Hi,

How is Energy Credit cost calculated for grown plants? Factor in human labour Wattage per the standard and other machine costs and what? Sun radiance power? If yes, which figure, the amount of solar power radiated per square meter of earth's surface, the amount that actually penetrates the atmosphere, the amount that is usable by photosynthesis or the amount that is actually utilized by photosynthesis (due to the inefficiency of the process)?

Thanks.

LP,
Jure

I would count the sun light that the plant actually receives per a given area. About 96% of this light we can use. I would then add in the human labour another machine power utilisation.

This sounds like something interesting for experimentation.

ui

Dr. Andrew Wallace BEng(hons) PhD EurIng wrote:


Meaning the amount of sun power that the plant can utilize trough photosynthesis? The efficiency of photosynthesis for a typical plant where 100% is the sun power reaching the leafs is around 0.2%. Wouldn't this unfairly bias sunlight utilization via plants vs say photovoltaics which hovers around 20% (ok maybe these figures warrant further research, but essentially)?

LP,
Jure

Hey guys, just FYI, we (growtwain.com) are preparing the proposal for the local government and university to build a little structure to test the different agricultural solutions for the urban areas. I would like to include the testing of the EC as a part of the objective calculation of energy consumption and usage.

I will send you the proposal for the review soon as we have it done (next Monday).

Jure Sah begin_of_the_skype_highlighting     end_of_the_skype_highlighting wrote:


Now this is getting interesting. I’m thinking in terms of exergy, which the figures normally give as 96% of the incoming energy. I think I would try and put this forward to Göran Wall and see what he says.

ui

Rafal MSc. wrote:


interesting!

btw, I'm still looking for the algae book.

The more I look at it the more I think this way:

We have light coming in with X amount of energy of which we can utilise 93 % (of not 96 % as I said earlier). If the plant has 0.2% efficiency them we waste the remaining exergy. I think then the EC value should account for both utilised and wasted exergy.

Thinking about it more, that most of the exergy it goes into producing the plant so we have two exergy costs here; that the one for the fruit and for the remainder of the plant. That Bio mass we could use for other functions so the Exergy cost of the fruit represents the energy contained within the fruit.

ui

drats, I messed up this post! -AW

Jure Sah wrote:

This question gets to the root question of why do we use energy accounting. (When I write "energy", the term exergy mentioned by Andrew is closer to what I actually mean, although I'm not being rigorous in this brief reply).

In a society substantially dependent upon exhaustible fossil fuels, energy accounting acts as a mechanism to parcel out that resource in terms of time and consumers. Properly full energy accounting would measure upstream energy inputs to produce downstream energy. For example, the energy costs of a liter of petrol (gasoline) would include not only the exergy contained in the petrol, but the energy utilized to find the oil, develop the oil field, pump the oil, refine it and deliver it. As long as all of these activities are substantially powered by fossil fuels, our accounting system is sound. Once the energy is ultimately consumed, that's the end of it and the accounts are balanced.

Alas, Jure's question shows how akin energy can be to money in the price system. What is a consumer uses energy to create a device that outputs more energy (such as from sunlight or the wind)? An energy "profit" can result, and production and consumption are now out of balance! This "profit" (more properly called a positive Energy Return on Investment or EROI) raises important questions. In fully sustainable (technically, economically, socially), who should be entitled to this positive EROI and under what circumstances can be transferred?

If the consumer reinvests the energy profit in additional energy producing devices, an exponential growth in energy profit can result. If this profit (or "surplus" if you prefer) is transferred in a bargained-for-exchange, a debt can potentially arise. If the surplus is not accounted for, energy "inflation" could conceivably result.

The operational purpose of energy accounting is to make better decisions. Since we are just starting out, and NOT part of a large system, perhaps it is best to ignore the energy from the sunlight itself and merely consider BOTH the usable net energy output for purposes of accounting and the EROI when comparing this to other opportunities. (Once we really do get going, the energy from sunlight should be included for decision-making purposes beyond this discussion).

