Photovoltaics - Diagrams

Owned by Iris Reichenbach
Last updated: Dez. 10, 2020 by Artur Sartison
6 min read

The results of the calculation are displayed graphically and in tabular form.

The simulation can only be started if the design has been configured in the previous step. If this has not been done, a note appears that the design must first be carried out under the menu item "Plant".

An overview shows the general data of the plant. Here you can choose between the entire plant and the individual fields. The general data are divided into 4 areas:

Dimensioning

  • Total gross area [m²] - Sum of the module areas of all installed PV modules, either related to the total system or the respective field.
  • Total rated power [kWp] - Sum of the rated power of all installed PV modules, also related to the total system or the respective field.

Yearly results:

  • Yearly output / [kWh] 
  • specific output [kWh/kWp/a] - the specific yearly output is the ratio of the annual "output photovoltaic AC" to the "total nominal output".
  • Performance Ratio [%] - the performance ratio is the ratio of the useful output to the theoretical nominal output of a PV system

Own consumption

  • Own consumption share [%]: The part of the electricity supplied by the PV system that is consumed by the user. This can be used either to cover the household electricity or the demand of the systems, e.g. for heating rods or heat pumps. This proportion is 100% if no PV electricity is fed into the grid.
  • Self-sufficiency percentage [%]: The part of the total electricity demand that is covered by the system. With a self-sufficiency percentage of 100%, the entire electricity demand could be covered by the PV system and no connection to the grid would be necessary.

Solar Power Storage

This area is only displayed if a power storage device has been selected for solar power storage. The following relevant characteristics of the battery system are displayed here:

  • Nominal capacity battery [kWh] : the theoretical capacity or nominal capacity of the battery
  • Usable capacity of the battery [kWh] : the nominal capacity multiplied by the maximum depth of discharge gives the actual usable capacity of the battery. For example, if a battery with a nominal capacity of 10 kWh and a depth of discharge of 70% is discharged only as long as there are at least 3 kWh left in the battery. Therefore it has a usable capacity of 7 kWh.
  • Number of battery cycles [1/a] : How many times a year the battery is charged and discharged. This is relevant, because many batteries reduce their capacity after a number of charging cycles.

Overview

Here an overview of the total annual production of PV electricity is shown in two pie charts. 

PV power consumption

This shows where the electricity produced by the PV system over the year flows to. The segments of the pie chart are divided as follows:

  1. Own consumption direct: The electricity used directly by the PV system (after conversion in the inverter) to cover the household electricity or the electricity requirements of the system.
  2. Battery charge: The current used to charge the battery, if any.
  3. Grid Feed: The current fed directly into the grid, which cannot be used to cover the load or to charge the battery. 

Coverage of electricity demand

This cake chart shows where all the electricity required for the year comes from. There are the following three segments:

  1. PV- direct: The electricity used directly by the PV system to cover the load. This corresponds exactly to segment 1 of the electricity consumption diagram.
  2. Battery charging: This is the electricity that can be drawn from the battery to cover the load. This value is always lower than the battery charge in the power consumption diagram, because there are always losses during battery charging and discharging and therefore not all of the power used for battery charging can be made available again. 
  3. Grid supply: This is the electricity demand that cannot be covered by the PV system, but has to be obtained from the grid. 

It should be noted that the own consumption share shown above is composed of the own consumption directly plus the battery discharge, since the battery losses are not included in the own consumption share.


Diagrams

The results of the simulation are shown here graphically as a diagram. Both the temporal resolution and the type of representation can be configured:

Displayed period

  • a whole year
  • a certain month
  • a specific day of a selected month

Representation of the values - depending on the displayed period

  • Hourly average values
  • Daily average values
  • Daily total values

By clicking on a diagram, it is given the focus (colored background). Now you have the possibility to move it with the left mouse button pressed down. With the mouse wheel the resolution of the graphic representations can be increased and decreased. The button with the green arrow resets the zoom and shifting to the initial state. The button with the paper and the green arrow is used for CSV export. To save the individual diagrams as an image file, use the button with the image symbol and the green arrow.
The display of the results is divided into four areas:

Climate data [kWh/m²] 

the following "climate data" are generated from the coordinates of the selected location

  • Global radiation - sum of solar radiation on the horizontal plane per square meter. The diffuse, direct and reflected radiation is summed
  • Diffuse radiation - solar radiation that is scattered, diffracted, refracted, reflected or absorbed by the Earth's atmosphere before entering the Earth's surface. It is the radiation of light that prevails in overcast weather
  • Direct radiation - this is the direct radiation that prevails when the sky is clear.
  • Irradiation <name module field> - radiation intensity on the aligned and inclined module field.

Electricity generation [kWh]

  • Irradiation <name module field> - solar energy on the aligned and inclined module surface, which can (theoretically) be used for conversion into electricity
  • DC output <name module field> - electrical energy generated by the PV modules of the module field, taking into account all losses
  • AC output of the PV system - electrical energy produced by the PV system after the direct current of the PV modules is converted into alternating current by the inverter. This generated energy can be fed into the public power grid or used for own purposes
  • AC output <name module field> - Share of the module field in the AC output of the plant
  • Theoretical output <Inverter> - AC output without reduction by e.g. KfW 275 or other programs to reduce the maximum feed

Electricity distribution [kWh]

  • Load profile - output of the defined load profile, i.e. the house's own requirements calculated in the project
  • Grid supply Load coverage
  • Battery Discharge Load Coverage
  • PV Energy Load Coverage - Proportion of PV energy generated to cover the company's own needs. The electricity that still has to be purchased from the utility company to cover the load
  • PV energy grid feed-in
  • PV energy Battery charging

Battery state of charge [%]

The type of display is also available for all individual diagrams in this area:

  • Labeling
  • 3D display
  • staggered

Table

In the tabular overview, the simulated values are displayed as annual yield and in monthly values, regardless of whether the corresponding position in the diagram has been checked. The same positions are displayed as indicated under Diagrams.