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Saturday, December 14, 2013

Pumped hydro storage will eliminate wind and solar intermittency ...really?

I'm a big fan of wind and solar if properly sited to minimize impact to wildlife and ecosystems. I'm a fan because I know that nuclear energy can't replace fossil fuels on its own. I'm a fan of nuclear energy because the latest National Renewable Energy Lab study demonstrated that renewables can't do it alone. I wrote this article so that I (and others) can point to it the next time I (we) encounter someone claiming that storage is the answer for intermittency.

According to the U.S. Energy Information Administration there are only 40 pumped hydro storage sites in the entire United States (producing just 2% of our electric power) because the powerplants have to be situated near two bodies of water that have very different elevations and there are not many places with those characteristics located where powerplants need to be. From the EIA:

"The last pumped hydroelectric facility to come online in the United States was in 2002, with the prior facility built seven years earlier.

There has been increased interest in building new pumped storage plants, although construction has not yet been authorized. According to the National Hydropower Association, as of January 2012, the Federal Energy Regulatory Commission had granted preliminary permits for 34 GW of pumped storage capacity over a total of 22 states, which would more than double existing capacity. There are, however, significant challenges to building new pumped storage plants, including licensing, environmental regulations, and uncertainty in long-term electric markets.
In 2011, pumped storage plants produced 23 billion kilowatthours (kWh) of gross generation—roughly as much as petroleum-fired generation in that year [2 %]. Pumped storage plants, however, consumed 29 billion kilowatthours (kWh) of electricity in 2011 to refill their storage reservoirs, resulting in a net generation loss of 6 billion kWh. "

In other words, the relatively few potentially economically viable sites suitable for pumped hydro storage have largely already been spoken for. If pumped hydro were always an economically viable thing to do, all powerplants would have it. There are not anywhere near enough suitable sites to eliminate the intermittent nature of wind and solar power.

Ironically, it is thanks to pumped hydro that some nuclear power plants can produce both steady baseload power and extra power from its pumped hydro to help make wind power more viable by taking over when the wind quits blowing:

"Pumped storage plants play an important role in electric load shifting. They typically consume electricity during low-demand hours (e.g., nighttime), helping baseload plants to operate more efficiently by minimizing unwanted cycling on and off (a particular concern for nuclear plants, where cycling is extremely expensive and time-consuming). Subsequently, the gross generation that pumped storage plants put back on the grid is produced when electricity demand is high (daytime). This load shifting helps reduce generation from less efficient and more expensive plants, such as combustion turbines, that would otherwise operate during peak-demand hours."

Personally, I can't see humanity reducing GHG emissions in time, so this is largely an academic exercise for me. Because it is unlikely that renewables and nuclear together will be able to replace most fossil fuels in the time frame necessary to prevent the worst impacts of global warming, ocean acidification, etc, anyone who claims to know with certainty, or thinks we should take the risk that one or the other can do it alone has failed to grasp the sheer magnitude of the problem.

Tuesday, December 10, 2013

Nuclear energy kills more birds than wind ...really?

In a rebuttal, and in the comment fields that followed, the author of the study that kicked off the internet urban legend claiming that nuclear energy kills more birds than wind said that his study does not advance the conclusion that nuclear power causes more bird kills than wind. He also said:

"...the numbers in my study are preliminary, first-order guesses ...A final secondary conclusion is that if there is a real “bird killer,” it is neither wind energy nor nuclear power but coal and fossil fuels, especially if you factor in climate change ...I have just started engaging people on Wikipedia to try and correct distortions of my research."

Read the following articles and be sure to read the comments below them as well:
  1. Nukes kill more birds than wind? This is a critique of the study that purportedly claimed that nuclear energy kills more birds per kWh than wind.
  2.  Benjamin Sovacool takes issue with Lorenzini’s criticism of his work. This is a rebuttal of the above critique by the author of the paper being critiqued.
  3. Lorenzini rebuts Sovacool’s defense of nuclear bird kill paper as weak. This is a rebuttal of the rebuttal.
 And finally, read this peer review of the study in question: Bats are not birds and other problems with Sovacool's (2009) analysis of animalfatalities due to electricity generation and its rebuttal.

The study in question was done by an Associate Professor at Vermont Law School, who doesn't care much for nuclear energy, acknowledging that he sometimes blurs ..."the line more than most; some of it is considered “research,” some is considered “advocacy and service.” From the abstract of his study:
"It estimates that wind farms are responsible for roughly 0.27 avian fatalities per gigawatt-hour (GWh) of electricity while nuclear power plants involve 0.6 fatalities per GWh and fossil-fueled power stations are responsible for about 9.4 fatalities per GWh. Within the uncertainties of the data used, the estimate means that wind farm-related avian fatalities equated to approximately 46,000 birds in the United States in 2009, but nuclear power plants killed about 460,000 and fossil-fueled power plants 24 million."

Although the study concluded that nuclear would kill 50 times fewer birds than fossil fueled power plants, it was the claim that nuclear power plants kill more birds per kWh than wind that is being used as a weapon in articles and comment fields to attack nuclear energy. Even if the conclusions were valid (and they aren't), the study still suggested that nuclear is 50 times better than fossil fuels when it comes to bird deaths.

Attacking nuclear energy does not promote wind and solar for the following reasons:

  1. Nuclear, being baseload, does not compete with wind and solar photovoltaic, which, because of their intermittent nature, can only be used to reduce the fuel bills of natural gas or diesel peaking and load following power plants which can vary power output to match the fluctuations from wind and solar.
  2. The latest National Renewable Energy Lab study found that renewables can only provide maybe a third of our total energy needs, making nuclear the only low carbon technology available to help replace the reaming 2/3 of our energy needs. If we are going to replace fossil fuels, we will need both renewables and nuclear.

This same paper also summarized:

"... the wildlife benefits from a 580-MW wind farm at Altamont Pass in California, a facility that some have criticized for its impact on wildlife."

Some have criticized? Considering that an estimated 1300 raptors (among them 70 golden eagles) are killed annually at the Altamont Pass wind farm, one can certainly hypothesize that the population of common ground squirrels that they prey upon are doing very well (sarcasm alert).

Some findings of the above reviews (here and here) follow:

A claim that the abandoned Berkeley uranium pit mine kills 300 snow geese per year turns out not to be true, and to make matters worse, it was a copper mine, not a uranium mine. Note that because wind farms tend to be located further from the cities that use their power, they consume far more copper in the form of power lines than nuclear power, which could also be used in many instances to replace coal power plants in existing coal power plant locations, requiring no new power lines.

A grossly exaggerated estimate of birds killed when colliding with smokestacks during nightly migrations at a nuclear power plant turned out to be smokestacks used by a coal fired power plant which was co-located with a low-profile nuclear power plant that does not use the smokestacks or nearby cooling tower. And to make matters worse, lights were installed on those coal plant towers which ended the bird strikes.

The rest of his data linking bird strikes with nuclear power plant cooling towers shows that they kill ten times fewer birds than his wind estimates.

Also, his wind bird kill numbers were about five times too low, making wind 15 times worse than nuclear, and if you include bats, wind kills 20 times more flying vertebrates than nuclear.

Had the author included all of the mining that supports wind power and bird kills from all of the extra power lines needed by wind, nuclear would have looked even better in comparison.

Photo by Xavier de Jaur├ęguiberry via Flickr Creative Commons.