Space-Time of Solar Radiation as Guiding Principle for Energy and Materials Choices: Embodied Land Instead of Primary Energy as Universal Performance indicator

Abstract

Renewable energy is based on using a direct route from solar radiation to consumption, as an efficiency improvement from a long term route via fossils. However, both routes put a claim on space/land and the time of use of that land/space to intercept and convert it to useful forms. However, the same solar radiation is needed, to produce materials in a similar change from fossil materials to renewable materials, and materials are needed as well to produce the conversion devices for renewable energy. Similar processes take place in the realizing sustainable buildings, especially 0-energy buildings: : there is space time involved to generate the renewable energy, but also to generate for instance the renewable material based insulation materials, or the wooden construction. These insights lead to the notion that looking to production of renewable energy only is sub-optimization of systems, and could in fact be counterproductive. This has defined our r esearch to explore ne w ways of evaluation of activities, and in our case buildings. We have developed a indicator called Embodied Land, to evaluate the time and space occupied by generating both renewable energy and renewable materials. This has been tested in two cases, and runs out to be a interesting approach, showing clearly how the optimization of land and space use over a cer tain time period relates to choices in materials and energy together, and makes it possible to optimise from both resources together, using an minimum of land occupation.

Zero-Energy and Beyond: A Paradigm Shift in Assessment

“…First steps in that direction have been made already by Odum in the 1980s, known as the "Emergy" approach [25,26], and recently by our research group, known as the "Maxergy" approach using Embodied Land© as indicator. In this "Maxergy" project, materials (depletion and compensation) are introduced into the equation, with land use (to make "exergy" available via solar radiation) as the common denominator [27]. More work has to be done in this field.…”