U.S. NRC Blog

Transparent, Participate, and Collaborate

The Electric Grid, Energy Demands and Nuclear Power Plants

Neil Sheehan
Public Affairs Officer, Region I

A question we receive with some frequency from reporters involves how the grid copes with the power loss when a large baseload electricity producer such as a nuclear power plant suddenly goes off-line. Put another way, what keeps the lights on, the coffee-maker brewing and the refrigerator humming along when a reactor in their area isn’t in operation?

gridThis question takes on greater urgency during peak energy demand seasons, summer being number one in this regard thanks to all of the air-conditioners merrily cranking away as temperatures creep up.

The simple answer is that the various grid operators, like the Boy Scouts, always strive to be prepared. They do this by maintaining power reserves, though the amounts available can vary by region. So-called “peaker” power plants can be called into service when necessary to help maintain sufficient electricity flows.

Of course, since nuclear power provides about 20 percent of the electricity used in the U.S., close tabs are kept on the status of the nation’s reactors, especially during times of peak demand. The NRC makes that information available to the public on its website each day.

Here is a handy graphic compiled by the U.S. Energy Information Administration (EIA) that provides a good summary of reserve margins for the various grid operators around the country.

As the EIA so succinctly states, “The electricity industry uses a simple strategy for maintaining reliability: always have more generating and transmission capacity available than may be required, taking into account unexpectedly high demand or the possibility of unplanned outages of generators or a major transmission line.”

The good news is the reserves are projected to be sufficient as the summer of 2013 rolls on.

In addition to the EIA, another good source of information on U.S. power reserves is the North American Electric Reliability Corp.

5 responses to “The Electric Grid, Energy Demands and Nuclear Power Plants

  1. Shawn Ovenden August 14, 2013 at 2:26 pm

    CapD is correct sort of. Claiming that renewables can replace nuclear and fossil fuels is simply not true. Renewables have their place but they are not a consistent source of energy. The demands of the public, commerce, and industry demand a consistent reliable source of energy. Ask the folks running the power companies.

    Renewable sources of power have their place in the industry ans a secondary source of power. People. commerce, and industry require a consistent and reliable source of power. You reference a surplus of power in California. Though a surplus may be available there a factors that limit the effective use of this surplus. One is the ability of the grid to get the power from source to consumer. The other is the timing of the surplus. The power cannot be stored so if it cannot be used at the time of production that surplus is gone. In other words if there is a surplus of power at 6 pm on the west coast but peak demand is gone on the east coast by that time then there is no way to move or use that surplus.

  2. CaptD August 2, 2013 at 12:33 pm

    Left unsaid in the above NRC statement is the fact that some states like California for example, now have EXCESS energy capacity and can function without ANY nuclear energy generation.

    Here is a chart that illustrates the amount of spare capacity in California and it clearly illustrates that not only is ZERO nuclear generation needed but since additional Solar (of all flavors) is being added daily, future needs will require ever less fossil fuel provided energy!


    What is holding the USA back from racing Germany to become the first major country to be solar powered ASAP is our politically powerful Energy Utilities and the politicians that support them, which are now struggling to maintain their market share by keeping US as their customers (think energy slavery).

    The Germans are leading the world and here is what they say:

    The Future of Nuclear and fossil fuels: Only for Back-up for renewables
    The two largest electricity utilities in Germany – E.ON and RWE – have declared they will build no more fossil fuel generation plants because they are not needed, challenging a widespread belief that the phasing out of nuclear in Europe’s most industrialized economy will require more coal-fired generation to be built.

    Both E.ON and RWE say the rapid expansion of renewable energy, particularly solar but also wind, would make up for the loss of capacity from nuclear. “We won’t be building any more gas and coal power generation plants in western Europe, because the market does not need them,” a spokesman for E.ON told reporters at a briefing at the group’s headquarters on Friday. RWE made a similar statement a week earlier. A third major operator, Vattenfall, agreed that the market in Western Europe is oversupplied but said some limited capacity may be needed in the southern part of Germany.

    An important article about why Solar is such a threat to all US Utilities, which I think of as a Fiscal/Energy War for market share:
    Disruptive Challenges:
    Financial Implications and Strategic Responses to a Changing Retail Electric Business
    Energy Expert Predicts Solar Could Upend Major Utility in California on Price http://www.renewableenergyworld.com/rea/blog/post/2013/05/energy-expert-predicts-solar-could-upend-major-utility-in-california-on-price

    • hiddencamper August 5, 2013 at 12:53 pm

      I’d prefer we focus on removing carbon emitting power plants, than no emissions plants like nuclear power plants.

    • Paul Lindsey August 7, 2013 at 3:18 pm

      Really, we have excess power supply in CA? Then why am I seeing daily ads on TV about FlexAlert? In one of your recent comments, you stated that the losers in the SONGS shutdown were the SONGS employees. Today’s post demonstrates your hypocrisy. You don’t care a wit for the employees. Your real goal is nuclear power shutdown. I wish I had the time to analyze your attached chart, Its data is probably as fallacious as statements that describe wind farms by their nameplate capacity. Here’s a link to real-time BPA wind farm output, nameplated at 4,515MW but producing far, far less than that. http://transmission.bpa.gov/Business/Operations/Wind/baltwg3.aspx Can you run electric trains on wind farm output? Would you ride an elevator that says, “powered by wind”?

%d bloggers like this: