Choose one solution/drawing and check if it hasn’t already been used.
If is hasn’t, expand on it. For example, how does this invention help the environment? Why should we use it? Does making it cause damage to the environment? Is it hard to make? What is needed to make it? What do you need to do for it to help the environment? Are there other uses for it? Do not only use these questions, but also really try to ‘sell’ the environmentally friendly product.
Come up with a name for the invention and also a name for your team or yourself. Be creative.