Renewables at 90% only IF grid-level storage comes first

Renewables can't be a 90% unless we have grid-level storage

Renewable installations are growing fast, but we can't have huge percentages of wind and solar on the grid unless we first have grid-level storage.  With the exception of pumped storage, grid-level storage does not exist at this time.  (No, I don't count an occasional 2 MW project as "the answer.")

We can't grow wind and solar to a higher percentage on the grid than their capacity factor implies, unless we have storage. Moving to 50% wind on the grid is not possible, without utility level storage.  

The explanation follows, based on the New England grid.

A year on the New England grid (2008)
Shows the necessity of being able to dispatch electricity
Note rise in gas usage while nuclear plants refuel
Click to enlarge

Five million down and five million up (natural gas takes the lead)

In a guest post on January 7, Michael Twomey of Entergy used grid operator (ISO-NE) data to show that between 2014 (when Vermont Yankee was running) and 2015 (when Vermont Yankee was closed), nuclear kilowatt-hours decreased by about five million MWh and gas-fired generators increased their output by almost exactly the same amount.  Natural gas went from 46,200,000 MWh to nearly 51,900,000 MWh.  Nuclear kWh nuclear went down by almost the same amount of MWh.

Click to enlarge table

Wind and solar growing fast: Jeff Schmidt's comment

Looking at the table above, you can see that wind went from 1,892,000 MWh to 2,135,00 MWh, growing by approximately 243,00 MWh, and solar grew from 327,500 to 436,200 MWh, approximately 108,700 MWh.

This rapid rate of growth (though still only adding up to 2.4% of the power on the grid), prompted Jeff Schmidt to write this comment on the Twomey article:

"This article seems to dismiss the growth of wind and solar. While I am pro-nuclear, and think that nuclear needs to play a vital role in our future energy mix, I think the author of the article is neglecting something important - growth of wind and solar.

It's true that they are still small. But, if you look at the year-over-year growth rate, as shown by the statistics provided by the ISO and called out by Mr. Twomey, we see that Solar grew 33% in a year, and Wind grew 41%. Of course, one can't predict future growth rates based on one year, but IF wind and solar can keep up strong growth like that, they could conceivably become a very large proportion of the New England energy mix inside of 10 years.

It's true that it's likely an overly optimistic and simplistic projection, but just for the sake of argument, if they can keep up that growth rate, then 9 years from now, Wind could produce about 50% of the energy, and solar about 5%. If you projected it to 10 years instead of 9, that would account for more than 100% of current grid generation.

However, at the same time, it's very likely that at some point, Wind and Solar's growth must slow. Still, it's a valid point to concede that Wind and Solar, while currently small in absolute terms, are actually growing at a pretty fast rate."

Why renewables can't keep growing--unless we have storage

I wrote the following response to Schmidt.  I oversimplified, but I am also worried that "we can't grow wind and solar" arguments are often based on cost, or on complex technical issues that are hard to explain.  So, here's my oversimplification.  Basically correct, but oversimplified.

Basically, we can't grow wind and solar to a higher percentage on the grid than their capacity factor implies, unless we have storage. Moving to 50% wind on the grid is not possible, without utility level storage.



Jeff
I wrote about Vermont's plans to be 90% renewables in today's blog post. Of course, renewable growth from 1 to 3 to 5% is possible and looks great. However, it simply does not scale. Let's oversimplify a little, though not a lot.

Most of Vermont is one weather pattern, with some exceptions. Hot, dry and sunny...all over Vermont. Windy at night...all over Vermont. Cold and windless....all over Vermont. Now, obviously, the mountains are different from the river valleys and so forth, but the statement "weather is the same all over Vermont" is far closer to true than its opposite would be.

Okay. We cannot turn wind on and off. Let's say that wind has a 30% capacity factor. For wind to grow to 30% of the electricity supply overall, that means when wind is on the grid (the wind is blowing in Vermont)...the grid has to be 100% wind. Without this high percentage when wind is available, wind is not going to be able to be 30% of the electricity, overall. So we have to build a lot of wind to get wind to 30% of the electricity supply, and we have to turn everything else off if the wind is blowing.

