Podcast #015: Marc Perez: Can we capture more sunshine and save big on energy storage?

Powering a clean energy grid requires massive battery storage, right? Maybe not.

A team of grid experts has another approach that is so simple, it might just be the fastest path to clean energy.

Host Bill Nussey talks with Marc Perez of Clean Power Research about their groundbreaking research for the State of Minnesota. That study reveals how optimizing solar capacity and battery storage can help solve seasonal energy demand, save on energy storage costs and still be cost competitive with fossil fuel-based generation sources.

Listen to this podcast and others in our series on these platforms:

Listen on Apple PodcastsListen on Spotify Listen on Google Podcasts

Marc Perez: Can we capture more sunshine and save big on energy storage?

Host Bill Nussey talks with Marc Perez of Clean Power Research about their groundbreaking research for the State of Minnesota. That study reveals how optimizing solar capacity and battery storage can help solve seasonal energy demand, save on energy storage costs and still be cost competitive with fossil fuel based generation sources.

Additional reading

More references to the research from Marc and Clean Power Research

Transcription of the Interview

Bill:
Hello, Freeing Energy listeners. Bill Nussey here, your host today, and I have a really special treat for you. Now, if you think about the arguments against clean energy and everyone listening here is pretty excited about getting into clean energy as fast as we can, there’s a lot of arguments. One of them, which we all know is that solar and wind are too expensive, but we also know that in the last couple of years those prices have come down so much that they’re price competitive and often even less expensive than coal and nuclear and other alternatives. And so the new argument has started to emerge, which is, “I don’t get enough solar in the winter time, so I’ve got to generate all the solar panels on this summer and I’ve got to store it in giant batteries for use in the winter.” This is not a small idea. People, the likes of Bill Gates in his January year-end review made the case that renewables are simply too much storage and that storage is too expensive.

MIT has an article that it’s going to take, I think, seven, $8 trillion worth of batteries to store all this extra energy that’s generated in sunny summers for use in dark winters. And so that’s where the industry is today but maybe there’s another approach. Maybe there’s a much simpler answer and maybe the simple answer is the one that’s the hardest for everyone to see because people are so enmeshed in the way we’ve done things for a 100 years. So I am really excited today to introduce my guest, Dr. Marc Perez. He has done some absolutely groundbreaking work that I believe will become the de facto approach for building out clean energy grids in the years to come. And I’d like to think that our interview with him today will be one of the first glimpses the world is going to see. And we’re going to look back in when he’s super famous and everyone is citing his work, they’re going to say, “Hey, we first got to hear him early on here,” so, Marc, welcome to the podcast today.

Marc:
Well, thank you very much for that glowing introduction.

Bill:
What we try to do with the Freeing Energy podcast is start with a little bit of your background. You’re a hardcore solar guy. You’ve been in solar pretty much your entire life. How does one be in solar their entire life?

Marc:
That’s correct. I was pretty much born into the solar field. My father, Dr. Richard Perez, a professor at SUNY, Albany State University of New York at Albany in upstate New York has been involved in solar since his Ph.D. in the late 70s. Some of you may him because his models are at the core of a lot of the solar modeling software that you see out on the market today. So his main Ph.D. thesis was on a tilted plane irradiance calculation, so I’ve been involved in solar for a very long time. I know a lot of the early stage solar players and I’d been living and breathing the solar field for as long as I can remember.

Bill:
So I’m guessing you had solar panels in your house before most people in your neighborhood?

Marc:
That’s correct. We were one of the first houses in New York State to have solar. It was well before net metering regulations. As a matter of fact, 1995 my parents built their prefab home in Albany, New York, and it had about 2-1/2 kilowatts of solar on the roof. There was also passive solar, so big window facades on the southern facade for maximum solar gain. They had hot water tanks, painted black in the front for half of the windows to heat during the day and provide radiant heating at night. Earth tubes and all of those new technologies, very new technologies at the time, so I’d been in a solar home for as long as I can remember basically.

Bill:
Well, for those of you that are wondering how to raise your children so there’ll be the future solar warriors of the next generation take notes on this because if you see it early on it can inspire you to go out and change the world. So let’s fast forward a little bit. You were inspired by solar and you decided to get an advanced degree and you came up with a kind of crazy idea while you were there at Columbia.

