The first two installments of – The ‘Super Grid’ is Super Important for Renewables here and here – show where the the most renewable resources are and background on a concept for a nationwide Super Grid to aggregate those renewable sources and reduce the effective intermittency. This installment introduces you to some of the studies that studying the details of how the Super Grid would be implemented and what real advantages are received. I list several major studies that look at the integration of renewables into the individual grids and then a major NREL study that looks at the integration of all three to see what it would take to go to very high penetration renewables.
In particular the focus is on providing the Eastern Seaboard with a significant portion of its power from wind power in the Midwest and offshore on the Atlantic coast. If you are really interested in how we can take renewables to the next level, the NREL EWITS study, in particular, is great, starting with a birds eye view and drilling down to more detail and offering insight into how these studies are put together. It is also useful to consider scaling this out to cover the entire continental US and consider the further reductions in effective intermittency from renewables through broader aggregation.
The Eastern Wind Integration and Transmission Study study, (EWITS) examines at a variety of scenarios by which the contribution of wind power to the Eastern United States could be increased up to 30%. It is rather comprehensive but the executive summary is readable and offers a glimpse at the issues at hand. Most of the wind power comes from either off shore or the Great Plains.
This JCSP_Report_Volume_1 study lays the groundwork for the EWITS study by providing a practical design of the utility grid needed to accomodate a large build-out of wind power. Among other things it lays out specific changes that would be required for the transmission grid to accommodate moving massive amounts of power from the Midwest to the Eastern Seaboard. And it examines economics and curtailment implications for different scenarios.
For example, adding high voltage transmission lines and where they would go. This is an early step in the utility planning process. This is also a great glimpse into the esoteric world of large scale power transmission. It includes information on the price per mile transmission lines, the power carrying capacity and the various distances for which the various power transmission technologies are optimized. It is a great study for those interested in becoming conversant in the nuts and bolts of utility planning for renewable energy. It is a good sleep aid for pretty much anyone else.
NREL Western Wind and Solar Study looks at massive integration of solar and wind in the western US.
This study which I like to call the NREL 2050 study, is similar to the above but takes it out to 2050 and looks at a concept for building out to 80% renewable energy penetration.
ERCOT is the Electric Reliability Council of Texas. They are managing the integration of massive amounts of wind into the Texas grid. The US has three independent grids and Texas is one of those. In a recent report they found that solar and wind, properly integrated, will lower the overall cost of electricity.
So why do we need high voltage power transmission and why is higher voltage sought. Currently most power transmission is done at under 700,000Volts (700kV). And a lot is done at or under 345kV. However much of the new transmission being discussed for bringing midwest windpower East is at 765kV AC and 800Vdc. Why ever higher voltages? If you double the voltage the losses drop to 1/4 of what they were at the lower voltage. To see why, go here: The Advantage of High Voltage
NREL is doing a lot of work in this area, the relevant portion of their web site is here.
I ran across this technology which looks interesting but have not had time to go through it in detail.
2012 Wind Technologies Market Report – offers a lot of useful information on the status of windpower in the US.
The Super Grid is Super Important for Renewables Part I – Here
The Super Grid is Super Important for Renewables Part II – Here
Installed Renewables Here
Declining Cost of Renewables and Storage Here
supersmartgrid, supergrid, smartgrid, smart grid, Clayton Handleman,