But renewable energy is free...

 

You'll often hear it said that so-called "renewable energy" is free energy. Energy from the sun, from the wind — it's just there for the collection.

But because collection locations are so dispersed, 'cos collection itself not to straightforward — and because the energy density is so low — it takes a lot of stuff to collect all that "free" energy. 

A 2015 estimate by the US Department of Energy showed just how much stuff:

So free energy is not free.

And since mining for all these raw materials would have to increase by >300% to achieve “net zero” goals, which would make that [arbitrary] target date by 2050 impossible. In order for the world to meet Net Zero by 2050 one estimate says the amount of stuff needed would be 4,575,523,674 tons of copper. 940,578,114 tons of Nickel. 8,973,640,257 tons of Graphite, and 4,163,162 tons of Germanium. At todays mining rates that would take over 1000 years. Not to mention the many rare earth metals, which are so-called for good reason.

So it's not so straightforward. And nowhere near so free.

But, in case you didn't notice (it's bar chart being so small down there) it's gas for the win.

[Hat tip Chris Martz]