This scenario says it is realistic to consider that, by 2050, coal use ends and there is a reduced use of nuclear and natural gas. Lights would stay on even “when the wind doesn’t blow … and the sun doesn’t shine”. The executive summary is here.
If the U.S. ceases to burn coal, shuts down a quarter of existing nuclear reactors, and trims its use of natural gas by 2050, the resulting increased reliance on wind, solar, and other renewables will not result in a less-reliable-electricity grid, says a report prepared by Synapse Energy Economics for the nonprofit Civil Society Institute (CSI).
Available online at http://www.civilsocietyinstitute.org/synapsereport, the new study finds that, in the envisioned 2050 with a heavy reliance on renewables, regional electricity generation supply could meet or exceed demand in 99.4% of hours, with load being met without imports from other regions and without turning to reserve storage. In addition, surplus power would be available to export in 8.6% of all hours, providing an ample safety net where needed from one region of the U.S. to the next.
Grant Smith, senior energy analyst, Civil Society Institute said, “This study shows the U.S. electricity grid could integrate and balance many times the current level of renewables with no additional reliability issues. Recent improvements in renewable technologies and that used to control and balance the grid have been proceeding at a rapid pace, and the incentives and rewards for success in this area continue to drive substantial progress.
In contrast, the alternative – continuing to rely on increasing combustion of fossil fuels to generate electricity, and producing ever-increasing levels of greenhouse gases – is far less feasible, and presents much more daunting technical, economic, and social challenges to human and environmental welfare. In comparison, the challenge of integrating increasing levels of solar and wind power on the U.S. power grids requires only incremental improvements in technology and operational practices.”
Report co-author Dr. Thomas Vitolo, analyst, Synapse Energy Economics, says “The message today is this: It is a myth to say that the U.S. cannot rely on renewables for the bulk of its electricity generation. This study finds that the projected mixes, based entirely on existing technology and operational practices, are capable of balancing projected load in 2030 and 2050 for each region-in nearly every hour of every season of the year.”
In 2011, Synapse prepared a study for the Civil Society Institute that introduced a “Transition Scenario” in which the U.S. retires all its coal plants and a quarter of its nuclear plants by 2050, moving instead toward a power system based on energy efficiency and renewable energy. The Synapse study for CSI showed that this Transition Scenario, in addition to achieving significant reductions in emissions of carbon dioxide (CO2) and other pollutants, ultimately costs society less than a “business as usual” or status-quo strategy — even without considering the cost of carbon. The 2011 study also projected that, over 40 years, the Transition Scenario would result in savings of $83 billion (present value) compared to the status quo strategy.
To achieve these lower-cost and low-emissions results, the Transition Scenario included large amounts of renewable energy resources with “variable output,” such as wind and solar. While the need for variable-output resources is well defined, questions have been raised about the impact of large-scale wind and solar integration on electric system reliability. To address this, Synapse paid careful attention to the amount of wind and solar in each region when designing the Transition Scenario for the 2011 report, taking steps to ensure that the projected regional resource mixes could respond to all load conditions.
The 2013 study for the Civil Society Institute takes the analysis one big step farther to explore the extent to which the Transition Scenario’s resource mixes for 2030 and 2050 are capable of meeting projected load for each of the 10 studied regions – not just during peak demand conditions, but in every hour of every season of the year as consumers require.
The study’s method
Synapse developed a spreadsheet-based hourly dispatch model to test the capability of the Transition Scenario resource mix in each study region to meet hourly demand in that region. Hourly load data for each region was based on 2010 actual demand, and was adjusted – considering changes in demographics, wealth, and energy efficiency – so peak load and annual energy requirements closely matched those in the 2011 Transition Scenario. Data for these tasks were obtained from FERC 2011, NERC 2012, and U.S. EPA 2011. The generators used in the model came from the BBAU 2011 Transition Scenario.
To model the hourly generation of variable resources, study authors used a number of National Renewable Energy Laboratory (NREL) studies and data sets. To model hourly wind generation, data sets from NREL’s Eastern Wind Integration and Transmission Study (EnerNex Corporation 2011) and Western Wind and Solar Integration Study (GE Energy 2010) were applied to the power curve of a Vestas V112 3.0-MW turbine. To model solar output, authors used site specific data from NRELs PVWatts calculator. Annual hydroelectric capacity factors from the 2011 report were used for the Northeast, Southeast, Eastern Midwest, and Texas regions. Monthly hydroelectric capacity factors from the U.S. Bureau of Reclamation were used for the Northwest, California, Arizona/New Mexico, Rocky Mountains, Western Midwest, and South Central regions.
Civil Society Institute
American Clean Energy Agenda
Synapse Energy Economics
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