With the rise of green energy, can we trade green energy? Like something similar to WTI, Brent Crude?

Alternatively, you can go for green energy companies like Sunpower, Solarcity, Sunrun to name a few.

As of now, all these are not known/open to retail investors. However you can check with your brokerages if they have any idea/recommendation on it.

Just my personal opinion, though green energy is rising, but if I am not wrong the cost of producing green energy is also expensive. Oil/coal is still dominant in the market, and I do see green energy only being "competitive" in 10 years time. But.. I told myself never to trade commodities! Feels like it's pegged to just market sentiments, no underlying to it.. Depends on individual risk preferences!