Skip to content

NERC Report: Wind and Solar Hurt Grid Reliability

January 9, 2015

The North American Electric Reliability Corporation (NERC) is an international regulatory authority (for the United Sates and Canada) established to evaluate and improve the reliability of the Bulk Power System (BPS) in North America. “[It is] subject to oversight by the U.S. Federal Energy Regulatory Commission (FERC) and governmental authorities in Canada.”

In its 2014 Long-Term Reliability Assessment report, NERC said: “Reserve margins in several assessment areas are trending downward.”

And NERC also said: “North America’s resource mix is undergoing a significant transformation at an accelerated pace with ongoing retirements of fossil-fired and nuclear capacity and growth in natural gas, wind, and solar resources. This shift is caused by several drivers, primarily existing and proposed federal, state, and provincial environmental regulations.”

This means, grid reliability is decreasing.

NERC established that a 15% reserve margin is required for a highly reliable grid. As this chart from the report indicates, a 15% reserve margin results in 0.1 events per year over a ten year period.

NERC Reserve Margin Method Graph

NERC Reserve Margin Method Graph

Further, “This metric does not fully capture important reliability attributes essential for ensuring BPS reliability. The Reference Margin Level assumes that various types of operating reserves are available (e.g., regulating reserves, spinning reserves, non-spinning reserves, and load-following reserves) to balance load and supply in real time and enable System Operators to quickly and reliably respond to a system contingency.”

The report indicates that wind and solar do not provide these additional reliability attributes. Toward that end the report said, “Higher concentrations of VERs [Variable Energy Resources] must accommodate added variability by increasing the amount of available regulating reserves and carrying additional operating reserves.”

Note from the graph, that a reduction in reserve margins from 15% to 10% results in a five fold decrease in reliability.

The NERC report also indicated that the EPA’s Proposed Clean Power Plan, that primarily targets coal-fired power generation to cut CO2 emissions, will likely exacerbate the reliability problem.

Two additional items:

Because wind is remotely located, there would need to be large new investments in transmission lines.

Remote wind will also likely have much lower capacity factors.

NERC also examined the negative problems associated with PV rooftop solar, including a discussion of the problems associated with wind and PV rooftop solar in Germany.

The growth in natural gas demand resulting from the closure of coal-fired power plants, especially in the Northeast, is also discussed in the report.

Speaking of the pipelines and homeowners first right to natural gas service, the report said, “If a generator served by interruptible service has no secondary fuel source, then that generating capacity could be unavailable during peak periods.”

Specifically, “Projected reserve margins combined with the projected increased dependence on natural gas will increase the adverse impacts to BPS [Bulk Power System] reliability if similar [polar vortex] extreme weather events occur in the future.”

The NERC report makes it clear that variable energy sources, such as wind and solar, degrade grid reliability, and that the EPA’s drive to cut CO2 emissions, which results not only in the addition of wind and solar, but also in an increase in natural gas power generation to replace coal-fired power plants, will negatively affect grid reliability.

Decreased grid reliability is over and above the higher cost of electricity to consumers and industry as the result of wind and solar power generation.

* * * * * *

It’s easy to subscribe to articles by Donn Dears.

Go to the photo on the right side of the article where it says email subscription. Click and enter your email address. You can unsubscribe at any time.

If you know people who would be interested in these articles please send them a link to the article and suggest they also subscribe.

© Power For USA, 2010 – 2015. Unauthorized use and/or duplication of this material without express and written permission from this blog’s author, Donn Dears LLC, is strictly prohibited. Excerpts and links may be used, provided that full and clear credit is given to Power For USA with appropriate and specific direction to the original content.

2 Comments leave one →
  1. donb permalink
    January 9, 2015 1:12 pm

    Donn, a question: Many homeowners use electricity rather than NG for heating. How does the NERC prioritize these, when that electricity may be produced in power plants using NG?

  2. January 9, 2015 3:34 pm

    I don’t know. It’s good question, but I think it’s been ignored on the general principle that most homes use natural gas for heating.
    The law requires that homeowners have preference when natural gas supplies are tight.
    Another facet that isn’t really considered, is that some natural gas pipelines require electricity to run their compressors.
    Until recently these issues haven’t really been a problem, because so much electricity was generated using coal.

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s