Vermont has taken a large step forward for US states, outlining in its Comprehensive Energy Plan how it will get 90% of all its energy from renewable sources by 2050. Currently Vermont gets 23% of its energy from renewable sources, mostly biomass and hydropower which supply roughly 50% of the state's electricity.
The report gives a snapshot of the challenge facing the Green Mountain State; it's essentially the same challenge facing the entire United States:
Robust electric efficiency efforts in the past decade have...helped significantly—we are keeping our electric demand down and using many renewable sources to meet our need. However, we have made comparatively little progress on improving our energy usage in transportation and heating. We drive more than we did a generation ago, using fossil fuels to power our vehicles. Although biomass and solar thermal systems have made a dent in our fossil fuel heating usage, Vermont continues to be heavily reliant upon heating oil. We have not made enough progress in improving the comfort and affordability of our homes reducing the energy usage.
More info: Vermont Comprehensive Energy Plan