I'll have to check this out it sounds really cool!
I'd say solarpunk isn't incompatible with conflict - though some people in solarpunk spaces have also said that so you're definitely not alone. I think it's important to note that solarpunk is aspirational but it's not (or at least I don't think it usually is or should be) utopian.
In fact, I've been helping with a solarpunk TTRPG that started as a cyberpunk game where the original group playing it kept revising the setting to make it more optimistic. Even when everyone has their basic needs met, there's still intellectual espionage, theft of rare items, crimes of passion, and mayhem created by people trolling.
In general I think a solarpunk society is going to have many of the conflicts any human civilization tends to see. By working on fundamental inequalities and striving to provide safety nets and stability, we can remove a lot of motivations for crimes, but there’ll always be people who’ll try to cheat others, take harmful shortcuts, or commit crimes for reasons other than necessity. Serial killers spring to mind. Even within a fairly equal society you may have people who feel they could have had more, that they’ve been cheated out of a birthright of millionaire-hood or some good-old-days existence, real or imagined.
Depending on the setting there may also be groups outside solarpunk communities. People who ascribe to old world values, who prioritize extraction and hoarding of resources, who push their externalities like waste onto others or their environment.
For the solarpunk stuff I make, I see it as a pretty postapoclyptic setting, focused mostly on people rebuilding in a better way, so I don’t think it’s a stretch to say bandits and accelerationist survivalists would still be around on the fringes. There's room for conflict with them, but also just with the challenges of rebuilding and over how best to go about it. IRL environmental movements are full of disagreements over which tradeoffs to accept.
I think narrative conflicts also encompass things I wouldn't really call conflicts in other contexts, so there's probably some room there for other story options.
I will say it's more difficult, writing solarpunk stuff, not least because you're trying to write an aspirational setting so you have to do more research and be willing to stand by whatever solutions come with your setting.