LCA

Verso la valutazione ambientale degli edifici. Life Cycle Assessment a supporto della progettazione eco-sostenibile

by Eliana Cangelli

Fuel Consumption in Forwarders

by Bruce Talbot

Nordfjell, T., Athanassiadis,D., & Talbot, B. 2003. International Journal of Forest Engineering 14(2):11-20.

Forwarder fuel consumption was studied by examining a total of 27 forwarders under field conditions. Three datasets,... more Forwarder fuel consumption was studied by examining a total of 27 forwarders under field conditions. Three datasets, representing different data acquisition methods, were used. In a field study, time and fuel consumption by work-element of two 20-21 tonne forwarders in final felling were recorded. In a questionnaire survey, daily data concerning fuel consumption, productivity and average extraction distance was provided on 18 forwarders, divided between final felling and thinning. Finally, accounting data on fuel consumption for 11 forwarders were obtained.

In the field study, the fuel consumption varied between 8.3 to 15.7 l/PMH (productive machine hour) for different work elements. The total fuel consumption was 0.28-0.36 l/m3sub (solid under bark) at average extraction distances on 360-412 m for loads of sawlogs and 0.43-0.66 l/m3sub (458-514 m) for loads of pulpwood. 61-62% of that fuel was consumed during loading and driving during loading. The forwarders consumed 0.23-0.38 /100 m driving and the difference was only 10% with and without load. In the questionnaire survey, the fuel consumption averaged 0.62 l/m3sub (sawlogs and pulpwood, 318 m average xtraction distance) for final felling (16-20 tonne forwarders) and .92 l/m3sub (644 m) for thinning (11-14 tonnes). An exception was 2.5 tonne forwarders that consumed only 0.35-0.37 l/m3sub (120-180 m). 89% of the extracted volume in the accounting data was from thinnings and the fuel consumption as in average 0.67 l/m3sub (100-200 m) for 9 to11 tonne forwarders.

More difficult terrain conditions, the use of tracks and wheel-chains and one more assortment in the questionnaire survey are the most probable reasons for higher fuel consumption than in the field study. At long extraction distances it is especially important to utilize the maximum load capacity to benefit low fuel consumption on m3 basis.

Life Cycle Assessment of electricity generated by photovoltaic systems manufactured in Europe and installed in buildings in the city of Rome

by Adriana Sferra

WIT press - ASHURST, SOUTHAMPTON-UK 2010
DOI code: 10.2495/ARC100271

The aim of this paper is to evaluate the impact on human health and on the ecosystem caused by electricity produced by... more The aim of this paper is to evaluate the impact on human health and on the ecosystem caused by electricity produced by photovoltaic systems.
The analysis was carried out with the life cycle assessment methodology (LCA) and the eco indicators method. It includes a study of raw materials and energy consumption and their polluting emissions in air, water and soil during the production phase in Europe and transport, use and disposal in the city of Rome of the crystalline silicon and all other materials and components used to produce 1 kWh of electricity.
The kWh is the functional unit of the LCA analysis. The study considers the relationship between the energy consumption needed to build a PV system and the energy produced by the same system over 25 years. The study also considers the relationship between global and local environmental impact caused by the manufacturing and disposal of the PV system and the avoided environmental impact due to the energy produced by renewable sources. Finally, the analysis compares global and local emissions of CO2 caused by the PV system’s manufacturing and disposal and the avoided emissions of CO2 using electricity from renewable sources.
The study describes the possible solutions to reduce environmental impact through innovation.

Keywords:
PV system, LCA, Mayor’s Pact, saving CO2.

1 Introduction:
The IV Report on Climate Change, referenced by the European Union in its climate policies points out that within the first half of the century global emissions should be reduced by at least one half compared to 1990...

