategy toward energy security of the country.Originality/valueThis paper can supplement and act as the support for decision-making in conflicting situations specifically to have outlook of the sub-sector project on different flexible scenarios. Moreover, such work can synergize conflicting ideas of decision makers and various stakeholders of the Indian energy sector.

Thermal Hydrogen: An emissions free hydrocarbon economy

Envisioned below is an energy system named Thermal Hydrogen developed to enable economy-wide decarbonization. Thermal Hydrogen is an energy system where electric and/or heat energy is used to split water (or CO2) for the utilization of both byproducts: hydrogen as energy storage and pure oxygen as carbon abatement. Important advantages of chemical energy carriers are long term energy storage and extended range for electric vehicles. These minimize the need for the most capital intensive assets of a fully decarbonized energy economy: low carbon power plants and batteries. The pure oxygen pre-empts the gas separation process of “Carbon Capture and Sequestration” (CCS) and enables hydrocarbons to use simpler, more efficient thermodynamic cycles. Thus, the “externality” of water splitting, pure oxygen, is increasingly competitive hydrocarbons which happen to be emissions free. Methods for engineering economy-wide decarbonization are described below as well as the energy supply, carrier, and distribution options offered by the system.

Low-Carbon Communities between Vision and Implementation The Case of Borg Al Arab

Several cities are facing the problem of running-out of fossil fuels and are contributed to an estimated 70% of the world’s energy-related greenhouse gases (GHGs). Consequently, there is a tremendous need for low-carbon communities which will lead to more livable, efficient and ultimately sustainable cities. Furthermore, well-planned and designed communities can effectively provide the basic human needs and reduce reliance on fossil fuels. Some communities have developed strategies to reach net zero-carbon future by reducing demands for energy and supplying the remaining demands with renewable resources. In the meantime, Egyptian cities face the problem of greenhouse gases and the lack of energy and water. Therefore, passive, energy efficient and energy offset design are needed. This can be achieved through sustainable transportation systems and the shift to efficient management of water and waste. The paper discusses the problem of climate change and its relation with communities. It investigates examples of communities that have focused on reducing their carbon emissions in different parts of the world. Also, it examines some of the most important aspects of design strategies that help to implement low-carbon communities and how could they be achieved in the Egyptian context (Borg Al Arab-Alexandria). The aim of the paper is to highlight certain cities that demonstrate a deeper understanding of what a low-carbon community is and how to achieve it through reducing energy demand and providing the best options for passive design and renewable energy supply in the Egyptian communities to become self-contained in terms of energy.

Optimal energy supply structures for industrial sites in different countries considering energy transitions: A cheese factory case study

This present study focuses on analysing the most efficient utility energy supply structure in terms of primary energy efficiency, carbon emissions and energy costs. In the German dairy industry, separate conversion with gas fired steam boiler, and cooling with ammonia chillers are the-state-of-the-art technologies. It is attractive due to its robustness and low investment costs. But given the ongoing energy transition to renewable energy, opportunities to reduce emissions will become increasingly important. There are other energy supply options, such as Combined Heat and Power (CHP) and Heat Pumps (HP), that if implemented need to compete against the conventional energy supply systems. One option is CHP to provide cogenerated electricity and heat while cooling remains supplied by ammonia chillers. In countries with high electricity Grid Emissions Factors (GEF) such as Germany and the USA, the use of decentralised CHP results in savings of primary energy and emissions. However, this option is less attractive for countries with low GEF such as France and Norway, and for places like Germany where the energy transition lowering its GEF by 50 % in 2030. In these cases, HP solutions provide the lowest emissions and highest primary energy efficiency.

Positioning Nuclear Power in the Low-Carbon Electricity Transition

Addressing climate change requires de-carbonizing future energy supplies in an increasingly energy-dependent world. The IEA and the IPCC (2014) mention the following as low-carbon energy supply options: ‘renewable energy, nuclear power and fossil fuels with carbon capture and storage’. Positioning nuclear power in the decarbonization transition is a problematic issue and is overridden by ill-conceived axioms. Before probing these axioms, we provide an overview of five major, postwar energy-related legacies and some insight into who is engaged in nuclear activities. We check whether low-carbon nuclear power passes the full sustainability test and whether it is compatible with the unfettered deployment of variable renewable power sourced from the sun and from wind and water currents, which delivers two negative answers. We show that the best approach of the sustainable energy transition was Germany’s 2011 decision to phase out nuclear power for a fast development and full deployment of renewable power. This is the best approach for the sustainable energy transition. We offer five practical suggestions to strengthen and accelerate carbon- and nuclear-free transitions. They are related to institutional issues like the role of cost-benefit analysis and the mission of the International Atomic Energy Agency, to the costs of nuclear risks and catastrophes, and to the historical record of nuclear technology and business.

