Utilities prices & consumption
I know, I know. It is not new and also it can be the most impopular idea but the reality is simple. People spent because it doesn't have to pay much more. There are many histories in the world probing this theory. Create some scale having a basic levels consumption and scales and increase prices for higher volumes and for sure it will impact the "behavior" of people and all the industries.
But this idea has a special component, with the extra money received create a fund for the other green projects for the city.
Drive More commented
BC Hydro already has a two tier electricity price. You pay more if you consume over the threshold amount.
Do you even pay for utilities?