scholarly journals Evaluating the Energy Metabolic System in Sri Lanka

2020 ◽  
Vol 13 (4) ◽  
pp. 235
Author(s):  
Konara Mudiyanselage Gayani Kaushalya Konara ◽  
Akihiro Tokai

Fast growing economy of Sri Lanka with an annual GDP growth rate of 5% has significantly increased demand for energy. As energy supply must grow in a sustainable way to meet the demand, concern over the environmental impact of energy flows have been gaining attention during policy development and implementation. Therefore, there is a need of comprehensively evaluating energy metabolic system in Sri Lanka to identify resource dependencies of the country that must be addressed to increase the sustainability. A conceptual energy metabolic model was developed identifying economic, social and demographic variables affecting energy demand, transformation and supply and GHG emissions in Sri Lanka. Developed model was used to evaluate the current energy flows and forecast the behaviour of energy metabolism while assessing the sustainability of the energy system using number of sustainability indicators. Developed model indicates an average annual growth rate of 4.06% in energy demand, 4.17% in non-renewable energy supply and 3.36% in GHG emissions. Transport sector has the highest GHG emissions percentage of 73%. Sustainability evaluation of the energy metabolic system shows that Sri Lanka is becoming more efficient and less energy intensive over the years. However, increase in GHG emissions per capita and emission intensity has a negative impact on the environmental sustainability while increase renewable energy share in total energy supply can be considered positive. The findings of the research give new insights to the energy system of Sri Lanka which enable energy planners to implement policies to transition towards a more secure and sustainable energy system.

2020 ◽  
Author(s):  
Markus Millinger ◽  
Philip Tafarte ◽  
Matthias Jordan ◽  
Alena Hahn ◽  
Kathleen Meisel ◽  
...  

<p>The increase of variable renewable energy sources (VRE), i.e. wind and solar power, may lead to a certain mismatch between power demand and supply. At the same time, in order to decarbonise the heat and transport sectors, power-based solutions are often seen as promising option, through so-called sector coupling. At times when VRE power supply exceeds demand, the surplus power could be used for producing liquid and gaseous electrofuels. The power is used for electrolysis, producing hydrogen, which can in turn be used either directly or combined with a carbon source to produce hydrocarbon fuels.</p><p>Here, we analyse the potential development of surplus power for the case of Germany, at an ambitious VRE expansion until 2050 and perform a cost analysis of electrofuels at different production levels using sorted residual load curves. These are then compared to biofuels and electric vehicles with the aid of an optimisation model, considering both cost- and greenhouse gas (GHG)-optimal options for the main transport sectors in Germany.</p><p>We find that, although hydrocarbon electrofuels are more expensive than their main renewable competitors, i.e. biofuels, they are most likely indispensable in addition for reaching climate targets in transport. However, the electrofuel potential is constrained by the availability of both surplus power and carbon. In fact, the surplus power potential is projected to remain limited even at currently ambitious VRE targets for Germany and carbon availability is lower in an increasingly renewable energy system unless direct air capture is deployed. In addition, as the power mix is likely to contain fossil fuels for decades to come, electrofuels based on power directly from the mix with associated conversion losses would cause higher GHG-emissions than the fossil transport fuel reference until a very high share of renewables in the power source is achieved. In contrast, electric vehicles are a more climate competitive option under the projected power mix with remaining fossil fuel fractions, due to a superior fuel economy and thereby lower costs and emissions.</p><p>As part of the assessment, we quantify the greenhouse gas abatement costs for different well-to-wheel pathways and provide an analysis and recommendations for a transition to sustainable transport.</p>


2021 ◽  
Vol 11 (4) ◽  
pp. 1819
Author(s):  
Roman Geyer ◽  
Sophie Knöttner ◽  
Christian Diendorfer ◽  
Gerwin Drexler-Schmid ◽  
Verena Alton

The need for decarbonization raises several questions. How can renewable energy supply for the industrial sector be realized in the long term? Furthermore, how must the existing energy system be transformed to achieve the ambitious climate targets in place? In Austria, the share of renewable energy supplying industrial energy demand currently accounts for only 45% of final energy consumption. This clearly shows that a conversion of industrial energy systems is necessary. Different ambitious perspectives for a renewable energy supply for the Austrian industrial sector are calculated for three defined scenarios (base, efficiency, transition) in this paper. In addition, corresponding requirements for the energy infrastructures are discussed. The scenario results show a range of industrial final energy consumption from 78 TWh (efficiency) to 105 TWh (transition) through decarbonizing the industrial energy supply (cf. 87 TWh in 2019). Decarbonization requires an increasing shift towards electrical energy, especially in the transition scenario, whereas in the base and efficiency scenarios, biogenic fuels play an important role. Comprehensive decarbonization and the associated substitution of energy carriers in industry pose significant challenges for the existing energy infrastructure, its expansion, and optimization.


