Marcelle McManus

Use of LCA as a development tool within early research: challenges and issues across different sectors

PurposeThe aim of this paper is to highlight the challenges that face the use of life cycle assessment (LCA) for the development of emerging technologies. LCA has great potential for driving the development of products and processes with improved environmental credentials when used at the early research stage, not only to compare novel processing with existing commercial alternatives but to help identify environmental hotspots. Its use in this way does however provide methodological and practical difficulties, often exacerbated by the speed of analysis required to enable development decisions to be made. Awareness and understanding of the difficulties in such cases is vital for all involved with the development cycle.MethodsThis paper employs three case studies across the diverse sectors of nanotechnology, lignocellulosic ethanol (biofuel), and novel food processes demonstrating both the synergy of issues across different sectors and highlighting the challenges when applying LCA for early research. Whilst several researchers have previously highlighted some of the issues with use of LCA techniques at an early stage, most have focused on a specific product, process development, or sector. The use of the three case studies here is specifically designed to highlight conclusively that such issues are prevalent to use of LCA in early research irrespective of the technology being assessed.Results and discussionThe four focus areas for the paper are system boundaries, scaling issues, data availability, and uncertainty. Whilst some of the issues identified will be familiar to all LCA practitioners as problems shared with standard LCAs, their importance and difficulty is compounded by factors distinct to novel processes as emerging technology is often associated with unknown future applications, unknown industrial scales, and wider data gaps that contribute to the level of LCA uncertainty. These issues, in addition with others that are distinct to novel applications, such as the challenges of comparing laboratory scale data with well-established commercial processing, are exacerbated by the requirement for rapid analysis to enable development decisions to be made.ConclusionsBased on the challenges and issues highlighted via illustration through the three case studies, it is clear that whilst transparency of information is paramount for standard LCAs, the sensitivities, complexities, and uncertainties surrounding LCAs for early research are critical. Full reporting and understanding of these must be established prior to utilising such data as part of the development cycle.

Energy analysis and environmental life cycle assessment of a micro-wind turbine

The life cycle energy use and environmental impact of an installed micro-wind turbine for domestic (residential) electricity generation has been determined. The turbine examined was a horizontal-axis wind turbine, which has a rotor diameter of 1.7 m, a power rating of 600 W at 12 m/s, and an assumed lifetime of 15 years. The system boundaries for the study encompass energy and material resources in the ground and extend to the point of delivery of electricity. The energy output of the turbine in different terrains has been estimated via a dataset of hourly measured wind speeds, and the environmental impact of producing and maintaining the micro-wind turbine was determined. The environmental performance of the turbine was assessed by assuming that each unit of electricity generated displaces (avoids the use of) a unit of grid electricity. The whole life cycle performance of a micro-wind turbine was found to be dependant on a number of factors, primarily the geographical positioning of the turbine, the available wind resource, and the use of recycled materials within the production of the microturbine.

Towards Carbon-Neutral CO2 Conversion to Hydrocarbons

With fossil fuels still predicted to contribute close to 80 % of the primary energy consumption by 2040, methods to limit further CO2 emissions in the atmosphere are urgently needed to avoid the catastrophic scenarios associated with global warming. In parallel with improvements in energy efficiency and CO2 storage, the conversion of CO2 has emerged as a complementary route with significant potential. In this work we present the direct thermo-catalytic conversion of CO2 to hydrocarbons using a novel iron nanoparticle-carbon nanotube (Fe@CNT) catalyst. We adopted a holistic and systematic approach to CO2 conversion by integrating process optimization-identifying reaction conditions to maximize conversion and selectivity towards long chain hydrocarbons and/or short olefins-with catalyst optimization through the addition of promoters. The result is the production of valuable hydrocarbons in a manner that can approach carbon neutrality under realistic industrial process conditions.

Challenge clusters facing LCA in environmental decision-making—what we can learn from biofuels

PurposeBioenergy is increasingly used to help meet greenhouse gas (GHG) and renewable energy targets. However, bioenergy’s sustainability has been questioned, resulting in increasing use of life cycle assessment (LCA). Bioenergy systems are global and complex, and market forces can result in significant changes, relevant to LCA and policy. The goal of this paper is to illustrate the complexities associated with LCA, with particular focus on bioenergy and associated policy development, so that its use can more effectively inform policymakers.MethodsThe review is based on the results from a series of workshops focused on bioenergy life cycle assessment. Expert submissions were compiled and categorized within the first two workshops. Over 100 issues emerged. Accounting for redundancies and close similarities in the list, this reduced to around 60 challenges, many of which are deeply interrelated. Some of these issues were then explored further at a policy-facing workshop in London, UK. The authors applied a rigorous approach to categorize the challenges identified to be at the intersection of biofuels/bioenergy LCA and policy.Results and discussionThe credibility of LCA is core to its use in policy. Even LCAs that comply with ISO standards and policy and regulatory instruments leave a great deal of scope for interpretation and flexibility. Within the bioenergy sector, this has led to frustration and at times a lack of obvious direction. This paper identifies the main challenge clusters: overarching issues, application and practice and value and ethical judgments. Many of these are reflective of the transition from application of LCA to assess individual products or systems to the wider approach that is becoming more common. Uncertainty in impact assessment strongly influences planning and compliance due to challenges in assigning accountability, and communicating the inherent complexity and uncertainty within bioenergy is becoming of greater importance.ConclusionsThe emergence of LCA in bioenergy governance is particularly significant because other sectors are likely to transition to similar governance models. LCA is being stretched to accommodate complex and broad policy-relevant questions, seeking to incorporate externalities that have major implications for long-term sustainability. As policy increasingly relies on LCA, the strains placed on the methodology are becoming both clearer and impedimentary. The implications for energy policy, and in particular bioenergy, are large.

