Honestly I'm not saying that this chia project is a total failure but it's far from green energy mining like many thinks, this coin isn't easy to mine like ravencoin or even ETH, using terabytes of HDD and plotting with higher end Servers or CPU will draw watts power you've never prepared for, o don't see different in mining ETH and Chia when it comes to power efficiency
Just the on-ramp cost is expensive. The CPU intensive plotting. But after that the HDDs don't draw much power. So there is a huge difference plotting once and then farming vs. GPU mining, which continuously draws a lot of power.