Accurate Allocation of energy in production processes - the importance of using metamodels

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Example graph based model with CHP and hot water conversions Source node Electricity grid connection Distribution node Electricity Sink node Building product line 1 Source node Wind turbine Conversion node Combined heat power Sink node Building product line 2 Source node Natural gas grid connection Distribution node Natural gas Conversion node Hot water boilers Conversion node Hot water Source node Water grid connection Distribution node Water Sink node Building product line 3 Figure 3: Graph-based model example. As is immediately clear from the picture above, a graph-based model is not restricted to the one-on-one relationships between a datapoint and the entity it belongs to. Interpreting total energy consumption that went into a batch on product line three, for example, is now possible as the model can trace back meter data on how much electricity (and from which sources) was used, which fraction of natural gas was used - both for heating water and for generating electricity - and how much water went in. The efficiency of the hot water distribution and the combined heat-and-power (CHP) plant is readily available from the meter readings and can be taken into account as well. Do note that hierarchical models can be seen as a less complex instance of graph-based ones. In a process where no energy sources are combined or converted, every step gets only one input from its predecessor. There would be only one arrow arriving at each node - which is the conceptual equivalent of the datapoint/node belonging to a single category. Static vs. versioned models A second perspective is to distinguish between static models on the one hand and versioned models on the other. The few software packages we found to have been built around metamodels in the first place, were all based on static ones. The word ‘static’, however, does not necessarily mean the metamodel cannot change - indeed, one or two of the packages did offer (limited) options to adjust the configuration of datapoints/ meters that are fed into the program. They are still ‘static’ in our vocabulary, however, as they lack the essential feature: they do not track the changes that were at the basis of the change in the model. There is no way to uncover the alterations to the structure of the energy flows, to the company structure or to the positions of key people. There are, in other words, no pathways that 14
logically link the old and the new model to each other. The lack of pathways is a major impediment for energy reporting in complex and changing organisations. • Trend data are no longer meaningful after a change. The information being reported - and the conclusions based on it - may or not be about the same entities or processes as before. The model itself will only allow for interpretation based on the configuration based on the new situation, even when the bulk of the trendline is based on data being collected in the old situation. The issue is further compounded when several, consecutive changes occur - each time wiping out the meaning that could have been given to older data readings. • The allocation of consumption or costs to entities, loses its value as a management tool. Whether the goal is to track performance, draft department P&Ls, do accurate cost accounting or inform CSR policy, the information gained from a changed metamodel can no longer be put to use the same way as it may no longer cover the same underlying elements. Versioned models offer a solution. They are essentially a series of timestamped metamodels, each of which has been valid for a given period of time. Whenever a change occurs, the old version gets archived with the appropriate time stamp and the new one is generated. In addition, the links between the previous and the new model are made explicit. This means each new, changed or altered datapoint must be highlighted as such; get its place in the overall structure and have its relationships with other datapoints defined. Examples include fitting an extra meter in a given process or adding a new building to an existing department. Do note that a versioned model is a generalisation of a static one much the same way a graph-based model is a generalisation of a hierarchical one. As long as there are no changes to the underlying energy or company structure, the versioning does not come into play and the model is identical to a static one. 15
Page 1 and 2: Condugo Accurate allocation of ener
Page 3 and 4: Many companies struggle with correc
Page 5 and 6: Market drivers impacting energy man
Page 7 and 8: A brief history of energy managemen
Page 9 and 10: What exactly are metamodels? ‘To
Page 11 and 12: Position of key people and responsi
Page 13: Hierarchical vs. graph-based metamo
Page 17 and 18: A detailed graph-based versioned me
Page 19 and 20: 2. Allocating shares to sinks and c
Page 21 and 22: Sink nodes represent the internal c
Page 23 and 24: associated with an acquired commodi
Page 25 and 26: Not all companies have the same nee
Page 27 and 28: Condugo is a young company - founde
Page 29 and 30: Metamodels are starting to show up

Accurate Allocation of energy in production processes - the importance of using metamodels

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