Electricity Generation Scenarios Research Articles

Greenhouse Gas Emission of Electricity Generation and Field Abandonment Scenarios Using Empty Fruit Bunches at a Palm Oil Mill, Surat Thani Province, Thailand

In Indonesia, Malaysia, and Thailand, the pile abandonment of empty fruit bunches (EFBs) in the fields of palm oil mills is a common practice. This practice results in environmental issues such as generation of unpleasant odors and methane production due to anaerobic decomposition. In the present study, an abandoned moist EFB sample from Rubber Oil Co. Limited, a palm oil mill in the Thachi sub-district municipality, Surat Thani Province, southern Thailand, was collected and sun dried for physical analysis. The bulk density at 13.2% moisture content was 0.118 kg/L. Greenhouse gas (GHG) emissions for electricity generation and methane production due to anaerobic decomposition were compared applying life cycle assessment. A cargo capacity of 621 kg of EFBs and a 59 km distance to the Surat Thani Biomass Power Plant in Surat Thani province were adapted with reference to Thailand’s GHG emission factors. The system boundary included the EFBs in the palm oil mill and the nearest power plant. The CO2 equivalent GHG emissions per kg of EFB for the transportation, generation, and field abandonment (methane emission) were 0.077, -0.877, and 2.136 kg-CO2e, respectively; a sum of -0.8 kg-CO2e emission via electricity generation use was noted as a significant environmental advantage.

Future European shale gas life-cycle GHG emissions for electric power generation in comparison to other fossil fuels

The carbon footprint of shale gas combusted in Europe was estimated from nine European shale gas plays as potential production regions. Greenhouse gas emission sources during shale gas production, such as fugitives from hydraulic fracturing or combustion emissions from horizontal drilling, were added to emissions occurring for conventional gas extraction. Greenhouse gas emissions are expressed as g CO2-equivalents per MJ delivered, and calculated for a kWh of electricity generated. Estimated total GHG emissions from the use of European shale gas for electricity production range from 0.42 to 0.75 kg CO2-eq/kWh when the combustion in the power plant is included. This is within the range reported in the literature. The cumulative carbon footprints for a number of fossil electricity generation scenarios for Europe were also calculated. The results indicate an advantage of gas over other fossil sources in a wide range of scenarios. These results are only reversed with very high (10%) upstream losses for shale gas. With the current knowledge there is still a substantial climate benefit of replacing coal with (shale) gas even in the EU reference scenario.

Dinitrogen tetroxide and carbon dioxide mixtures as working fluids in solar tower plants

The competitiveness of concentrated solar power technology in the near-future electricity generation scenario, requires a substantial reduction of the Levelized Cost of Energy which can be achieved with an increase of the energy conversion efficiencies while maintaining or reducing the investment costs. This paper discusses the use of pure Dinitrogen tetroxide N2O4, and N2O4/CO2 mixture, as working fluids in supercritical Brayton cycles applied to solar tower power plants. When N2O4 is combined with CO2, the resulting mixture has a comparatively higher critical temperature than pure CO2, allowing a condensing cycle even at the fairly high ambient temperatures of desert areas, where solar power plants are typically installed. This allows the adoption of simpler cycle configurations than the one used in sCO2 cycles (cost reduction) while achieving very high thermodynamic efficiency (47% at 700 °C). The N2O4/CO2 mixture with optimized composition, integrated in a solar tower unit, increases the solar-electric efficiency by 1% with respect to commercial plants based on steam cycle with 550 °C maximum temperature (22.3% vs. 21.3%). At 700 °C, the overall solar-electric efficiency can reach 24.5% which is slightly higher than supercritical CO2 cycles, yet with a foreseeable reduction of the investment costs as consequence of the simpler plant lay-out.

