I'm new to the concept of PoS. Would the underlying mechanism of Burstcoin be proof of stake, i.e. large amounts of HDD space instead of computing the solution

I'm new to the concept of PoS. Would the underlying mechanism of Burstcoin be proof of stake, i.e. large amounts of HDD space instead of computing the solution hash problems? Or is Burstcoin still proof of work? I'm just curious because the proof of space model seems much more environmentally friendly instead of solving random problems with massive amounts of computation.