From Tetra Materia, to Trias eXergetica 2/2

The Tetra Materia (see previous article) approach might be useful for practice, its not the whole story. It guides direction, but does not set targets. And our system has an overall limit as well. Materials, even renewables, come exclusively from within our own system, while (renewable) energy is available in large quantities , without the risk of depletion,

Therefor, materials are the system-critical issue. And just a little bit less is not enough, we have to manage our resources in cycles, otherwise it ends somewhere. A materials cycle ( or continuous flow) are characterized by 4 properties: The kind of source , the volume/mass, the speed of use and the energy to drive the cycle, to process and use materials (Which in turn are materials as well, to harvest renewable energy sources) .

Which turns , on building level in another four mains steps:

  1. close the cycle: on possible with resources that can be regenerated.
  2. 2) reduce volume/mass in the cycle : limit demand, limit use, use less resources for the same function, sometimes with a change for services in stead of products
  3. reduce speed in cycle: prolong the lifespan of products, low maintenance design, repairable, which provides more time for resource to regenerate ( or to be regenerated)
  4. limit driving energy : use of local materials, low tech applications, local labor, system innovation and re-organization.

Which brings us a few steps closer to a real sustainable and maintainable management of our resources. But not quit the end. If we really want to operate within closed cycles, there are some other considerations to address: In the first place: If the materials used are renewable, then thats fine, however crucial is that it is really renewed! Otherwise its a loose claim. And renewing resources is bound to a maximum, since the earth is a limited and finite system.

There is another important observation: There is in fact no distinction between energy and materials: both resources use should be limited, and both should be from renewable origin, or at least should be renewed.. You can express materials impacts in energy, since its all energy which is required to treat and renew materials, to bring them in a closed cycle modus ( think of solar energy to make a hectare forest (re)grow. ( See circular Energy [1]). Even if its renewable energy or labor, we want to limit that use, we cant build windturbines forever, it would ruin our material base..

Therefor, a optimization of cycles also requires that as little as possible renewable energy is need, to provide a function ,to transform materials, and keep cycles closed.

Energy and mass are in fact two of the same kind: energy is sometimes referred to as rest mass, and vice versa, mass as rest energy. Those two are inextricably linked, you can not actually treat them separately from each other. It is about the potential of a system, whether it is a hectare , a city or a country, its what about can be produced within that system: with energy, and for food or material, and its closely interwoven: one hectare can yield x kg potatoes, or y kg of wood, both from direct solar energy. Some of it will have to be converted into energy for harvesting or processing other resources. Or to build energy conversion systems, such as a wind turbine (and yes it can also be made from renewable material, see the German wooden 2 MW turbine, Incidentally, the same applies to fossil energy, that originates also from a hectare of biomass. We never include that conversion step into our calculations. Which gets very annoying now ….

Energy and raw material are condemned to each other. So the question is in fact what can be harvested up to a maximum of 1 hectare (or: can be renewed), in random or desired combinations. Of course more is impossible , because then we go beyond the boundary of the system: either by exergetically exhausting the system itself, by burning fossil resources (with system changes as a result, as a result of which we may not survive), or by going to the neighbors, to borrow, or to steal, as we did in the past (?). But they will have the same problem. And globally, as a system, it stops there: neighbors are no longer available. So there is a maximum, whether in a small system , or in the whole world is not so relevant. Which requires us to formulate a trias or tetra that stays within that maximum. A Trias Exergetica: Exergy as the measure for what can be withdrawn from a system on an annual basis as a maximum, to bring about change: The Energy is not lost, but becomes unusable, like heat assumes the ambient temperature, no further change can be obtained from it, though there is still energy. * The same applies to materials: Materials are not lost, the higher the concentration, the more potential to fulfill a function. This decreases as the raw materials degrade and are dispersed or diluted (as dust). Only to be upgraded again by adding energy (making burnt clay brikcs from erosion dust, for example) and will consume increasing amounts of energy as the dust is more dispersed or diluted. So the exergy increase of one resource requires exergy destruction of the other. (The other way around as well: energy can be upgraded by the use of materials, in other words the degradation of raw materials potential sacrificed to top up energy) (see also article on the material cycle)[2]

That is the connection between the two, with a maximum exergy potential determined by what comes from outside our earthly system (or from our hectare, as converter of solar radiation). The smarter we use this potential (directly, without the use of materials), the more effective we are. ( the more ‘change’ we can create, the more we get out of it exergetically).
Thus we automatically stay within cycle limits (apart from additional requirements from maintaining biological balance).

But then we have to turn around our way of arguing: not improving from the point of view of a limited application (‘reduce’ and so on), but from a maximum system viewpoint: What is possible within the system evaluated. Whether that is a construction site, and city or region or country, or ultimately even the earth as a whole, the system has a maximum. That is also true of what the future brings us: the world is becoming overcrowded, and countries are becoming more and more self-reliant, simply because we run out of foreign countries to deplete, those countries will need their own resources, and there is nothing more to ‘steal” , at the neighbors, at most here and there we could swap some resources. You already see it in ‘ America first’ , The Chinese focus on the domestic economy, the English who want to mind their own business, and in many other places.

So not try to improve what we are actually doing, as with the trias energetica or tetra materia, assuming a need or product, but we must start arguing and calculating from a limited system, a hectare, a city, or a country, and determine the maximum potential ( exergy) within: That which can contribute to development (energy and mass with potential to bring about changes) without exhausting the system. In other words: We have to formulate a Trias Exergetica , with the following three steps:

1 Determine maximum exergetic potential within considered system / area (with regard to resources)
2 determine the desired (converted) optimal distribution over the resource yields water, food, material and energy that is usable for humans.
3 (re) organize functions within system area in such a way that maximum use is made of those sources, but also no more than that.

Only then we have a integral approach, of material and energy combined, working in a circular way, at a level maintainable into the future . Land availability will play a key role, taking into account biological boundaries, might be obvious by now: Land as a conversion system for usable amounts of food, water, material and energy. But also obvious is that the potential is limited to this.





* its about end-use energy, and end-use mass,which are in fact the ‘working fractions’ of energy and mass, the fractions that create change that people directly profit from.

Author: ronald rovers