Energy self-reliance, net-energy production and GHG emissions in Danish organic cash crop farms

2008 ◽  
Vol 23 (1) ◽  
pp. 30-37 ◽  
Author(s):  
N. Halberg ◽  
R. Dalgaard ◽  
J.E. Olesen ◽  
T. Dalgaard
Keyword(s):  
Energy Production ◽  
Fossil Fuels ◽  
Energy Use ◽  
Nutrient Management ◽  
Biogas Production ◽  
Ghg Emissions ◽  
Net Energy ◽  
Pig Slurry ◽  
Cash Crop ◽  
Crop Fields

AbstractOrganic farming (OF) principles include the idea of reducing dependence of fossil fuels, but little has been achieved on this objective so far in Danish OF. Energy use and greenhouse gas (GHG) emissions from an average 39 ha cash crop farm were calculated and alternative crop rotations for bio-energy production were modeled. Growing rapeseed on 10% of the land could produce bio-diesel to replace 50–60% of the tractor diesel used on the farm. Increasing grass-clover area to 20% of the land and using half of this yield for biogas production could change the cash crop farm to a net energy producer, and reduce GHG emissions while reducing the overall output of products only marginally. Increasing grass-clover area would improve the nutrient management on the farm and eliminate dependence on conventional pig slurry if the biogas residues were returned to cash crop fields.

Design for Sustainable Data Center Energy Use and Eco-Footprint

2010 ◽  
Author(s):  
Milton Meckler
Keyword(s):  
Data Center ◽  
Air Conditioning ◽  
Fossil Fuels ◽  
Energy Use ◽  
Data Centers ◽  
Ghg Emissions ◽  
High Energy ◽  
Operational Reliability ◽  
Energy Utilization ◽  
Air Conditioning Systems

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.

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 ◽  
...  
Keyword(s):  
Energy Efficiency ◽  
Fossil Fuels ◽  
Energy Use ◽  
National Level ◽  
Ghg Emissions ◽  
Industrial Sector ◽  
Increase Energy Efficiency ◽  
High Dependency ◽  
Generation Capacity ◽  
Tropical Climates

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%.

scholarly journals Life Cycle Assessment of Ethiopian Cement Manufacturing: A Potential Improvement on the Use of Fossil Fuel in Mugher Cement Factory

2021 ◽  
pp. 100-112
Author(s):  
Lemma Beressa ◽  
Battula Vijaya Saradhi
Keyword(s):  
Life Cycle ◽  
Portland Cement ◽  
Impact Assessment ◽  
Life Cycle Impact Assessment ◽  
Fossil Fuels ◽  
Energy Use ◽  
Fossil Fuel ◽  
Ghg Emissions ◽  
Energy Sources ◽  
Cement Production

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.

scholarly journals CONSUMPTION-BASED AND EMBODIED CARBON IN THE BUILT ENVIRONMENT: IMPLICATIONS FOR APEC’S LOW-CARBON MODEL TOWN PROJECT

2020 ◽  
Vol 15 (3) ◽  
pp. 67-82
Author(s):  
David A. Ness ◽  
Ke Xing
Keyword(s):  
Sustainable Development ◽  
Built Environment ◽  
Greenhouse Gas ◽  
Fossil Fuels ◽  
Energy Use ◽  
Ghg Emissions ◽  
Assessment Tools ◽  
Asia Pacific ◽  
Low Carbon ◽  
Embodied Carbon

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.

scholarly journals Life Cycle Assessment Analysis of Alfalfa and Corn for Biogas Production in a Farm Case Study

Processes ◽  
2020 ◽  
Vol 8 (10) ◽  
pp. 1285
Author(s):  
Fabiola Filippa ◽  
Francesco Panara ◽  
Daniela Leonardi ◽  
Livia Arcioni ◽  
Ornella Calderini
Keyword(s):  
Life Cycle Assessment ◽  
Life Cycle ◽  
Anaerobic Digestion ◽  
Greenhouse Gases ◽  
Energy Production ◽  
Fossil Fuels ◽  
Biogas Production ◽  
Life Cycle Assessment Study ◽  
Energy Inputs

