# Evaluating the Effect of Financing Costs on PV Grid Parity by Applying a Probabilistic Methodology
## 2 Materials and Methods
### Costs of a Photovoltaic Installation
#### 2.1.1 Solar Modules  
In the past five years, the system costs decreased to as much as 25% of their initial cost [14]. From 2009 to 2014, the cost of the PV panels decreased by 75% [20]. In September 2012, the European Commission started an antidumping investigation into solar panel imports from China and their key components (wafers and cells). In international trade, dumping is defined as charging a lower price in an export market than is charged in the home country of the producer. It is seen as an anticompetitive strategy aimed at capturing market share in the export market using profits made in the domestic market. Companies that import directly from China, such as distributors, large-scale solar installers and investors, have to provide a bank guarantee for 11.8% of the customs-cleared value of the invoice from 6 th June to midnight 5 th August on all Chinese manufacturers, and between 37.3% and 67.9% from 6 th August, dependent on the Chinese manufacturer [21]. Due to current antidumping charges and legislation imposed by the European Union, it is not possible to assume a lower cost for Chinese-manufactured solar panels [22]. However, some manufacturers have moved factories out of the minimum import (MIP) cost area, and they are offering panels at a price below the MIP. So, the scenario considered in the present study of buying panels from these manufacturers is likely.  
The size of the installation directly impacts the cost of the panels. As a result of our benchmark, in May 2015, the cost per Wp to install a 6 kWp/5 kWn (PV panel peak power/inverter nominal power: 6 kW peak/5 kW nominal) grid-connected PV system mounted on a rooftp was 3 \(\upmu\)/Wp, and the cost of a single solar module was 1.5 \(\upmu\)/Wp. The solar module cost for a single solar module was around 0.8 \(\upmu\)/Wp in 2018. This means that the cost per Wp to install a 6 kWp/5 kWn grid-connected PV system mounted on a roof was below 2 \(\upmu\)/Wp. For a 50 kWp ground-mounted grid-connected PV system, the cost was 2 \(\upmu\)/Wp, and the cost of a single solar module was 1 \(\upmu\)/Wp. In 2018, the solar module cost was around 0.6 \(\upmu\)/Wp. This means that the cost per Wp to install a 6 kWp/50 kWn grid-connected PV system mounted on a roof top is below 1.2 \(\upmu\)/Wp. For a 500 kWp ground-mounted grid-connected PV system, the cost was 1.5 \(\upmu\)/Wp, and the cost of a single solar module was 0.8 \(\upmu\)/Wp. In 2018, the solar module cost was set at 0.4 \(\upmu\)/Wp, which means that the cost per Wp to install a 600 kWp/500 kWn grid-connected PV system on a rooftp was below 0.8 \(\upmu\)/Wp.  
The PDF used for the cost of solar modules is log-normal with a range between 1 \(\upmu\)/kWp and 0.2 \(\upmu\)/kWp, and, depending on the size of the installation (500 kWn, 50 kWn and 5 kWn), the mean is determined by the costs described above, set as the current-day cost. The choice of this PDF is suitable for representing the cost of a power generation installation [18]. In this case, taking into account that we only consider uncertainty in the cost of the panels, it is logical to use this PDF to represent its cost.