Simulating a PV Power Plant

There are many aspects that can be interesting about simulating solar power. People who develop or manufacture solar cells have an interest in simulating them. And people who plan or monitor entire power plants have an interest in simulating those. While at first glance it sounds like those simulations could be combined or used together, they are usually not. So we thought it might be fun to create simulations for different aspects of a power plant and combine them as good as we can. So here is our idea.

We imagine a pv power plant. Usually that means we come up with plant parameters like its location and orientation. We have some background in pv power simulation and we usually do that using pvlib. When simulating the power, we do not actually get to see the plant, but since we think that would be an interesting aspect we want to do this as well. Therefore we create a scene in cinema4d, where we model a pv power plant and simulate it for a day. This is what we call the environment simulation, we see shadow effects and we can observe the actual plant. And lastly we want to add a third simulation. A while ago we saw a talk on a solar cell simulation software, Griddler. Back then we thought it was very interesting, but since we don't work with solar cells, we never got to do anything with it. Here is a picture showing all the simulation tools we are using including the sources for our 3d scene and how we connected them.

First we went on turbosquid a site for trading 3d models. While they have many models of PV modules, we decided to make our own and simply use theirs as inspiration. We found a polycrystalline solar cell texture from textures.com which we used for our module model. Next we created a power plant from our module and placed it on a meadow. To make the scene more interesting we also downloaded a tree model from turbosquid and surrounded our plant with some nice vegetation. Cinema4d comes with a sun simulation, that allows you to define a location by geocoordinates and a timestamp. The sun will then behave like it would on that time at that location. We placed our imaginary power plant close to Colmar, France on August 26th 2019. The modules have a tilt angle of 45° and are oriented south-ish. Here's a render of our plant at 11 am. Also we are aware of tools that are more appropriate to simulate shading like e.g. radiance.

Our next method of simulating the power plant is through pvlib. The basic parameters of our plant like, orientation and location are already defined in the cinema4d render, so we could start by creating clearsky irradiance for that day. What we're still missing before we can simulate the plant is temperature. We looked up temperatures for colmar that day online and upsampled them to the right resolution.

Our inputs for the pv simulation were global horizontal irradiance and ambient temperature. We choose some module and inverter type for our plant and used pvlib to simulate the pv power. In order to align the simulations we created an animated plot showing both the power and temperature curves. From the environment simulation we knew when the plant is in shadow, so we added that information to our power simulation by tweaking the direct irradiance for those timestamps.

Last but not least we used our third method of simulating the power plant, Griddler. When defining our solar cell we looked at the solar cell texture we had used before and defined a cell similar to that. Here's a picture of the texture and the griddler configuration:

We simulated our solar cell for different diode voltages and compiled the plots into a video. Finally we took our three simulation results and combined them into a single movie. While the simulations are not really connected, the resulting video gives an impression of how a full simulation with respect to all aspects from cell to environment could look like. Our code and project files are on our github. Here's our final result: