International Environmental Technology Centre 



Sustainable Assessment of Technologies MethodologyWhen making decisions on investments, economic considerations often takes precedence over environmental and social factors. This may lead to unsustainable decisions and investments. Based on this observation,

  • The importance of the promotion of environmentally sound technologies (ESTs) in the context of sustainability was recognized in 1992 by the United Nations Conference on Environment and Development in Rio de Janeiro, Brazil.

  • The necessity to develop a technology assessment framework that takes environmental and social as well as economic aspects into account was identified.

In response to these needs, IETC developed the SAT methodology through a process of research and consultation with international experts. This methodology provides a framework for the selection of technologies that will best provide a solution to a given problem, from combined economic, social, environmental and technical perspectives.

The SAT methodology aims at providing decision makers with the right analysis to select the appropriate technology:

  • To address a specific issue
  • In a given geographical and social frame
  • In the context of sustainability
  • While taking into account all criteria surrounding the issue, which can be:
    • economics
    • social
    • environmental
    • technical

The first steps of the methodology consist of:

  • An analysis of the situation
  • The setting of clear, measurable targets
  • The identification and consultation (usually through a dedicated workshop) of key stakeholders for each criteria (economics, social environmental, technical)

Then,  a wide range of available technologies are assessed against the criteria, in a four stages process.

Sustainable Assessment of Technology (SAT)

Throughout the entire process,  the regular consultation and the implication of key stakeholders for each criteria (economics, social, environmental, technical) is essential to a successful application of the SAT methodology.

The SAT methodology can be applied at two different levels:

  • The strategic level, at which root decisions are made about the technologies that will be used.
  • The operational level, at which end the very technology that will be used in the field is decided upon, together with technical details.

A concrete example: SAT for waste agricultural biomass in Nepal

The Madhyapur Thimi municipality in Nepal took up a project for the conversion of waste agricultural biomass (WAB) into material and / or energy resource. The SAT methodology was then applied to identify the best fitted technologies for this purpose.

A survey was first conducted in the project area to determine the availability of WAB, its quantification and categorization, as well as to identify the current waste management systems in place. It turned out that the WAB quantity was 3,932 tons per annum, and that it was composed of rice straw (22%), wheat straw (4%), waste vegetable (55%) and rice husk (19%). Rice straw, husk and wheat straw have commercial value and were then sold, some other WAB were burnt in the fields and only the waste vegetable were used for composting.  

A consultation workshop was held, gathering various stakeholders of the project: local governments, political parties, community representatives, local chamber of commerce and industry, representative of the local agricultural and industrial sectors. Together, the participants identified key targets for the technology to be put in place:

  • Environmentally friendliness
  • Financially profitability
  • Ability to utilize agro-waste from domestic sources
  • Possibility to utilize waste from forests
  • Minimal space use as the price of land is increasing
  • Simple technology not requiring skilled labor

After the screening stage, three technologies were selected: briquetting, gasification and biomethanation. The other technologies considered (densification for use as cattle food, electricity or ethanol generation, strawboard manufacturing) were discarded as they could not fit the criteria defined during the stakeholders meeting.

During the scoping and detailed assessment stages, these three technologies were assessed using the weighted score method against a range of criterions: a weight was affected to each criterion; each technology was evaluated against each criterion. The total score obtained by the technology was the sum of its score against criterion factored by the criterion’s weight.

The criterions were “Low on air pollution, “Low on odour”, “Proven Technology”, “Can use all types of WAB”, “Provides additional economic benefit”, “Social acceptance is high”, “Additional processing needed”.

A final ranking, together with a complete analysis of the solution, was then provided to the Madhyapur Thimi municipality for decision. Biomethanation was recommended over briquetting (2nd) and Gasification (3rd) as it fared better, on a weighted average basis, against the above mentioned criterions.

Sustainability Assessment of Technologies (SAT)

The methodology of sustainability assessment of technologies (SAT) has been developed to assist decision-makers in selecting appropriate technologies from several options. The methodology is very flexible and can be applied across a wide range – policy level macro decision making to project level micro decision making. The methodology is being tested in different IETC projects and will soon be published.

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