The visualization shows how renewable energy production per capita (in kilograms of oil equivalent) evolves from 2002 to 2011 across OECD countries and the world. It uses a bar chart race, where each country is represented by a horizontal bar that updates its length and position over time. The code employs D3.js with `d3.forceSimulation` for smooth animated transitions of bar heights, and it reads the time-series data from the `renewable_energy.csv` file. The data source is the OECD, with values displayed as numeric labels beside each bar.