Energy Balance
The energy flows of an energy system are balanced in the components, transferred to the Variant analysis, and displayed there in processed form.
After successfully completing the simulation, the mass, energy (enthalpy), and exergy flows can be displayed in the form of a Sankey diagram.
The Variant comparison covers the energy balances of up to four energy system variants recorded in the Variant analysis nodes.
The Result time series, which reflect the energy balance of an individual component or the energy system of an entire scheme, can be opened automatically in the ETA. All incoming or outgoing energy quantities converted in the scheme or in the component–depending on the selection of the element in the project explorer–are displayed in stacked plots sorted by energy form. When selecting the scheme, all incoming or outgoing energy quantities converted in the scheme system are displayed (see following figure).
Select the component or scheme in the Project explorer and invoke the function with the 
Result time series button in the Home ribbon or via the context menu entry 
Engineering Time Series Analyzer → Open energy balance time series in ETA in the Project explorer (see following figure).
Energy Data in the Technical Components
Essential data of the energy balance of an energy system are stored in the Input and Output data forms of the technical components.
Input Data
In the Input data of the technical components, the power limits are defined. This applies, for example, to the maximum power supply in the suppliers and to the nominal capacities and efficiencies in the conversion plants. As a rule, time series, such as an electricity or a heat load profile, are stored in the demand components.
During the simulation, the operation of the energy conversion plants is calculated on the basis of the energy balances in such a way that the respective demands of the energy system are covered. Here the respective power limits of the suppliers and conversion plants are taken into account. TOP-Energy calculates the ideal operating modes in a system with degrees of freedom by optimization during the simulation process.
Output Data
The Output data of the technical components each contain their own Energy conversion form, in which the incoming and outgoing energy flows are displayed.
For suppliers, the final energy supply (e.g., by the Electricity supplier Supplied electric power) and, if applicable, the feed-in (Consumed electrical power, see following figure) are displayed.
The Technical output data also contain the incoming and outgoing energy flows. In the case of conversion systems, e.g., CHP, for example, the energy flows resulting from the efficiencies and the part load behavior can be viewed. In the Technical output data of the demands, the Consumed power of the respective form of energy is displayed. The Technical output data of the suppliers contain the Supplied power (Electricity, Cooling, Heating, and gas Suppliers) and the Consumed power (Electricity suppliers).
Energetic Evaluation in the Variant Analysis
The Energy balance has a separate tab in the form of the variant 
node under the Start year tab (see following figure with the Energy balance of the Demand for electricity).
An Energy balance form is organized by headings and broken down into the following energy sources and forms of energy if they occur in the variant.
Each form of energy and each energy source can be subdivided by further sub-headings, e.g., Electricity can be subdivided into Demand for electricity, Power supply, Feed-in into the power grid and Purchase from the power grid. Heat losses to the environment are not displayed in the energy balance of the Variant analysis. Therefore, there is no subheading for the environment (fresh air). Only the forms and sources of energy present in the system of the variant in question are listed.
The Start year form contains the information on the start or reference year, even if no additional support years have been specified. When using the scenario manager, there is also a separate sub-form for the Energy balance of the support year under each Support year tab (see following figure).
The data of a Variant analysis node refer exclusively to the energy system of this Variant analysis node.
Energy Balance in the Variant Comparison
To compare up to three variants with a reference case, the data from the Variant analysis nodes are transferred into a 
Variant comparison node. The Variant comparison also compares the Energy balances transferred from the Variant analysis nodes in tables under the Energy balance tab. Each energy source and each form of energy appears on its own subform (see following figure).
Export
The Excel export of the Variant comparison calculation contains detailed balances of the individual energy sources and forms Electricity, Fuel, Heat, Cold, Steam, and Compressed Air.
