Editing IPCC:AR6/WGIII/Chapter-16 (section)

==== 16.2.1.4 Technology Readiness Levels ====

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Technology readiness levels (TRLs) are a categorisation that enables consistent, uniform discussions of technical maturity across different types of technology. They were developed by the National Aeronautics and Space Administration (NASA) in the 1970s ( [[#Mankins--1995|Mankins 1995]] , 2009) and originally used to describe the readiness of components forming part of a technological system. Over time, more classifications of TRLs have been introduced, notably the one used by the European Union (EU). Most recently, the International Energy Agency (IEA) extended previous classifications to include the later stages of the innovation process ( [[#IEA--2020b|IEA 2020b]] ) and applied it to compare the market readiness of clean energy technologies and their components ( [[#OECD--2015a|OECD 2015a]] ; [[#IEA--2020b|IEA 2020b]] ). TRLs are currently widely used by engineers, business people, research funders and investors, often to assess the readiness of whole technologies rather than single components. To determine a TRL for a given technology, a technology readiness assessment (TRA) is carried out to examine programme concepts, technology requirements, and demonstrated technology capabilities. In the most recent version of the IEA ( [[#IEA--2020b|IEA 2020b]] ), TRLs range from 1 to 11, with 11 indicating the most mature (Table 16.2).

The purpose of TRLs is to support decision-making. They are applied to avoid the premature application of technologies, which would lead to increased costs and project schedule extensions ( [[#US%20Department%20of%20Energy--2011|US Department of Energy 2011]] ). They are used for risk management, and can also be used to make decisions regarding technology funding, and to support the management of the R&amp;D process within a given organisation or country ( [[#De%20Rose--2017|De Rose et al. 2017]] ).

In practice, the usefulness of TRLs is limited by several factors. These include limited applicability in complex technologies or systems, the fact that they do not define obsolescence, nor account for manufacturability, commercialisation or the readiness of organisations to implement innovations ( [[#European%20Association%20of%20Research%20Technology%20Organisations--2014|European Association of Research Technology Organisations 2014]] ) and do not consider any type of technology-system mismatch or the relevance of the products’ operation environment to the system under consideration ( [[#Mankins--2009|Mankins 2009]] ). Many of these limitations can be eased by using TRLs in combination with other indicators such as system readiness levels and other economic indicators on, for example, investments and returns ( [[#IEA--2020b|IEA 2020b]] ).

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