Wind electric will grow by 5.4% per year and solar thermal electric by 3.6%, while the largest annual increase in renewable energy will come from transportation ethanol used in E85, which will see an annual increase of 23.3%. Overall, marketed renewable energy will grow by 3.1% a year until 2035, says the Annual Energy Outlook 2010 reference case released by DoE’s Energy Information Administration (EIA).

“Our projections show that existing policies that stress energy efficiency and alternative fuels, together with higher energy prices, curb energy consumption growth and shift the energy mix toward renewable fuels,” explains EIA administrator Richard Newell. "However, assuming no new policies, fossil fuels would still provide about 78% of all the energy used in 2035.”

In terms of actual consumption, wind electric grows from 0.51 quadrillion Btu (quad) in 2008 to 2.12 quad in 2035, while solar thermal electric increases from 0.01 to 0.02 quad and solar PV goes from 0 to 0.01 quad over the period.

The consumption of non-marked renewable energy (not sold at retail) grows one of the largest percentage amounts, with residential wind growing at 19.2% per year over the period, solar PV at 19%, geothermal heat pumps at 9.5% and solar water heating at 2.1%.

Projections in EIA’s reference case do not include the impact of any potential future policies that have not yet become law in the United States, and include only those renewable energy technologies which are commercially available or are expected to become commercially available over the next decade.

Total primary energy consumption grows by 14% from 2008 to 2035, as the share of fossil fuel of total energy consumption falls from 84% to 78%. There is a decline in the reliance on imported oil and gas, as total consumption of liquid fuels (both fossil liquids and biofuels) grows from 19 million barrels per day in 2008 to 22 million in 2035. Biofuels account for all of that growth, as use of oil-based liquids stays flat and imports of oil decline significantly over the next 25 years.

Emissions of CO₂ from the use of energy will grow at 0.3% per year, assuming no new policies to limit emissions, and total energy-related CO₂ emissions grow from 5,814 million metric tonnes (Mt) in 2008 to 6320 Mt in 2035, although per capita emissions fall by 0.6% per year. Most of the CO₂ growth in the reference case is caused by the electric power and transportation sectors, the report notes.

Total consumption of electricity, including purchases from power producers and on-site generation, grows by 1% per year over the period, from 3873 TWh in 2008 to 5021 TWh in 2035. Natural gas and renewable energy plants account for most of these additions in generating capacity, with the share from natural gas falling slightly due to the completion of coal-fired plants under construction and the addition of new green power facilities.

By 2035, the share of generation from natural gas increases to 21% although green and renewable  power shows the strongest growth until 2035, spurred by incentive programmes in more than half of the states. The share of green and renewable power generation grows from 9% in 2008 to 17% in 2035.

The full Annual Energy Outlook 2010, including projections with different assumptions on the price of oil, the rate of economic growth, and the characteristics of new technologies such as renewable energy, will be released in early 2010.