I feel two part in your question: 1-What is a good use with excess money? 2-How to manage the money? For (2) I would hire someone good with tax optimisation

I feel two part in your question: 1-What is a good use with excess money? 2-How to manage the money? For (2) I would hire someone good with tax optimisation and also try to understand it myself and I would invest in the stock market. For 1, you can look into effective altruism and see if it resonate with you. It might be possible to make 1 and 2 work together ex: micro lending, investment in renewable company, etc You can see the capital as a way to accelerate the change you want to see in the world.