In the last years the greenhouse effect has been significantly intensified due to human activities, generating large additional amounts of Greenhouse gases (GHG). The fossil fuels are the main causes of that. Consequently, the attention on the composition of the national fuel mix has significantly grown, and the renewables are becoming a more significant component. In this context, biomass is one of the most important sources of renewable energy with a great potential for the production of energy. The study has evaluated, through an LCA (Life Cycle Assessment) study, the attitude of alfalfa (Medicago sativa) as “no food” biomass alternative to maize silage (corn), in the production of biogas from anaerobic digestion. Considering the same functional unit (1 m3 of biogas from anaerobic digestion) and the same time horizon, alfalfa environmental impact was found to be much comparable to that of corn because it has an impact of about 15% higher than corn considering the total score from different categories and an impact of 5% higher of corn considering only greenhouse gases. Therefore, the analysis shows a similar environmental load in the use of alfalfa biomass in energy production compared to maize. Corn in fact, despite a better yield per hectare and yield of biogas, requires a greater amount of energy inputs to produce 1m3 of biogas, while alfalfa, which requires less energy inputs in its life cycle, has a lower performance in terms of yield. The results show the possibility to alternate the two crops for energy production from an environmental perspective.

scholarly journals The Potential of Agricultural Biogas Production in Ukraine—Impact on GHG Emissions and Energy Production

Energies ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 5755
Author(s):  
Adam Wąs ◽  
Piotr Sulewski ◽  
Vitaliy Krupin ◽  
Nazariy Popadynets ◽  
Agata Malak-Rawlikowska ◽  
...  
Keyword(s):  
Renewable Energy ◽  
Greenhouse Gas ◽  
Economic Performance ◽  
Energy Production ◽  
Biogas Production ◽  
Ghg Emissions ◽  
Economic Implications ◽  
Self Sufficiency ◽  
Renewable Energy Production ◽  
Biogas Plants

Renewable energy production is gaining importance in the context of global climate changes. However, in some countries other aspects increasing the role of renewable energy production are also present. Such a country is Ukraine, which is not self-sufficient in energy supply and whose dependency on poorly diversified import of energy carriers regularly leads to political tensions and has socio-economic implications. Production of agricultural biogas seems to be a way to both slow down climatic changes and increase energy self-sufficiency by replacing or complementing conventional sources of energy. One of the most substantial barriers to agricultural biogas production is the low level of agricultural concentration and significant economies of scale in constructing biogas plants. The aim of the paper was thus to assess the potential of agricultural biogas production in Ukraine, including its impact on energy self-sufficiency, mitigation of greenhouse gas (GHG) emissions and the economic performance of biogas plants. The results show that due to the prevailing fragmentation of farms, most manure cannot be processed in an economically viable way. However, in some regions utilization of technically available manure for agricultural biogas production could cover up to 11% of natural gas or up to 19% of electricity demand. While the theoretical potential for reducing greenhouse gas emissions could reach 5% to 6.14%, the achievable technical potential varies between 2.3% and 2.8% of total emissions. The economic performance of agricultural biogas plants correlates closely with their size and bioenergy generation potential.

Full scale experience with the BIOCEL process

2000 ◽  
Vol 41 (3) ◽  
pp. 299-304 ◽  
Author(s):  
E. ten Brummeler
Keyword(s):  
Energy Production ◽  
Fossil Fuels ◽  
Volatile Fatty Acids ◽  
Full Scale ◽  
Net Energy ◽  
Organic Fraction ◽  
Complete Inactivation ◽  
Organic Solid ◽  
Animal Pathogens ◽  
Key Factor

The BIOCEL process is a mesophilic dry anaerobic batch digestion system for solid organic wastes. In the BIOCEL process organic solid wastes, such as source separated organic fraction of MSW (biowaste) is converted into enriched compost and biogas. In the process net energy production is achieved by converting the biogas to heat and power with a heat-electric power production unit. In September 1997 the first full scale plant is started-up in Lelystad, The Netherlands. This plant is processing 50,000 tons of biowaste (organic fraction of MSW from source separation) per year. The plant has a net energy production and therefore contributes to prevention of CO2 emissions from fossil fuels. In the BIOCEL-system the several compost fractions are produced with a “wet” separation process. During the wet separation sand and contaminants are removed. An important aspect of compost quality is the absence of several types of pathogens. It appears that anaerobic digestion with the BIOCEL- process results in complete inactivation of several important groups of plant and animal pathogens. The mechanism that causes the inactivation is not yet fully understood, but the relatively high Volatile Fatty Acids concentration during the first two weeks of the digestion process might presumably be the key factor.