RER Based Hybrid Technology for power Generation System: Pollution Free from GHG

This paper is presented to observe the conversion of renewable strength resources (RER) into electric power in a standalone hybrid electricity generation system. Recent electricity generation scenarios all over the world are not eco-friendly because the generation systems are by and large depending on fossil fuels that produce greenhouse gasoline (GHG) which contributes to worldwide warming. In this, the aggregate of two electricity resources is taking location i.e. Wind and solar energy. Solar panels are used for converting solar power and wind generators are used for converting wind power into strength. This electrical electricity era can function for numerous purposes. Generation of strength will take place at an affordable cost. This paper provides the Renewable Energy Based Hybrid Technology for Power technology that extracts the renewable energies in Sun and Wind to generate power. System manage relies particularly at the microcontroller. It ensures the optimal utilization of assets and consequently improves the efficiency as related to their person mode of the technology system. Also, it will increase the reliability and decreases the dependence on one unmarried source. This hybrid solarwind energy generating machine is appropriate for industries and additionally for home areas with reasonable price without unfavorable the natural stability like Pollution Free from GHG.

Hybrid power plant for energy storage and peak shaving by liquefied oxygen and natural gas

The increasing penetration of renewable energy sources in the electricity generation scenario forces to face new challenges to achieve an effective management of the power system both in technical and economic terms. Traditional energy storage solutions, like electrochemical cells and pumped hydro energy storage appear critical in terms of economic sustainability and site-dependency. The use of compressed air as energy storage has been investigated since the 20th century, but, in its first configuration, it was affected by site constraints as pumped hydro plants do. Liquid air energy storage has the chance to overcome those limits, but the experimental studies have far reached low efficiency. However, by rising the highest cycle temperature with the addiction of fossil fuel energy, these results can be largely improved.The paper deals with the thermodynamic analysis of a hybrid system including energy storage and production based on a liquid air energy storage plant where only oxygen is liquefied, while liquefied natural gas is used as fuel. In the production phase, liquefied oxygen and natural gas react in an oxy-combustion chamber where a large amount of water is added to keep the temperature at an acceptable level by evaporation. The system does not require an external water supply since all the water needed is produced by the cycle itself, allowing the plant to be placed also in remote areas with poor water resources. At the beginning of the cycle, both the reagents are liquid at very low temperature (below −150 °C) and they need heat to be gasified; a large amount of this heat can be recovered from the combustion products, which, being cooled at suitable pressure, release liquid carbon dioxide which can thus be easily separated. Optimized arrangements, compared to the performances of the best available hybrid peak plants, even with sufficiently conservative hypotheses, reach high equivalent round trip efficiencies, even higher than 90%.

Multi-Criteria Analysis of Electricity Generation Scenarios for Sustainable Energy Planning in Pakistan

The now over a decade-long electricity crisis in Pakistan has adversely affected the socio-economic development of the country. This situation is mainly due to a lack of sustainable energy planning and policy formulation. In this context, energy models can be of great help but only a handful of such efforts have been undertaken in Pakistan. Two key shortcomings pertaining to energy models lead to their low utilization in developing countries. First, the models do not effectively make decisions, but rather provide a set of alternatives based on modeling parameters; and secondly, the complexity of these models is often poorly understood by the decision makers. As such, in this study, the Analytical Hierarchy Process (AHP) methodology of Multi-Criteria Decision-Making (MCDM) has been used for the sustainability assessment of energy modeling results for long-term electricity planning. The four scenario alternatives developed in the energy modeling effort, Reference (REF), Renewable Energy Technologies (RET), Clean Coal Maximum (CCM) and Energy Efficiency and Conservation (EEC), have been ranked using the Expert Choice® tool based on the AHP methodology. The AHP decision support framework of this study revealed the EEC scenario as the most favorable electricity generation scenario followed by the REF, RET and CCM scenarios. Besides that, this study proposes policy recommendations to undertake integrated energy modeling and decision analysis for sustainable energy planning in Pakistan.

Impact analysis of electricity supply unreliability to interdependent economic sectors by an economic-technical approach

Abstract This paper proposes a novel framework to quantify the economic impact of electricity supply interruptions to other economic sectors considering their interdependency and increasing penetration of wind power. It is achieved by a novel integrated model that combines economic interdependency and electricity supply reliability. Leontief Input-Output model is used to determine the dependency of other economic sectors on electricity supply and electricity reliability theory is utilised to quantify electricity supply interruptions. The two models are combined to quantify two key indexes: the inoperability of different economic sectors and their losses under electricity supply unreliability. Further, an optimal model is designed to allocate available electricity to minimise the economic losses of these sectors when electricity supply is interrupted. Two UK electricity generation scenarios are used to demonstrate the concept. It is found that economic sectors have various degrees of dependency on electricity supply and their losses also differ significantly. In addition, more wind power penetration could jeopardize electricity supply adequacy and consequences to other sectors. The findings can assist policy makers to understand the importance of electricity security to other sectors and quantify potential economic losses so that new policies and regulations can be designed to mitigate the adverse consequences, such as developing the capacity market.

