A report released this week by the U.S. Energy Information Administration projects national growth amongst renewables — including hydroelectric power — in coming decades.

According to EIA’s Annual Energy Outlook 2014 (AEO2014), the increase in kilowatt hours generated by renewables will fall second only to natural gas through 2040, while nuclear, coal, petroleum liquid and other forms will flatline or decrease.

EIA cites the United States’ emphasis on reducing carbon emissions and both state and federal legislation as the biggest contributors to green energy’s growth.

Key amongst these policies are state renewable portfolio standards (RPS) — many of which have been amended in recent years to include eligibility for larger hydropower plants. Tax credit extensions for hydroelectricity and other renewables will also be a significant factor in their development, AEO2014 said.

The development of American hydropower has been a point of emphasis in recent months, with the Department of Energy announcing a plan to set long-term goals for the sector’s growth in April.

The Annual Energy Outlook 2014 report is available via EIA’s website here.