Forbes recently released an interesting article on the importance of grid expansion in the US. They did a nice job of highlighting some of the critical issues. Upgrading the electric power transmission system is an infrastructure upgrade that can contribute substantially to getting more renewable energy on the system. For example, much of the electricity is used on the coasts but there is vast potential for wind in the great plains states and off shore on the East Coast.
This blog post includes a map showing the vast potential of the great plains states. It also shows the enormous potential for off shore wind. Off the East Cost there is a strong wind resource and the water is relatively shallow. This post points to maps of the solar resource which is vast in the Southwest and reliable as cloudy weather is rare.
In other words, in addition to improving grid stability, expanding the grid makes it possible to add more renewables without increasing peaking power plants or adding storage!
The article mentions transmission lines that are to carry renewable energy gaining approval, albeit, with somewhat of a regulatory struggle. The article also looks at transmission lines that had not been given approval. These were to go through the Appalacians and move power from coal power plants. In effect, these lines would have provided incentive for a continued build out of coal power plants, in an area where the mining practices are devastating. What the article failed to mention is the Atlantic Wind Connection off shore transmission line, made famous because it has gained financial backing from Google. It will provide high quality transmission up and down the eastern seaboard but rather than favoring coal would favor off shore wind development. Furthermore it will be far enough out that the turbines would not be visible from shore. This could be a game changer, truly revolutionary.
Expanding the grid has two benefits, as far as renewables go: One is that the expanded grid can bring the power from its, often distant, point of generation to the population centers that need it. The second is that by stringing together geographically spread out renewable energy systems the effects of intermittency are dramatically reduced. For example, in this study, the output of a cluster of wind plants in the Southwest was studied and it was found that, if interconnected by the grid, 37% of the output of this group of turbines could be counted as equivalent in reliability as a coal power plant. And they found that the more wind farms you add the higher percentage of their output is stable enough to be counted as baseload by the utility. In other words, in addition to improving grid stability, expanding the grid makes it possible to add more renewables without increasing peaking power plants or adding storage! A later study examined this on the Eastern seaboard and found similar results.
See Part II of this post Here
See Part III of this post Here
Transmission Line Upgrades could unlock the Saudi Arabia of Wind
Susan Tierney White Paper 21st Century Transmission Super Highway
Renewable Resource maps here
More on aggregation of wind here
AWEA paper from 2015 looking at impact of wind expansion on grid stability. Includes graphs on decorrelation with distance and many good references with hyperlinks.
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