Would high levels of renewable energy sources be able to maintain the U.S. electrical grid? Meeting Load with Resource Mix Beyond Business as Usual, a report released in April 2013 by Synapse Energy, answered this question using a model to see how a renewable energy intensive grid would be able to handle future energy load. The study determined that using “a combination of inter-regional transfers, local storage, and demand response would be more than adequate to provide a high level of reliability” for almost all hours of the entire year in ten studied regions.
This report built on the research performed by Synapse in 2011, Toward a Sustainable Future for the U.S. Power Sector: Beyond Business as Usual 2011 (BBAU 2011), “that introduced a ‘Transition Scenario’ in which the United States retires all of 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. Synapse’s study showed that this transition scenario, in addition to achieving significant reductions in emissions of CO2 and other pollutants, ultimately costs society less than a “business as usual” strategy—even without considering the cost of carbon. BBAU 2011 projected that, over 40 years, the Transition Scenario would result in savings of $83 billion (present value) compared to the business as usual strategy.”
Most of the data used to create the model came from FERC, NERC, the U.S. EPA, the National Renewable Energy Laboratory (NREL), GE Energy, and data gathered from BBAU 2011. The model was created to match the mixed energy sources to the energy load at the current hour, instead of having periods of time where energy output was either in surplus or insufficient for demand.
The data was used to determine if electric demands for the years 2030 and 2050 could be met in ten regions in the United States, including the northeast, eastern midwest, western midwest, Rocky Mountains, Texas, California, Arizona/New Mexico, southeast, south central and northwest. Only the northwestern region in the year 2050 showed signs of struggle to meet the energy load. The remaining nine regions showed little or no shortage of energy using Synapse’s model. The figure above models a week in the summer in the Rocky Mountains, where no energy shortage occurred. To see the figures from other regions, view the report.
A good short profile of the city of Freiburg, Germany, and their many sustainability initiatives. Freiburg is a little more than double Boulder’s size — both in population and area, so it has a similar average population density. It’s also a university town with a strong tech sector locally. The whole city was re-built post WWII, but they chose to build it along the same lines as the old city, with a dense core, and well defined boundaries. Today about half of daily trips are done by foot or on bike, with another 20% on public transit. They have a local energy efficiency finance program, on top of the national one administered by KfW, and higher building efficiency standards than Germany as a whole. Half their electricity comes from combined heat and power facilities that also provide district heating and hot water. It seems like they’d be a good model city to compare Boulder to, and learn from.
Could it be possible to have renewable energy sources powering a large grid system up to 99.9% of the time at costs comparable to energy rates today? A new research report by the University of Delaware and the Delaware Technical Community College demonstrates how this system could exist by 2030. Through a combination of wind power, solar power, and storage in batteries and fuel cells, an almost completely renewable energy grid could be established.
The scientists developed a computer model that considered 28 billion combinations of renewable energy sources and storage mechanisms. Each combination tested historical hourly weather data and electricity demands over a four year period. Using the historical data, the model was able to determine when energy would not be produced by renewable sources, and would tap into storage devices during those periods of time. When energy generation was in excess, the model would first refill storage devices, then use the remaining to replace natural gas usage, and would only waste excess generated energy afterward. A press release from the University of Delaware on the new report discussed one of the several outcomes of the model with co-author Cory Budischak, the instructor in Energy Management Department at Delaware Technical Community College, “’For example, using hydrogen for storage, we can run an electric system that today would meet a need of 72 GW, 99.9 percent of the time, using 17 GW of solar, 68 GW of offshore wind, and 115 GW of inland wind’”.
The model was not only required to maintain demand as needed through renewable energy generation and storage, but was also expected to minimize costs. A discussion of how costs were determined was also included. Costs of each model combination were determined by calculating true cost of electricity without subsidies, elimination of renewable generation subsidies, and inclusion of fossil fuel pollution externalities, costs which are currently paid for by third parties. The scientists determined that 90% of the load hours can be met at prices below today’s electric costs under these conditions.