Marc:
When I originally set out at Columbia, I knew I wanted to study high-penetration renewables and high-penetration solar, in particular, so that means meeting our actual grid loads with solar. How is it possible, in the cheapest way, can we make solar more dispatchable? So to be able to control it in a similar fashion to a conventional generator, like a natural gas peaker plant that is inherently dispatchable. This means you can turn it on and turn it off at your leisure. With solar, on the other hand, you’re at the mercy of the sun, and same thing with wind. You’re at the mercy of when the wind is blowing, so that creates a distinct challenge. And I wanted to see if I could come up with a way to minimize the cost of dealing with that challenge.

The first way that I initially worked on it was geographic dispersion — spreading solar and wind out over large geographic areas in order to minimize the aggregate variability. So as many of you may know, sometimes when there’s a cloud over your house, there’s not a cloud over your neighbor’s house and you can leverage the fact that you have differential solar or radiants in different regions to minimize the net variability of the resource, so that was the first concept, spread everything out and reduce costs that way.

Bill:
For a lot of people outside the industry, it seems a pretty straightforward solution. If you have sun in some places in clouds in others, you just connect them with big wires. We see plenty of wires, so how hard could that be? Well, it turns out that a lot of people don’t want this stuff in their backyards and it’s been nearly impossible in the United States to pull these large transmission grids between the places you’d expect them to be.

Marc:
That’s true. There’s significant value for distributed solar and wind over large geographic areas. You do see the value in that. You see a giant reduction in the cost of supplying energy when you spread things out. But it comes at the cost of this interconnection that you mentioned, that’s expensive and it takes forever to build these things. Decades in many cases, you need to pass through multiple regulatory bodies at multiple geographic scales, local, state, federal, et cetera. It’s a challenge. So in researching this, I discovered another path forward.

INTERMISSION START

Sam Easterby:
Before we get back to Bill and Marc, it’s time for your pop quiz. So here’s your question. What percentage of Americans favor alternative fuels over fossil fuels? Public opinion helps shape public policy, but so does economics, which is why the word Clean Power Research is done in Minnesota is so important. The study findings show that by adding solar generation capacity and then curtailing its usage at certain times can help solve seasonal energy demands, lower generation, and storage costs and address resource deployment issues. This goes a long way towards supporting just how cost competitive and reliable properly optimized renewable energy strategies can be for today’s electricity consumers, and that is something that it seems more and more of us want. If you’re interested in the work Marc and Clean Power Research has done in Minnesota, you can read the full report by visiting mnsolarpathways.org/spa.

Here’s your answer. According to a 2018 Gallup Poll, 73% of those surveyed favor using alternative energy sources over fossil fuels, and in another study, the Pew Research Center in 2018 reveals that 89% of US adults favored adding more solar panel farms. You can read about these studies and a special article on freeingenergy.com called Five Trends That Will Lead to the End of Fossil Fuels. Visit freeingenergy.com and search for Five Trends. Now, back to Marc and Bill.

INTERMISSION END

Bill:
So if you go and read a lot of people’s thoughts on how to get to clean energy, the so-called 100% renewable grid or even approaching that in many, many cases, if not most cases, they’re assuming that we’re going to build a lot more transmission wires. But from a practical point of view, it’s really, really hard and expensive and very few additional transmission wires have been pulled in the United States, and that’s probably not going to change any anytime soon. And frankly, a lot of the big thinkers on this 100% clean grid get criticized because this is impractical to tie it together. So you started out, you reached an early conclusion a lot of people have reached more recently that it probably wasn’t the only way to do it and you came up with a different idea, which is what we’re here to really talk about. And I think this idea is one of the coolest things I’ve heard in a long time. So tell us a little bit more about what you did next.

Marc:
Sure. So if we have a demand throughout the course of a year, there’s a pretty strong correlation, at least on most of the eastern seaboard, between the amount of solar resource and the demand because it’s air conditioning driven. So you have a lot more demand in the summer than in the winter, so there’s a pretty good seasonal correlation

Bill:
Because we get a lot more sun in the summer.