Multi-scale integrated assessment of soybean biodiesel in Brazil

by Matteo Borzoni

published in Ecological Economics, 2011, vol 70 (11), pp. 2028-2038

Developing counties are often believed to have excellent conditions for biofuel production, however studies aimed at... more Developing counties are often believed to have excellent conditions for biofuel production, however studies aimed at assessing the sustainability of large scale biofuel programs have generally focused on a few variables related to one scientific domain and one scale. Contrary to this approach, this paper analyzes soybean biodiesel in Brazil using a parallel biophysical and economic assessment at different scales. A Multi-Scale Integrated Analysis of Societal and Ecosystem Metabolism (MuSIASEM) approach is applied as a scenario analysis tool. A soybean biodiesel energy balance for the specific conditions of Brazil is included and the energy ratio turns out to be 1.09. This means that the energy delivered is higher than the energy invested, however the net energy is very low. The economic impacts are analyzed through input–output analysis. The results show that soybean biodiesel increases energy consumption per hour of work without a corresponding increase in economic labor productivity. Consequently the already low energy efficiency of Brazilian production could get worse. Although Brazil has large expanses of land, the substitution of 20% fossil diesel (i.e. just 3.3% of the country's primary energy consumption) with fully renewable biodiesel might destroy protected areas and forests and increase the GHGs emitted

A Beginner's Guide to Carbon Footprinting

by Laurence Wright

Williams, I. Kemp, S. Coello, J. Turner, D.A. & Wright, L.A. (in press) Carbon Management 3(1)

Carbon footprinting is one of the foremost methods available for quantifying anthropogenic environmental impacts and... more Carbon footprinting is one of the foremost methods available for quantifying anthropogenic environmental impacts and for helping tackle the threat of climate change. However, for any person undertaking a carbon footprinting analysis for the first time, they will almost certainly be struck by the broad array of definitions, approaches and terminology surrounding the field. This paper provides an introductory guide to some basic concepts in carbon footprinting for researchers and lay people interested in the area. Each stage of calculating a carbon footprint is considered and an introduction to the main methodologies is provided. The advantages and disadvantages of the various approaches are discussed and a rough framework of procedures is provided for the calculation of carbon footprints over a variety of subjects. Some general data sources and a glossary of key carbon footprinting terminology are included.

Life cycle assessment of an alkaline fuel cell CHP system

by Iain Staffell

published in the International Journal of Hydrogen Energy
co-authored with A. Ingram

A life cycle assessment (LCA) of an alkaline fuel cell based domestic combined heat and power (CHP) system is... more A life cycle assessment (LCA) of an alkaline fuel cell based domestic combined heat and power (CHP) system is presented. Literature on non-noble, monopolar cell design and stack construction was reviewed, and used to produce a life cycle inventory for the construction of a 1 kW stack. Inventories for the ancillary components of other commercial fuel cell products were consulted, and combined with information on the fuel processing requirements of alkaline cells to suggest a hypothetical balance of plant that would be required to produce AC electricity and domestic grade heat from natural gas and air.

The emissions from manufacturing and disposing of this fuel cell CHP system were estimated to be equivalent to 510–1000 kg of CO2 and 1.0–2.0 kg of particulate matter. As with platinum based polymer electrolyte fuel cells (PEMFC), emissions of sulphur dioxide were the most significant impact, resulting in degraded human health in the regions where catalyst metals are mined. Improving the operating lifetime and reducing catalyst loadings were identified as the most effective routes to reducing this environmental impact, as they are with other fuel cell technologies.

These impacts were compared to the results of existing LCAs for other fuel cell technologies. It was found that an alkaline fuel cell stack produces less environmental impact than an equivalent solid oxide or phosphoric acid (SOFC or PAFC) stack, while no conclusive comparison with PEMFC could be made. The inclusion of energy consumption during stack manufacture and data on the more exotic material inputs were highlighted as a problem in these studies.

Energy and carbon payback times for solid oxide fuel cell based domestic CHP

by Iain Staffell

published in the International Journal of Hydrogen Energy
co-authored with A. Ingram and K. Kendall

Fuel cells already provide heat and power to people’s homes with lower direct CO2 emissions and fuel consumption than... more Fuel cells already provide heat and power to people’s homes with lower direct CO2 emissions and fuel consumption than traditional methods. However, their whole life cycle, including manufacture and disposal, must be considered to verify that these environmental impacts are actually reduced and not merely shifted elsewhere. The total carbon footprint and energy payback times have been widely reported for other emerging microgeneration technologies, but have not previously been calculated for fuel cell systems.