2021 ◽  
Vol 24 ◽  
Author(s):  
Flávia Mendes de Almeida Collaço ◽  
Célio Bermann

Abstract This study analyzes the local energy planning (LEP), a set of urban energy strategies and potential scope, for São Paulo from 2014 to 2030. A simulation model is used to quantify the impacts of implementing LEP strategies on the city’s energy system based on three indicators: energy demand, percentage usage of renewable sources, and greenhouse gas (GHG) emissions. The performance of LEP strategies was analyzed for two scenarios: the first reproduces the city policies in force, and the second expands the population’s access to city energy services. Considering the implementation of LEP in the first scenario, the city exhibits a 65% usage of renewable energy and a 43% reduction in GHG emissions in 2030. Furthermore, implementation of the same strategies in the second scenario, also for 2030, results in a 67% usage of renewable energy with a 24% reduction in emissions compared to 2014.


2021 ◽  
Vol 3 ◽  
Author(s):  
Giovanni Barone ◽  
Annamaria Buonomano ◽  
Cesare Forzano ◽  
Giovanni Francesco Giuzio ◽  
Adolfo Palombo

The Canary Islands have great potential for the implementation of sustainable energy systems due to its availability of natural resources. The archipelago is not connected to the mainland electricity grid and the current generation system is mainly based on traditional fossil fuel. Therefore, the islands strongly dependent on fuel importations, with high costs due to logistics. Furthermore, due to the inadequate coverage of residential heating and cooling needs, the per capita energy consumption is far below the Spanish national average. This occurrence has inspired an intense debate on the current development model of the Canary Archipelago, which has led to the implementation of actions and measures aimed at achieving greater energy sustainability in the archipelago. Furthermore, at a local scale, an important investment plan has been carried out by the Spanish grid operator to ensure energy supply, to improve the system security and reliability, and to optimize the integration of renewable energies. Future measures and investments will be crucial to ensure a sustainable growth, both from the economic and the environment point of views. In this framework, this paper aims to discuss and compare the energy solutions, based on renewable energy technologies, identified to boost the sustainable transition of the islands. To this aim, multiple configurations of a wind power plant coupled with reversible hydro power/storage system for the distributed and on-site energy production in the island of Gran Canaria were modeled, simulated, and optimized by a TRNSYS/Matlab algorithm suitably developed. Specifically, along with the proposed system layouts, different scenarios related to diverse annual costs growth rate of fuel were investigated. The proposed analysis covers a time horizon of 20 years, up to 2040, and aims at assessing the impact of the investigated solution on energy demand, energy supply, and population incomes. Depending on the considered fuel cost growth rate, the best system configurations allow a primary energy saving in the range of 58.1–68.1%. Based on the system choice, the enterprise will generate significant revenues to the island population. The net present values are estimated in the range 1.50 × 103 ÷ 1.84 × 103 and 0.85 × 103 ÷ 1.27 × 103 M€, respectively for the two considered scenarios (annual costs growth rate of fuel 2 and −2%). The analysis demonstrates the importance of investments targeted at the implementation of renewables. The proposed scenarios indicate that the current energy model has the potential to radical change and to tackle climate change and energy issues while producing substantial economic savings and better life conditions for the population in the next years.


Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 658
Author(s):  
Elmar Zozmann ◽  
Leonard Göke ◽  
Mario Kendziorski ◽  
Citlali Rodriguez del Angel ◽  
Christian von Hirschhausen ◽  
...  

The urgency to combat climate change and the widely distributed, increasingly competitive renewable resources in North America are strong arguments to explore scenarios for a renewable energy supply in the region. While the current power system of North America is heavily dependent on fossil fuels, namely natural gas, coal and oil, and some nuclear power plants, some current policies at the state level, and future federal policies are likely to push the share of different renewable sources available in Mexico, the U.S., and Canada. This paper explores three scenarios for a renewable energy supply, using a bottom-up energy system model with a high level of spatial and time granularity. The scenarios span the extremes with respect to connecting infrastructure: while one scenario only looks at state-level supply and demand, without interconnections, the other extreme scenario allows cross-continental network investments. The model results indicate that the North American continent (a) has sufficient renewable potential to satisfy its energy demand with renewables, independent of the underlying grid assumption, (b) solar generation dominates the generation mix as the least-cost option under given renewable resource availability and (c) simultaneous planning of generation and transmission capacity expansion does not result in high grid investments, but the necessary flexibility to integrate intermittent renewable generation is rather provided by the existing grid in combination with short-term and seasonal storages.


