The week 10 prac was punctuated by group discussions in the midst of individual work on energy sources and paired work between Edward and Peter on the Google Doc. Edward, while participating occasionally, often continued working alone when others talked. Physically, they were aware of each other’s movements: one student would turn towards the centre of the aisle and at least one other would turn to listen, with more students then joining in, turning their chairs and orienting towards the centre of the aisle between desks. Dave and Michael especially used the time in class to give an overview of what they found about their designated energy sources; a chance to put their case in their own words and gain other students’ acceptance of the information and point of view.
The knowledge work centred on the individual energy sources, with some discussion of the
combined solution. For a minute or two, up to around 10 minutes at a time, students worked silently at their own computers, but then would consult with one or more group members. Notable
exchanges are outlined below.
Dave launched the first discussion of their approach to the problem, with a negative assessment of his allocated energy source of biogas. The focus at this point was efficiency of the different energy sources. They arrived again at the same mix of energy sources they had anticipated at the beginning of the project (wind, solar and hydro-electric). Dave, who used yield information from a source he found online, explained his reasoning on biogas:
Dave: I did calculations on a population of 100,000. A city. If everyone’s waste went to the same place, I think it generated 120,000 megawatts per year ((Peter grimaces, others chuckle)) which is what a coal power plant produces in a day, so ((laughing)) not very helpful.
Peter: ((starts counting on hand again)) I think we should do wind, hydro, ()
Dave: I think if you have an unlimited budget, why not do it, because it’s (new). It’s good for the environment and stuff but you don’t have the budget, so what’s the point?
Later in the session, with Michael, Dave calculated further numbers on gas production from human waste (accompanied by scatological comments), clarifying the relative sizes of measurements in megawatts and kilowatts in the process. Michael extrapolated those numbers for the entire population of the earth and summed up:
OK, so you ready? There are 7 billion people in the world. ((puts in numbers in calculator)) 7 billion people in the world. Get it into the quantities (you have for 100,000 people) ((points to screen and inputs to calculator)) and divide that by the amount of power produced by those 100,000 people, which is 0.43% and then work it out for the entire population. 301% of one power station from the entire population. So three power stations could equal the energy of the entire population of the world.
Taking the calculations to an extreme confirmed to Michael that “It just doesn’t seem viable.” They related their calculations to the output of coal power stations, the implicit measure of the energy generation mode to be replaced.
Michael pointed out the lack of hot water springs for geothermal and Dave noted the lack of places to “do” hydro-electric. This exchange hinted at underlying issues of the economical and geographical constraints of acting for environmental good. Similar issues were touched upon during the project but not necessarily covered more deeply or situated in a wider context.
All four students joined in a discussion about the mix of different sources for electrical generation, and alternative sources for electrical energy. Dave’s first statement indicated an initial misreading of the energy output for biogas—he had thought it ten times more than the actual output:
Dave: … It’s not the greatest, I’m not gonna lie.
Michael: No, that would be enough to power a couple of light bulbs ((Peter laughs)) Dave: A year, you’re going to need ((stops))
Michael: We’re going to need a lot of cows!
Dave: Basically, you’re better off not wasting biogas on electricity generation. It can be used instead of natural gas. You’re better off using it for cooking,
Peter: or heating
Michael: Maybe we can do that, only use it for heating. Though I’d prefer to use geothermal. Peter: Though we don’t have much of that
Dave: Though it would be good in New Zealand ((they laugh))
Michael: Maybe a combination of the two for heating and a combination of you guys for the rest? The other group members supported Dave’s conclusion that biogas was better used for heating, after his outline of its lack of efficiency as a fuel source for generation of electricity. He further validated the use of biogas soon after by noting that burning it “does release CO2 but it is far less volatile I guess a greenhouse gas” than “methane ((dramatic hand gesture upwards)) which is destroying the environment apparently in landfill.”
They were still making sense of the task instructions at this late stage:
Dave: ((leaning forward, elbows on knees)) Is the project asking for electrical or (all energy) Michael: Or just electrical energy?
Peter: ((turning back after looking at computer screen for the task description)) Well, it’s a bit vague. Michael: We’ve gotta become geothermal, ((corrects mis-speak)) we’ve gotta become carbon neutral. Peter: Hmm.
Michael: That means all energy so, everything really.
As they noted, the task did ask for a solution to total energy needs, but was vaguely worded, with specific mention of the “power grid / distribution.” In the context of ambiguous instructions, a statement of the problem beyond the assessment wording, that is, “we’ve gotta become carbon neutral,” brought a holistic perspective. This led to Peter reiterating Michael’s earlier suggestion of dividing between heating and “the rest”:
Peter: So how about you guys focus on using that, like any (heating) and we’ll ((indicating self and Edward)) focus on power generation.
Michael: Yep, and when I’ve done that I’ll work on stuff for Kevin. He’s doing wind again isn’t he? Dave’s information on biogas and the resulting discussion had helped the students engage with the problem, organise themselves and agree on some direction for the report.
Michael pointed Peter, who had rolled his chair over beside Michael, to his screen displaying a page from the Australian Geothermal Energy Association site20.
Peter: ((after looking at the page)) EGS
Michael: EGS. Which is they basically create a reservoir of hot rocks, hot rocks underneath the earth and they pump water through them () ((Edward briefly looks over at Michael and Peter))
Peter: So they’re doing that in Australia?
