Date: Apr 19, 2013 Author: Zachary Shahan Source: Company Data (
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I think most of us know by now that there's enough renewable energy potential to power the world several times over. However, the key is matching what can be generated in a specific location with what is needed in that location (with the "location" generally being a relatively large region). Naturally, many homes can generate all the power they need from rooftop solar panels. However, many cannot -- about 75% is the figure I've read. Think of all the (highly land- and energy-efficient) apartment buildings, tree-covered roofs, etc. that cannot generate enough electricity from rooftop solar panels. Then, there are also energy-intensive businesses, and there's also the simple fact that the sun does goes down every day, while our electricity needs go on.
So, the question arises, how much can renewables such as wind and solar really cover our electricity needs? Well, according to a new report by Synapse Energy Economics (prepared for the Civil Society Institute), with heavy reliance on renewables, "regional electricity generation supply could meet or exceed demand in 99.4 percent of hours, with load being met without imports from other regions and without turning to reserve storage," by 2050.
civil society renewable energy study
The report doesn't specifically indicate how much of the grid would be supplied by renewables. The chart above is the best you get for that. However, I'm actually happy about that, because a focus on one dubious number would take emphasis away from the fact that this scenario is far from perfect and overly pessimistic (see below) but still finds that we could have a ton more renewable energy integrated into our grid.
The full report is available online. But some more key points are as follows:
8.6% of the time, excess electricity would actually be available for export;
a 2011 study conducted and funded by the same parties found that this option would cost less than a "business as usual" scenario (notably, that's the same finding similar studies have come to) -- $83 billion less over 40 years; the study uses energy storage technology available today, but has a good section noting that a ton of research and development is going on in this sector, meaning that costs are likely to fall considerably, while efficiency and practicality improves (in other words, the results of the study are beyond pessimistic); the report is also excessively pessimistic/unrealistic in that it doesn't include the possibility of interregional transfers and demand response (already in use to some degree today, but sure to be in greater use in the future).
Grant Smith, senior energy analyst at the Civil Society Institute, said: "This study shows that the U.S. electricity grid could integrate and balance many times the current level of renewables with no additional reliability issues. Recent improvements in both renewable technologies themselves and in the technologies that are 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, and analyst at Synapse Energy Economics, Inc, added: "Put simply, the message today is this: It is a myth to say that the United States 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."
As noted above, this was not a general look at electricity needs and potential. On the contrary, it was a very close look at specific needs and potential in 10 regions. And it didn't just do so for peak load, but for every hour of every season of the year.
There are several additional regional graphs like those above in the report -- they are very interesting to look at, so I'd recommend checking out the full report.
For now, I'm going to repost some select quotes that I think are really worth paying attention to.
Much Higher Renewable Energy Integration Is Possible & Logical
The key point of the study is that, even using technology available today, we could have much higher integration of renewables in the grid. Here's a key quote on that:
"Our findings are consistent with other studies, such as MIT 2012, which suggest that much of the U.S. grid could integrate and balance many times the current level of renewables with no additional reliability issues. Recent improvements in both renewable technologies themselves and in the technologies that are 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."
Energy Storage
As noted above, energy storage (as well as solar and other renewables, for that matter) is likely to advance tremendously in the coming years, making this report overly pessimistic about what's possible and even likely to happen. Here's a good quote on that topic from the report itself:
"Energy Storage exists today in the forms of pumped hydropower, compressed air storage, flywheels, and batteries. Thermal energy storage in buildings and industrial settings is also used today. Storage provides the ability to both absorb electricity during hours of surplus and to dispatch it as a generator at a later time. Energy storage will always involve some level of losses--for example, it takes more energy to fill a pumped hydro storage reservoir than can be recovered by releasing the water. Today's advanced storage technologies, such as batteries and flywheels, are relatively expensive and limited in scale, and have thus been applied mostly for specialty applications. However, lower-cost energy storage is an area of very active research and development, including efforts to improve batteries, develop hydrogen production and storage, and implement end-use storage such as thermal storage in buildings, electric water heaters that can respond to system operator controls, and plug-in electric vehicles. Energy storage will almost certainly play an important role in any energy future with higher levels of renewable resources, because storage effectively converts intermittent energy generation to highly flexible dispatchable generation. This study assumed that future storage would have the same cost and efficiency structure as current storage; however, technological advancements will only improve the cost and performance of electrical storage over time."
Methodology
Also, from the press release, here's a little bit more on the research methodology for those interested in digging in a little bit further:
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 that the 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, a number of National Renewable Energy Laboratory (NREL) studies and data sets were used. 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 V 112 3.0 MW turbine. To model solar output, site specific data from NRELs PVWatts calculator was used. 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.
