scholarly journals Potential and Impacts of Cogeneration in Tropical Climate Countries: Ecuador as a Case Study

Energies ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 5254
Author(s):  
Manuel Raul Pelaez-Samaniego ◽  
Juan L. Espinoza ◽  
José Jara-Alvear ◽  
Pablo Arias-Reyes ◽  
Fernando Maldonado-Arias ◽  
...  

High dependency on fossil fuels, low energy efficiency, poor diversification of energy sources, and a low rate of access to electricity are challenges that need to be solved in many developing countries to make their energy systems more sustainable. Cogeneration has been identified as a key strategy for increasing energy generation capacity, reducing greenhouse gas (GHG) emissions, and improving energy efficiency in industry, one of the most energy-demanding sectors worldwide. However, more studies are necessary to define approaches for implementing cogeneration, particularly in countries with tropical climates (such as Ecuador). In Ecuador, the National Plan of Energy Efficiency includes cogeneration as one of the four routes for making energy use more sustainable in the industrial sector. The objective of this paper is two-fold: (1) to identify the potential of cogeneration in the Ecuadorian industry, and (2) to show the positive impacts of cogeneration on power generation capacity, GHG emissions reduction, energy efficiency, and the economy of the country. The study uses methodologies from works in specific types of industrial processes and puts them together to evaluate the potential and analyze the impacts of cogeneration at national level. The potential of cogeneration in Ecuador is ~600 MWel, which is 12% of Ecuador’s electricity generation capacity. This potential could save ~18.6 × 106 L/month of oil-derived fuels, avoiding up to 576,800 tCO2/year, and creating around 2600 direct jobs. Cogeneration could increase energy efficiency in the Ecuadorian industry by up to 40%.

2020 ◽  
Vol 12 (4) ◽  
pp. 1402 ◽  
Author(s):  
Ya Chen ◽  
Wei Xu ◽  
Qian Zhou ◽  
Zhixiang Zhou

The phenomena of “large energy consumption, high carbon emission, and serious environmental pollution” are against the goals of “low energy consumption, low emissions” in China’s industrial sector. The key to solving the problem lies in improving total factor energy efficiency (TFEE) and carbon emission efficiency (TFCE). Considering the heterogeneity of different sub-industries, this paper proposes a three-stage global meta-frontier slacks-based measure (GMSBM) method for measuring TFEE and TFCE, as well as the technology gap by combining meta-frontier technology with slacks-based measure (SBM) using data envelopment analysis (DEA). DEA can effectively avoid the situation where the technology gap ratio (TGR) is larger than unity. This paper uses the three-stage method to empirically analyze TFEE and TFCE of Anhui’s 38 industrial sub-industries in China from 2012 to 2016. The main findings are as follows: (1) Anhui’s industrial sector has low TFEE and TFCE, which has great potential for improvement. (2) TFEE and TFCE of light industry are lower than those of heavy industry under group-frontier, while they are higher than those of heavy industry under meta-frontier. There is a big gap in TFEE and TFCE among sub-industries of light industry. Narrowing the gap among different sub-industries of light industry is conducive to the overall improvement in TFEE and TFCE. (3) The TGR of light industry is significantly higher than that of heavy industry, indicating that there are sub-industries with the most advanced energy use and carbon emission technologies in light industry. And there is a bigger carbon-emitting technology gap in heavy industry, so it needs to encourage technology spillover from light industry to heavy industry. (4) The total performance loss of industrial sub-industries in Anhui mainly comes from management inefficiency, so it is necessary to improve management and operational ability. Based on the findings, some policy implications are proposed.


