Life-cycle Environmental Impact of Energy Systems

What is it about?

Concerns about the environmental impacts associated with consumer products led to the development of environmental life-cycle assessment (LCA) from the early 1990s, and its codification by the International Standards Organization (ISO). This was followed by the realisation of the consequences of other devices and systems. The need for the energy analysis and environmental appraisal of energy systems to be conducted on a life-cycle basis therefore became evident. In a full or detailed LCA, the energy and materials used and pollutants or wastes released into the environment as a consequence of an activity or service are quantified over the whole life-cycle, typically ‘from cradle-to-grave’. Such studies are often geographically diverse; that is, the energy and material inputs associated with the activity may be drawn from any continent or geopolitical region of the world. But they enable a wide range of key environmental consequences to be examined as part of the device or system design process. There are four main stages of LCA that follow a logical sequence of goal definition and scoping, inventory analysis, impact assessment, and interpretation. LCA methodology is critically reviewed from a state-of-the-art perspective and illustratedusingseveral energy sector case studies. These examples concern specific energy technologies, as well as the ‘whole systems’ appraisal of national energy sectors and transition pathways. The current strengths and weaknesses of LCA are identified for energy practitioners and policy analysts. Material has been incorporated on life-cycle embodied energy and carbon accounting and comparisons made with related approaches, such as carbon and environmental footprinting.

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Photo by Karsten Würth (@inf1783) on Unsplash

Photo by Karsten Würth (@inf1783) on Unsplash

Why is it important?

Techniques of environmental life-cycle assessment (LCA) play an important role in the context of sustainability assessment. They are at the heart of methods for the quantifying the direct ecological impacts that are an inevitable side-effect of material ‘progress’. Concepts such as the life-cycle of products and processes, and the need for clearly defined system boundaries, are key elements in environmental problem-solving. The present state-of-the-art of (mainly) process-LCA methodology has been critically reviewed in the broad context of sustainability appraisal and its use illustrated via a series of energy sector examples and case studies. These will include specific technologies, such as fossil-fuelled power plants with and without CCS and solar BIPV systems, as well as the ‘whole systems’ appraisal of national transition pathways. Clearly much more research is needed to refine LCA methods and thereby make them more robust. It is critically important that environmental life-cycle assessment studies are peer reviewed. This is normally undertaken as part of the refereeing process when the results of studies are submitted for publication in the scientific and technical media. Unfortunately, many industrial studies are not subject to a similar level of rigorous evaluation. There is consequently a need for Government departments and agencies with an interest in the application of LCA techniques over a range of products and systems to establish a "College of Peers" for this purpose. This could have a very real and near-term effect on improving the reliability of LCA studies.

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