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
Cryptocurrency market are very risky, after a green market will be a red market. But because cryptocurrency market raise a lot of newbies came to the industry and if they do not want to risk there are investments funds like
https://defiscale.io/ that invest money in gambling and finance and offer a stable income from investments.