A recent thesis published by the Swedish Uppsala University has questioned whether the rapid expansion of renewable energies enables them to be sustainable. The study found that if the materials being used to create the renewable energy technologies themselves are not sustainable, then inherently it is not a renewable energy. 
The thesis was published by PhD student, Simon Davidsson, whom articulated that the key factor to ensuring energy expansion remains sustainable is to have regard for the materials being used and whether these are actually sustainable, especially with the current rate of global growth in the field of renewable energies. Specifically, even though solar and wind technologies produce renewable energy, the materials used in the construction of every solar panel and wind turbine are not necessarily sustainable in and of themselves, nor are the industries involved in their construction.
“Renewable energy technology can lead to reduced emission of greenhouse gases, but for a complete analysis we need to make sure the whole production chain is sustainable, “explained Simon Davidsson. “For instance, it is not obvious that the production of wind turbines and solar cells is sustainable, that the materials have been sourced in a sustainable way, or that the industries are capable of recycling the technology in the future.”

“To assess the feasibility and consequences of a global energy transition, we need to consider material flows and how sustainable emerging industries are with regard to aspects other than climate,” Davidsson added. “Truly sustainable energy systems require the creation of sustainable industries, which not only can produce large amounts of renewable energy technology, but also maintain a working system on a longer time scale, and do so in a resource efficient way.”

Simon identifies that the main problem occurring is the rapid need for renewables, in order to combat the quickly evolving climate. However, he also suggests that we will only come across future shortages for the creation of renewable energies if we don’t find a way of making the entire chain sustainable, similar to what is being experienced now with fossil fuels.