This is exactly what Chia (https://www.chia.net) has done by using hard drive storage space to hold the proofs. This allows the generic hardware of general purpose computers with hard drives to operate profitable and energy efficient full nodes on the network. Especially if these are existing machines people already own. Also, the computing infrastructure needed to farm (mine) the plot files (files holding the proofs) is minimal enough that it can be run from a Raspberry Pi.