Michael: They’re looking for, they are looking to, but there is like only one place they can do it ((reads while pointing to screen)) ‘Most companies mmmm ((mumbling)) proof of concept mmm before full scale development forthcoming provide power in 2010.’ But it’s updated 2015.
Peter: OK
Michael: ((humorously)) I’d say they failed!
Peter: It’s interesting though (.) cause Australia doesn’t have much volcanic activity. It could be uranium and radioactive decay.
Michael: Yeah. That’s from the centre of the earth, that’s how geothermal is done. Peter: That and volcanic activity. I mean, volcanic activity is the cause of it.
Michael: But, yeah. I dunno how much to believe that. ((indicating the web page)) Peter: See if you can find another source, so you can cross-check
This conversation showed again a personal understanding of what geothermal energy requires— Peter’s explanation of volcanic activity or radioactive decay as the cause of geothermal heat, and Michael’s heat source as the “centre of the earth.” The suggestion to find another information source to “cross-check” showed concern with verifying information and its sources: the dates on the site had shown it was probably poorly maintained. The content on the page did not strictly support Michael’s statement that “there is likely only one place” for this type of energy generation. Michael also later stated, “I’m starting to think geothermal will produce more waste than nuclear” and read a list of chemical emissions from a page on his screen, ‘Environmental Impacts of Geothermal21’.
Despite the article stating that the emissions from geothermal energy were much lower than some other energy sources, Michael concentrated on the list of toxic byproducts, concluding “We’re all screwed if we use geothermal.” Michael later shared further information from a government website22 with Peter and Dave, reading out loud that “geothermal energy shallower than five
kilometres and hotter than 1500C could supply Australia’s total energy requirements for 26,000 years,” saying “That seems to contradict everything that I’ve read.” They speculated that perhaps it was unfeasible to dig that deep, but Peter cited a borehole in Russia that was drilled to fifteen kilometres.
In another example of personal understanding, Edward and Peter, when talking about biofuels, agreed that carbon neutrality as Peter expressed it, “means that the amount of carbon that it produces ((gestures with left hand)) is the same amount as it takes in ((gestures with right hand)),” echoed by Edward, as “It’s only producing the amount that it is going to take away.” Later in the session, Dave explained how methane gas, for volume of emissions, had a very high proportional effect on global warming. This led to exposition on the carbon cycle and carbon neutrality:
Dave: So that’s the thing. You’re better off honestly the amount of carbon dioxide you produce is kind of, it’s not like you are getting it out of the ground. Cause originally it was that carbon dioxide was photosynthesised or something like that, or breathed in or whatever by plants which would convert to oxygen so it’s kind of like still part of the cycle ((circular hand gesture. Voice - upward inflection)) I guess
Michael: Yeah, kind of
Dave: I guess. So it’s kind of carbon neutral (if you put it that way). If you pull it out of the ground ((plucking gesture)) and burn it it’s carbon that shouldn’t be put into the air, ((Michael: yeah)) whereas biogas is kind of a that’s why they call it carbon neutral.
Michael: ((turning back to own computer)) Yeah, rather than carbon non-existent. Carbon extinct. The various concepts of carbon neutrality were not checked against an authoritative definition. However, in combining personal understandings with selective sources of information, and despite some mis-readings, the students were working towards an understanding of energy sources and related issues.
21http://www.ucsusa.org/clean_energy/our-energy-choices/renewable-energy/environmental-impacts-
geothermal-energy.html
5.2 Nuclear group
(KC2 - Whole group shared knowledge creation)
This group of three—Quinn, Sam and Jessie—chose the same assessment task as the Renewables group, “Renewable energy solutions for Australia,” however, investigated only nuclear generation. The Nuclear group was notable for being made up of members of a larger engineering study group that had been meeting since the previous year, and for the collaborative way in which they worked and wrote their report. This pattern of work seemed to be one they had developed in the study group. They did not tend to work individually during pracs, but discussed content and structure, often sharing a screen or working on the same document simultaneously. They used a shared Google Doc from initial dot-pointed notes through to the final report, adding notes from discussions and sources as they went.
The information and sources for the project were found as they worked together as a trio or duo. Nuclear energy was addressed as a technical issue, with little regard for the surrounding political and environmental issues, although the group built some awareness of these. In dealing with an
experimental technology, the group found it difficult to answer the task’s question of practical application of the energy source.
5.2.1 Object diagram
The diagram of objects of the Nuclear group (Figure 32) shows a steady shared development of knowledge of the physics and practicalities of nuclear energy production. Much of the knowledge work was completed as a group, added to a shared Google Doc, and the crowded detail in the diagram represents the very collaborative nature of the project. The diagram shows an ease with online contributions, but an emphasis on in-person collaboration for most of the project. The work on the report on the Saturday and Sunday of week 10, conducted wholly online using Google Doc and Skype, continued conceptual development, combined with peer review of sections. On that last weekend, students sometimes worked individually, sometimes with one or two other students simultaneously editing. Jessie’s recurring interest in questions such as whether they should cost the construction of mines and reactors, and the big picture of providing energy are connected by lines marked with (a). The group took some time to amass research and concentrate on just fusion. This process is highlighted by lines marked with (b) and was led by Quinn, who initially directed the project towards both fusion and fission, then changed to fusion alone.