General Information About Structural Optimization Components
A large number of components in TOP-Energy can additionally function as components for structural optimization. For these components, the button 
Optimize structurally is active in the Component Ribbon in the Features group (see the following figure). This button converts a component into a structural optimization component.
There are structural optimization components in the categories
- Combined Generation,
- Cooling Supply,
- Electricity Supply,
- Fuel Supply,
- Heat Supply,
- Renewable Energy Sources, and
- Steam Supply.
Structural optimization components can be identified in the scheme by the Overlay Symbol for structural optimization (see following figure).
Technical Input Data
In contrast to conventional components, Minimum and Maximum nominal capacities must be entered in the Technical input data of the structural optimization components. These determine the limits for dimensioning the design variables. Depending on the component, this is the nominal thermal or electric capacity, or the power rating (connected load) of fuel suppliers: for example, the electrical capacity of a CHP and the Electric power of an Electrical_Source, the cooling capacity of an Absorption_Refrigerating_System, or the Minimum and Maximum collector area of Photovoltaics.
The specification of a (positive) minimum nominal capacity does not necessarily mean that the installation represented by the component is really integrated into the optimized system. This is only reliably the case if the Installation mandatory option is selected (see the following figure).
Because the nominal capacities of the systems are unknown, the part-load performance must be entered as a relative characteristic curve. There, value 1 corresponds to the nominal power. The characteristic curve should connect the points (0.0) and (1.1). Therefore the first line always contains 0/0 and the last line 1/1.
Economic Input Data
Data for calculating the cost function are entered under Economic input data. Structural optimization considers only the Investment cost functions and not the fixed Investment costs.
Depending on the component, the Investment costs are entered as a function of the Nominal capacity, the Collector area (concentrating collectors), or the Nominal mass flow (steam generator). These costs are a key element of the objective function in the structural optimization. They play a decisive role in determining the result of the dimensioning. The definition range of the characteristic curve should at least cover the range between zero and Maximum nominal capacity (0,0; 1,1). The same applies to Reinvestment costs.
If you specify fixed Investment cost instead of an Investment cost function, these investment costs are included in the result independently of structural optimization even if the design parameters of the component are null, i.e., the component is not implemented at all. You should therefore always specify investment costs as an Investment cost function.
If you specify fixed Operating costs independently of the Investment costs, the operating costs are included in the result regardless of the structural optimization, even if the component is not implemented at all, i.e., the design value is zero (null). You should therefore avoid this input. The system size is calculated depending on the Operating costs per energy unit, operating hour, or Partial operating costs per investment, which are included in both the structural and operating optimization.