Well, what if we build more wind? If we do that, when the wind is blowing....what then? We have to curtail some of the wind, because the grid can't take more than 100% of wind. So, without grid level storage, wind reaches a VERY hard stop at 30%.

Well, it is windier in the mountains, and the southern part of the state gets less wind and so forth and this is an oversimplification. And the grid requires more power in the day, and less in the night (when the wind usually blows). So it is quite complicated in reality. But the basics remain.

IF you can turn things on and off, you don't reach this sort of hard stop. 100% of the electricity from natural gas...this could work. No "hard stop" involved. 100% from nuclear...well, current nuclear doesn't follow load well, but there is no "hard stop" involved, where you have more nuclear than you can use on the grid. You don't need grid level storage for nuclear, just plants that follow load a little better. And so forth.

This is why I am so cynical about the Vermont energy plan. The plan is kind of "We don't just hope for miracles, we expect them."
------

Jeff Schmidt has two guest posts at this blog:

The Nuclear Safety Paradox, which describes how experience (such as building new nuclear plants) increases safety.

Flawed Analogies, which describes the analogies nuclear opponents made in a debate against nuclear energy.

Illustration

The illustration showing the need for dispatchable power
From Sustainability presentation by David Lamont
Vermont Department of Public Service
October 18, 2010
Presentation is no longer on the web, but I had saved it to my computer.

Flawed Analogies: A Guest Post by Jeff Schmidt

Jeff Schmidt is a computer geek and software-developer-in-training, currently working for a small business software developer in Ohio and pursuing a bachelor's degree at the University of Cincinnati. He recently sent me an email commenting on the flawed analogies in the Debate Goes On.

(The debate was about relicensing Vermont Yankee. Howard Shaffer and I debated James Moore of VPIRG and Senator Dick McCormack of the Vermont Senate.)

I am grateful to Mr. Schmidt for allowing me to post his (somewhat edited) email as a guest blog.

Flawed Analogy #1: Vermont Yankee is an old person in failing health.

Vermont Yankee is like an old person whose health is failing.

Both the Senator and Mr. Moore made this analogy early on and kept repeating it.

Flaw: Power plants are manufactured machines and buildings. Machines/buildings are not like people. When people get old, if their eyes are failing, you cannot replace their eyes with brand new ones (at least, not yet. . . maybe someday). If their joints get arthritic, you cannot easily just replace the joints (in some cases, like hips and knees, joints can be replaced, but that's pretty limited), and so on.

Machines, on the other hand, can have faulty components and even major parts replaced, can have failing welds inspected and re-welded, can have leaky pipes, valves, turbines, whatever needs it, replaced, while keeping that which is still good. Any machine or building can be restored to a pristine condition, if the responsible party is willing to put the necessary funds and effort into the job.

You can even take that a step farther - machines and buildings can be upgraded with new technology or features, and made better than the day they were new. There are a lot of cars that have been beautifully preserved and restored by people who love historic cars. They run great, and in many cases, are safer than the day they rolled off the lot. They may have had seatbelts added to them (which they didn't originally have), or perhaps the owner added an anti-lock braking systems. Maybe the owner added a turbo-charger to make the engine perform better, or an upgraded suspension, better tires, etc.

I think almost everyone has at some point been to a classic car cruise-in, and seen the amazingly restored vehicles on display, with their hoods open and their engines roaring. While nuclear plants are not exactly like cars, it still holds true that they can be repaired and restored, as they too are machines.

Machines can be kept running almost forever as long as someone does the necessary repairs and replacements.

What it ultimately comes down to is an economic analysis of whether it's cheaper to fix the plant, or to decommission it and put the refurbishing funds towards the construction of a brand new facility of some sort. This is an analysis which is best done by the company itself, not the State of Vermont. If Entergy were willing (and I'm not saying they are, but let's assume for argument's sake that they are), to put the money into whatever repairs and upgrades are necessary to keep the plant safe and reliable, then there is no legitimate state interest in forcing the plant to close.

Flawed Analogy #2. Relicensing the plant is a game and you are changing the rules.

The analogy is that decisions regarding the disposition of Vermont Yankee are a game and you cannot change the rules of the game at the end of the match.