Thermodynamic efficiency of low-carbon domestic heating systems: heat pumps and micro-cogeneration

Energy and exergy analysis is employed to compare the relative thermodynamic performance of low-carbon domestic energy systems based on air source heat pumps and micro-combined heat and power (cogeneration) units. A wide range of current units are modelled under different operating conditions representative of the United Kingdom to determine the energy and exergy flows from primary energy inputs through to low-carbon heating system and then to end use. The resulting performances are then analysed in order to provide insights regarding the relative merits of the systems under the different operating constraints that may be experienced both now and into the future. Although current mid-range systems achieve comparable performance to a condensing gas boiler, the state-of-art offers considerable improvements. Micro-combined heat and power units and air source heat pumps have the technical potential to improve the energy performance of dwellings. The relative performance and potential of the systems is dominated by the electrical characteristics: the grid electrical generation efficiency, the power-to-heat demand ratio and the availability of electrical export. For total power-to-heat demands below 1:1.5, air source heat pumps have greater improvement potential as their energy efficiency is not constrained. At higher power-to-heat ratios, micro-combined heat and power units offer the potential for higher overall efficiency and this generally occurs irrespective of whether or not the thermal energy from them is used effectively.

Collected marine litter — A growing waste challenge

Marine litter, in particular plastic debris, poses a serious threat to marine life, human health and the economy. In order to reduce its impact, marine litter collections such as beach clean-ups are frequently conducted. This paper presents a systematic review of temporal developments, geographical distribution, quantities and waste treatment pathways of collected marine litter. Results from over 130 studies and projects highlight the worldwide increase in collection efforts. Many of these are in wealthy countries that do not primarily contribute to the problem. Over 250 thousand tonnes, have already been removed, but there is little or no information available regarding how this waste is treated or used post collection. This paper highlights the need for a whole-system quantitative assessment for the collection and waste treatment of marine litter, and identifies the challenges associated with utilising this waste in the future.

Feedstocks for Aviation Biofuels

The cost, availability, and sustainability of feedstocks are key to successfully producing aviation biofuels. There are numerous routes to aviation fuels, and as such, it is likely that multiple feedstocks will be used globally to produce future aviation biofuels. In this chapter, a general overview of all the major feedstocks available, where they are regionally produced, the challenges inherent in increasing production to necessary levels, and key forecasts for bioenergy use ahead to 2050, will be presented and briefly discussed.

Environmental Auditing of a Packaging System for Redesign: A Case Study Exploration

Within the United Kingdom a significant portion of the energy consumed each year is done so through industry. It is therefore desirable to take measures that reduce this consumption. A process common to all manufacturing sectors is that of packaging, and this research focused on identifying, quantifying and reducing the environmental impact of one such system. It finally took the form of an abridged life cycle assessment focusing on the manufacturing and assembly stage of a packaging systems life. Two separate studies were conducted to evaluate the performance of specific tools for such environmental studies. Where, the total embodied energy and carbon of each sub-assembly of the systems was calculated and their contribution to the whole machine established. These were further broken down into material production and machine processes in order to establish where the major impacts were and potential areas for redesign. Both approaches were found to be resource hungry in their application, an output that may restrict their application in the type of company that operate in this domain. A surprising finding was that producing a design with lower environmental impact could be less expensive.

The Use of LCA for the Development of Bioenergy Pathways

Bioenergy and biofuels are key to meeting renewable energy and carbon reduction targets. Life Cycle Assessment (LCA) techniques are being used, with varying success and consistency, to help determine the sustainability of the current fuels and pathways selected. In order to meet our longer term targets and pursue long term sustainability emerging processes and systems need to be examined, as well as existing processes. Designers recognise that a large percentage of impacts and costs are pre-ordained within the design stage; so it makes sense to use LCA at the start of the research process in order to minimise these. Determining impacts at this stage could also help select the most promising options with maximum sustainability/GHG reduction potential. At the same time policy makers are beginning to use LCA as a tool to help inform policy choices for future energy pathways. Never the less, there are various uncertainties involved with its use at early stage research level, and also the expansion of LCA to look at wider consequences of the use of a particular product or system. LCA is changing from a traditional, retrospective tool to a more dynamic, forward thinking tool. Whilst this brings a multitude of benefits in terms of ability to predict impacts and minimise these in advance, this method of LCA use is not without uncertainties and difficulties. This paper explores why LCA is important within the bioenergy context and highlights some of the benefits, disadvantages, and changes that are seen through its use.

Greenhouse Gas Balances of Bioenergy Systems: The Role of Life Cycle Assessment

Abstract LCA originated in the 1960s and 1970s in the energy industry. Since then, it has evolved into a wide ranging tool used to determine impacts of products or systems over several environmental and resource issues. The use of LCA has become more prevalent in research, industry, and policy and its use continues to expand as users seek to encompass impacts as diverse as resource accounting and social well-being. Carbon policy for bioenergy has driven many of these changes. Enabling assessment of complex issues over a life cycle basis is beneficial, but the process is sometimes difficult. The use of LCA to help frame policy and global impacts is becoming increasingly complex and more uncertain. The charged environment surrounding biofuels and bioenergy exacerbates this. Reaching its full potential to help guide difficult policy discussions and emerging research involves successfully managing LCAs transition from attributional to consequential and from retrospective to prospective. This chapter explores LCAs evolution, use, and associated challenges within bioenergy.