Tipo de fracturas en los cilindros de concreto

The purpose of this thesis is to assess the security of possible future low-carbon electricity systems; in order to do this, there needs to be an idea of what a low-carbon electricity system in the UK might look like. In recent years, a large number of studies in the energy field and elsewhere have sought to take a ‘futures-based’ approach, outlining what the future might look like (Dixon 2011). These analyses can take many forms: McDowall and Eames (2006), in a study on methods used in the field of hydrogen, identified six

overlapping types of futures study. These types are shown in table 3.1, which has been adapted to make it relevant to low-carbon energy studies. The distinction between a ‘normative’ and ‘descriptive’ method is important. ‘Descriptive’ methods take today’s system as their starting point, and seek to elaborate how the system might evolve in a variety of plausible directions; for example, studies which offer a range of scenarios, some of which may not meet climate change mitigation targets. ‘Normative’ approaches on the other hand focus on reaching a desired goal or ‘vision’, and seek to elaborate how best to get there; for example, studies which focus on meeting a specific carbon reduction target. It should be emphasised however that the elements of these six types of futures study are overlapping and not always clear, and that the language is often used interchangeably; for instance, the EU Roadmap 2050 project (European Climate Foundation 2010) states that its aim is to “provide analysis of pathways to achieve a low-carbon economy in Europe” (European Climate Foundation 2015; emphasis added). The overlapping nature means that it is not always possible to precisely label a particular approach or study, and some studies use a combination of several approaches.

For the purposes of this thesis, it is important to identify which of these approaches to use, in order to inform the choice of transitions studies which will form the basis for the security assessment. The purpose of the thesis is to assess the security of a low-carbon electricity system; therefore it makes sense to choose futures studies which achieve a low-carbon target. For the purpose of this thesis, ‘low-carbon’ is defined as meeting (or at least

attempting to meet) the UK’s legally-binding target of an 80% emissions reduction by 2050. For this reason, normative approaches would be more suitable, because of the existence of

a set end-goal, and the ‘pathways’ approach is overall probably the most suitable approach for this thesis. Several normative studies take a ‘roadmap’ approach,in which a single ‘ideal’ route for decarbonisation is mapped out in detail; these are less suitable for the purposes of this thesis, because one of the main objectives of this thesis is to identify synergies and trade-offs, therefore it is more useful to make comparisons between a range of possible options. Using a set of different pathways from the same source also allows interesting comparisons to be made, whilst avoiding inaccuracies arising from using raw data from more than one source. The methodology for choosing a set of pathways from the numerous possible options is outlined in the next chapter, in section 4.2.

Table 3-1: Types of futures study. Adapted from McDowall and Eames (2006)

Character Type Description Example

Descriptive

Forecast Uses formal quantitative extrapolation and modelling to predict likely futures from current trends

IEA World Energy Outlook (IEA 2014)

Exploratory scenario

Explores possible futures, emphasising drivers; does not specify a predetermined desirable end state

Mountains and Oceans (Shell International 2013) Technical

scenario

Explores possible future technological systems, emphasising the technical feasibility and implications of different options, rather than exploring how different futures might unfold

‘Sustainability Without the Hot Air’ (MacKay 2009)

Normative

Vision Describes a desirable and (more or less) plausible future, emphasising the benefits of a low-carbon transition rather than the pathways through which a low-carbon transition might be achieved

World Resources Institute (WRI) Roadmap for a Secure, Low-Carbon Economy (Ladislaw et al 2009)

Pathway Starts with a predetermined end point (i.e. a desirable and plausible future), and investigates possible pathways to that point

DECC 2050 Pathways Analysis (DECC 2010a) Roadmap Describes a sequence of measures designed

to bring about a desirable future

WRI Roadmap for a Secure, Low-Carbon Economy (Ladislaw et al 2009)

Using ‘pathways’ rather than an alternative futures approach can help to address some of the drawbacks inherent in other approaches. For instance, Hughes et al (2009) suggest that ‘scenarios’ are problematic because they often fail to give adequate recognition of the way in which technology interacts with social, cultural and political systems, and fail to identify actors and key social networks which engender change. ‘Pathways’ on the other hand seek to focus on the co-evolution of actors and technologies in transition processes (Hargreaves and Burgess 2009; Hughes et al 2009). Building on transitions literature, pathways

recognise the fact that technologies exist as part of a wider socio-technical network of interlinked and interdependent actors, markets, products, institutions and behaviours, and that transitions entail not only a new technology, but also changes in this wider socio- technical network (Berkhout 2002; Bijker 1995; Geels 2002; 2004; Hughes 1987).

It is recognised that it is not possible to predict the future, and as such, transition pathway studies do not aim to accurately model the future system. However, despite the

inevitability of such drawbacks, achieving a low-carbon electricity system necessitates a clear direction and early action to move in that direction, because decisions made today will impact upon the electricity system for a long time to come (DECC 2010a). Immediate choices must be made on the basis of a long-term understanding of the development of the system and the challenges and trade-offs involved. Thus transition pathway studies aim to contribute to an ongoing discussion between policy-makers, researchers and stakeholders, in order to better inform the debate about the ways in which the energy system might evolve as we move towards decarbonisation. As such, the use of transition pathways in this thesis does not aim to accurately predict the systems of the future. Rather, the pathways can be used as the basis for a discussion and an illustration of some of the key issues faced in transitioning towards a low-carbon electricity system.