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On Can Nuclear Power and Renewable Energy Learn to Get Along?

Hi Ben,

Thanks for the comment. I'll look again at the NREL Futures report which I included in the recommended resources at the end of my post. 

RE larger balancing/control areas, you are of course correct. As I noted in another comment, when I said "power system" in the post above, I meant the full interconnected, balanced system (i.e. a closed system). The larger that system, the more renewables you can get in there and the less correlated their output is likely to be. But once you get to an energy share equal to about their capacity factor, you certainly can see ramping from 0 to 100% of demanded energy on a regular basis, necessitating lots of storage/sinks/flexibility. So larger balancing issues helps renewables integration (or renewables-nuclear integration) as you say, but it doesn't really solve the problem.

Cheers,

Jesse

April 15, 2014    View Comment    

On Can Nuclear Power and Renewable Energy Learn to Get Along?

Thanks for the comment Ed! Power to gas is actually what I had in mind when I wrote about "energy sinks" in the post. Desalination maybe also. But the example "energy sink" I linked to was actually Hydrogenics efforts to use excess power production during peak wind output/low demand days in Denmark to produce electroyltic hydrogen used to upgrade sewage gas into pipeline quality natural gas. It's a very interesting example of the kind of use of excess power we'd likely see much more of in a high-renewables or renewables-nuclear hybrid system.

Jesse

April 15, 2014    View Comment    

On Can Nuclear Power and Renewable Energy Learn to Get Along?

Thanks for the thoughtful comment. Cheers,

Jesse

April 15, 2014    View Comment    

On Can Nuclear Power and Renewable Energy Learn to Get Along?

Thanks Paul!

April 15, 2014    View Comment    

On Can Nuclear Power and Renewable Energy Learn to Get Along?

How do you support that bottom line though Alan? That sounds like an assertion, but it's not clear how that's the case. It's one thing to assert that the most economical low-carbon energy mix is all renewables. It's another to say that renewables and nuclear "don't really play well together, except in small doses." I think I've shown how they do, assuming you have storage/flexibility. And assuming you don't have storage/flexibility, an ultra-low carbon renewables dominated system itself isn't possible (except at extraordinary cost) due to necessary curtailment. 

April 15, 2014    View Comment    

On Can Nuclear Power and Renewable Energy Learn to Get Along?

I've not seen any technical literature on that question. But I'm talking with one of my colleagues here about doing some modeling to answer just that. This could make for a very interesting paper...

April 15, 2014    View Comment    

On Can Nuclear Power and Renewable Energy Learn to Get Along?

Thanks for this excellent resource Robert! I just spent a while poking through this data set, which is really really helpful. It looks like today, France's aggregate nuclear output ramped up/down by 4.5 gigawatts already. That's about as much ramping as we saw from their (very flexible) hydro plants and about 4 times as much ramping as we've seen today from their entire coal and gas fleet. So clearly France has figured out how to operate their nuclear plants more flexibly than most anywhere else. The data is clear.

This PDF of a technical presentation from French utility EDF also discusses their flexible reactor operation. It even shows plants cycling off over weekends during low demand periods sometimes (see slide 8), although this obviously comes at a cost, and it does take a couple days to get back online after powering off fully. The slides do note a set of technical and operating challenges to modulating reactor output flexibly. Reactor operators need to be well trained to do this, but its certainly possible.

Cheers,
Jesse

April 15, 2014    View Comment    

On Can Nuclear Power and Renewable Energy Learn to Get Along?

Hi Alan,

I grant that without lots of economic storage/sinks, you'd hit the cieling on renewables faster if you have a share of nuclear in the system as well. So if your goal is to increase renewables to their highest penetration before hitting their cieling before needing storage, then you'd want to back off of nuclear. But if your goal is to get to the lowest carbon power system as possible before needing storage, then I doubt that's the best way to go. 