Cloud point analysis of the palm biodiésel blend (elaeis guineensis) with additives of synthetic origin (visxoplex® 10-330, xp3®w-bd) and natural (biodiésel from jatropha curcas l b100)

The growing agro-industry of biofuels has developed a new energy supply option, with biodiesel being one of them, which has promoted productive chains such as palm oil and other oilseeds, where it focuses on the production of first generation biodiesel. from vegetable oils such as African palm. The palm biodiesel (Elaeis guineensis) has drawbacks with its cloud point, where at low temperatures in some regions of cold climates in Colombia, some esters product of the process of transesterification of fatty acids begin to generate a type of agglomeration of esters, which in large proportions can obstruct filters or damage diesel engines, for this reason an analysis of the cloud point of the mixture of palm biodiesel and additives of synthetic origin (VISXOPLEX® 10-330, XP3®W-BD) was carried out and natural (Biodiesel from Jatrofa curcas l B100) at different concentrations (0.22% and 1%). For the evaluation of this it was necessary to produce at laboratory level the biodiesel from Palma and Jatropha, by means of a process of having a reactor using anhydrous ethanol as a solvent for transesterification; similarly, the different quality parameters were evaluated, resulting in values within the range determined by NTC 5444 (Colombian Technical Standard) and likewise a lower cloud point in the mixture of palm biodiesel and additives of synthetic and natural origin.

Financial attractiveness of decentralized renewable energy systems – A case of the central Himalayan state of Uttarakhand in India

Financial viability is arguably the most important requirement for large scale dissemination of decentralized renewable energy systems (DRESs). Financial viability of a DRES can vary from region to region as it depends on various geographical and socio-economic factors. With sufficient solar radiation availability throughout the year, abundant forest cover, dependence of majority of population on agriculture and remote villages facing energy access related challenges, the state of Uttarakhand in India has significant potential for the application of solar and biomass based DRESs. Based on the current fuel prices, subsidies and rebates, this study is an attempt to assess the financial attractiveness of solar and biomass based DRESs under various scenarios for their potential users in Uttarakhand.Improved biomass cookstove, domestic solar water heater, solar lantern and solar home system are found to be financially viable under almost all scenarios for household applications while dish type solar cooker, solar PV pump and solar dryer are not so attractive for household applications. It has also been found that the financial attractiveness of DRESs improve significantly with the removal of subsidy presently being given to fossil fuel based energy supply options.

Scoping exercise to determine load profile archetype reference shapes for solar co-generation models in isolated off-grid rural African villages

For many off-grid rural communities, renewable energy resources may be the only viable option for household and village energy supply and electrification. This is especially true for many rural regions in Southern Africa, where the population spread is characterised by small villages. These rural villages rely heavily on firewood and biomass to meet thermal energy needs (hot water and cooking), while candles, kerosene and paraffin are mostly used for lighting. Hybrid concentrated solar micro-CHP (combined heat and power) technology systems have been proposed as viable energy solutions. This paper conducts a scoping exercise to determine realistic hourly reference profile shapes for thermal and power energy consumption in isolated rural African villages. The results offer realistic energy consumption load profiles for a typical rural African village in time-series format. These reference load profiles enable experimental comparison between computer modelled solar micro-CHP systems and control automation solutions in isolated rural village micro-grid simulations.