The Senator made this analogy early in the show, and I thought that was the most bizarre analogy I've heard in a very long time.

Flaw: How is public policy anything like a sport? Is this really how we make important public policy decisions? By saying, "we made this decision 20 or 40 years ago to license it until this date, and to change it now is unfair? Who is it unfair to? The decision should be made on what is best for the State's residents/taxpayers/ratepayers, not based upon some immaterial sense of fairness because you are re-thinking a decision made years (or even decades) previously.

My driver's license expires on my birthday in January. Since it was set to expire on that date, does that mean I should not have the chance to renew it? Re-licensing is an opportunity to review the situation, to make sure it is appropriate to re-license something, but there's no reason it needs to be a hard-and-fast, set-in-stone termination date.

The only reason I can think that this person is complaining about fairness, is that they have been a committed anti-nuke for a long time. They may feel that since the nuclear plant got to operate, but they never wanted it operating in the first place, it's unfair that they don't get their way in being able to shut the plant down, if you consider re-licensing it.

Flawed Analogy #3. A power plant is perishable, like milk. It has a magic sell-by date, and nothing can be done to make it useful after that date.

The analogy the power plant is a perishable item. Forty years ago, we chose forty years as the magic date, and there's no reason to believe we made a mistake.

The Senator repeatedly appealed to this idea that it was licensed until 2012, why should we relicense it? The question, really, should be why shouldn't we relicense it, if it is safe for it to continue operating, or if it can be made safe to continue operating at relatively low expense? Machines don't have expiration dates that are set in stone - as I said above, basically it comes down to, if you are willing to spend enough money, any machine can be repaired, so it's really just a question of if it is worth repairing.

The Senator also asked, "What mistake did we make in the past when we decided the plant would be obsolete by 2012?" I don't really know what went into the original decision making process, so I suppose I can't specifically answer that, but I also don't see how an arbitrary date can ever be correct in such matters. You don't make decisions based upon arbitrary dates, you make decisions based upon the facts of the situation, including such things as an economic analysis of whether it's more cost effective to fix/upgrade the plant, or to build other plants, or to get power from other sources. Magic dates are largely stupid, unless it's based upon some particular scientific principle (e.g. the sell-by date on milk and other perishable goods - we have science which tells us how long the milk will be good for - but machines are not like milk, again, you can fix machines, but you can't make sour milk good again).

Some Thoughts about the NRC

James Moore and the Senator made repeated assertions that the plant was failing and was really no longer safe - that it's developing too many problems. Didn't the NRC go through a re-licensing process where they evaluated the plant on it's technical merits, when considering whether to re-license it, and didn't the NRC evaluation find that the plant should be relicensed?

Note from Meredith: The NRC has not officially ruled on the relicensing yet, but a ruling is expected within a few weeks. The plant has been extensively inspected and reviewed. Everyone expects the plant to be relicensed by the NRC. Even the opponents expect the NRC to rule for relicensing. As you can see by this NRC summary, more than forty plants have had their licenses renewed to date. End of note.

Do the Senator and Mr. Moore think the NRC is corrupt, or just incompetent? Do they think themselves better suited to evaluate the plants condition than the engineers and scientists who work for the NRC to do these inspections and evaluations? I certainly would have challenged them on that point, but perhaps I'm too confrontational, I dunno.

Overall, I think you and Howard did a pretty good job, but I just offer these thoughts in the hopes that, as you will likely continue to encounter these ideas and these expressions of the ideas, you can, perhaps, have some ideas of how to attack the flaws in those lines of thought.

The Use and Misuse of Analogies

When people depend too much on analogies to understand problems, they usually end up making bad decisions. Don't get me wrong, analogies can sometimes be helpful, but it usually is just a cover for overly-simplistic analysis which misses key parts of the problem immediately at hand. When you debate someone using analogies, look for the flaws in every analogy and attack the analogies. Show how the analogy fails to adequately address the problem at hand.

Vermont Yankee image from Wikipedia

Old Man With A Crutch, I. M. Kramskoi, 1872, Wikimedia

1955 Packard, Wikimedia

Texas Tech versus Navy Football, Wikimedia

Foil Top Milk Bottle Wikimedia