Or consider solar lanterns as a replacement for kerosene. They are safer, cheaper and far healthier. But that’s not the problem. The problem is building a marketing and distribution network that permits you to rapidly educate a billion people as to why they want to buy one at a price that would permit you to make them in quantity.
Sure, you need a solution to the problem. But mostly what you need is a self-funding method to scale your solution, a way of interacting with the market that gains in strength over time so you can start small and get big, solving the problem as you go.