Author(s):  
Milton Meckler

What does remain a growing concern for many users of Data Centers is their continuing availability following the explosive growth of internet services in recent years, The recent maximizing of Data Center IT virtualization investments has resulted in improving the consolidation of prior (under utilized) server and cabling resources resulting in higher overall facility utilization and IT capacity. It has also resulted in excessive levels of equipment heat release, e.g. high energy (i.e. blade type) servers and telecommunication equipment, that challenge central and distributed air conditioning systems delivering air via raised floor or overhead to rack mounted servers arranged in alternate facing cold and hot isles (in some cases reaching 30 kW/rack or 300 W/ft2) and returning via end of isle or separated room CRAC units, which are often found to fight each other, contributing to excessive energy use. Under those circumstances, hybrid, indirect liquid cooling facilities are often required to augment above referenced air conditioning systems in order to prevent overheating and degradation of mission critical IT equipment to maintain rack mounted subject rack mounted server equipment to continue to operate available within ASHRAE TC 9.9 prescribed task psychometric limits and IT manufacturers specifications, beyond which their operational reliability cannot be assured. Recent interest in new web-based software and secure cloud computing is expected to further accelerate the growth of Data Centers which according to a recent study, the estimated number of U.S. Data Centers in 2006 consumed approximately 61 billion kWh of electricity. Computer servers and supporting power infrastructure for the Internet are estimated to represent 1.5% of all electricity generated which along with aggregated IT and communications, including PC’s in current use have also been estimated to emit 2% of global carbon emissions. Therefore the projected eco-footprint of Data Centers into the future has now become a matter of growing concern. Accordingly our paper will focus on how best to improve the energy utilization of fossil fuels that are used to power Data Centers, the energy efficiency of related auxiliary cooling and power infrastructures, so as to reduce their eco-footprint and GHG emissions to sustainable levels as soon as possible. To this end, we plan to demonstrate significant comparative savings in annual energy use and reduction in associated annual GHG emissions by employing a on-site cogeneration system (in lieu of current reliance on remote electric power generation systems), introducing use of energy efficient outside air (OSA) desiccant assisted pre-conditioners to maintain either Class1, Class 2 and NEBS indoor air dew-points, as needed, when operated with modified existing (sensible only cooling and distributed air conditioning and chiller systems) thereby eliminating need for CRAC integral unit humidity controls while achieving a estimated 60 to 80% (virtualized) reduction in the number servers within a existing (hypothetical post-consolidation) 3.5 MW demand Data Center located in southeastern (and/or southern) U.S., coastal Puerto Rico, or Brazil characterized by three (3) representative microclimates ranging from moderate to high seasonal outside air (OSA) coincident design humidity and temperature.


2021 ◽  
pp. 100-112
Author(s):  
Lemma Beressa ◽  
Battula Vijaya Saradhi

The use of imported fuel in the Ethiopian cement industry increased the cost of production and the environmental burden, necessitating intervention. The greenhouse gas (GHG) emission, energy usage intensity, and resource exploitation of Ethiopian cement production were evaluated using the life cycle impact assessment (LCA) tool, aiming to recommend improvements. The LCA study used cumulative energy demand (CED) and Intergovernmental Panel on Climate Change (IPCC) 2006 life cycle impact assessment (LCIA) methods. For the case study of Mugher cement factory (MCF), the results on energy use intensities showed 3.74, 3.67, and 2.64 GJ/ton of clinker, Ordinary Portland cement (OPC), Pozzolana Portland cement (PPC), respectively. The result revealed MCF's energy use intensity was within the global range of 3.32 to 5.11 GJ/ton of cement production using similar kiln technology. The results on the GHG emissions were 0.87, 0.84, and 0.59 tons of CO2-equivalent/ton of clinker, OPC, and PPC, respectively. Process emissions accounted for 60% of overall CO2 emissions, with energy-related emissions accounting for the remaining 40%. CO2 emissions of MCF are below the global limit of 0.9 tons/ton of clinker, where all energy sources are fossil fuels. However, it is higher than the 0.65 ton/ton of clinker from a moderate rotary kiln in China. MCF used 70% of its total energy sources from imported fossil fuels, and transportation of the imported fuel added 1.2% CO2 to total emissions. A suggested fossil fuel use improvement scenario for MCF, where coffee husk replaces 50% of the imported coal improved the energy intensity, GHG emissions, and total cost of coal in clinker production by 1.2%, 14%, 36%, respectively.


