The other thing you can consider, svelte, is if your kids are still young and planning to go to college, and you are planning to pay for all/part of it, you can increase your contributions to a 529 plan.
As far as your solar + mortgage question. I would probably just put the extra cash aside and keep it as emergency cash, maybe split it 50/50 with half paying of mortgage and half as emergency cash.
I would mention tax exempt munis, but the moment I do that, I think phaster would hijack this thread.
I would contribute to a Roth IRA via backdoor if I could. Unfortunately, I made the mistake of rolling out one of my previous employer’s 401k into a rollover IRA. So I can’t do a backdoor Roth IRA without paying taxes for the conversion. But my then again, my current and previous employer both offered a traditional 401k and a Roth 401k account.
