EcoPoW intends to use PoW as the encoding algorithm, meanwhile the blockchain is PoW protected as well.
This particular sentence doesn't make sense to me. What's encoding with Proof-of-Work? Did you perhaps mean to timestamp-based algorithm?
It is like a free protection to the PoW blockchain network.
How is it free? Miners will have to increase their expenses with extra hardware. I'm still not sure how Proof-of-Work helps the "decentralized-storage-network" situation.
People can mine the blockchain at home with common devices.
Why would ordinary people (I presume, the storage users?) pay for mining?
For a normal user, they may prefer to purchase the storage with stable coin such as USDT or DAI, which is also different from Filecoin.
This abruptly centralizes the project. Stable coins are not decentralized.
What's the problem with purchasing hard drives? Safe, private, efficient, cheap.