Emissions implications of downscaled electricity generation scenarios for the western United States

This study explores how emissions from electricity generation in the Western Interconnection region of the U.S. might respond in circa 2030 to contrasting scenarios for fuel prices and greenhouse gas (GHG) emissions fees. We examine spatial and temporal variations in generation mix across the region and year using the PLEXOS unit commitment and dispatch model with a production cost model database adapted from the Western Electricity Coordinating Council. Emissions estimates are computed by combining the dispatch model results with unit-specific, emissions-load relationships. Wind energy displaces natural gas and coal in scenarios with relatively expensive natural gas or with GHG fees. Correspondingly, annual emissions of NOx, SO2, and CO2 are reduced by 20–40% in these cases. NOx emissions, which are a concern as a precursor of ground-level ozone, are relatively high and consistent across scenarios during summer, when peak electricity loads occur and wind resources in the region are comparatively weak. Accounting for the difference in start-up versus stabilized NOx emissions rates for natural gas plants had little impact on region-wide emissions estimates due to the dominant contribution from coal-fired plants, but would be more important in the vicinity of the natural gas units.

Is it wise to compromise renewable energy future for the sake of expediency? An analysis of Pakistan's long-term electricity generation pathways

Pakistan's acute energy crisis has critically affected its already fragile economy, costing in recent years up to 4% it's of Gross Domestic Product. Political expediency in the wake of the current power crisis in Pakistan together with the current high investment costs of renewable energy technologies have shifted focus of the policy to thermal power plants in the short run to meet the deficit. This paper presents a long-term view of the current power policy and forecasts electricity demand in Pakistan in the long run congruent with anticipated strong economic growth, as envisaged in 'Pakistan Vision 2025', its medium-term development framework. Using Long Range Energy Alternatives Planning (LEAP), a bottom-up scenario modelling framework, different electricity generation scenarios are developed to meet an estimated annual requirement of 303.7 terawatt-hours (TWh) by 2035. Government policy (GP) scenario models the current economic and power policy, while Renewable Energy (REN) and Demand Side Management (DSM) scenarios provide alternative power generation pathways. These scenarios are compared based on net present cost (NPC) at different discount rates (5%, 7% and 10%). Interestingly, the REN scenario with a 35% share of solar PV and wind power turns out to be economically more viable than GP and DSM scenarios saving $26 billion and $17 billion in NPC respectively, due to sizeable savings on imported fuels. Greenhouse gas (GHG) emissions associated with all three scenarios over the study period are also estimated, whereby the RE scenario appears to save over 221 MtCO2 and 159 MtCO2 more emissions compared to GP and DSM scenarios. The results of the least cost scenario are also analysed to depict falling investment and installation costs of renewable energy technologies making them more profitable as a long run energy security option for Pakistan. Policy implications in the light of the study are discussed.

Influence of storm surge on tidal range energy

The regular and predictable nature of the tide makes the generation of electricity with a tidal lagoon or barrage an attractive form of renewable energy, yet storm surges affect the total water-level. Here, we present the first assessment of the potential impact of storm surges on tidal-range power. Water-level data (2000–2012) at nine UK tide gauges, where tidal-range energy is suitable for development (e.g. Bristol Channel), was used to predict power. Storm surge affected annual resource estimates −5% to +3%, due to inter-annual variability, which is lower than other sources of uncertainty (e.g. lagoon design); therefore, annual resource estimation from astronomical tides alone appears sufficient. However, instantaneous power output was often significantly affected (Normalised Root Mean Squared Error: 3%–8%, Scatter Index: 15%–41%) and so a storm surge prediction system may be required for any future electricity generation scenario that includes large amounts of tidal-range generation. The storm surge influence to tidal-range power varied with the electricity generation strategy considered (flooding tide only, ebb-only or dual; both flood and ebb), but with some spatial and temporal variability. The flood-only strategy was most affected by storm surge, mostly likely because tide-surge interaction increases the chance of higher water-levels on the flooding tide.

