Disproving the Skeptics: 10x More Windpower and Solar is No Problem!

October 25, 2013 | 4:11 pm
Mike Jacobs
Senior Energy Analyst

What would happen if we tried to make the electric supply 30% wind and solar? Air pollution goes down, and reliability is unaffected. Ok, now picture adding as much as 50,000 MW of wind and 60,000 MW of solar by the year 2026, and the engineers saying, “Sure, we can do that.”

That’s the finding of a study previewed today by the grid operator PJM and a consulting team led by General Electric. The results from a multi-year study show that adding 10 times more windpower than currently used in PJM’s 13 state area, and 5 times more solar power than in the U.S., creates reliability benefits and reduces greenhouse and toxic air emissions.

credit: U.S. DOE

credit: U.S. DOE

This is a technical report by the people with the longest records running an integrated electric grid, and modeling the specific impacts of wind and solar on the power supply. PJM has been running grids tied together since 1927. For over a decade, power system operators in the US, and experts included in this study have provided the public these kind of studies. The power system engineering community has reviewed and discussed these studies, their methods, and the reforms that are projected, adopted, or expected in numerous meetings, including next week’s Utility Variable Generation Integration Group workshop in Portland, OR.

The repeated results of these studies? “Sure, we can do that.”

So, what did we learn?

How much does each solar rooftop contribute to reliability needs of the grid? The measure is known as the effective load carrying capability, and in the PJM grid (when it reaches 20 – 30% variable renewables), the contribution to peak demands from residential solar photovoltaic (PV panels) is 57% of the solar panels’ rating!

credit: Mike Jacobs

credit: Mike Jacobs

How much generation is needed to manage the variability of all this wind and solar? The need for reserves to manage the variability of the combined wind and solar (spread over 13 states and the District of Columbia) is 4% (yes four) of the 100,000 MW of added wind and solar. These resources will be used more than today. It is unclear how this reflects the recent “pay-for-performance” reforms PJM applied to this service. PJM has said elsewhere that they see more fast-performing reserve sources than presently needed.

So, next time someone says that wind and solar can’t help us run the modern power grid, you can tell that they are simply behind in their reading.  This study adds to the body of knowledge, as well as the day-to-day experiences around the U.S. and the world, that “sure, we can do that.”

About the author

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Mike Jacobs is leading the Union of Concerned Scientists’s work on electricity markets and regulatory reform. He develops proposals in an effort to shape federal, regional and state electricity markets, regulation and policies to encourage the expansion of renewable energy resources and the reduction of coal-fired generation.