2020 ◽  
Vol 10 (12) ◽  
pp. 4061 ◽  
Author(s):  
Naoto Takatsu ◽  
Hooman Farzaneh

After the Great East Japan Earthquake, energy security and vulnerability have become critical issues facing the Japanese energy system. The integration of renewable energy sources to meet specific regional energy demand is a promising scenario to overcome these challenges. To this aim, this paper proposes a novel hydrogen-based hybrid renewable energy system (HRES), in which hydrogen fuel can be produced using both the methods of solar electrolysis and supercritical water gasification (SCWG) of biomass feedstock. The produced hydrogen is considered to function as an energy storage medium by storing renewable energy until the fuel cell converts it to electricity. The proposed HRES is used to meet the electricity demand load requirements for a typical household in a selected residential area located in Shinchi-machi in Fukuoka prefecture, Japan. The techno-economic assessment of deploying the proposed systems was conducted, using an integrated simulation-optimization modeling framework, considering two scenarios: (1) minimization of the total cost of the system in an off-grid mode and (2) maximization of the total profit obtained from using renewable electricity and selling surplus solar electricity to the grid, considering the feed-in-tariff (FiT) scheme in a grid-tied mode. As indicated by the model results, the proposed HRES can generate about 47.3 MWh of electricity in all scenarios, which is needed to meet the external load requirement in the selected study area. The levelized cost of energy (LCOE) of the system in scenarios 1 and 2 was estimated at 55.92 JPY/kWh and 56.47 JPY/kWh, respectively.


Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2045
Author(s):  
Pierpaolo Garavaso ◽  
Fabio Bignucolo ◽  
Jacopo Vivian ◽  
Giulia Alessio ◽  
Michele De Carli

Energy communities (ECs) are becoming increasingly common entities in power distribution networks. To promote local consumption of renewable energy sources, governments are supporting members of ECs with strong incentives on shared electricity. This policy encourages investments in the residential sector for building retrofit interventions and technical equipment renovations. In this paper, a general EC is modeled as an energy hub, which is deemed as a multi-energy system where different energy carriers are converted or stored to meet the building energy needs. Following the standardized matrix modeling approach, this paper introduces a novel methodology that aims at jointly identifying both optimal investments (planning) and optimal management strategies (operation) to supply the EC’s energy demand in the most convenient way under the current economic framework and policies. Optimal planning and operating results of five refurbishment cases for a real multi-family building are found and discussed, both in terms of overall cost and environmental impact. Simulation results verify that investing in building thermal efficiency leads to progressive electrification of end uses. It is demonstrated that the combination of improvements on building envelope thermal performances, photovoltaic (PV) generation, and heat pump results to be the most convenient refurbishment investment, allowing a 28% overall cost reduction compared to the benchmark scenario. Furthermore, incentives on shared electricity prove to stimulate higher renewable energy source (RES) penetration, reaching a significant reduction of emissions due to decreased net energy import.


Energies ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2879
Author(s):  
Xinxin Liu ◽  
Nan Li ◽  
Feng Liu ◽  
Hailin Mu ◽  
Longxi Li ◽  
...  

Optimal design of regional integrated energy systems (RIES) offers great potential for better managing energy sources, lower costs and reducing environmental impact. To capture the transition process from fossil fuel to renewable energy, a flexible RIES, including the traditional energy system (TES) based on the coal and biomass based distributed energy system (BDES), was designed to meet a regional multiple energy demand. In this paper, we analyze multiple scenarios based on a new rural community in Dalian (China) to capture the relationship among the energy supply cost, increased share of biomass, system configuration transformation, and renewable subsidy according to regional CO2 emission abatement control targets. A mixed integer linear programming (MILP) model was developed to find the optimal solutions. The results indicated that a 40.58% increase in the share of biomass in the RIES was the most cost-effective way as compared to the separate TES and BDES. Based on the RIES with minimal cost, by setting a CO2 emission reduction control within 40%, the RIES could ensure a competitive total annual cost as compared to the TES. In addition, when the reduction control exceeds 40%, a subsidy of 53.83 to 261.26 RMB/t of biomass would be needed to cover the extra cost to further increase the share of biomass resource and decrease the CO2 emission.


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