Any green (sustainability or eco-friendly) stocks worth checking on for millennials?

Definitely worth checking out some with green energy taking center stage over the next few years. However, do also note that not all green energy are equal (like solar, wind, hydrogen, nuclear aren't all equally efficient and that should be a consideration in your analysis), as such, not all sectors are as likely to succeed. Do also note that not all companies will succeed in each sector so good due diligence is required, especially in an industry that is getting so much attention. One such way to work around this would be through sector investing, which I also wrote about here! This allows you to slightly reduce the risk through diversifying in the sector to get exposure to the potential upside that it provides.