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

commodity costs, like depreciation costs, operational costs and maintenance,
to the internal customers. A graph-based model which includes commodity
conversions will be very helpful in implementing this application.
All in all, three steps are needed to correctly allocate commodity costs to a
company’s internal customers.
Assigning cost centers
The first step in building a cost allocation application model is to assign cost
centers to all nodes in the graph based model. Four types of nodes exist in
the graph model: source nodes, conversion nodes, distribution nodes and sink
nodes.
Source nodes apply to acquired commodities on the one hand and locally
generated ones on the other (e.g. electricity from wind turbines or solar plants).
For acquired commodity types the monthly invoices will be assigned to their
cost centers. For locally generated commodity types, the depreciation costs,
operational costs and maintenance costs will be assigned.
Conversion nodes are used for industrial installations which convert one or more
commodity types into others. A typical example would be the conversion of
natural gas into heat, which is distributed across the site via a pipeline network
of superheated pressurized water. The costs for the conversion installation like
depreciation costs, operating costs and maintenance costs are assigned to
their cost center.
Distribution nodes are used to bundle all the sources of a single commodity
type and distribute the commodity among the other conversion, sink or
distribution nodes of the same type. Even when distribution nodes for the
same commodity type form a hierarchy, cost allocation is no problem as long
as all the distribution nodes of the same type have the same cost center.
Depreciation costs and maintenance costs for the distribution network on the site
can be assignedtotheircostcenter. Typicallythedistributionnodewillalsodealwith
lossesin the distribution network which represent a cost. These losses will be
distributed to the sink nodes according to their usage, ensuring these loss costs
will be assigned to the internal customers automatically.
For example a site converts natural gas and water into steam. This steam is
distributed over the site via a pipeline network. This pipeline network represents
an investment which is depreciated on a regular interval and will also require
maintenance. Pipes corrode and need replacing or valves break down and need
replacement as well. Tiny leaks in the pipeline network cause pressure drops
and represent losses. All these costs are addressed by the distribution node.
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