The search for most cost-effective way of achieving environmental sustainability status in electricity generation: Environmental life cycle cost analysis of energy scenarios

Over 80% of Alberta's electricity supply comes from fossil fuels; coal fired plants made up 43%. Alberta has announced its climate leadership plan, in which it is going to end electricity from coal and move towards sustainable power production. All categories of renewable energy sources, including bioenergy are expected to significantly contribute to the transition and transformation of Alberta's fossil-intensive electricity. As Alberta searches for measures to phasing out coal power plants, understanding the environmental and economic impact of alternatives can support decision-making. The main purpose of this research was to determine a cost-effective way of achieving environmental sustainability status in electricity generation. An environmental life cycle costing approach was applied to compare three biomass-based alternative scenarios, which represented energy transition and transformation in Alberta's electricity sector, with the prevailing scenario of coal-fired energy.All alternative energy scenarios showed environmental life cycle improvement from 47 to 92% for global warming, 46–90% for human health, and 47–91% for ecosystem impacts, when compared to a reference coal-fired generation scenario. On the other hand, the coal-fired electricity generation scenario demonstrated approximately 63–83% lower life cycle cost impact than alternative scenarios. The life cycle cost of wood biomass-based alternatives demonstrated 83–87% and 22–45% lower than the maximum and minimum average historical electricity generation cost for Alberta, respectively. Bioenergy can support the transition and transformation of coal power plants to a more sustainable power production.

Is biomass energy really clean? An environmental life-cycle perspective on biomass-based electricity generation in China

A bottom-up approach combined with national and provincial statistical data was used to evaluate the potential environmental effects of electricity generation scenarios based on five mature biomasses in China. Coal-based electricity generation technology was used as control. Uncertainty analysis was conducted to confirm and add credibility to this study. The electricity generation capacities of municipal solid waste, sewage sludge, and corn straw account for approximately 0.86%, 0.085%, and 8.18%, respectively, of electricity generated in China in 2012. The estimated national environmental burden caused by biomass-based electricity generation was mainly observed in eastern China, which can be attributed to the relatively high population density and economic levels of this region. For each biomass-based scenario, the key factors that contribute to the overall environmental burden include direct emissions of nitrogen oxides, phosphorus, mercury, and particulate matter. In addition, carbon dioxide pollution generated from methane incineration, road transport, and electricity consumption play a dominant role in the overall environmental burden. The environmental benefits of biomass mainly vary depending on the technologies applied and their electricity generation efficiency. Compared with the corn straw scenario, coal-based electricity generation technology yields strong environmental benefits in most key categories with the exception of climate change and human toxicity. Accordingly, biomass is not unconditionally cleaner than fossil fuel. The utilization and popularization of biomass-based electricity generation technologies must be systematically and scientifically evaluated to avoid secondary pollution generation and pollutant transformation.

Developing an optimal electricity generation mix for the UK 2050 future

The UK electricity sector is undergoing a transition driven by domestic and regional climate change and environmental policies. Aging electricity generating infrastructure is set to affect capacity margins after 2015. These developments, coupled with the increased proportion of inflexible and variable generation technologies will impact on the security of electricity supply. Investment in low-carbon technologies is central to the UK meeting its energy policy objectives. The complexity of these challenges over the future development of the UK electricity generation sector has motivated this study which aims to develop a policy-informed optimal electricity generation scenario to assess the sector's transition to 2050. The study analyses the level of deployment of electricity generating technologies in line with the 80% by 2050 emission target. This is achieved by using an excel-based “Energy Optimisation Calculator” which captures the interaction of various inputs to produce a least-cost generation mix. The key results focus on the least-cost electricity generation portfolio, emission intensity, and total investment required to assemble a sustainable electricity generation mix. A carbon neutral electricity sector is feasible if low-carbon technologies are deployed on a large scale. This requires a robust policy framework that supports the development and deployment of mature and emerging technologies.

