Meghan Gunn

Around the world, entrepreneurs are trying to turn green tech ideas into viable businesses. Many are working with technology that has been proven to work, but is too expensive for widespread use. The challenge is finding ways to bring the costs down enough so that their solutions can be scaled up to effect real change.Here is a collection of innovative companies and inventors who believe they are close to hitting that mark with products ranging from the world’s whitest paint to high-efficiency e…