Category Renewables-Based Technology

Where Are We Going in Assessing Renewables-Based Technology?

This book has shown that sustainability assessment of renewables-based technology is still at an early stage. It has been shown in particular that there are a large number of metrics available, being quite diverse in nature, presented by academics, public and private financed research institutes, and industry. The question may be raised if, in the long run, we are moving towards one single generic assessment tool. This may be very doubtful given the diversity of renewables-based technology and the questions that have to be answered. According to Levett (1998), we should take a modest ‘fitness-for-purpose’ approach in developing indicators, i. e...

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Case Studies of Assessment Metrics

Chapters 11-19 show applications of different sustainability metrics for different sectors. Since biomass is a predominant renewable resource and since its production requires substantial land area, effects on land use are discussed in the first chapter of this part of the book. Chapter 12 focuses on a rather traditional renewable resource-based sector: forestry. An assessment diagram of renewables and non-renewables-based doorframes is presented in Figure 12.1.

The assessment of renewable resources for energy production purposes is dealt with in Chapters 13-15. Chapter 13 focuses on the emissions that are generated when biomass is employed for energy purposes. The possible contribution of biofuels to greenhouse gas emission reduction is the topic of Chapter 14...

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The Basic Metrics

Chapters 5-10 show six different metrics that can be put into practice as sustainability metrics. Chapter 5 focuses on metrics especially designed to assess renewables-based energy: biofuels. The presented net energy balancing method may be the preferred method in systems where the input of renewables versus non-renewables is so obvious. Chapter 6 presents the typical environmental life cycle analysis, where a major emphasis is on emissions into the environment, rather than resource extraction from the environment. Chapter 7, on the other hand, presents a thermodynamics-based method – exergy analysis – where emphasis is put on the nature (renewable versus non-renewable) and technical potential of natural resources...

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Definition of Functional Unit and System Boundaries

With respect to the question ‘What technology has to be assessed?’, two major definitions have to be considered. First, there is the definition of the functional unit. If one aims, for example, at comparing a fossil resource-based technology with a renewable resource-based technology, one needs to define a functional unit allowing comparison. In the past, products have been considered frequently as the functional unit. However, the sustainability idea, which, according to the UN definition of it in 1987, must be ‘fulfilling the needs’, makes a shift from product to service: products are only a vehicle to deliver the service one uses to fulfil the needs of the population. This fits with the one-liner ‘doing more with less’ and the dematerialization concept.

Next to an appropriat...

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The Themes in Sustainability Metrics

Looking at the available metrics, it turns out that indicators are often limited to one or two dimensions of sustainability, predominantly environment and economics. Economic metrics

are available in the market economy and are typically integrated in company and national reports. With respect to environmental sustainability, the predominant metric that was developed in the 1980s and 1990s is environmental life cycle analysis (Chapter 6). In this era, concern about the environmental effects of technologies was focused on emissions...

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The Available Sustainability Metrics

Measuring sustainability of technology is complex. One reason for this has to do with sustainability itself: it is a broad holistic issue with environmental, economic and social dimensions. A second reason for the complexity is the large number of levels at which the sustainability concept can be applied, and thus the definition of the technology to be assessed. Do we want to assess a product, a service, a production process, a production facility, a company or an industrial sector? Chapter 3 deals with these critical questions in a clear manner. As a third focus for our attention we have to be aware that ‘technology’ is not an isolated system delivering only one product...

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Conclusions

Jo Dewulf and Herman Van Langenhove

19.3 Introduction

Although the word did not exist as such, renewables have been the main sources for energy and material supply in societies for many centuries, and this roughly until 1850. With the start of the era of power machines based on coal and other fossil fuels (first coal, later oil), the predominance of renewables decreased. The explosive growth of mainly the organic chemical industry after World War II, driven by the production of fossil fuel-based polymers, further reduced the role of renewables. However, in the last decades of the twentieth century, some drawbacks of the fossil resource-based society became obvious...

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Emissions

This aggregated parameter constitutes waste (90% reduction in landfill waste), emissions to water (reduced by 52%) and emissions to air. The latter are quantified in terms of contribution to global warming potential (reduced by 83%), photochemical ozone creation potential (reduced by 50%) and acidification potential (reduced by 55% in the bio-route). For example, halogenated solvents are completely eliminated in the bio-based process.

Toxicity potential

Elimination of numerous toxic solvents and reagents results in a 58% reduction, the third largest impact on the total score.

Risk potential

The risk potential is reduced by 63% for virtually the same reasons as for toxicity.

Area demand

The area demand is reduced by 50%, mainly due to lower electricity demand for the bio-route...

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