Implementation of Open Source GIS Tools to Identify Bright Rooftops for Solar Photovoltaic Applications – A Case Study of Creek Lanes, DHA, Karachi

The mega city of Karachi is still mainly dependent on conventional sources of energy to cater its daily electricity requirements. Dependence on conventional sources of energy for power production results in environmental degradation and depletion of fossil fuel resources. In particular, it also highlights an immense need of alternate sustainable solution for current electricity generation scenario. In this research work, an innovative methodology has been proposed to identify bright rooftops using open source geographic information system (GIS) tools which may be utilized for sustainable power generation in Karachi metropolis. First, bright rooftops have been extracted using open source Quantum GIS (QGIS) software. Edge extraction technique using gradient filter; an open source algorithm of QGIS has been utilized. Furthermore, image processing techniques have been used to extract and refine building rooftops. Then, rooftops have been polygonized and their area has been calculated using Measure Area function of QGIS. To assess the accuracy of the extracted rooftops, field validation work has been performed and sample rooftops have been physically measured. A comparison of extracted and physically measured sample rooftops yielded 90.45% accuracy. Reduction in total roof area has been made considering different roof uses and shading effect from nearby trees and buildings. Then, unshaded bright rooftops area of 4,626 m2 has been calculated which can be used for solar photovoltaic (PV) applications in Creek Lanes, DHA Phase 7 Karachi. An annual energy output of 2.1 MWh has been estimated using Crystalline Silicon (c-Si) solar PV panel and available rooftop area. The methodology adopted can be extrapolated to macro-scale as well. However, challenges and limitations for extrapolation of methodology have also been highlighted. Solar radiation studies that demonstrate the use of open source GIS tools for sustainable power generation for this region have been scarce. Thus, this study is a preliminary research work to highlight an immense solar electricity potential that exists for Karachi metropolis.

Socio-economic impacts of future electricity generation scenarios in Europe: Potential costs and benefits of using CO2 Capture and Storage (CCS)

Carbon capture and storage (CCS) is a potential key-technology to mitigate greenhouse gas (GHG) emissions as its use can lead to lower mitigation cost. However, research on other economic impacts of using CCS is scarce. In this paper, we look into economic upstream impacts of CCS use in terms of employment, Gross Value Added (GVA) and import dependency on the macro- and sector-level in Western Europe. We determine these impacts by a static comparison of two scenarios of power production with and without CCS (differences in energy efficiency investments between these scenarios were not accounted for). The two scenarios, both representing a stringent climate policy regime, were produced with the energy-system-simulation-model (TIMER) following the same emission profile until 2050. Data from the two scenarios were respectively implemented into a projected version of a global-multiregional IO-Model (EXIOBASE). Macro-level results suggest slightly higher gross employment, but lower Gross Value Added (GVA) (by 25%), and higher import dependency in the CCS-including scenario compared to the CCS-excluding scenario, given that biomass with CCS (BECCS) is available. Sector-level results show disproportionally higher differences between the scenarios in GVA and employment for some sectors compared to other sectors. Particularly, sectors providing fuels (here mostly bio-energy) have significantly higher GVA and employment in the CCS scenario. This study thus reveals interesting upstream economic effects, which can be linked to the technology choice. However, the exact quantitative results depend strongly on model assumptions. Results therefore need to be further explored in other models.

Cost combined life cycle assessment of lignite-based electricity generation

Life cycle assessment and life cycle costing were carried out to identify the environmental and economic burdens of six lignite-based electricity generation scenarios. Coal-based electricity generation is used as control. Results showed that diesel consumption for road transport, energy (i.e., electricity and steam) consumption for lignite drying, and the use of coal/lignite had dominant contributions to overall environmental and economic burden. Direct heavy metal and dibenz(a,h)anthracene emissions form electricity generation represented an additional important role to the total environmental effect for all scenarios. Lignite drying with steam drum and steam fluid bed scenarios present higher economic benefits than the coal-based scenario, whereas their environmental burden is higher than that of the coal-based scenario. Results indicate that lignite drying with microwave, tube type, and rotary drum technologies are unsuitable for lignite utilization in terms of cost and environmental views.