Simple math here but I think this gets at the gist of it: if your system is say 20% nuclear, then you'd hit the renewables cieling roughly when their energy share = their capacity factor x (100% - nuclear's share). So for solar at 10% CF, you'd hit the cieling at 10% x (100% - 20%) = about 8% of the energy mix from solar instead of 10% if you had no nuclear in the system. For wind at 33% CF, you'd hit the cieling at 33% x (100% - 20%) = about 26% of the energy mix from wind instead of about 33% if you had no nuclear in the system.

So yes, you lose a few percentage points of renewables share if you have 20% nuclear in your system versus if you don't. But if carbon is your priority, it makes no sense to give up that 20% from zero-carbon nuclear in order to get 2% more solar or 7% more wind! 

So again: if you want an ultra low-carbon energy system with high penetrations of solar or wind, you need massive amounts of economic storage and sinks and DR. And if you have those, nuclear and renewables seem to work just fine together. And if nuclear and renewables aren't mutally exclusive, the lowest CO2 for the least money may very well be a hybrid system.

Jesse

April 15, 2014    View Comment    

On Can Nuclear Power and Renewable Energy Learn to Get Along?

Thanks Robert. I forgot about your great post in October on capacity factors and challenges for high penetrations of renewables (and nuclear). I highly recommend folks head over there to read it and then come back to join this discussion. Cheers,

Jesse

April 15, 2014    View Comment    

On Can Nuclear Power and Renewable Energy Learn to Get Along?

Hi Joris,

I think your categorization of technologies is a little bit of a simplication. Yes, variable renewables as operated in a system today are primarily used to provide energy (and not really capacity) and thus to save fuel from other power plants. But in a high-renewables system, they would be paired with storage, sinks, and flexible demand in a different operating paradigm. Additionally, nuclear plants aren't really "power technologies." As baseload plants, they supply a tremendous amount of energy to the system (operating nearly 24x7x365) and also provide power to match base demand levels. In a conventional system, peaking power plants like gas-fired or oil-fired plants are the ones that primarily contribute "power" or capacity to the system to meet peak demands. But again, in a high nuclear system, operations would have to look different as well. 

So the question is: what could the power system of the future look like (not how do these generation technologies typically operate today). Thoughts?

Jesse

April 15, 2014    View Comment    

On Can Nuclear Power and Renewable Energy Learn to Get Along?

Hi Paul, thanks for commenting.

The question I'm asking though is can nuclear and renewables work well together? Not do we want them to

I know that many folks here are perfectly happy choosing one of those potentially mutually exclusive paths I outlined at the start of the post: a nuclear dominanted system or a renewables dominated system. For some of you, there's no reason to consider any other options. 

But I see both of those options as very challenging. Getting to very high penetrations of nuclear is clearly technically possible, but given the social opposition to new nuclear, by no means an easy feat. Very high penetrations of renewables face more technical challenges, and they also face NIMBY opposition to large-scale projects and the transmission needed to bring renewable power to load centers. So neither a high nuclear or high renewables future is fiat accompli.

That leads me to search for more options. Can we design a hybrid system of 30% nuclear, 60% renewables and 10% gas for peaking? What about 60% nuclear, 30% renewable, 10% gas? Something else? 

The conventional wisdom is such hybrids are impossible. This post is about questions that. I'm curious what you think about those questions (not whether or not we'd want to go there, but could we go there if we did want to).

Cheers,

Jesse

April 15, 2014    View Comment    

On Can Nuclear Power and Renewable Energy Learn to Get Along?

Joris, I think you overstate the role nuclear plays in France. Nuclear plants there do some load following, but they rarely cycle, and they don't match peak load. France has hydro and gas plants for that role, and they are part of a continent-wide interconnected power system with the rest of Europe, where they can import power at times of peak demand and export power at times of low demand. (Imports/exports is also how Denmark manages with a very high penetration of wind btw). So while nuclear looks like a very high share of France's electricity supply (or wind in Denmark), it is actually a smaller share of the European power system. And that full interconnected system is what I have in mind when talk about this post. I should have made that more clear. Thanks for commenting,

Jesse

April 15, 2014    View Comment