Marc:
Exactly, and that drives heat, that drive temperature and the temperature drives air conditioning and that air conditioning drives load increases, so all of our peak loads on the east coast are in the summer. So you have a pretty good correlation on that front. However, you still have really big winter loads. And if you were to just design PV to meet load on an energy basis for a region, you would need a lot of storage. You’d need to size the storage to charge in the summer and discharge during the winter.

Bill:
Now, that’s dozens of times more storage than we would have for a day or a week.

Marc:
Oh yeah, it’s 180 days. It’s a half a year of storage. You’re charging in the summer and discharging in the winter.

Bill:
If I have a Powerwall, for example, from Tesla in my house and I need it to run it for a night, I might need one Powerwall.

Marc:
Yeah.

Bill:
But if I needed to store it over the entire season, I mean 180 Powerwalls, just to put a perspective on the scale difference, and this is why a lot of people think that seasonal storage is a game-stopper.

Marc:
Exactly. Because storage, right now, is expensive and even if it’s much cheaper in the future, it’s still going to be pretty expensive. The thing is that recently PV has dropped dramatically in cost and because of that we can leverage this low capital cost of PV to oversize the PV and have more energy being generated in the winter than in the summer and therefore we don’t need as much storage.

Bill:
And so, folks, this is the really core point. Everyone that designed solar systems, wind systems or fossil fuel systems is doing it to perfectly match the load of the requirements from the customers using the power and you want to spend as little as you possibly can building the solar, the wind, the coal, whatever it is. And so when you have seasonality from sun and wind, wind is also seasonal, you got to store all the extra and this is extremely expensive. And so Marc’s huge idea, and I can’t emphasize what a big idea is because it’s almost a little simple. Instead of building the right amount of solar for the summer, you build it for the winter.

Marc:
Exactly. Double the size of the solar or the wind and you overcome the entire seasonal component. You just cut off a little bit of the excess during the peak season, during the summer in the case of solar and during the winter in the case of wind.

Bill:
When I first heard about this, and it’s something I’ve been thinking about, it seemed like it couldn’t possibly be that simple. And I’ve run it by a couple of people and they’re like, “I suppose. But it’s such a radical idea,” and the point that’s so exciting about Marc’s work is that he didn’t just think of this sort of notion, but he did a deep long-term research project, which I’d love to hear you tell us about on actually doing the hard math on how this might work. So tell us a little bit about that project that you and your colleagues did.

Marc:
So there was my PhD thesis where I first built this over-sizing curtailment optimization model, but recently we were funded by a DOE SunShot grant, prime on that is Minnesota Department of Commerce. And this was a project I, with my colleagues at Clean Power Research, that sought to look at the cheapest way to meet load in Minnesota at high penetrations of renewables. So we optimized the amount of overbuild of solar and wind and the ratio of solar and wind in order to minimize the cost of firmly delivering load, guaranteed, using storage and using a little bit of demand-side management also.

Bill:
So firmly delivering load means that people’s lights stay on and their air conditioners turn on when they want them to.

Marc:
Guaranteeing that there’s enough resource on the grid in order to firmly meet demand at all times.

Bill:
Which is what we’ve come to expect.

Marc:
Exactly.

Bill:
Excellent, and so you guys did this project with a wide variety of stakeholders in Minnesota at the end of this project and you guys came up with some pretty remarkable results. Can you summarize those?

Marc:
The nice thing about wind and solar in Minnesota, at least, not the case everywhere, is that they’re seasonally anti-correlated. So that means that there’s much more sun in the summer in Minnesota and there’s more wind in the winter than in the summer. So they kind of balance each other out. And based on the future cost projections that we got from NREL, one of our project partners, National Renewable Energy Lab, we’re able to optimize the relative capacity of wind and solar in order to meet load and the amount of overbuild of those assets in order to reduce some of the aggregate residual seasonality or multi-week supply deficit that you might see even with the combination of both of those resources.

Bill:
And so numerically, how much more solar do we need to build? How much more wind do we need to build to get a balanced cost-effective clean energy grid?

Marc:
It depends on the cost, on the relative price of storage and PV. If the price of storage is much more expensive than the relative price of PV, well, you’re going to want to do more overbuilding because there’s more value in building more PV or wind capacity relative to storage. If the price of storage is really low, really, really low relative to the price of overbuild well, then you’re going to want to do less curtailment. But even if the price was really, really small for storage, the smallest we can get now is probably pumped hydroelectric storage, it’s 80 a kilowatt hour. Even despite that, we’re still going to want to do a little bit of overbuild because otherwise the storage is really being under-utilized significantly and we can reduce the cost if we just have a little bit more resource flooding into the grid.