scholarly journals Current Trends in Slovak Legislation Regulating Renewable Energy Production

2019 ◽  
Vol 8 (1) ◽  
pp. 13-17
Author(s):  
Ondrej Beňuš ◽  
Dominika Čeryová
Keyword(s):  
Renewable Energy ◽  
Energy Production ◽  
Fossil Fuels ◽  
Energy Use ◽  
Legal Regulation ◽  
Electricity Production ◽  
Current Trends ◽  
Renewable Energy Production ◽  
New Instruments ◽  
The Eu

Abstract Renewable energy production is one of key actions undertaken by the EU to lower its dependency on energy imports from third countries. Renewable energy is not competitive compared to fossil fuels at this moment. Under these circumstances, there is a need for an effective legal regulation. The EU has set main targets relating renewable energy use in the directive (EU) 2018/2001. Slovak policymakers have recognized these new targets. The main objective of the paper is to examine the latest changes to the Slovak legal regulation of the renewable energy production with focus on electricity production. We analyse changes made by the amendment of the Act No. 309/2009 Coll. and provide a short explanation of new instruments.

Automation of Marginal Grass Harvesting

2019 ◽  
pp. 106-146
Author(s):  
Paulo Peças ◽  
Gonçalo Manuel Fonseca ◽  
Inês Inês Ribeiro ◽  
Claus Grøn Sørensen
Keyword(s):  
Fossil Fuels ◽  
Biogas Production ◽  
Ghg Emissions ◽  
The European Union ◽  
Alternative Technologies ◽  
Marginal Areas ◽  
Significant Difference ◽  
Biogas Plants ◽  
Increasing Demand ◽  
Materials Used

In the European Union (EU), the use of fossil fuels brings several disadvantages, as they are the main culprits responsible for pollutants and GHG emissions. The increasing demand for sustainable fuels leads to the research of alternative technologies, such as biogas production from lignocellulosic materials. Therefore, the acquisition of biomass from marginal areas under Danish conditions has been evaluated in terms of alternative harvesting equipment: an automated robot (Grassbot) versus a regular tractor for key grass materials used for biogas plants (chopped, unchopped, and baled grass) and compared regarding operational, economical, and environmental performances. The evaluation uses two operations models (IRIS and DRIFT) to consider the field characteristics, machinery characteristics, etc. Selected results show that in terms of fuel consumption, chopping, and mowing are the most demanding operations, and that there is no significant difference between the harvesting equipment regarding CO2 emissions.

scholarly journals Energy production analysis of Common Reed – Phragmites australis (Cav.) Trin.

2017 ◽  
Vol 44 (2) ◽  
pp. 107-113
Author(s):  
Jaroslav Demko ◽  
Ján Machava ◽  
Miroslav Saniga
Keyword(s):  
Energy Storage ◽  
Phragmites Australis ◽  
Energy Production ◽  
Fossil Fuels ◽  
Biogas Production ◽  
Calorific Value ◽  
Common Reed ◽  
Combustion Heat ◽  
Direct Combustion ◽  
The Common

AbstractSlovakia is acountry with limited natural resources, therefore its essential task is to search for new renewable sources of energy to reduce its dependence on imported fossil fuels. The results of research confirmed that the Common Reed (Phragmites australis(Cav.) Trin.) has considerable potential of phytomass production and energy storage (calorific value reached 17,448 J g−1d.w.). Biomass production of Common Reed under natural conditions of the lower Liptov region reached 12.702 tons of a dry mater per hectare with the calculated energy storage of 221.622 GJ ha−1. The average biogas production was 351.31 l kg−1of a dry matter of which the methane (CH4) content represents 185.21 l kg−1(52.72%). With regards to the values of combustion heat, a calorific value and the production of methane it can also be noted that in case of Common Reed it is more profitable to focus on direct combustion of biomass than the production of biogas and methane.

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