The perfect fit for green coin is helium coin, your miners will use less than 10w just like any routers out there, chia isn't close to green mining because it requires lots of watts just like GPU, you need high CPU cores to plot and many HDD for farming, if you do calculation on watts the results wil be like GPU mining
it seems interesting if it is true that miners only use less than 10w, this is clearly an advantage because the costs are small compared to other mines that use higher costs. however, looks like I'll try to research the helium project further. can the low cost of 10w be flat or increase in the future