If you don't like these, a short-term approach to account for this energy follows (speaking economically, in addition to everyone's valuable technical suggestions). Determine the substitution value of the energy cost of the BENEFIT obtained. For example, what is the energy cost of the food or energy that the production from the algae system is replacing? I'm not enthusiastic about this approach, but it may be useful.

Sorry if this is rambling. I'm on a deadline elsewhere. Hopefully I'll have some time to delve into this further with you soon.

Jure Sah begin_of_the_skype_highlighting end_of_the_skype_highlighting wrote::


We have two sides to this. On one side the we have people interacting with the system and allocating energy credits the for the production of an item. On the other side, we have the experts who manage and maintain the system. Both sides require energy to operate. We can see the tomato as part of the people interaction side; an item that we produce. The plant then becomes part of the infrastructure needed to produce the tomato.

ui

Dr. Andrew Wallace BEng(hons) PhD EurIng wrote:


There are some very big open questions here. I find that my earlier work with Igor on this subject were based on the emergy model. I can accept that exergy is more suitable somehow as this is not exactly my area (I simply find emergy easier to understand), however these open questions will have to be addressed.

It's a little hard to see but just making an arbitrary separation between the people side and the technical side is terribly vague. How exactly will this look? What will determine who is where. How will we transition between this system and the one you describe?

The emergy model makes the answers a little like this: Every product is labeled with the energy that goes into it's creation, transitionally perhaps as an "Energy Added" value. When these labels are applied to products, an internet-based system collects this information to produce the total which is distributed equally into energy bank accounts of all the users. If a product disappears from availability, the amount is subtracted with a yet-undetermined mechanism ensuring no negative balances occur due to untimely spending while keeping the system free of spending-timing artifacts (it's a balance). On purchasing a product the energy total is input, as well as the total monetary cost if any, which finances in the EA and monetary sense the entire production process for that particular product, according to the costs incurred with it's production technology.

What do I have to change to make this work with exergy? Where does the social and technical side come in here?

Perhaps we can use something we have learned from the Technate we already have operating?

LP,
Jure

Jure Sah wrote:


This is where the fun starts

Working out all the details is what we aim to do here. So, try one way and then try another and see how it works.

Jure Sah wrote:


Hmm ... well exergy would measures the actual energy used. Other I would say much the same.

Jure Sah wrote:


We cold look at what does it take to keep and maintain the plant (technical side) and then what energy does the tomato contain (people side). But at the end of the day we want to look at different possible ideas and implementations and see what works. So, try a variety of possibilities and report back.

This looks good

ui

Dr. Andrew Wallace BEng(hons) PhD EurIng wrote:


True, but it'd be nice to have one to start out with.



However the model I have described for emergy has a substantially different layout: There the technical side are the people manning the production organizations and the people side is the "consumers". When a consumer invests his EC into a product, the organization uses a part of these same EC to "fund" the resources used and so forth down the production chain (because in emergy the EC cost equates the ultimate sum of input energy this works out) -- thus the consumer regulates the entire production chain automatically simply by acquiring desired products.

With exergy this chain does not appear possible and so you introduce a separation into the control mechanisms that ensure the resources which are needed are produced. Am I thinking this wrong? How exactly do you ensure the experts are working in the interests of the consumers and the other issues mentioned in relation to a centrally planned economy?

EDIT: During our original research with Igor we determined a problem even with this approach: Because the EC cost of the products does not cover for issues such as research, the organization was supposed to define the EC cost of a product to reflect their intended spending for research as well (a computer costs X, but a computer based on new technology costs X + N). This approach has some of the problems of the monetary system with arbitrarily set prices, however we had hoped that the mechanics of the system (people looking for cheaper products so they can have more for the same amount) would result in organizations setting realistic cost figures. Thinking of it now it is distinctly possible that this would not suffice either, but in either case finding out how to verify if the EC cost is being set realistically is a challenge to overcome. A standard-based (P&C) approach might even work with fixing some of the issues of the monetary system.

LP,
Jure

Jure Sah wrote:


same as always, goals and openness.

Jure Sah wrote:


yeap, so we end up back to the people and technical sides.

I think the EC value should equate to the actual exergy content of the tomato.

I will try and look and see if any1 has done any exergy calculations of this kind.

ui