Quantifying the Impact of Renewable Energy Futures on Cooling Water Use

AbstractThis article presents an empirically based model, WiCTS (Withdrawal and Consumption for Thermoelectric Systems), to estimate regional water withdrawals and consumption implied by any electricity generation portfolio. WiTCS uses water use rates, developed at the substate level, to predict water use by scaling the rates with predicted energy generation. The capability of WiCTS is demonstrated by assessing the impact of renewable electricity generation scenarios on water use in the United States (U.S.) through 2050. The energy generation scenarios are taken from the Renewable Energy Futures Study performed by the U.S. National Renewable Energy Laboratory of the U.S. Department of Energy. Results indicate reductions in water use are achieved under these renewable energy scenarios. The analysis further explores the impact of two modifications to the modeling framework. The first modification presumes geothermal and concentrated solar power generation technologies employ water‐intensive cooling systems vs. cooling technology that requires no water. The second modification presumes all water‐intensive cooling technologies use closed cycle cooling (as opposed to once‐through cooling) technologies by 2050. Results based on one of the renewable generation scenarios indicate water use increases by over 20% under the first modification, and water consumption increases by approximately 40% while water withdrawals decrease by over 85% under the second modification.

Integrated and realistic approach to energy planning – a case study of Slovenia

Purpose – The purpose of this paper is to present how multi-criteria methods can be used in the process of National Energy Programme development and analysis of the electricity generation planning in relatively small energy systems. Design/methodology/approach – Due to dependence on many input and output parameters which can be very complex and uncertain, energy systems have become extremely difficult to analyse and use of multi-criteria decision-making methods is essential. This paper presents and compares results of the analysis of electricity generation scenarios with three widely used multi-criteria methods, analytic hierarchy process (AHP), preference ranking organisation method for enrichment evaluation (PROMETHEE) and multi-attribute utility theory (MAUT). Findings – AHP, due to its transparency and simplicity in comparison with PROMETHEE and MAUT, is the most suitable method for the analysis of the electricity generation decision alternatives in a small energy system, such as Slovenian. The case study proposed in this research confirms that transition from environment unfriendly fossil-fuelled economy to sustainable and climate friendly development requires a realistic approach, which must be based on excellent knowledge of alternative possibilities of development and especially awareness of new opportunities in exploitation of energy efficiency and renewable energy sources. Originality/value – The case study presented in this research represents a repeatable and practical application of three widely used multi-criteria methods in the process of national energy policy development. It provides a methodological approach for finding realistic solutions to the problem of the future development challenges in small energy systems.

Japan's energy conundrum: Post-Fukushima scenarios from a life cycle perspective

This study aimed at evaluating the co-benefit implications of alternative electricity generation scenarios in Japan, in a post-Fukushima context. Four scenarios were designed assuming different shares of energy sources in a 2030 timeframe. Applying a life cycle assessment (LCA) methodology, scenarios were assessed in terms of cumulative non-renewable energy (NRE) consumption, global warming potential (GWP), terrestrial acidification potential (TAP), and particulate matter formation (PMF). Additionally electricity generation costs were evaluated. Results demonstrate that the current dependence on fossil fuel is unfeasible in the long run, as it results in 14% higher NRE consumption, an increase of 32% on GHG emissions, 29% on TAP and 34% on PMF, and 9% higher cost than the baseline scenario under pre-Fukushima conditions. On the other hand, a share of up to 27% of renewable energies is technically possible and would result in a 34% reduction of NRE consumption, 29% decrease of GHG emissions, and contribute to the mitigation of 24% of TAP and PMF impacts, at minor increase of levelized costs. Increasing the share of renewables and phasing-out thermal power would therefore increase the resilience of the Japanese economy toward external oil markets, cope with environmental protection priorities, while promoting economic development.

Comparative economic and environmental analysis of conventional, hybrid and electric vehicles – the case study of Greece

Plug-in hybrid electric vehicles as well as electric vehicles are recognized as one of the most promising avenues to materially reduce automobile contributions to petroleum dependency, air pollution and carbon dioxide emissions. Based on published data from various sources an economic and environmental comparison of a conventional, hybrid and electric vehicle – currently available at the Greek market – is performed. The production and utilization stages of the vehicles are taken into consideration. Three different electricity generation scenarios-high, medium and low carbon – are investigated. According to the comparison hybrid and electric cars exhibit advantages over conventional. In a carbon free electricity generation scenario the environmental benefits of electric cars are significant since 55.2% of the total Greenhouse gas emissions and 61.4% of the total Air Pollution emissions are stemming from conventional car; whereas 6.85% and 5.76% of total air emissions produced are emanating from electric car. It is shown that the environmental impact of electric car use depends on the source of electricity. Furthermore, three scenarios regarding the penetration rate of alternative energy propulsion systems into the Greek market are investigated for the years 2012–2025.