2020 ◽  
Vol 180 ◽  
pp. 02005
Author(s):  
Madalina Ghilvacs ◽  
Razvan Carlanescu ◽  
Maria Paraschiv ◽  
Malina Prisecaru

In a world where the energy demand is increasing daily, energy efficiency and renewable energy play a major role. Our research comes to help fighting the biggest problem that our world is facing today, global warming. This study aims to evaluate the energy potential of biofuels obtained from camelina sativa in order to reduce fossil fuel dependence, greenhouse gas emissions and increase energy efficiency. Camelina (Camelina sativa L.) is a cruciferous oilseed plant belonging to the Brassicaceae (mustard) family with the common name false flax and gold of pleasure. Since camelina can grow under different conditions without being a competitor of food land, this energetic plant can be used for production of both, firstand second-generation biofuels. In our study we determined the elemental analysis of the subproducts obtained from camelina sativa, through experimental tests, and we built a mathematical model to determine the calorific power and to simulate the burning of the biofuels into a steam generator in order to analyse the energy potential. The results show us that the biofuels obtained from camelina sativa can represent an alternative to fossil fuels and should be considered in the transition to green energy.


2020 ◽  
Vol 15 (3) ◽  
pp. 67-82
Author(s):  
David A. Ness ◽  
Ke Xing

ABSTRACT In accordance with international protocols and directions, the APEC Energy Working Group has concentrated on constraining operational energy use and greenhouse gas (GHG) emissions in cities across the Asia Pacific, especially from the widespread consumption of fossil fuels. In addition to economy level policies and recognising the different characteristics within the region, APEC has sought to take action at the town/city level via the Low-Carbon Model Town (LCMT) project, including the development of self-assessment tools and indicator systems. However, the “low carbon” landscape is changing. There is increasing recognition of embodied carbon, accompanied by the emergence of methods for its measurement, while the C40 Cities Climate Leadership Group has recently highlighted the significance of consumption-based carbon. Similarly, the Greenhouse Gas Protocol for Cities (GPC) is likely to extend its ambit from Scope 1 GHG emissions, derived from energy use within a city boundaries, and Scope 2 emissions from grid-supplied electricity, heating and / or cooling, to Scope 3 emissions derived from materials and goods produced outside the boundaries of a city but associated with construction within that city. After describing these emerging approaches and the current landscape, the paper examines the significance and implications of these changes for APEC approaches, especially in relation to the LCMT project, its indicators and the varying characteristics of towns and cities within the Asia-Pacific region. Special attention is given to the built environment, which is known to be a major contributor to operational and embodied emissions. Consistent with the theme of the Asia-Pacific Energy Sustainable Development Forum covering “sustainable development of energy and the city,” a case is put forward for the current APEC approach to be extended to encompass both embodied and consumption-based emissions.


Energies ◽  
2019 ◽  
Vol 12 (13) ◽  
pp. 2581 ◽  
Author(s):  
Xu Liu ◽  
Jiang Lin ◽  
Junfeng Hu ◽  
Hongyou Lu ◽  
Jiaru Cai

This paper conducts panel analysis to evaluate the effects of a structural economic shift from the industrial to the tertiary sector, a reduction in industrial overcapacity, and improvements in energy efficiency on energy consumption using data for 30 Chinese provinces from 1995 to 2015. We find that, at the national level, the structural shift to the tertiary sector, the reduction in cement and steel production, and the increase in energy efficiency in the industrial sector all have statistically significantly negative effects. We also divide the sample into three geographic and economic regions to evaluate regional differences. We find that the gross domestic product (GDP) share of the tertiary sector shows its greatest impact on reducing energy consumption in the eastern region, a decline in heavy industry production would reduce energy demand more in the central region, and improvement in industrial electricity efficiency would also help reduce energy consumption the most in eastern China. We also forecast energy consumption in China will reach 4.8–4.9 billion tonnes of coal equivalent (tce) in 2020 and further grow to 5.0–5.4 billion tce in 2030.


Energies ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 3543 ◽  
Author(s):  
Patrick Moriarty ◽  
Damon Honnery

Given that global energy use today is still dominated by fossil fuels, there is an urgent need to rapidly reduce its use in order to avert serious climate change. However, the alternatives to fossil fuels—renewable and nuclear energy—are more expensive, and have so far done little to displace fossil fuels. Accordingly, reducing energy use must play an important part in both averting climate change and avoiding the depletion of high energy return easily recoverable fossil fuel reserves. This paper examined both the potential and barriers to the adoption of energy reduction measures, with particular attention to domestic energy and passenger transport. The main finding was that energy efficiency approaches alone are unlikely to deliver anywhere near the energy reductions needed in the limited time available. Instead, most energy reductions will have to come from energy conservation, involving less use of energy-using devices, including private vehicles. Achieving such reductions will require changes in lifestyles, especially for residents of OECD nations.


2012 ◽  
Vol 16 (3) ◽  
pp. 747-758 ◽  
Author(s):  
Davor Biscan ◽  
Veljko Filipan

Waste heat recovery in Croatian industry is of the highest significance regarding the national efforts towards energy efficiency improvements and climate protection. By recuperation of heat which would otherwise be wasted, the quantity of fossil fuels used for production of useful energy could be lowered thereby reducing the fuel costs and increasing the competitiveness of examined Croatian industries. Another effect of increased energy efficiency of industrial processes and plants is reduction of greenhouse gases i.e. the second important national goal required by the European Union (EU) and United Nations Framework Convention on Climate Change (UNFCCC). Paper investigates and analyses the waste heat potential in Croatian industrial sector. Firstly, relevant industrial sectors with significant amount of waste heat are determined. Furthermore, significant companies in these sectors are selected with respect to main process characteristics, operation mode and estimated waste heat potential. Data collection of waste heat parameters (temperature, mass flow and composition) is conducted. Current technologies used for waste heat utilization from different waste heat sources are pointed out. Considered facilities are compared with regard to amount of flue gas heat. Mechanisms for more efficient and more economic utilization of waste heat are proposed.


Agriculture ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 449
Author(s):  
Indrė Bručienė ◽  
Domantas Aleliūnas ◽  
Egidijus Šarauskis ◽  
Kęstutis Romaneckas

Rapidly warming climate, tightening environmental requirements, an aging society, rising wages, and demand for organic products are forcing farming to be more efficient and sustainable. The main aim of this study was to perform an analytical analysis and to determine the energy use and GHG emissions of organic sugar beet production using different weed control methods. Seven different methods of non-chemical weed control were compared. Mechanical inter-row loosening, inter-row cutting and mulching with weeds, weed smothering with catch crops, and thermal inter-row steaming were performed in field experiments at the Experimental Station of Vytautas Magnus University (Lithuania, 2015–2017). The other three, namely, automated mechanical inter-row loosening with cameras for row-tracking, inter-row loosening with a diesel-powered robot, and inter-row loosening with an electric robot were calculated analytically. The results showed that the average total energy use of organic sugar beet production was 27,844 MJ ha−1, of which manure costs accounted for 48–53% and diesel fuel for 29–35%. An average energy efficiency ratio was 7.18, while energy productivity was 1.83 kg MJ ha−1. Analysis of GHG emissions showed that the total average GHG emissions to the environment from organic sugar beet production amounted to 4552 kg CO2eq ha−1, and the average GHG emissions ratio was 4.47. The most sustainable organic sugar beet production was achieved by using mechanical inter-row loosening with a diesel-powered robot for weed control.


Buildings ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 81
Author(s):  
Heangwoo Lee ◽  
Sowon Han ◽  
Janghoo Seo

Some recent research in the area of light shelves has been focused on applying photovoltaic modules to light shelves to save building energy. However, due to the modules installed on the light shelf reflectors, most such light shelves have failed to improve both daylighting and generation efficiency. This study proposes a folding technology to improve light shelves’ daylighting and generation efficiency that uses photovoltaic modules and validates their performance using a testbed. The major obtained findings are as follows: (1) The proposed folding technology has a structure in which reflectors and photovoltaic modules fold alternately by modularizing the light shelf. The reflector and photovoltaic modules are controlled by adjusting the degree of folding. (2) Because light shelf angles for improving daylighting and generation differed depending on the application of the photovoltaic module, the optimal light shelf specifications differed. (3) Compared to previous light shelf technologies, the light shelf with folding technology and a photovoltaic module reduced energy use by 31.3% to 38.2%. This demonstrates the efficacy of the proposed system. (4) Applying a photovoltaic module can lower the indoor uniformity ratio, which means that the daylighting performance of the light shelf is degraded due to the reduction of the area occupied by the reflector.


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