## Torque tube inclusion

We're excited to introduce a new feature that allows users to include the tracker torque tube in their simulations. This enhancement enables more precise modeling by accounting for the structural components of single-axis trackers, leading to a more accurate simulation of rear-side shading.

**How?**

You can prepare this structural element using PVcase Ground Mount. Find more information here.

You can check whether the torque tube is actually included in the PVcase Yield simulations by opening the desired layout in the *Layouts & Electrical* section and looking at the *Layout preview*:

## Changes in Performance Ratio calculations

Our latest update includes a revised methodology for calculating the Performance Ratio (PR) of photovoltaic (PV) systems. This improvement focuses on evaluating the system's performance on the AC side, offering a more comprehensive assessment in addition to the pre-existing DC Performance Ratio.

**What is the Performance Ratio?**

The PR is a location-independent quality metric that represents a power plant's efficiency. It is defined as the energy effectively produced divided by a plant's maximum theoretical energy output when operating at nominal capacity and without losses. A value of 100% is impossible to achieve due to unavoidable losses; however, the higher this value, the more efficient the PV plant is.

In technical terms, the maximum theoretical energy output is given by the product of the * Irradiance at the plane of array (PoA) [kWh/m^2] * Total module area [m^2] * PV module efficiency [-]*.

In PVcase Yield, the annual Performance Ratio value is calculated and provided in two different versions:

**DC Performance Ratio:**with the energy effectively produced as the DC array output without MPPT losses divided by the maximum theoretical energy output.

**AC Performance Ratio:**with the energy effectively injected into the grid, divided by the maximum theoretical energy output.

For grid-connected power plants, the most common PR definition corresponds to our definition of the AC Performance Ratio.