In 2007, solar output was 6 TWh while geothermal was 57 TWh, and solar will gain rapidly until 2025 when it will generate 140 TWh compared with 119 TWh from geothermal. By 2035, the respective outputs will be 165 TWh and 160 TWh.
World marketed energy consumption increases by 49% from 2007 to 2035 in DoE’s reference case, with total energy demand in non-OECD countries increasing by 84% compared with a 14% increase in demand among OECD countries.
The reference case (which does not include prospective legislation or policies) predicts that total world energy use rises from 495 quadrillion Btu in 2007 to 590 quad in 2020 and 739 quad in 2035.
World net electricity generation increases by 87% from 18.8 PWh in 2007 to 25 PWh in 2020 and 35.2 PWh in 2035.
Although the economic recession slowed growth in electricity demand for the past two years, growth returns to pre-recession rates by 2015 with generation in non-OECD countries rising by 3.3% per year compared with 1.1% per annum in OECD nations.
Global renewable energy output to grow 3% per year
“The rapid increase in world energy prices from 2003 to 2008, combined with concerns about the environmental consequences of greenhouse gas emissions, has led to renewed interest in alternatives to fossil fuels - particularly nuclear power and renewable resources,” it explains.
“As a result, long-term prospects continue to improve for generation from both nuclear and renewable energy sources, supported by government incentives and by higher fossil fuel prices.”
From 2007 to 2035, world renewable energy use for electricity generation grows by an average of 3% per year, with the share from renewable sources increasing from 18% to 23% over the period.
Coal-fired generation increases by an annual average of 2.3%, making coal the second fastest-growing source for electricity generation in the projection although the outlook for coal could be altered “substantially” by any future legislation to control GHG emissions.
Much of the global increase in renewable energy is fueled by hydropower and wind power. Of the 4.5 PWh of increased renewable generation over the period, 2.4 PWh (54%) is attributed to hydroelectricity and 1.2
PWh (26%) to wind.
Most renewable sources economically competitive to 2035
“Except for those two sources, most renewable generation technologies are not economically competitive with fossil fuels over the projection period, outside a limited number of niche markets,” the outlook explains.
“Typically, government incentives or policies provide the primary support for construction of renewable generation facilities.
“Although they remain a small part of total renewable generation, renewables other than hydroelectricity and wind (including solar, geothermal, biomass, waste, and tidal/wave/ocean energy) do increase at a rapid rate over the projection period."
The Outlook projects only marketed energy; not standalone or off-grid power or thermal output from renewable sources.