Bill:
And so this is a pretty remarkable idea. So instead of getting 180 or a 100 times more storage that most of the big thinkers in clean energy are telling us, we can build two or three times as much solar and wind, which is really inexpensive.

Marc:
And I think even less than that, honestly, if you blend wind and solar together, the overbuild is something like 20% or something like that, 30% it’s not 2x anymore. If you do solar alone or wind alone, then the overbuild is probably two, 3x maybe, at least with solar alone because there’s a huge seasonality in Minnesota at least. And then again, if you interconnect across MISO, the Midwestern Interconnect in the United States project where we’re just kicking off on right now, you can reduce that cost even further because you’ve reduced the seasonality the further south you interconnect, obviously, with solar. There’s less of a seasonal trend the closer you get to the equator. If you’re at the equator, there’s some monsoon stuff going on but overall you get around the same amount of solar year round. So the more you can interconnect north-south, the less seasonality you have in each individual resource. Same is true for wind.

Bill:
It’s an amazing idea and it’s recently gotten a tremendous amount of traction in the trade media and even some of the mainstream media. What I love about it is the title is it’s a radical idea. There’re many other businesses outside of energy where this is just what we do.

Marc:
Look at the New York City Subway System. We don’t design the New York City Subway System to exactly match demand of the subway system at any given point. It’s not like we reduced the amount of tracks depending on the throughput of people in the subway system. We build it for peak or as close to peak as possible but it’s underutilized. As a result, it’s overbuilt functionally and there’s a lot of other examples. There’re parking garages, parking lots, in general, where they’re really underutilized. I’m sure you listeners can think of plenty of other examples of this overbuilding concept in other fields.

Bill:
One of my favorite examples is computing. You go back 30, 40 years ago and you have these mainframe computers, timesharing computers, and these guys with white lab coats would be putting your program in at exactly the right time and they’d give you results and it might be two in the morning and you’d have to get up and look at it to put the data back into it and you roll forward 20, 30, 40 years and computing is so inexpensive that we use it for screensavers.  I don’t think we’ll see quite such a dramatic drop in the cost per unit of energy (compared to computing), but I think the brilliance and elegance of your idea is that it’s one of the few times that anybody has realized that economics of electricity will not always be governed by scarcity.

Marc:
Exactly. We have an electricity system that’s predicated on exactly matching supply to demand at any given moment and that makes sense because we got fuel that’s being burned and you literally burn the fuel. In this case, we’re already wasting the fuel. I mean, there’s so much solar resource out there on the planet that we only need to capture it. If we don’t use it who cares? We’re already not using 99.9% of it on the planet. It’s being converted into biomass. It’s reflecting off of things and contributing to the greenhouse effect in combination with the CO2 et cetera. We’re not using all the solar resource out there and we won’t, we still won’t use all the solar energy that’s hitting the continents alone, so there’s plenty of it out there.

Bill:
Well, Marc, this has been fantastic and I’m really honored and thrilled to be able to have you share these ideas. Your mental shift from electricity as a scarcity to electricity as an abundance is going to lead the industry. And I think in the future, hopefully, the very near future, the idea that you have that you’ve proven out, by the way, your paper has been peer-reviewed, so this is not something you just made up on your own. This is passing strong tests. And you’re just getting started. And so the potential for this idea to change the way we think about getting to clean energy, I’m excited that your idea may be one of the most powerful and elegant ideas to get to clean energy faster than anything I’ve come across in my research. So if people want to learn a little more about this, where should they go?

Marc:
Sure, they can go to my personal website, marcjrperez.com. They can go to cleanpowerresearch.com that’s my current company.

Bill:
Well, listen, thank you very much for your time today. It’s been a pleasure here. We’re here in Napa Valley, so thank you for taking some time to share all this great idea. And for all the listeners out there, let’s spread the word out there. Let’s let everybody know that there is a more elegant, simple and less expensive way to get to clean energy much faster, and you heard it here today.

Marc:
Much faster and much cheaper than you otherwise would’ve thought.

Leave a Reply