Technological efficiency comes down to how well some means achieve some ends. Our underlying conception of efficiency greatly affects the development and evolution of technologies. To understand why, we need to ask: what does it mean to be efficient?

Before we can judge whether something was efficient, we first need to know the end we want to achieve. From this, we can develop a technology with some function that achieves this end. However, if the end was achieved in a horrendous way, we would not claim this technology to be efficient.

The qualifier for efficiency is not whether the task was solved—but if it was solved in a good way.

Should something be done fast? Or at low cost? Or with high quality? Or cleanly? Or regenerative? Or beautifully? Or silently? Deciding on some combination of qualifiers for efficiency lies at the core of achieving the intended technological functioning. However, we need to know more than the instrumental aim of the technology to make this choice. We need an idea of its purpose. First then it is possible to evaluate which forms of efficiency that are relevant.

At this instant, the technological question becomes a philosophical one. The task of defining a technology’s purpose precedes those of technical solution, physical construction and method of implementation—and thus affects all of them. In our study we attempt to analyze green technologies in light of their basic purpose to establish sound criteria to judge them by a kind of efficiency that agrees with the fundamental purpose of green technologies (Chapter 3 of the study).