This paper presents a life cycle assessment comparing solid oxide fuel cell (SOFC) based domestic CHP with the current embedded technologies in the UK. An inventory is given for the construction of a 1 kW stack and then its operation is simulated in detail using measured energy demands from hundreds of UK houses. Producing a 1 kW planar SOFC micro-CHP system was estimated to require 12–17 GJ of energy input and emit 700–950 kg of CO2, although these impacts triple when including the production of replacement stacks needed over the 10 year system life.

The carbon intensity of electricity generation from an SOFC was estimated to be 325–375 g/kWh, and is primarily determined by the operating efficiency as manufacturing only adds 10% to this. By displacing electricity generation in less efficient centralised power stations, operating an SOFC in UK homes would reclaim the energy and carbon from its manufacture in under 2 years; however, payback may not be possible if only high efficiency CCGT units are displaced.

Is grass biomethane a sustainable transport biofuel?

by Nicholas Korres

Can we meet targets for biofuels and renewable energy in transport given the constraints imposed by policy in agriculture and energy?

by Nicholas Korres

Methodology for systematic analysis and improvement of manufacturing unit process life cycle inventory (UPLCI) Part 1: Methodology Description

by Karel Kellens

Kellens, K., Dewulf, W., Overcash, M., Hauschild, M. and Duflou, J.R. (2011). Methodology for systematic analysis and improvement of manufacturing unit process life cycle inventory (UPLCI) Part 1: Methodology Description, The International Journal of Life Cycle Assessment. DOI: 10.1007/s11367-011-0340-4

The Problem of the Competitiveness of Nuclear Energy: A Biophysical Explanation

by François Diaz Maurin

This Working Paper intends to provide a sound explanation for the systemic problem of low competitiveness of nuclear energy.

Parts of this working paper are under process for publication in different international peer reviewed journals soon.

Refer to as:
F. Diaz Maurin: The Problem of the Competitiveness of Nuclear Energy: A Biophysical Explanation, Working Papers on Environmental Sciences
http://www.recercat.net/handle/2072/169668
Institut de Ciència i Tecnologia Ambientals (ICTA)
Edifici Cn, Campus UAB
08193 Cerdanyola del Vallès, Spain
Tel: (+34) 935812974
http://icta.uab.cat
icta@uab.cat

This work is licensed under Creative Commons Attribution-Noncommercial-No Derivative Works 2.5 (http://creativecommons.org/licenses/by-nc-nd/2.5/)

In this study I try to explain the systemic problem of the low economic competitiveness of nuclear energy for the... more In this study I try to explain the systemic problem of the low economic competitiveness of nuclear energy for the production of electricity by carrying out a biophysical analysis of its production process. Given the fact that neither econometric approaches nor onedimensional methods of energy analyses are effective, I introduce the concept of biophysical explanation as a quantitative analysis capable of handling the inherent ambiguity associated with the concept of energy. In particular, the quantities of energy, considered as relevant for the assessment, can only be measured and aggregated after having agreed on a pre-analytical definition of a grammar characterizing a given set of finite transformations. Using this grammar it becomes possible to provide a biophysical explanation for the low economic competitiveness of nuclear energy in the production of electricity. When comparing the various unit operations of the process of production of electricity with nuclear energy to the analogous unit operations of the process of production of fossil energy, we see that the various phases of the process are the same. The only difference is related to characteristics of the process associated with the generation of heat which are completely different in the two systems. Since the cost of production of fossil energy provides the base line of economic competitiveness of electricity, the (lack of) economic competitiveness of the production of electricity from nuclear energy can be studied, by comparing the biophysical costs associated with the different unit operations taking place in nuclear and fossil power plants when generating process heat or net electricity. In particular, the analysis focuses on fossil-fuel requirements and labor requirements for those phases that both nuclear plants and fossil energy plants have in common: (i) mining; (ii) refining/enriching; (iii) generating heat/electricity; (iv) handling the pollution/radioactive wastes. By adopting this approach, it becomes possible to explain the systemic low economic competitiveness of nuclear energy in the production of electricity, because of: (i) its dependence on oil, limiting its possible role as a carbon-free alternative; (ii) the choices made in relation to its fuel cycle, especially whether it includes reprocessing operations or not; (iii) the unavoidable uncertainty in the definition of the characteristics of its process; (iv) its large inertia (lack of flexibility) due to issues of time scale; and (v) its low power level.

"Describing the elephant": A framework for supporting sustainable development processes

by Philip Sinclair