Validation of a Bayesian-based method for defining residential archetypes in urban building energy models

Urban Building Energy Modeling (UBEM) is an emerging method for exploring energy efficiency solutions at urban or district scales. More versatile than statistical models, physical bottom-up UBEMs allow planners to quantitatively assess retrofit strategies and energy supply options, leading to more effective policies and management of energy demand. The most common approach for formulating an UBEM involves segmenting a building stock into archetypes, characterizing each type, and validating the model by comparing its output to aggregated measured energy consumption. This paper presents a more detailed methodology for setting up UBEMs while faced with incomplete information about the buildings. The procedure calls for defining unknown or uncertain parameters in archetype descriptions as probability distributions and, if available, using measured energy data to update these distributions by Bayesian calibration. The methodology is validated on residential houses in Cambridge, Massachusetts. Distributions for uncertain parameters are initially generated using a training set of 399 homes with monthly electricity and gas consumption records and then applied to a larger test set of 2263 homes. The procedure is applied both for monthly and annual metered energy usage data. Results show that both annual and monthly Bayesian calibration lead to significantly better annual energy use intensity (EUI) fits compared to traditional deterministic archetype definitions. As expected, an UBEM calibrated with monthly metered data more truthfully mimics monthly EUI distributions than one based on annual data, revealing the benefit of calibrating UBEMs using the smallest measurement time step available.

Micro-Tomographic Investigation of Ice and Clathrate Formation and Decomposition under Thermodynamic Monitoring.

Clathrate hydrates are inclusion compounds in which guest molecules are trapped in a host lattice formed by water molecules. They are considered an interesting option for future energy supply and storage technologies. In the current paper, time lapse 3D micro computed tomographic (µCT) imaging with ice and tetrahydrofuran (THF) clathrate hydrate particles is carried out in conjunction with an accurate temperature control and pressure monitoring. µCT imaging reveals similar behavior of the ice and the THF clathrate hydrate at low temperatures while at higher temperatures (3 K below the melting point), significant differences can be observed. Strong indications for micropores are found in the ice as well as the THF clathrate hydrate. They are stable in the ice while unstable in the clathrate hydrate at temperatures slightly below the melting point. Significant transformations in surface and bulk structure can be observed within the full temperature range investigated in both the ice and the THF clathrate hydrate. Additionally, our results point towards an uptake of molecular nitrogen in the THF clathrate hydrate at ambient pressures and temperatures from 230 K to 271 K.

A Combined Approach for Production Parameter Selection and On-site Energy Supply Management in Manufacturing Industry

Integrated management of manufacturing plant’s production and on-site energy supply systems has shown potential economic, environmental and resource efficiency advantages for the industry. However, existing approaches are solely based on pure mathematical models with a high degree of abstraction with limited applicability, which becomes impractical for industrial applications. In this paper a simulation methodology for production parameters selection and on-site energy supply management is presented. In this case, state-based models and operational strategies of manufacturing processes and on-site energy supply options are integrated to represent interdependency between production processes, technical building services and on-site energy supply system. As a result, the proposed methodology covers manufacturing system complexity without compromising the required accuracy. This is applied to a batch based manufacturing plant and the impact of particular production parameters on energy demand profile is evaluated. The results indicate the impact of production parameters on energy supply system. In addition, the proposed approach enables manufacturers to evaluate the implications of potential production approaches in order to select appropriate operational strategies for on-site energy supply systems.

User-Centered Innovation and Regulatory Framework: Energy Prosumerss Market Access in EU Regulation

European energy consumers who previously had a rather passive, consuming role, and were confronted with top-down determined energy supply options, services, as well as prices, are now assuming a more proactive role, in some cases becoming prosumers of energy. Originally the focus of both individual and collective prosumers has been on local sustainable energy production. However currently the focus is slowly shifting to both own production and own consumption of local sustainable energy, as well as to participation in the local and national market (e.g. supplying energy to one’s neighbors or to one’s family residing in a different region). As technology progresses and the formats of market design evolve, the problem of ‘regulatory disconnection’ could arise, meaning that the existent regulatory framework might not be ‘fit for purpose’ any longer due to its disconnection from rapidly developing innovation. In such cases the existing regulatory framework (perhaps unintentionally) represent obstacles for (further) development of the local energy in Europe. In the current research we focus on the specific type of innovation, and namely user-centered innovation by the local sustainable energy collectives, illustrated by the transactions between individual and collective prosumers of the local energy, be it peer-to-peer transactions or interaction with national energy market players, e.g. energy suppliers. In order to perform such transactions, prosumers necessitate market access. The issue of prosumers’ market access is used as a case study in order to test current degree of ‘fit’ between the European regulatory framework on one hand and innovation in the energy sector on the other hand.