The phrase "mass scale" refers to something being done or happening on a very large or widespread level. It suggests that it involves a large number of people, objects, or actions. Full definition
I think the technology is worth exploring, and perhaps we will come up with a chemical solution for producing hydrogen on mass scale as opposed to cracking water with large amounts of electricity. (ddears.com)
A new electric truck company comes out of stealth mode, promising delivery of medium - duty electric vehicles «at mass scale» this fall. (treehugger.com)
That's probably when — and if — the company reaches a commercial mass scale. (fortune.com)