The main drivers of energy use are typically going to be transportation, home heating, electrical generation, and industry.

One of the sliding scales that you have to be very careful of when implementing green energy policies is if your electrical costs go up, then you can end up taking people who were previously using renewable energy to eat their homes and push them into using fossil fuels.

One guy I knew was heating his home using 100% renewable energy from hydroelectric, but then the electric company started building a bunch of solar panels and wind farms that weren't generating electricity during the times that it was needed, so costs went up substantially. When he moved from electric to propane, the cost difference was so much that he paid for the entire system and all the fuel for the year in one month of not paying for electric heat.

One really interesting thing about the page that I linked, is that in 1987 the same percentage of electricity generation was renewable as today, Which was followed by a massive drop and a swing to rely on fossil fuels.