Renewable Electricity Futures Study — Executive Summary
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analysis suggests that under a high-demand scenario, greater and more rapid deployment of
renewable and other supply- and demand-side technologies would be required. For example,
while 32–46 GW/yr of renewable capacity additions were estimated from 2041 to 2050 in the
low-demand core 80% RE scenarios, approximately 66 GW/yr would be needed during the same
time period under a more-traditional, higher-demand trajectory. The analysis also found that in
the 80%-by-2050 renewable electricity high-demand scenario, variable resources (wind and PV)
were deployed to a greater extent in absolute and percentage terms than they were in the low-
demand scenarios due to the greater resource available for wind and solar generation compared
with other forms of renewable generation. As a consequence, additional flexible supply- and
demand-side technologies, such as storage facilities, natural gas combustion turbine power
plants, and interruptible load, were deployed and greater transmission expansion was needed to
connect remotely located renewable resources of all types.
Higher end-use electricity demand increased the environmental impacts from the electric sector,
such as greater greenhouse gas emissions, water use for thermoelectric cooling, and land use. In
addition, higher demand growth also resulted in a greater increase in electricity prices. For
example, in the High-Demand 80% RE scenario, the average annual retail electricity price
increased by 1.3% per year (2011–2050, in real dollar terms) compared with 1.1% per year in the
(low-demand) 80% RE-ITI scenario.
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The increase in retail electricity prices driven by higher
demand growth is not restricted to the high renewable penetration scenarios; it is evident under
the baseline scenario as well. In particular, the average annual retail electricity price increased by
0.6% per year (2011–2050, in real dollar terms) in the High-Demand Baseline scenario
compared with 0.3% per year in the Low-Demand Baseline scenario. While these results indicate
that higher demand growth would lead to greater electricity price increases, they also
demonstrate that the direct incremental costs associated with high renewable generation levels
actually decreased under higher demand growth.
Conclusions
The RE Futures study assesses the extent to which future U.S. electricity demand could be
supplied by commercially available renewable generation technologies—including wind, utility-
scale and rooftop PV, CSP, hydropower, geothermal, and biomass—under a range of
assumptions for generation technology improvement, electric system operational constraints, and
electricity demand. Within the limits of the tools used and scenarios assessed, hourly simulation
analysis indicates that estimated U.S. electricity demand in 2050 could be met with 80% of
generation from renewable energy technologies with varying degrees of dispatchability together
with a mix of flexible conventional generation and grid storage, additions of transmission, more
responsive loads, and foreseeable changes in power system operations. While the analysis was
based on detailed geospatially rich modeling down to the hourly timescale, the study is subject to
many limitations both with respect to modeling capabilities and the many assumptions required
about inherently uncertain variables, including future technological advances, institutional
choices, and market conditions. Nonetheless, the analysis shows that realizing this significant
transformation of the electricity sector would require:
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To isolate the effect of demand growth, the High-Demand 80% RE Scenario is compared with the 80% RE-ITI
scenario since they both relied on the same technology improvement projection and used the same assumptions
related to transmission, system flexibility, and renewable resources.